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Methyl Chloride

PubChem CID
6327
Structure
Methyl Chloride_small.png
Methyl Chloride_3D_Structure.png
Molecular Formula
Synonyms
  • Chloromethane
  • METHYL CHLORIDE
  • 74-87-3
  • Methane, chloro-
  • Monochloromethane
Molecular Weight
50.49 g/mol
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Dates
  • Create:
    2005-03-26
  • Modify:
    2025-01-11
Description
Chloromethane is also known as methyl chloride. It is a clear, colorless gas. It has a faint, sweet odor that is noticeable only at levels that may be toxic. It is heavier than air, and it is extremely flammable.
Methyl Chloride can cause developmental toxicity according to The National Institute for Occupational Safety and Health (NIOSH). It can cause male reproductive toxicity according to The Environmental Protection Agency (EPA).
Methyl chloride appears as a colorless gas with a faint sweet odor. Shipped as a liquid under its vapor pressure. A leak may either be liquid or vapor. Contact with the liquid may cause frostbite by evaporative cooling. Easily ignited. Vapors heavier than air. Can asphyxiate by the displacement of air. Under prolonged exposure to fire or intense heat the containers may rupture violently and rocket. Used to make other chemicals and as a herbicide.

1 Structures

1.1 2D Structure

Chemical Structure Depiction
Methyl Chloride.png

1.2 3D Conformer

1.3 Crystal Structures

COD records with this CID as component

2 Names and Identifiers

2.1 Computed Descriptors

2.1.1 IUPAC Name

chloromethane
Computed by Lexichem TK 2.7.0 (PubChem release 2021.10.14)

2.1.2 InChI

InChI=1S/CH3Cl/c1-2/h1H3
Computed by InChI 1.0.6 (PubChem release 2021.10.14)

2.1.3 InChIKey

NEHMKBQYUWJMIP-UHFFFAOYSA-N
Computed by InChI 1.0.6 (PubChem release 2021.10.14)

2.1.4 SMILES

CCl
Computed by OEChem 2.3.0 (PubChem release 2024.12.12)

2.2 Molecular Formula

CH3Cl
Computed by PubChem 2.2 (PubChem release 2021.10.14)
CH3Cl

2.3 Other Identifiers

2.3.1 CAS

74-87-3
2108-20-5
6806-86-6

2.3.2 Deprecated CAS

1173018-35-3, 1474045-09-4, 1474045-10-7, 1474045-11-8, 1596379-05-3, 16786-44-0
1173018-35-3, 1474045-09-4, 1474045-10-7, 1474045-11-8, 1596379-05-3, 16786-44-0, 2692599-23-6

2.3.3 European Community (EC) Number

2.3.4 UNII

2.3.5 UN Number

2.3.6 ChEBI ID

2.3.7 ChEMBL ID

2.3.8 DSSTox Substance ID

2.3.9 HMDB ID

2.3.10 ICSC Number

2.3.11 KEGG ID

2.3.12 Metabolomics Workbench ID

2.3.13 NCI Thesaurus Code

2.3.14 Nikkaji Number

2.3.15 RTECS Number

2.3.16 Wikidata

2.3.17 Wikipedia

2.4 Synonyms

2.4.1 MeSH Entry Terms

  • Chloride, Methyl
  • Chloromethane
  • Methyl Chloride

2.4.2 Depositor-Supplied Synonyms

3 Chemical and Physical Properties

3.1 Computed Properties

Property Name
Molecular Weight
Property Value
50.49 g/mol
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
XLogP3-AA
Property Value
0.8
Reference
Computed by XLogP3 3.0 (PubChem release 2021.10.14)
Property Name
Hydrogen Bond Donor Count
Property Value
0
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Hydrogen Bond Acceptor Count
Property Value
0
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Rotatable Bond Count
Property Value
0
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Exact Mass
Property Value
49.9923278 Da
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Monoisotopic Mass
Property Value
49.9923278 Da
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Topological Polar Surface Area
Property Value
0 Ų
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Heavy Atom Count
Property Value
2
Reference
Computed by PubChem
Property Name
Formal Charge
Property Value
0
Reference
Computed by PubChem
Property Name
Complexity
Property Value
2
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Isotope Atom Count
Property Value
0
Reference
Computed by PubChem
Property Name
Defined Atom Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Undefined Atom Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Defined Bond Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Undefined Bond Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Covalently-Bonded Unit Count
Property Value
1
Reference
Computed by PubChem
Property Name
Compound Is Canonicalized
Property Value
Yes
Reference
Computed by PubChem (release 2021.10.14)

3.2 Experimental Properties

3.2.1 Physical Description

Methyl chloride appears as a colorless gas with a faint sweet odor. Shipped as a liquid under its vapor pressure. A leak may either be liquid or vapor. Contact with the liquid may cause frostbite by evaporative cooling. Easily ignited. Vapors heavier than air. Can asphyxiate by the displacement of air. Under prolonged exposure to fire or intense heat the containers may rupture violently and rocket. Used to make other chemicals and as a herbicide.
Gas or Vapor; Liquid
Colorless gas with a faint, sweet odor which is not noticeable at dangerous concentrations; Note: Shipped as a liquefied compressed gas; [NIOSH]
COLOURLESS LIQUEFIED GAS.
Colorless gas with a faint, sweet odor which is not noticeable at dangerous concentrations.
Colorless gas with a faint, sweet odor which is not noticeable at dangerous concentrations. [Note: Shipped as a liquefied compressed gas.]

3.2.2 Color / Form

Colorless compressed gas or liquid
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 823

3.2.3 Odor

Faint sweet ethereal odor
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 823
Mild odor
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013., p. 1120

3.2.4 Taste

Sweet taste
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013., p. 1120

3.2.5 Boiling Point

-11.6 °F at 760 mmHg (NTP, 1992)
National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
-23.7 °C
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013., p. 1120
-12 °F

3.2.6 Melting Point

-143 °F (NTP, 1992)
National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
-97.6 °C
Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 95th Edition. CRC Press LLC, Boca Raton: FL 2014-2015, p. 3-108
-97 °C
-144 °F

3.2.7 Flash Point

-49.9 °F (NTP, 1992)
National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
-45.6 °C
-50 °F (closed cup)
National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 325-83
<32 °F
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 2408
Flammable gas
-49.0 °F
NA (Gas)

3.2.8 Solubility

Slightly soluble (NTP, 1992)
National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
In water, 5040 mg/L at 25 °C
Horvath AL; Halogenated hydrocarbons: solubility-miscibility with water. New York, NY: Marcel Dekker, Inc pp. 889 (1982)
Solubility at 20 °C (mL/100 mL): benzene 4723, carbon tetrachloride 3756, glacial acetic acid 3679, ethanol 3740; miscible with chloroform, ether
Soluble in ethanol; miscible with ethyl ether, acetone, benzene and chloroform
Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 95th Edition. CRC Press LLC, Boca Raton: FL 2014-2015, p. 3-108
Solubility in water, g/100ml at 25 °C: 0.5
0.5%

3.2.9 Density

0.997 at -11.2 °F (USCG, 1999) - Less dense than water; will float
U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
0.911 g/cu cm at 25 °C (pressure > 1 atm)
Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 95th Edition. CRC Press LLC, Boca Raton: FL 2014-2015, p. 3-108
Bulk density: 7.68 lb/gal at 20 °C
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 823
Saturated liquid density: 62.170 lb/cu ft at -20 °F; liquid heat capacity: 0.362 Btu/lb-F at -20 °F; liquid viscosity: 0.320 centipoise at -20 °F; saturated vapor pressure: 67.520 lb/sq in at 65 °F; saturated vapor density: 0.60530 lb/cu ft at 65 °F; ideal gas heat capacity: 0.192 Btu/lb-F at 75 °F
U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.
Relative density (water = 1): 0.91
0.997 at -11.2 °F
1.78(relative gas density)

3.2.10 Vapor Density

1.8 (NTP, 1992) - Heavier than air; will sink (Relative to Air)
National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
1.8 (Air = 1)
NOAA; CAMEO Chemicals. Database of Hazardous Materials. Methyl Chloride (74-87-3). Natl Ocean Atmos Admin, Off Resp Rest; NOAA Ocean Serv. Available from, as of Jan 19, 2016: https://cameochemicals.noaa.gov/
Relative vapor density (air = 1): 2.47
1.78

3.2.11 Vapor Pressure

760 mmHg at -11 °F ; 3672 mmHg at 68 °F (NTP, 1992)
National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
4300 mm Hg at 25 °C
Daubert, T.E., R.P. Danner. Physical and Thermodynamic Properties of Pure Chemicals Data Compilation. Washington, D.C.: Taylor and Francis, 1989.
Vapor pressure, kPa at 25 °C: 573
5.0 atm

3.2.12 LogP

log Kow = 0.91
Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants. Washington, DC: American Chemical Society., 1995., p. 3
0.91

3.2.13 Henry's Law Constant

Henry's Law constant = 8.82X10-3 atm-cu m/mol at 24 °C
Gossett JM; Environ Sci Technol 21: 202-6 (1987)

3.2.14 Stability / Shelf Life

Chemical stability: Stable under recommended storage conditions.
Sigma-Aldrich; Safety Data Sheet for Chloromethane. Product Number: 295507, Version 4.6 (Revision Date 03/03/2015). Available from, as of December 15, 2015: https://www.sigmaaldrich.com/safety-center.html
Above 400 °C or in strong UV light in the presence of air and moisture it decomposes with the emission of hydrogen chloride, carbon dioxide, carbon monoxide and phosgene.
International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983., p. 464
... Thermally stable up to 427 °C (800 °F). ...
USEPA; Chemical Hazard Information Profile: Chloromethane (Draft) p.V-6 (1978) EPA-560/10-78-001
Chloromethane is stable when dry. ...
USEPA; Chemical Hazard Information Profile: Chloromethane (Draft) p.V-6 (1978) EPA-560/10-78-001

3.2.15 Autoignition Temperature

1170 °F (USCG, 1999)
U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
1170 °F
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 2408
632 °C

3.2.16 Decomposition

... In contact with moisture undergoes slow decomposition to hydrochloric acid and methanol.
USEPA; Chemical Hazard Information Profile: Chloromethane (Draft) p.V-6 (1978) EPA-560/10-78-001
When heated to decomposition it emits toxic fumes of chloride, hydrogen chloride gas, carbon monoxide, carbon dioxide, and phosgene.
Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. V5 4
When heated to decomposition it emits highly toxic fumes of /chloride/.
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 2409

3.2.17 Viscosity

0.00027 Pa.s at 20 °C (liquid, 0.5 MPa)
Rossberg M et al; Chloromethanes. Ullmann's Encyclopedia of Industrial Chemistry. 7th ed. (1999-2015). New York, NY: John Wiley & Sons. Online Posting Date: Oct 15, 2011.
0.1834 cP at 20 °C

3.2.18 Corrosivity

Methyl chloride will attack some forms of plastics, rubber and coatings.
Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) Publication No. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981., p. 2
Attacks aluminum, magnesium, and zinc.
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 823

3.2.19 Heat of Combustion

-5290 Btu/lb = -2939 cal/g = -123.1X10+5 J/kg
NOAA; CAMEO Chemicals. Database of Hazardous Materials. Methyl Chloride (74-87-3). Natl Ocean Atmos Admin, Off Resp Rest; NOAA Ocean Serv. Available from, as of Jan 19, 2016: https://cameochemicals.noaa.gov/

3.2.20 Heat of Vaporization

18.92 kJ/mol at 25 °C; 21.40 kJ/mol at boiling point
Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 95th Edition. CRC Press LLC, Boca Raton: FL 2014-2015, p. 6-133

3.2.21 Surface Tension

Liquid Surface Tension: 16.2 dynes/cm = 0.0162 N/m at 20 °C
NOAA; CAMEO Chemicals. Database of Hazardous Materials. Methyl Chloride (74-87-3). Natl Ocean Atmos Admin, Off Resp Rest; NOAA Ocean Serv. Available from, as of Jan 19, 2016: https://cameochemicals.noaa.gov/

3.2.22 Ionization Potential

11.28 eV

3.2.23 Odor Threshold

Odor Threshold Low: 10.0 [ppm]

Odor threshold from AIHA is >10 ppm

Odor recognition in air: 1.00x10+1 ppm (chemically pure)
Fazzalari, F.A. (ed.). Compilation of Odor and Taste Threshold Values Data. ASTM Data Series DS 48A (Committee E-18). Philadelphia, PA: American Society for Testing and Materials, 1978., p. 101
Odor ... not noticeable at dangerous concentrations.
Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) Publication No. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981., p. 1
Odor Threshold (air) 21 mg/cu m
USEPA/ODW; Drinking Water Health Advisories for 15 Volatile Organic Chemicals p. A-3 (1990)

3.2.24 Refractive Index

Index of refraction: 1.3712 at -23.7 °C (liquid)
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013., p. 1120

3.2.25 Kovats Retention Index

Standard non-polar
332.92 , 332.92 , 332 , 340 , 332 , 325.2 , 332 , 326 , 332 , 332
Semi-standard non-polar
329 , 324 , 326 , 327 , 329 , 301

3.2.26 Other Experimental Properties

1 mg/L = 484 ppm; 1 ppm = 2.06 mg/cu m at 25 °C, 760 torr
Reid JB, Muianga CV; Halogenated One-Carbon Compounds. Patty's Toxicology. 6th ed. (1999-2015). New York, NY: John Wiley & Sons, Inc. On-line Posting Date: Aug 17, 2012.
Enthalpy of fusion: 6.43 kJ/mol
Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 95th Edition. CRC Press LLC, Boca Raton: FL 2014-2015, p. 6-152
Hydroxyl radical rate constant= 3.06X10-14 cu cm/molecule-sec at 25 °C
Atkinson R et al; Atmos Chem Phys 8: 4141-4496 (2008). Available from, as of Jan 19, 2015: https://www.atmos-chem-phys.net/special_issue8.html

3.3 SpringerMaterials Properties

3.4 Chemical Classes

Volatile Organic Compound (VOC)

3.4.1 Solvents

Solvents -> Chlorinated Aliphatics

4 Spectral Information

4.1 1D NMR Spectra

1 of 2
1D NMR Spectra
13C-NMR: 128 (Stothers, Carbon-13 Spectroscopy, Academic Press, New York)
2 of 2
1D NMR Spectra

4.1.1 13C NMR Spectra

1 of 2
Source of Sample
MCB Manufacturing Chemists, Norwood, Ohio
Copyright
Copyright © 1980, 1981-2024 John Wiley & Sons, Inc. All Rights Reserved.
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2 of 2
Copyright
Copyright © 2002-2024 Wiley-VCH Verlag GmbH & Co. KGaA. All Rights Reserved.
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4.2 Mass Spectrometry

4.2.1 GC-MS

1 of 5
View All
MoNA ID
MS Category
Experimental
MS Type
GC-MS
MS Level
MS1
Instrument
JEOL JMS-01-SG
Instrument Type
EI-B
Ionization Mode
positive
Top 5 Peaks

50 99.99

52 34.20

49 13.30

47 11.90

35 8.40

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License
CC BY-NC-SA
2 of 5
View All
NIST Number
18894
Library
Main library
Total Peaks
14
m/z Top Peak
50
m/z 2nd Highest
15
m/z 3rd Highest
52
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4.2.2 Other MS

1 of 2
Other MS
MASS: 18894 (NIST/EPA/MSDC Mass Spectral Database, 1990 Version); 132 (Atlas of Mass Spectral Data, John Wiley & Sons, New York)
2 of 2
Authors
KOGA M, UNIV. OF OCCUPATIONAL AND ENVIRONMENTAL HEALTH
Instrument
JEOL JMS-01-SG
Instrument Type
EI-B
MS Level
MS
Ionization Mode
POSITIVE
Ionization
ENERGY 70 eV
Top 5 Peaks

50 999

52 342

49 133

47 119

35 84

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License
CC BY-NC-SA

4.3 IR Spectra

IR Spectra
IR: 15290 (Sadtler Research Laboratories IR Grating Collection)

4.3.1 Vapor Phase IR Spectra

Source of Spectrum
Sigma-Aldrich Co. LLC.
Source of Sample
Sigma-Aldrich Co. LLC.
Catalog Number
295507
Copyright
Copyright © 2021-2024 Sigma-Aldrich Co. LLC. - Database Compilation Copyright © 2021 John Wiley & Sons, Inc. All Rights Reserved.
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4.4 Other Spectra

SADTLER REFERENCE NUMBER: 842 (IR, PRISM)
Weast, R.C. (ed.). Handbook of Chemistry and Physics. 60th ed. Boca Raton, Florida: CRC Press Inc., 1979., p. C-373

6 Chemical Vendors

7 Pharmacology and Biochemistry

7.1 Absorption, Distribution and Excretion

Physiologically based pharmacokinetic (PBPK) models are often optimized by adjusting metabolic parameters so as to fit experimental toxicokinetic data. The estimates of the metabolic parameters are then conditional on the assumed values for all other parameters. Meanwhile, the reliability of other parameters, or the structural model, is usually not questioned. Inhalation exposures with human volunteers in our laboratory show that non-conjugators lack metabolic capacity for methyl chloride entirely, and that elimination in these subjects takes place via exhalation only. Therefore, data from these methyl chloride exposures provide an excellent opportunity to assess the general reliability of standard inhalation PBPK models for humans. A hierarchical population PBPK model for methyl chloride was developed. The model was fit to the experimental data in a Bayesian framework using Markov chain Monte Carlo (MCMC) simulation. In a Bayesian analysis, it is possible to merge a priori knowledge of the physiological, anatomical and physicochemical parameters with the information embedded in the experimental toxicokinetic data obtained in vivo. The resulting estimates are both statistically and physiologically plausible. Model deviations suggest that a pulmonary sub-compartment may be needed in order to describe the inhalation and exhalation of volatile methyl chloride adequately. The results also indicate that there may be significant intra-individual variability in the model parameters. ...
Jonsson F et al; Arch Toxicol 75 (4): 189-99 (2001)
After exposure to 50 ppm, chloromethane breath levels range from 50-80 ug/L; while chloromethane blood levels range from 35-100 ug/L.
Lelkin, J.B., Paloucek, F.P., Poisoning & Toxicology Compendium. LEXI-COMP Inc. & American Pharmaceutical Association, Hudson, OH 1998., p. 664
... Methyl chloride is rapidly absorbed from the lungs and rapidly reaches equilibrium with levels in blood and expired air approximately proportional to the exposure concentrations. At high concentrations, kinetic processes such as metabolism or excretion may become saturated limiting the rate of uptake. Animals studies show that methyl chloride is absorbed from the lungs and extensively distributed throughout the body.
Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. V5 6
During inhalation exposure to methyl chloride, blood:gas equilibrium is rapidly attained. Respiration and hepatic perfusion appear to be rate-limiting factors of gas uptake at low toxicant concentrations, while capacity of liver to conduct metabolism is rate-limiting at high concentrations.
Andersen ME et al; Toxicol Appl Pharmacol 54 (1): 100-16 (1980)
For more Absorption, Distribution and Excretion (Complete) data for METHYL CHLORIDE (15 total), please visit the HSDB record page.

7.2 Metabolism / Metabolites

The aim of the present study was to investigate how the genetic polymorphism in glutathione transferase T1 (GSTT1) affects the metabolism and disposition of methyl chloride in humans in vivo. The 24 volunteers (13 males and 11 females) who participated in the study were recruited from a group of 208 individuals previously phenotyped for GSTT1 by measuring the glutathione transferase activity with methyl chloride in lysed erythrocytes ex vivo. Eight individuals with high (+/+), eight with medium (+/0) and eight with no (0/0) GSTT1 activity were exposed to methyl chloride gas (10 ppm) in an exposure chamber for 2 hr. Uptake and disposition was studied by measuring the concentration of methyl chloride in inhaled air, exhaled air and blood. A two-compartment model with two elimination pathways corresponding to exhalation and metabolism was fitted to experimental data. The average net respiratory uptake of methyl chloride was 243, 158, and 44 umol in individuals with high, intermediate and no GSTT1 activity, respectively. Metabolic clearance was high (4.6 L/min) in the +/+ group, intermediate (2.4 L/min) in the +/0 group, and close to zero in 0/0 individuals, while the exhalation clearance was similar in the three groups. No exposure related increase in urinary S-methyl cysteine was detected. However, gender and the GSTTl phenotype seemed to affect the background levels. In conclusion, GSTT1 appears to be the sole determinant of methyl chloride metabolism in humans. Thus, individuals with nonfunctional GSTT1 entirely lack the capacity to metabolize methyl chloride.
Lof A et al; Pharmacogenetics 10 (7): 645-53 (2000)
Hepatic to formaldehyde and carbon dioxide. Elimination: Renal (N-acetyl-S-methylcysteine).
Lelkin, J.B., Paloucek, F.P., Poisoning & Toxicology Compendium. LEXI-COMP Inc. & American Pharmaceutical Association, Hudson, OH 1998., p. 664
Methyl chloride is metabolized by conjugation with glutathione to yield S-methylglutathione, S-methylcysteine, and other sulfur-containing compounds that are excreted in the urine or further metabolized to methanethiol. Cytochrome P450-dependent metabolism of methanethiol may yield formaldehyde and formic acid, whose carbon atoms are then available to the one-carbon pool for incorporation into macromolecules or for formation of CO2. Alternatively, formaldehyde may be directly produced from chloromethane via a P450 oxidative dechlorination.
Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. V5 6
The conjugation of chloromethane with glutathione is primarily enzyme-catalyzed. In contrast to all other animal species investigated (rats, mice, bovine, pigs, sheep, and rhesus monkeys), human erythrocytes contain a glutathione transferase isoenzyme that catalyzes the conjugation of glutathione with methyl chloride. There are two distinct human subpopulations based on the amount or forms of this transferase.
Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. V5 6
For more Metabolism/Metabolites (Complete) data for METHYL CHLORIDE (13 total), please visit the HSDB record page.

7.3 Biological Half-Life

50-90 minutes
Lelkin, J.B., Paloucek, F.P., Poisoning & Toxicology Compendium. LEXI-COMP Inc. & American Pharmaceutical Association, Hudson, OH 1998., p. 664
... Apparent steady-state blood methyl chloride (MeCl) concentrations were proportionate to exposure concentration in rats and dogs exposed to 50 and 1000 ppm. Furthermore, blood MeCl concentrations were similar in both species when they were exposed to the same concentration. A linear two-compartment open model described the blood MeCl data: alpha and beta phase elimination half-times corresponded to approximately 4 and 15 min, respectively, in rats, and 8 and 40 min in dogs.
Landry TD et al; Toxicol Appl Pharmacol 68 (3): 473-86 (1983)

7.4 Mechanism of Action

/Chloromethane ... /causes/ central nervous system depression.
Lelkin, J.B., Paloucek, F.P., Poisoning & Toxicology Compendium. LEXI-COMP Inc. & American Pharmaceutical Association, Hudson, OH 1998., p. 664
Cytotoxicity, the primary effect of methyl chloride, resulted in the disruption of the cell metab. and altered the electron transport processes of the respiratory chain. Thus, following 2-30 day inhalation exposure in rats (4 hr daily), the response was max by 8th day. Initially the activities of succinate dehydrogenase, alpha-glycerophosphate dehydrogenase, nonspecific esterase, decreased somewhat, whereas NAD-diaphorase and cytochrome oxidase increased. The activity of the diaphorase in the lymphoid tissue was high during the progress of the primary response. The secondary response was noted by 30th day when cytochrome oxidase activities are informative of the progress of toxic processes.
Mamedov AM, Aliev VA; Gig Sanit 4: 84-5 (1986)
Previous data have demonstrated that methyl chloride is toxic to B6C3F1 mice under both acute and chronic exposure conditions, and that conjugation of methyl chloride with glutathione is a key step in the metabolism of methyl chloride. This study examined the role of glutathione in mediating the acute toxicity of methyl chloride to liver, kidney, and brain of male B6C3F1 mice. The lethal effects of a single 6 hr inhalation exposure of B6C3F1 males to 2500 ppm methyl chloride were completely prevented by pretreatment with the glutathione synthesis inhibitor, L-buthionine-S,R-sulfoximine (4 mmol L-BSO/kg, ip 1.5 hr prior to methyl chloride exposure). ... These results indicate that glutathione is an important component in the toxicity of methyl chloride to multiple organ systems in B6C3F1 mice. Reaction of methyl chloride with glutathione appears to constitute a mechanism of toxication, contrary to the role usually proposed for glutathione in detoxifying xenobiotics.
Chellman GJ et al; Toxicol Appl Pharmacol 86 (1): 93-104 (1986)
Inhalation of methyl chloride by male B6C3F1 mice resulted in a concentration-dependent depletion of glutathione in liver, kidney, and brain. Exposure for 6 hr to 100 ppm methyl chloride decreased the concentration of glutathione in mouse liver by 45%, while exposure to 2500 ppm for 6 hr lowered liver glutathione to approximately 2% of control levels. For those exposures which decreased liver glutathione to less than 20% of control levels, the extent of liver glutathione depletion was closely correlated with the capacity of a 9000 g supernatant fraction from the liver to undergo lipid peroxidation in vitro. Glutathione was depleted to a lesser extent in mouse brain and kidney, compared to liver, and no relationship to peroxidation was observed for single exposures to methyl chloride. ... Exposure of rats to 2000 ppm methyl chloride reduced liver glutathione to 20% of control levels, compared to 4.5% in mice similarly exposed, and under these exposure conditions the amount of lipid peroxidation measured in vitro was 40 fold greater in mouse liver than in rat liver. During exposure of mice to 2500 ppm methyl chloride, ethane expiration increased to an extent comparable to that produced by administration of 2 ml/kg of carbon tetrachloride. These findings suggest that glutathione depletion in liver may be an important component of methyl chloride induced hepatotoxicity.
Kornbrust DJ, Bus JS; Toxicol Appl Pharmacol 72 (3): 388-99 (1984)
The effect of acute methyl chloride inhalation on F-344 rat tissue nonprotein SH (NPSH), largely reduced glutathione was studied. Rats were exposed to methyl chloride concentrations of 1500, 500 or 100 ppm. A 6 hr exposure to 1500 ppm methyl chloride decreased the nonprotein SH content of liver, kidney and lungs to 17, 27 and 30% of control values, respectively, while 500 ppm methyl chloride lowered the liver, kidney and lung nonprotein SH to 41, 59 and 55% of control values, respectively, demonstrating a concentration-related effect. Blood nonprotein SH did not differ from controls in either group. No statistically significant changes from controls in tissue or blood nonprotein SH were observed following a 100-ppm methyl chloride exposure. The extent of tissue nonprotein SH loss depended on exposure duration. Liver and kidney nonprotein SH returned to control nonprotein SH concentrations within 8 hr following exposure of 1500 ppm methyl chloride. Pretreatment of rats with Aroclor 1254 or SKF-525A (proadifen hydrochloride) did not alter the methyl chloride-induced decrease in tissue nonprotein SH. Methyl chloride reacted extensively with tissue nonprotein SH in vivo in a concentration-related fashion following acute inhaltion exposure. The most likely nonprotein SH constituent with which methyl chloride reacted was reduced glutathione. The finding that blood nonprotein SH was not affected, in contrast to liver, kidney or lung nonprotein SH, indicated a tissue-specific reaction between methyl chloride and SH groups, a reaction in which the tissue enzyme glutathione-S-alkyltransferase may play a role.
Dodd DE et al; Toxicol Appl Pharmacol 62 (6): 228-36 (1982)

7.5 Biochemical Reactions

7.6 Transformations

8 Use and Manufacturing

8.1 Uses

Methyl chloride is used mainly in the production of silicones where it is used to make methylate silicon. It is also used in the production of agricultural chemicals, methyl cellulose, quaternary amines, and butyl rubber and for miscellaneous uses including tetramethyl lead.
EPA CPDat Chemical and Product Categories
The Chemical and Products Database, a resource for exposure-relevant data on chemicals in consumer products, Scientific Data, volume 5, Article number: 180125 (2018), DOI:10.1038/sdata.2018.125
Sources/Uses
Methyl chloride is used as a methylating agent in the synthesis of many organic chemicals. [ACGIH]
ACGIH - Documentation of the TLVs and BEIs, 7th Ed. Cincinnati: ACGIH Worldwide, 2020.
For methyl chloride (USEPA/OPP Pesticide Code: 53202) there are 0 labels match. /SRP: Not registered for current use in the U.S., but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./
National Pesticide Information Retrieval System's Database on Methyl Chloride (74-87-3). Available from, as of December 16, 2015: https://npirspublic.ceris.purdue.edu/ppis/
Monochloromethane is employed as a component in the Wurtz-Fittig reaction; it is also used in Friedel-Crafts reactions for the production of alkylbenzenes.
Rossberg M et al; Chloromethanes. Ullmann's Encyclopedia of Industrial Chemistry 7th ed. (1999-2015). NY, NY: John Wiley & Sons. Online Posting Date: October 15, 2011
... a methylating agent: examples include its reaction with hydroxyl groups to give the corresponding ethers (methylcellulose from cellulose, various methyl ethers from phenolates), and its use in the preparation of methyl-substituted amino compounds (quaternary methylammonium compounds for tensides). All of the various methylamines result from its reaction with ammonia. Treatment of CH3Cl with sodium hydrogen sulfide under pressure and at elevated temperature gives methyl mercaptan.
Rossberg M et al; Chloromethanes. Ullmann's Encyclopedia of Industrial Chemistry 7th ed. (1999-2015). NY, NY: John Wiley & Sons. Online Posting Date: October 15, 2011
Methyl chloride uses break down into the following categories: intermediates for silicons (89%); methyl cellulose ethers (3%); quaternary ammonium compounds (3%), herbicides (2%); butyl rubber (1%); and miscellaneous uses (2%).
Holbrook MT; Methyl Chloride. Kirk-Othmer Encyclopedia of Chemical Technology (1999-2015). John Wiley & Sons, Inc. Online Posting Date: August 3, 2003
For more Uses (Complete) data for METHYL CHLORIDE (13 total), please visit the HSDB record page.

8.1.1 Use Classification

Chemical Classes -> Volatile organic compounds
Hazardous Air Pollutants (HAPs)
Hazard Classes and Categories -> Teratogens, Flammable - 4th degree

8.1.2 Industry Uses

  • Monomers
  • Paint additives and coating additives not described by other categories
  • Intermediate
  • Solvent
  • Not Known or Reasonably Ascertainable
  • Intermediates

8.1.3 Consumer Uses

  • Intermediates
  • Sealant (barrier)

8.1.4 Household Products

California Safe Cosmetics Program (CSCP)

Cosmetics product ingredient: Methyl chloride (Chloromethane)

Source: Methyl chloride is a natural product of plankton. It is also produced synthetically for industrial uses. Methyl chloride is a colorless, mildly sweet smelling, flammable gas. It may be used in aerosol cosmetics (such as hairspray) to help the product spray out of the can. Methyl chloride may be used in aerosol foams (such as mousse) to make the product foamy. It may also be used as a topical anesthetic (to numb skin).

Potential health impacts: People are mainly exposed to methyl chloride by inhaling vapors. People may also be exposed by ingestion. Acute effects of exposure may include dizziness, changes in vision, fatigue, confusion, nausea, and vomiting. Exposure to high levels of methyl chloride can cause serious adverse effects on the nervous system, such as convulsions or coma. Studies of mice exposed to methyl chloride found impacts on the brain, liver, and kidney as well as increased rates of birth defects. California Proposition 65 lists methyl chloride as a developmental toxin.

Product count: 11

Household & Commercial/Institutional Products

Information on 2 consumer products that contain Methyl chloride in the following categories is provided:

• Inside the Home

• Pet Care

8.2 Methods of Manufacturing

Monochloromethane production from methanol and hydrogen chloride is carried out catalytically in the gas phase at 0.3-0.6 MPa (3-6 bar) and temperatures of 280-350 °C. The usual catalyst is activated aluminum oxide. Excess hydrogen chloride is introduced in order to provide a more favorable equilibrium point (located 96-99% on the side of products at 280-350 °C) and to reduce the formation of dimethyl ether as a side product (0.2 to 1%). The raw materials must be of high purity in order to prolong catalyst life as much as possible. Technically pure (99.9%) methanol is employed, along with very clean hydrogen chloride. In the event that the latter is obtained from hydrochloric acid, it must be subjected to special purification (stripping) in order to remove interfering chlorinated hydrocarbons.
Rossberg M et al; Chloromethanes. Ullmann's Encyclopedia of Industrial Chemistry 7th ed. (1999-2015). NY, NY: John Wiley & Sons. Online Posting Date: October 15, 2011
Derivation: (1) Chlorination of methane; (2) Action of hydrochloric acid on methanol either in vapor or liquid phase.
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 823

8.3 Impurities

The most likely contaminants in /chloromethane made by hydrochlorination of methanol/ ... are water vapor and hydrogen chloride gas.
USEPA; Chemical Hazard Information Profile: Chloromethane p.V-6 (1978) EPA-560/10-78-001
A representative technical grade of methyl chloride contains not more than the following indicated quantities in ppm of impurities: water, 100; acid, such as HCl, 10; methyl ether, 20; methanol, 50; acetone, 50; residue, 100. No free chlorine should be detectable. Traces of higher chlorides are generally present in methyl chloride produced by chlorination of methane.
Holbrook MT; Methyl Chloride. Kirk-Othmer Encyclopedia of Chemical Technology (1999-2015). John Wiley & Sons, Inc. Online Posting Date: August 3, 2003

8.4 Formulations / Preparations

Grades: Pure (99.5% min), technical and two refrigerator grades.
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 823
High purity (99.5%) grade
Kuney, J.H. (ed.). CHEMCYCLOPEDIA 90. Washington, DC: American Chemical Society, 1990., p. 239
Minimum purity 99.5%, liquid phase grades
Kuney, J.H. (ed.). CHEMCYCLOPEDIA 90. Washington, DC: American Chemical Society, 1990., p. 239

8.5 Consumption Patterns

CHEM INT FOR METHYLCHLOROSILANES, 76%; CHEM INT FOR TETRAMETHYL LEAD, 9%; SOLVENT & DILUENT IN PRODN OF BUTYL RUBBER, 3%; CHEM INT FOR OTHER CHEMS, EG, METHYL CELLULOSE, METHYLARSONATES, 12% (1981- EXCLUDES CHEM INT FOR METHYLENE CHLORIDE & CHLOROFORM)
SRI
Silicones, 72%; agricultural chemical, 8%; methyl cellulose, 6%; quaternary amines, 5%; butyl rubber, 3%; miscellaneous, including tetramethyl lead, 2%; export, 4% (1983)
CHEMICAL PROFILE: Methyl Chloride, 1983
CHEMICAL PROFILE: Methyl Chloride. Silicones, 74%; agricultural chemicals, 7%; methyl cellulose, 6%; quaternary amines, 5%; butyl rubber, 2%; miscellaneous, 2%; exports, 4%.
Kavaler AR; Chemical Marketing Reporter 235 (12): 58 (1987)
Methylchlorsilanes used as intermediates for silicones, 82%; methyl cellulose ethers, 6%; quaternary ammonium compounds, 4%; herbicides, 4%; butyl rubber, 2%; miscellaneous, 2%.
Chemical Marketing Reporter; Chemical Profile Methyl Chloride. November 17, 1997. NY, NY: Schnell Pub Co p. 37 (1997)

8.6 U.S. Production

Aggregated Product Volume

2019: 1,000,000,000 - <5,000,000,000 lb

2018: 1,000,000,000 - <5,000,000,000 lb

2017: 1,000,000,000 - <5,000,000,000 lb

2016: 1,000,000,000 - <5,000,000,000 lb

(1972) 4.54x10+2 million lb
USEPA; Chemical Hazard Information Profile: Chloromethane p.V-3 (1978) EPA-560/10-78-001
(1975) 3.66x10+2 million lb
USEPA; Chemical Hazard Information Profile: Chloromethane p.V-3 (1978) EPA-560/10-78-001
(1976) 3.78x10+2 million lb
USEPA; Chemical Hazard Information Profile: Chloromethane p.V-3 (1978) EPA-560/10-78-001
(1978) 2.06X10+11 GRAMS
SRI
For more U.S. Production (Complete) data for METHYL CHLORIDE (11 total), please visit the HSDB record page.

8.7 U.S. Exports

(1978) 3.80X10+9 GRAMS
SRI
(1982) 5.70X10+9 GRAMS
SRI
(1985) 8.98X10+9 g
BUREAU OF THE CENSUS. U.S. EXPORTS, SCHEDULE E, 1985 p.2-73

8.8 General Manufacturing Information

Industry Processing Sectors
  • Soap, Cleaning Compound, and Toilet Preparation Manufacturing
  • Synthetic Rubber Manufacturing
  • Not Known or Reasonably Ascertainable
  • Plastics Material and Resin Manufacturing
  • All Other Chemical Product and Preparation Manufacturing
  • Oil and Gas Drilling, Extraction, and Support activities
  • Computer and Electronic Product Manufacturing
  • Pesticide, Fertilizer, and Other Agricultural Chemical Manufacturing
  • All Other Basic Inorganic Chemical Manufacturing
  • Paint and Coating Manufacturing
  • All Other Basic Organic Chemical Manufacturing
EPA TSCA Commercial Activity Status
Methane, chloro-: ACTIVE

9 Identification

9.1 Analytic Laboratory Methods

Method: NIOSH 1001, Issue 2; Procedure: gas chromatography with flame ionization detection; Analyte: methyl chloride; Matrix: air; Detection Limit: 0.01 mg/sample.
CDC; NIOSH Manual of Analytical Methods, 4th ed. Methyl Chloride (74-87-3). Available from, as of December 17, 2015: https://www.cdc.gov/niosh/docs/2003-154/
Method: ASTM D5790; Procedure: gas chromatography/mass spectrometry; Analyte: methyl chloride; Matrix: treated drinking water, wastewater, and ground water; Detection Limit: 0.17 ug/L.
National Environmental Methods Index; Analytical, Test and Sampling Methods. Methyl Chloride (74-87-3). Available from, as of December 16, 2015: https://www.nemi.gov
Method: EPA-EAD 601; Procedure: gas chromatography with electrolytic conductivity or microcoulometric detector; Analyte: methyl chloride; Matrix: municipal and industrial discharges; Detection Limit: 0.08 ug/L.
National Environmental Methods Index; Analytical, Test and Sampling Methods. Methyl Chloride (74-87-3). Available from, as of December 16, 2015: https://www.nemi.gov
Method: EPA-EAD 624; Procedure: gas chromatography/mass spectrometry; Analyte: methyl chloride; Matrix: water; Detection Limit: not provided.
National Environmental Methods Index; Analytical, Test and Sampling Methods. Methyl Chloride (74-87-3). Available from, as of December 16, 2015: https://www.nemi.gov
For more Analytic Laboratory Methods (Complete) data for METHYL CHLORIDE (16 total), please visit the HSDB record page.

9.2 Clinical Laboratory Methods

S-METHYLCYSTEINE WAS DETECTED IN URINE OF WORKERS EXPOSED TO METHYL CHLORIDE BY GAS CHROMATOGRAPHY.
VAN DOORN R ET AL; INT ARCH OCCUP ENVIRON HEALTH 46 (2): 99-110 (1980)
The characteristics and routine use of colorimetric, gas chromatographic, and high performance liquid chromatographic methods for the determination of urinary metabolites of organic solvents are reviewed. The solvents studied included ... methyl chloride.
Ogata M; Acta medica Okayama 35 (6): 385-94 (1981)

9.3 NIOSH Analytical Methods

10 Safety and Hazards

10.1 Hazards Identification

10.1.1 GHS Classification

1 of 7
View All
Pictogram(s)
Flammable
Compressed Gas
Irritant
Health Hazard
Signal
Danger
GHS Hazard Statements

H220 (100%): Extremely flammable gas [Danger Flammable gases]

H280 (84%): Contains gas under pressure; may explode if heated [Warning Gases under pressure]

H332 (10.6%): Harmful if inhaled [Warning Acute toxicity, inhalation]

H351 (100%): Suspected of causing cancer [Warning Carcinogenicity]

H361f (11%): Suspected of damaging fertility [Warning Reproductive toxicity]

H373 (100%): May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure]

Precautionary Statement Codes

P203, P210, P222, P260, P261, P271, P280, P304+P340, P317, P318, P319, P377, P381, P403, P405, P410+P403, and P501

(The corresponding statement to each P-code can be found at the GHS Classification page.)

ECHA C&L Notifications Summary

Aggregated GHS information provided per 1165 reports by companies from 33 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown.

10.1.2 Hazard Classes and Categories

Flam. Gas 1 (100%)

Press. Gas (Liq.) (84%)

Acute Tox. 4 (10.6%)

Carc. 2 (100%)

Repr. 2 (11%)

STOT RE 2 (100%)

Flammable gas - category 1

Gases under pressure

Acute toxicity - category 4

Carcinogenicity - category 2

Specific target organ toxicity (repeated exposure) - category 2

10.1.3 NFPA Hazard Classification

1 of 2
View All
NFPA 704 Diamond
2-4-0
NFPA Health Rating
2 - Materials that, under emergency conditions, can cause temporary incapacitation or residual injury.
NFPA Fire Rating
4 - Materials that rapidly or completely vaporize at atmospheric pressure and normal ambient temperature or that are readily dispersed in air and burn readily.
NFPA Instability Rating
0 - Materials that in themselves are normally stable, even under fire conditions.

10.1.4 Highly Hazardous Substance

OSHA Highly Hazardous Chemicals, Toxics and Reactives
  • Chemical: Methyl Chloride
  • Threshold: 15000 [lb]
  • Note: Methyl Chloride in quantities at or above above 15000lb presents a potential for a catastrophic event as a toxic or reactive highly hazardous chemical.

10.1.5 Health Hazards

Inhalation causes nausea, vomiting, weakness, headache, emotional disturbances; high concentrations cause mental confusion, eye disturbances, muscular tremors, cyanosis, convulsions. Contact of liquid with skin may cause frostbite. (USCG, 1999)
U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
ERG 2024, Guide 115 (Refrigerant gas R-40)

· Vapors may cause dizziness or asphyxiation without warning, especially when in closed or confined areas.

· Some may be irritating if inhaled at high concentrations.

· Contact with gas, liquefied gas or cryogenic liquids may cause burns, severe injury and/or frostbite.

· Fire may produce irritating and/or toxic gases.

10.1.6 Fire Hazards

Special Hazards of Combustion Products: Toxic and irritating gases are generated in fires.

Behavior in Fire: Containers may explode (USCG, 1999)

U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
ERG 2024, Guide 115 (Refrigerant gas R-40)

· EXTREMELY FLAMMABLE.

· Will be easily ignited by heat, sparks or flames.

· Will form explosive mixtures with air.

· Vapors from liquefied gas are initially heavier than air and spread along ground.

CAUTION: Hydrogen (UN1049), Deuterium (UN1957), Hydrogen, refrigerated liquid (UN1966), Methane (UN1971) and Hydrogen and Methane mixture, compressed (UN2034) are lighter than air and will rise. Hydrogen and Deuterium fires are difficult to detect since they burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.)

· Vapors may travel to source of ignition and flash back.

· Cylinders exposed to fire may vent and release flammable gas through pressure relief devices.

· Containers may explode when heated.

· Ruptured cylinders may rocket.

CAUTION: When LNG - Liquefied natural gas (UN1972) is released on or near water, product may vaporize explosively.

Highly flammable. Heating will cause rise in pressure with risk of bursting. Gas/air mixtures are explosive.

10.1.7 Hazards Summary

Chloromethane is also known as methyl chloride. It is a clear, colorless gas. It has a faint, sweet odor that is noticeable only at levels that may be toxic. It is heavier than air, and it is extremely flammable.
Low levels of methyl chloride occur naturally in the environment. Higher levels may occur at chemical plants where it is made or used. Acute (short-term) exposure to high concentrations of methyl chloride in humans has caused severe neurological effects. Methyl chloride has also caused effects on the heart rate, blood pressure, liver, and kidneys in humans. Chronic (long-term) animal studies have shown liver, kidney, spleen, and central nervous system (CNS) effects. Inhalation studies have demonstrated that methyl chloride causes reproductive effects in male rats, with effects such as testicular lesions and decreased sperm production. Human cancer data are limited. EPA has classified methyl chloride as a Group D carcinogen (not classifiable as to human carcinogenicity).
Slurred speech and staggering gait were observed in six workers exposed at 200-400 ppm for at least 2 weeks, but no changes in blood chemistries were found in these six cases. Liver injury has been documented in animal studies. [ACGIH] Possible frostbite from contact with liquid; [NIOSH] In high-dose reproductive studies of mice and rats, methyl chloride causes testicular damage; it causes increased heart valve birth defects in mice only. [Frazier, p. 286-7] Compared to other haloalkanes, methyl chloride is nontoxic to the liver. Steatosis may be observed in high-dose feeding studies of animals. [Zimmerman, p. 333] Has acute effects on the CNS, heart, liver, and kidneys; Possible CNS and reproductive effects after chronic exposure; [ICSC] Empirical data in support of a skin notation for methyl chloride [PMID 29708856]
ACGIH - Documentation of the TLVs and BEIs, 7th Ed. Cincinnati: ACGIH Worldwide, 2020.
Frazier - Frazier LM, Hage ML (eds). Reproductive Hazards of the Workplace. New York: John Wiley & Sons, 1998., p. 286-7
Zimmerman - Zimmerman HJ. Hepatotoxicity. Philadelphia: Lippincott Williams & Wilkins, 1999., p. 333

10.1.8 Fire Potential

Flammable gas. Very dangerous fire hazard when exposed to heat, flame or powerful oxidizers. ... May ignite on contact with aluminum chloride or powdered aluminum.
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 2409
It is easily ignited.
Association of American Railroads; Bureau of Explosives. Emergency Handling of Hazardous Materials in Surface Transportation. Association of American Railroads, Pueblo, CO. 2005, p. 577

10.1.9 Skin, Eye, and Respiratory Irritations

/Methyl chloride/ is an eye, respiratory tract, and skin irritant.
Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. V5 4
Threshold of irritation: 1050 mg/cu m. /From table/
Ruth JH; Am Ind Hyg Assoc J 47: A-142-51 (1986)
Methyl chloride has slight irritant properties and may be inhaled without noticeable discomfort.
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 2409

10.1.10 EPA Hazardous Waste Number

U045; A toxic waste when a discarded commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or manufacturing chemical intermediate.

10.2 Safety and Hazard Properties

10.2.1 Acute Exposure Guideline Levels (AEGLs)

10.2.1.1 AEGLs Table
AEGLs
AEGL 1: Notable discomfort, irritation, or certain asymptomatic non-sensory effects. However, the effects are not disabling and are transient and reversible upon cessation of exposure (Unit: ppm)
10 min
NR
30 min
NR
60 min
NR
4 hr
NR
8 hr
NR
AEGLs
AEGL 2: Irreversible or other serious, long-lasting adverse health effects or an impaired ability to escape (Unit: ppm)
10 min
1100
30 min
1100
60 min
910
4 hr
570
8 hr
380
AEGLs
AEGL 3: Life-threatening health effects or death (Unit: ppm)
10 min
3800
30 min
3800
60 min
3000
4 hr
1900
8 hr
1300
10.2.1.2 AEGLs Notes

NR = Not recommended due to insufficient data

AEGLs Status: Final

10.2.2 Flammable Limits

Lower flammable limit: 8.1% by volume; Upper flammable limit: 17.4% by volume
National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 325-83
Flammability
Flammable Gas

10.2.3 Lower Explosive Limit (LEL)

8.1 % (NTP, 1992)
National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
8.1%

10.2.4 Upper Explosive Limit (UEL)

17.2 % (NTP, 1992)
National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
17.4%

10.2.5 Critical Temperature & Pressure

Critical temperature: 416.25 K; critical pressure: 6.679 MPa
Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 95th Edition. CRC Press LLC, Boca Raton: FL 2014-2015, p. 6-61

10.2.6 Physical Dangers

The gas is heavier than air and may travel along the ground; distant ignition possible. The gas is heavier than air and may accumulate in lowered spaces causing a deficiency of oxygen.

10.2.7 Explosive Limits and Potential

Lower 8.1%, upper 17%
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 2408
Moderate explosion hazard when exposed to flame and sparks.
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 2409
Under prolonged exposure to fire or intense heat the containers may rupture violently and rocket.
Association of American Railroads; Bureau of Explosives. Emergency Handling of Hazardous Materials in Surface Transportation. Association of American Railroads, Pueblo, CO. 2005, p. 577
Explosive limits , vol% in air: 8.1-17.4

10.2.8 OSHA Standards

Permissible Exposure Limit: Table Z-2 8-hr Time Weighted Avg: 100 ppm.
29 CFR 1910.1000 (USDOL); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of December 14, 2015: https://www.ecfr.gov
Permissible Exposure Limit: Table Z-2 Acceptable Ceiling Concentration: 200 ppm.
29 CFR 1910.1000 (USDOL); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of December 14, 2015: https://www.ecfr.gov
Permissible Exposure Limit: Table Z-2 Acceptable maximum peak above the acceptable ceiling concentration for an 8-hour shift. Concentration: 300 ppm. Maximum Duration: 5 minutes in any 3 hours.
29 CFR 1910.1000 (USDOL); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of December 14, 2015: https://www.ecfr.gov
Vacated 1989 OSHA PEL TWA 50 ppm (105 mg/cu m); STEL 100 ppm (210 mg/cu m) is still enforced in some states.
NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997., p. 367

10.2.9 NIOSH Recommendations

NIOSH considers methyl chloride to be a potential occupational carcinogen.
NIOSH. NIOSH Pocket Guide to Chemical Hazards. Department of Health & Human Services, Centers for Disease Control & Prevention. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2010-168 (2010). Available from: https://www.cdc.gov/niosh/npg
NIOSH usually recommends that occupational exposures to carcinogens be limited to the lowest feasible concentration.
NIOSH. NIOSH Pocket Guide to Chemical Hazards. Department of Health & Human Services, Centers for Disease Control & Prevention. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2010-168 (2010). Available from: https://www.cdc.gov/niosh/npg

10.3 First Aid Measures

Inhalation First Aid
Fresh air, rest. Artificial respiration may be needed. Refer for medical attention.
Skin First Aid
ON FROSTBITE: rinse with plenty of water, do NOT remove clothes. Refer for medical attention .

10.3.1 First Aid

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

SKIN: CAUTION: Exposure of skin to compressed gases may result in freezing of the skin. Treatment for frostbite may be necessary. Remove the victim from the source of contamination. IMMEDIATELY wash affected areas gently with COLD water (and soap, if necessary) while removing and isolating all contaminated clothing. Dry carefully with clean, soft towels. If symptoms such as inflammation or irritation develop, IMMEDIATELY call a physician or go to a hospital for treatment.

INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.

INGESTION: This compound is a gas, therefore inhalation is the first route of exposure. (NTP, 1992)

National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
ERG 2024, Guide 115 (Refrigerant gas R-40)

General First Aid:

· Call 911 or emergency medical service.

· Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination.

· Move victim to fresh air if it can be done safely.

· Administer oxygen if breathing is difficult.

· If victim is not breathing:

-- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingestedor inhaled the substance.

-- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped with a one-way valve or other device).

-- If no pulse detected or no respiratory medical device available, provide continuouscompressions. Conduct a pulse check every two minutes or monitor for any signs of spontaneous respirations.

· Remove and isolate contaminated clothing and shoes.

· For minor skin contact, avoid spreading material on unaffected skin.

· In case of contact with substance, remove immediately by flushing skin or eyes with running water for at least 20 minutes.

· For severe burns, immediate medical attention is required.

· Effects of exposure (inhalation, ingestion, or skin contact) to substance may be delayed.

· Keep victim calm and warm.

· Keep victim under observation.

· For further assistance, contact your local Poison Control Center.

· Note: Basic Life Support (BLS) and Advanced Life Support (ALS) should be done by trained professionals.

Specific First Aid:

· Clothing frozen to the skin should be thawed before being removed.

· In case of contact with liquefied gas, only medical personnel should attempt thawing frosted parts.

· In case of burns, immediately cool affected skin for as long as possible with cold water. Do not remove clothing if adhering to skin.

In Canada, an Emergency Response Assistance Plan (ERAP) may be required for this product. Please consult the shipping paper and/or the "ERAP" section.

(See general first aid procedures)

Eye: Frostbite - If eye tissue is frozen, seek medical attention immediately; if tissue is not frozen, immediately and thoroughly flush the eyes with large amounts of water for at least 15 minutes, occasionally lifting the lower and upper eyelids. If irritation, pain, swelling, lacrimation, or photophobia persist, get medical attention as soon as possible.

Skin: Frostbite - Compressed gases may create low temperatures when they expand rapidly. Leaks and uses that allow rapid expansion may cause a frostbite hazard. Wear appropriate personal protective clothing to prevent the skin from becoming frozen.

Breathing: Respiratory support

10.4 Fire Fighting

Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:

DO NOT EXTINGUISH A LEAKING GAS FIRE UNLESS LEAK CAN BE STOPPED. CAUTION: Hydrogen (UN1049), Deuterium (UN1957), Hydrogen, refrigerated liquid (UN1966) and Hydrogen and Methane mixture, compressed (UN2034) will burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.).

SMALL FIRE: Dry chemical or CO2.

LARGE FIRE: Water spray or fog. If it can be done safely, move undamaged containers away from the area around the fire. CAUTION: For LNG - Liquefied natural gas (UN1972) pool fires, DO NOT USE water. Use dry chemical or high-expansion foam.

FIRE INVOLVING TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. Do not direct water at source of leak or safety devices; icing may occur. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn. (ERG, 2024)

Shut off supply; if not possible and no risk to surroundings, let the fire burn itself out. In other cases extinguish with water spray. In case of fire: keep cylinder cool by spraying with water. Combat fire from a sheltered position.

10.4.1 Fire Fighting Procedures

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
Sigma-Aldrich; Safety Data Sheet for Chloromethane. Product Number: 295507, Version 4.6 (Revision Date 03/03/2015). Available from, as of December 15, 2015: https://www.sigmaaldrich.com/safety-center.html
Advice for firefighters: Wear self-contained breathing apparatus for firefighting if necessary.
Sigma-Aldrich; Safety Data Sheet for Chloromethane. Product Number: 295507, Version 4.6 (Revision Date 03/03/2015). Available from, as of December 15, 2015: https://www.sigmaaldrich.com/safety-center.html
Use water spray to cool unopened containers.
Sigma-Aldrich; Safety Data Sheet for Chloromethane. Product Number: 295507, Version 4.6 (Revision Date 03/03/2015). Available from, as of December 15, 2015: https://www.sigmaaldrich.com/safety-center.html
If material on fire or involved in fire: Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible.
Association of American Railroads; Bureau of Explosives. Emergency Handling of Hazardous Materials in Surface Transportation. Association of American Railroads, Pueblo, CO. 2005, p. 577
For more Fire Fighting Procedures (Complete) data for METHYL CHLORIDE (7 total), please visit the HSDB record page.

10.4.2 Firefighting Hazards

Vapors are heavier than air and will collect in low areas. Vapors may travel long distances to ignition sources and flashback. Vapors in confined areas may explode when exposed to fire. Containers may explode in fire. Storage containers and parts of containers may rocket great distances, in many directions.
Pohanish, R.P. (ed). Sittig's Handbook of Toxic and Hazardous Chemical Carcinogens 6th Edition Volume 1: A-K,Volume 2: L-Z. William Andrew, Waltham, MA 2012, p. 1772

10.5 Accidental Release Measures

Public Safety: ERG 2024, Guide 115 (Refrigerant gas R-40)

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

· Keep unauthorized personnel away.

· Stay upwind, uphill and/or upstream.

· Many gases are heavier than air and will spread along the ground and collect in low or confined areas (sewers, basements, tanks, etc.).

Spill or Leak: ERG 2024, Guide 115 (Refrigerant gas R-40)

· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.

· All equipment used when handling the product must be grounded.

· Do not touch or walk through spilled material.

· Stop leak if you can do it without risk.

· If possible, turn leaking containers so that gas escapes rather than liquid.

· Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material.

· Do not direct water at spill or source of leak.

CAUTION: For LNG - Liquefied natural gas (UN1972), DO NOT apply water, regular or alcohol-resistant foam directly on spill. Use a high-expansion foam if available to reduce vapors.

· Prevent spreading of vapors through sewers, ventilation systems and confined areas.

· Isolate area until gas has dispersed.

CAUTION: When in contact with refrigerated/cryogenic liquids, many materials become brittle and are likely to break without warning.

10.5.1 Isolation and Evacuation

Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 100 meters (330 feet) in all directions.

LARGE SPILL: Consider initial downwind evacuation for at least 800 meters (1/2 mile).

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 1600 meters (1 mile) in all directions; also, consider initial evacuation for 1600 meters (1 mile) in all directions. In fires involving Liquefied Petroleum Gases (LPG) (UN1075), Butane (UN1011), Butylene (UN1012), Isobutylene (UN1055), Propylene (UN1077), Isobutane (UN1969), and Propane (UN1978), also refer to the "BLEVE - Safety Precautions" section. (ERG, 2024)

Evacuation: ERG 2024, Guide 115 (Refrigerant gas R-40)

Immediate precautionary measure

· Isolate spill or leak area for at least 100 meters (330 feet) in all directions.

Large Spill

· Consider initial downwind evacuation for at least 800 meters (1/2 mile).

Fire

· If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 1600 meters (1 mile) in all directions; also, consider initial evacuation for 1600 meters (1 mile) in all directions.

· In fires involving Liquefied Petroleum Gases (LPG) (UN1075), Butane (UN1011), Butylene (UN1012), Isobutylene (UN1055), Propylene (UN1077), Isobutane (UN1969), and Propane (UN1978), also refer to the "BLEVE - Safety Precautions" section.

10.5.2 Spillage Disposal

Evacuate danger area! Consult an expert! Personal protection: complete protective clothing including self-contained breathing apparatus. Ventilation. NEVER direct water jet on liquid.

10.5.3 Cleanup Methods

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Remove all sources of ignition. Evacuate personnel to safe areas. Beware of vapors accumulating to form explosive concentrations. Vapors can accumulate in low areas; Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains; Methods and materials for containment and cleaning up: Clean up promptly by sweeping or vacuum.
Sigma-Aldrich; Safety Data Sheet for Chloromethane. Product Number: 295507, Version 4.6 (Revision Date 03/03/2015). Available from, as of December 15, 2015: https://www.sigmaaldrich.com/safety-center.html
Evacuate and restrict persons not wearing protective equipment from area of spill or leak until cleanup is complete. Remove all ignition sources. Establish forced ventilation to keep levels below explosive limit. Stop the flow of gas if it can be done safely. If source of leak is a cylinder and the leak cannot be stopped in place, remove leaking cylinder to a safe place in the open air, and repair leak or allow cylinder to empty. Keep this chemical out of confined space, such as a sewer, because of the possibility of explosion, unless the sewer is designed to prevent the buildup of explosive concentrations. It may be necessary to contain and dispose of this chemical as a hazardous waste.
Pohanish, R.P. (ed). Sittig's Handbook of Toxic and Hazardous Chemical Carcinogens 6th Edition Volume 1: A-K,Volume 2: L-Z. William Andrew, Waltham, MA 2012, p. 1771-72

10.5.4 Disposal Methods

Product: Burn in a chemical incinerator equipped with an afterburner and scrubber but exert extra care in igniting as this material is highly flammable. Offer surplus and non-recyclable solutions to a licensed disposal company. Contact a licensed professional waste disposal service to dispose of this material; Contaminated packaging: Dispose of as unused product.
Sigma-Aldrich; Safety Data Sheet for Chloromethane. Product Number: 295507, Version 4.6 (Revision Date 03/03/2015). Available from, as of December 15, 2015: https://www.sigmaaldrich.com/safety-center.html
Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number U045, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.
40 CFR 240-280, 300-306, 702-799 (7/1/91)
Methyl chloride is a waste chemical stream constituent which may be subjected to ultimate disposal by controlled incineration.
USEPA; Engineering Handbook for Hazardous Waste Incineration p.2-8 (1981) EPA 68-03-3025
A potential candidate for rotary kiln incineration at a temperature range of 820 to 1,600 °C and residence times of seconds for liquids and gases, and hours for solids. A potential candidate for fluidized bed incineration at a temperature range of 450 to 980 °C and residence times of seconds for liquids and gases, and longer for solids.
USEPA; Engineering Handbook for Hazardous Waste Incineration p.3-11 (1981) EPA 68-03-3025
For more Disposal Methods (Complete) data for METHYL CHLORIDE (6 total), please visit the HSDB record page.

10.5.5 Preventive Measures

Precautions for safe handling: Avoid contact with skin and eyes. Avoid inhalation of vapor or mist. Use explosion-proof equipment. Keep away from sources of ignition - No smoking. Take measures to prevent the build up of electrostatic charge.
Sigma-Aldrich; Safety Data Sheet for Chloromethane. Product Number: 295507, Version 4.6 (Revision Date 03/03/2015). Available from, as of December 15, 2015: https://www.sigmaaldrich.com/safety-center.html
Appropriate engineering controls: Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks and at the end of workday.
Sigma-Aldrich; Safety Data Sheet for Chloromethane. Product Number: 295507, Version 4.6 (Revision Date 03/03/2015). Available from, as of December 15, 2015: https://www.sigmaaldrich.com/safety-center.html
Gloves must be inspected prior to use. Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands.
Sigma-Aldrich; Safety Data Sheet for Chloromethane. Product Number: 295507, Version 4.6 (Revision Date 03/03/2015). Available from, as of December 15, 2015: https://www.sigmaaldrich.com/safety-center.html
Respirators may be used when engineering and work practice controls are not technically feasible, when such controls are in the process of being installed, or when they fail and need to be supplemented. Respirators may also be used for operations which require entry into tanks or closed vessels, and in emergency situations. ...
Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) Publication No. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981., p. 2
For more Preventive Measures (Complete) data for METHYL CHLORIDE (11 total), please visit the HSDB record page.

10.6 Handling and Storage

10.6.1 Nonfire Spill Response

Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. All equipment used when handling the product must be grounded. Do not touch or walk through spilled material. Stop leak if you can do it without risk. If possible, turn leaking containers so that gas escapes rather than liquid. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. Do not direct water at spill or source of leak. CAUTION: For LNG - Liquefied natural gas (UN1972), DO NOT apply water, regular or alcohol-resistant foam directly on spill. Use a high-expansion foam if available to reduce vapors. Prevent spreading of vapors through sewers, ventilation systems and confined areas. Isolate area until gas has dispersed. CAUTION: When in contact with refrigerated/cryogenic liquids, many materials become brittle and are likely to break without warning. (ERG, 2024)

10.6.2 Safe Storage

Fireproof. Ventilation along the floor.

10.6.3 Storage Conditions

Keep container tightly closed in a dry and well-ventilated place. Contents under pressure. Moisture sensitive. Storage class (TRGS 510): Gases
Sigma-Aldrich; Safety Data Sheet for Chloromethane. Product Number: 295507, Version 4.6 (Revision Date 03/03/2015). Available from, as of December 15, 2015: https://www.sigmaaldrich.com/safety-center.html
Store in well-ventilated place controlled below 40 °C. No exposure to direct sunlight. ... Electrical equipment of spark-resistant construction is preferred.
ITII. Toxic and Hazarous Industrial Chemicals Safety Manual. Tokyo, Japan: The International Technical Information Institute, 1982., p. 331
Store separately from all other flammable materials. ... Before entering confined space where this chemical may be present, check to make sure that an explosive concentration does not exist. Methyl chloride must be stored to avoid contact with oxidizers (such as perchlorates, peroxides, chlorates, nitrates, and permanganates) or chemically active metals (such as sodium, potassium, powdered aluminum, zinc, and magnesium), since violent reactions occur. Store in tightly closed containers in a cool, well-ventilated area away from heat and direct sunlight. Sources of ignition, such as smoking and open flames, are prohibited where methyl chloride is used, handled, or stored in a manner that could create a potential fire ot explosion hazard. Wherever methyl chloride is used, handled, manufactured, or stored, use explosion-proof electrical equipment for fittings. Procedures for the handling, use, and storage of cylinders should be in compliance with OSHA 1910.101 and 1910.169, as with the recommendations of the Compressed Gas Association. A regulated, marked area should be established where this chemical is handled, used, or stored in compliance with OSHA Standard 1910.1045.
Pohanish, R.P. (ed). Sittig's Handbook of Toxic and Hazardous Chemical Carcinogens 6th Edition Volume 1: A-K,Volume 2: L-Z. William Andrew, Waltham, MA 2012, p. 1771

10.7 Exposure Control and Personal Protection

Protective Clothing: ERG 2024, Guide 115 (Refrigerant gas R-40)

· Wear positive pressure self-contained breathing apparatus (SCBA).

· Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.

· Always wear thermal protective clothing when handling refrigerated/cryogenic liquids.

Maximum Allowable Concentration (MAK)
10.0 [ppm]

10.7.2 Permissible Exposure Limit (PEL)

100.0 [ppm], Ceiling(OSHA) = 200 ppm(300 ppm for 5-min peak in any 3 hrs)
PEL-TWA (8-Hour Time Weighted Average)
100 ppm (210 mg/m³)
PEL-C (Ceiling)
200 ppm; 300 ppm (Peak - 5 min in any 3 hrs)
TWA 100 ppm C 200 ppm 300 ppm (5-minute maximum peak in any 3 hours) See Appendix G

10.7.3 Immediately Dangerous to Life or Health (IDLH)

2000 ppm ; A potential occupational carcinogen. (NIOSH, 2024)
2000.0 [ppm]
NIOSH considers methyl chloride to be a potential occupational carcinogen.
NIOSH. NIOSH Pocket Guide to Chemical Hazards. Department of Health & Human Services, Centers for Disease Control & Prevention. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2010-168 (2010). Available from: https://www.cdc.gov/niosh/npg
2000 ppm

Ca [2000 ppm]

See: 74873

10.7.4 Threshold Limit Values (TLV)

50.0 [ppm]
TLV-STEL
100.0 [ppm]
8 hr Time Weighted Avg (TWA): 50 ppm; 15 min Short Term Exposure Limit (STEL): 100 ppm, skin
American Conference of Governmental Industrial Hygienists TLVs and BEIs. Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati, OH 2015, p. 40
A4: Not classifiable as a human carcinogen.
American Conference of Governmental Industrial Hygienists TLVs and BEIs. Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati, OH 2015, p. 40
50 ppm as TWA; 100 ppm as STEL; (skin); A4 (not classifiable as a human carcinogen).
TLV-TWA (Time Weighted Average)
50 ppm [1992]
TLV-STEL (Short Term Exposure Limit)
100 ppm [1992]

10.7.5 Occupational Exposure Limits (OEL)

EU-OEL
42 mg/m
MAK (Maximale Arbeitsplatz Konzentration)
21 mg/m

10.7.6 Emergency Response Planning Guidelines

Emergency Response: ERG 2024, Guide 115 (Refrigerant gas R-40)

· DO NOT EXTINGUISH A LEAKING GAS FIRE UNLESS LEAK CAN BE STOPPED.

CAUTION: Hydrogen (UN1049), Deuterium (UN1957), Hydrogen, refrigerated liquid (UN1966) and Hydrogen and Methane mixture, compressed (UN2034) will burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.)

Small Fire

· Dry chemical or CO2.

Large Fire

· Water spray or fog.

· If it can be done safely, move undamaged containers away from the area around the fire.

CAUTION: For LNG - Liquefied natural gas (UN1972) pool fires, DO NOT USE water. Use dry chemical or high-expansion foam.

Fire Involving Tanks

· Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles.

· Cool containers with flooding quantities of water until well after fire is out.

· Do not direct water at source of leak or safety devices; icing may occur.

· Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank.

· ALWAYS stay away from tanks in direct contact with flames.

· For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn.

ERPG-1: Not appropriate - one hour exposure limit: 1 = mild transient health effects or objectionable odor [AIHA]

ERPG-2: 400 ppm - one hour exposure limit: 2 = impaired ability to take protective action [AIHA]

ERPG-3: 1,000 ppm - one hour exposure limit: 3 = life threatening health effects [AIHA]

10.7.7 Other Standards Regulations and Guidelines

Monitoring requirements for unregulated contaminants: Contaminant, chloromethane; Minimum reporting level, 0.2 ug/L; Period during which monitoring to be completed, 1/1/2013-12/31/2015.
40 CFR 141.40 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of December 14, 2015: https://www.ecfr.gov
Australia: 50 ppm, STEL 100 ppm (1990); Federal Republic of Germany: 50 ppm, short-term level 100 ppm, 30 min, 4 times per shift, Group B, justifiably suspected of having carcinogenic potential, Pregnancy group B, a risk of damage to the developing embryo or fetus must be considered to be probable and cannot be excluded when pregnant women are exposed under conditions whereby MAK and BAT values are adhered to (1991); Sweden: 50 ppm, short-term value 100 ppm, 15 min (1990); United Kingdom: 50 ppm, 10-min STEL 100 ppm (1991).
American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I, II, III. Cincinnati, OH: ACGIH, 1991., p. 956
Emergency Response Planning Guidlines (ERPGs) for methyl chloride:
ERPG / LEL
ERPG-1: The maximum airborne concentration below which it is believed nearly all individuals could be exposed for up to 1 hour without experiencing more than mild, transient adverse health effects or without perceiving a clearly defined objectionable odor.
Airborne Concentration
150 ppm
Notations
Odor should be detectable near ERPG-1
ERPG / LEL
ERPG-2: The maximum airborne concentration below which it is believed nearly all individuals could be exposed for up to 1 hour without experiencing or developing irreversible or other serious health effects or symptoms that could impair an individual's ability to take protective action.
Airborne Concentration
1000 ppm
ERPG / LEL
ERPG-3: The maximum airborne concentration below which it is believed nearly all individuals could be exposed for up to 1 hour without experiencing or developing life-threatening health effects.
Airborne Concentration
3000 ppm
ERPG / LEL
LEL (Lower Explosive Limit): The minimum concentration in air of a flammable gas or vapor at which ignition can occur.
Airborne Concentration
None
2015 Emergency Response Planning Guidelines (ERPG) & Workplace Exposure Level (WEEL). American Industrial Hygiene Association, Falls Church, VA 2015, p. 27

10.7.8 Inhalation Risk

A harmful concentration of this gas in the air will be reached very quickly on loss of containment.

10.7.9 Effects of Short Term Exposure

The liquid may cause frostbite. The substance may cause effects on the central nervous system. Exposure far above the OEL could cause liver, cardiovascular system and kidney damage. Exposure could cause unconsciousness. Medical observation is indicated. The effects may be delayed.

10.7.10 Effects of Long Term Exposure

The substance may have effects on the central nervous system. This may result in effects measured using behavioural tests. Animal tests show that this substance possibly causes toxic effects upon human reproduction.

10.7.11 Acceptable Daily Intakes

An ADI of 0.54 mg/kg/day (37.8 mg/day) for a 70-kg human ... was derived by U.S. EPA (1982). The Reference Dose (RfD) of 0.0036 mg/kg/day ... supercedes the previously calculated ADI.
USEPA/ODW; Drinking Water Health Advisories for 15 Volatile Organic Chemicals p. A-17 (1990)

10.7.12 Personal Protective Equipment (PPE)

Excerpt from NIOSH Pocket Guide for Methyl chloride:

Skin: FROSTBITE - Compressed gases may create low temperatures when they expand rapidly. Leaks and uses that allow rapid expansion may cause a frostbite hazard. Wear appropriate personal protective clothing to prevent the skin from becoming frozen.

Eyes: FROSTBITE - Wear appropriate eye protection to prevent eye contact with the liquid that could result in burns or tissue damage from frostbite.

Wash skin: No recommendation is made specifying the need for washing the substance from the skin (either immediately or at the end of the work shift).

Remove: WHEN WET (FLAMMABLE) - Work clothing that becomes wet should be immediately removed due to its flammability hazard (i.e., for liquids with a flash point <100 °F).

Change: No recommendation is made specifying the need for the worker to change clothing after the workshift.

Provide: FROSTBITE WASH - Quick drench facilities and/or eyewash fountains should be provided within the immediate work area for emergency use where there is any possibility of exposure to liquids that are extremely cold or rapidly evaporating. (NIOSH, 2024)

Eye/face protection: Face shield and safety glasses. Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).
Sigma-Aldrich; Safety Data Sheet for Chloromethane. Product Number: 295507, Version 4.6 (Revision Date 03/03/2015). Available from, as of December 15, 2015: https://www.sigmaaldrich.com/safety-center.html
Skin protection: Handle with gloves.
Sigma-Aldrich; Safety Data Sheet for Chloromethane. Product Number: 295507, Version 4.6 (Revision Date 03/03/2015). Available from, as of December 15, 2015: https://www.sigmaaldrich.com/safety-center.html
Body Protection: Complete suit protecting against chemicals. Flame retardant antistatic protective clothing. The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.
Sigma-Aldrich; Safety Data Sheet for Chloromethane. Product Number: 295507, Version 4.6 (Revision Date 03/03/2015). Available from, as of December 15, 2015: https://www.sigmaaldrich.com/safety-center.html
Respiratory protection: Where risk assessment shows air-purifying respirators are appropriate use a full-face respirator with multipurpose combination (US) or type AXBEK (EN 14387) respirator cartridges as a backup to engineering controls. If the respirator is the sole means of protection, use a full-face supplied air respirator. Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).
Sigma-Aldrich; Safety Data Sheet for Chloromethane. Product Number: 295507, Version 4.6 (Revision Date 03/03/2015). Available from, as of December 15, 2015: https://www.sigmaaldrich.com/safety-center.html
For more Personal Protective Equipment (PPE) (Complete) data for METHYL CHLORIDE (11 total), please visit the HSDB record page.

(See personal protection and sanitation codes)

Skin: Frostbite - Compressed gases may create low temperatures when they expand rapidly. Leaks and uses that allow rapid expansion may cause a frostbite hazard. Wear appropriate personal protective clothing to prevent the skin from becoming frozen.

Eyes: Frostbite - Wear appropriate eye protection to prevent eye contact with the liquid that could result in burns or tissue damage from frostbite.

Wash skin: No recommendation

Remove: When wet (flammable)

Change: No recommendation

Provide: Frostbite wash - Quick drench facilities and/or eyewash fountains should be provided within the immediate work area for emergency use where there is any possibility of exposure to liquids that are extremely cold or rapidly evaporating.

10.7.13 Respirator Recommendations

NIOSH

At concentrations above the NIOSH REL, or where there is no REL, at any detectable concentration:

(APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode

(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus

Escape:

Any appropriate escape-type, self-contained breathing apparatus

Important additional information about respirator selection

10.7.14 Preventions

Fire Prevention
NO open flames, NO sparks and NO smoking. Closed system, ventilation, explosion-proof electrical equipment and lighting. Use non-sparking handtools.
Exposure Prevention
STRICT HYGIENE!
Inhalation Prevention
Use ventilation, local exhaust or breathing protection.
Skin Prevention
Cold-insulating gloves. Protective clothing.
Eye Prevention
Wear safety goggles, face shield or eye protection in combination with breathing protection.

10.8 Stability and Reactivity

10.8.1 Air and Water Reactions

Highly flammable.

10.8.2 Reactive Group

Halogenated Organic Compounds

10.8.3 Reactivity Alerts

Highly Flammable

10.8.4 Reactivity Profile

METHYL CHLORIDE can react vigorously with oxidizing agents. May react explosively with sodium, potassium, sodium-potassium alloy, magnesium, zinc. Reacts with aluminum powder in the presence of catalytic amounts of aluminum chloride to form pyrophoric trimethylaluminum. When heated to decomposition, it emits highly toxic fumes of chlorine [Bretherick, 5th ed., 1995, p. 176].

10.8.5 Hazardous Reactivities and Incompatibilities

Incompatible materials: Strong oxidizing agents, Iron
Sigma-Aldrich; Safety Data Sheet for Chloromethane. Product Number: 295507, Version 4.6 (Revision Date 03/03/2015). Available from, as of December 15, 2015: https://www.sigmaaldrich.com/safety-center.html
Contact with chemically active metals such as potassium, powdered aluminum, magnesium and zinc will cause fires and explosions.
Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) Publication No. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981., p. 2
Explodes on contact with interhalogens (e.g., bromine, trifluoride, bromine pentafluoride), magnesium and alloys, potassium and alloys, sodium and alloys, zinc. Potentially explosive reaction with aluminum when heated to 152 deg in a sealed container. Mixtures with aluminum chloride + ethylene react exothermically and then explode when pressurized to above 30 bar.
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 2409
Violent reaction with chemically active metals, such as potassium, powdered aluminum, zinc, and magnesium. Reaction with aluminum trichloride, ethylene. Reacts with water (hydrolizes) to form hydrochloric acid. Attacks many metals in the presence of moisture.
Pohanish, R.P. (ed). Sittig's Handbook of Toxic and Hazardous Chemical Carcinogens 6th Edition Volume 1: A-K,Volume 2: L-Z. William Andrew, Waltham, MA 2012, p. 1770
For more Hazardous Reactivities and Incompatibilities (Complete) data for METHYL CHLORIDE (9 total), please visit the HSDB record page.

10.9 Transport Information

10.9.1 DOT Emergency Guidelines

/GUIDE 115 GASES - FLAMMABLE (Including Refrigerated Liquids)/ Fire or Explosion: EXTREMELY FLAMMABLE. Will be easily ignited by heat, sparks or flames. Will form explosive mixtures with air. Vapors from liquefied gas are initially heavier than air and spread along ground. CAUTION: Hydrogen (UN1049), Deuterium (UN1957), Hydrogen, refrigerated liquid (UN1966) and Methane (UN1971) are lighter than air and will rise. Hydrogen and Deuterium fires are difficult to detect since they burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.) Vapors may travel to source of ignition and flash back. Cylinders exposed to fire may vent and release flammable gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket.
U.S. Department of Transportation. 2012 Emergency Response Guidebook. Washington, D.C. 2012
/GUIDE 115 GASES - FLAMMABLE (Including Refrigerated Liquids)/ Health: Vapors may cause dizziness or asphyxiation without warning. Some may be irritating if inhaled at high concentrations. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire may produce irritating and/or toxic gases.
U.S. Department of Transportation. 2012 Emergency Response Guidebook. Washington, D.C. 2012
/GUIDE 115 GASES - FLAMMABLE (Including Refrigerated Liquids)/ Public Safety: CALL Emergency Response Telephone Number on Shipping Paper first. If Shipping Paper not available or no answer, refer to appropriate telephone number listed on the inside back cover. As an immediate precautionary measure, isolate spill or leak area for at least 100 meters (330 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Many gases are heavier than air and will spread along ground and collect in low or confined areas (sewers, basements, tanks). Keep out of low areas.
U.S. Department of Transportation. 2012 Emergency Response Guidebook. Washington, D.C. 2012
/GUIDE 115 GASES - FLAMMABLE (Including Refrigerated Liquids)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection. Always wear thermal protective clothing when handling refrigerated/cryogenic liquids.
U.S. Department of Transportation. 2012 Emergency Response Guidebook. Washington, D.C. 2012
For more DOT Emergency Guidelines (Complete) data for METHYL CHLORIDE (8 total), please visit the HSDB record page.

10.9.2 DOT ID and Guide

10.9.3 Shipping Name / Number DOT/UN/NA/IMO

UN 1063; Methyl chloride
IMO 2.1; Methyl chloride

10.9.4 Standard Transportation Number

49 057 61; Methyl chloride
49 201 05; Methyl chloride and chloropicrin mixtures
49 057 64; Methyl chloride and methylene chloride

10.9.5 Shipment Methods and Regulations

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./
49 CFR 171.2 (USDOT); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of December 14, 2015: https://www.ecfr.gov
The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials. Methyl chloride is included on the dangerous goods list.
International Air Transport Association. Dangerous Goods Regulations. 55th Edition. Montreal, Quebec Canada. 2014., p. 270
The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article. Methyl chloride is included on the dangerous goods list.
International Maritime Organization. IMDG Code. International Maritime Dangerous Goods Code Volume 2 2012, p. 46

10.9.6 DOT Label

Flammable Gas

10.9.7 EC Classification

Symbol: F+, Xn; R: 12-40-48/20; S: (2)-9-16-33

10.9.8 UN Classification

UN Hazard Class: 2.1

10.10 Regulatory Information

The Australian Inventory of Industrial Chemicals
Chemical: Methane, chloro-
California Safe Cosmetics Program (CSCP) Reportable Ingredient

Hazard Traits - Developmental Toxicity; Environmental tox; Hazard Trait Under Review; Hepatotoxicity and Digestive System Toxicity; Nephrotoxicity and Other Toxicity to the Urinary System; Neurodevelopmental Toxicity; Neurotoxicity; Reproductive Toxicity

Authoritative List - ATSDR Neurotoxicants; CA TACs; CWA 303(c); CWA 303(d); IRIS Neurotoxicants; Prop 65

Report - regardless of intended function of ingredient in the product

REACH Registered Substance
New Zealand EPA Inventory of Chemical Status
Methane, chloro- (methyl chloride): HSNO Approval: HSR001006 Approved with controls

10.10.1 DHS Chemicals of Interest (COI)

Chemicals of Interest(COI)
Methyl chloride
Release: Minimum Concentration (%)
1
Release: Screening Threshold Quantities (in pounds)
10000
Security Issue: Release - Flammables
Flammable chemical that can be released at a facility.

10.10.2 Atmospheric Standards

This action promulgates standards of performance for equipment leaks of Volatile Organic Compounds (VOC) in the Synthetic Organic Chemical Manufacturing Industry (SOCMI). The intended effect of these standards is to require all newly constructed, modified, and reconstructed SOCMI process units to use the best demonstrated system of continuous emission reduction for equipment leaks of VOC, considering costs, non air quality health and environmental impact and energy requirements. Methyl chloride is produced, as an intermediate or a final product, by process units covered under this subpart.
40 CFR 60.489 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of December 14, 2015: https://www.ecfr.gov
Listed as a hazardous air pollutant (HAP) generally known or suspected to cause serious health problems. The Clean Air Act, as amended in 1990, directs EPA to set standards requiring major sources to sharply reduce routine emissions of toxic pollutants. EPA is required to establish and phase in specific performance based standards for all air emission sources that emit one or more of the listed pollutants. Methyl chloride is included on this list.
Clean Air Act as amended in 1990, Sect. 112 (b) (1) Public Law 101-549 Nov. 15, 1990

10.10.3 Federal Drinking Water Guidelines

EPA 3 ug/L
USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93) To Present

10.10.4 State Drinking Water Guidelines

(AZ) ARIZONA 0.19 ug/L
USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93) To Present
(CT) CONNECTICUT 55 ug/L
USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93) To Present
(FL) FLORIDA 2.7 ug/L
USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93) To Present
(ME) MAINE 3 ug/L
USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93) To Present
For more State Drinking Water Guidelines (Complete) data for METHYL CHLORIDE (6 total), please visit the HSDB record page.

10.10.5 Clean Water Act Requirements

Toxic pollutant designated pursuant to section 307(a)(1) of the Federal Water Pollution Control Act and is subject to effluent limitations. /Halomethanes/
40 CFR 401.15 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of December 14, 2015: https://www.ecfr.gov

10.10.6 CERCLA Reportable Quantities

Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 100 lb or 45.4 kg. The toll free number of the NRC is (800) 424-8802. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV.D.3.b).
40 CFR 302.4 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of December 14, 2015: https://www.ecfr.gov

10.10.7 TSCA Requirements

Pursuant to section 8(d) of TSCA, EPA promulgated a model Health and Safety Data Reporting Rule. The section 8(d) model rule requires manufacturers, importers, and processors of listed chemical substances and mixtures to submit to EPA copies and lists of unpublished health and safety studies. Chloromethane is included on this list. Effective date: 10/4/82; Sunset date: 10/4/92.
40 CFR 716.120 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of December 14, 2015: https://www.ecfr.gov

10.10.8 RCRA Requirements

U045; As stipulated in 40 CFR 261.33, when methyl chloride, as a commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate, becomes a waste, it must be managed according to Federal and/or State hazardous waste regulations. Also defined as a hazardous waste is any residue, contaminated soil, water, or other debris resulting from the cleanup of a spill, into water or on dry land, of this waste. Generators of small quantities of this waste may qualify for partial exclusion from hazardous waste regulations (40 CFR 261.5).
40 CFR 261.33 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of December 14, 2015: https://www.ecfr.gov

10.11 Other Safety Information

Chemical Assessment
IMAP assessments - Methane, chloro-: Human health tier II assessment

10.11.1 Toxic Combustion Products

Special hazards arising from the substance or mixture: Carbon oxides, Hydrogen chloride gas
Sigma-Aldrich; Safety Data Sheet for Chloromethane. Product Number: 295507, Version 4.6 (Revision Date 03/03/2015). Available from, as of December 15, 2015: https://www.sigmaaldrich.com/safety-center.html
Toxic gases and vapors (such as hydrogen chloride and carbon monoxide) may be released in a fire involving methyl chloride.
Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) Publication No. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981., p. 2
Methyl chloride forms toxic decomposition products, incl phosgene, when exposed to open flames.
Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984., p. II-158

10.11.2 History and Incidents

Over 200 cases /of human poisonings resulting from the use of chloromethane as a refrigerant/ have been reported prior to 1961, involving ... 20 deaths.
USEPA; Chemical Hazard Information Profile: Chloromethane (Draft) p.V-7 (1978) EPA-560/10-78-001

10.11.3 Special Reports

Repko JD, Lasley SM; CRC Crit Rev Toxicol 6 (4): 283-302 (1979). A review with 67 references on the biochemical basis for and the behavioral and neurological effects of methyl chloride toxicity.
USEPA; Chemical Hazard Information Profile: Chloromethane (Draft) p.V-3 (1978) EPA-560/10-78-001
USEPA; Subst Risk Notice, 8EHQ-0180-0324 (1980)
Repko Jd; Neurobehav Toxicol Terotol 3 (4): 425-9 (1981). This review focuses on the human case reports of acute and chronic exposures as well as some of the more important inhalation studies conducted with animals. The chemical and physical properties and the more important industrial uses are also discussed.
DHHS/ATSDR; Toxicological Profile for Chloromethane (1990) ATSDR/TP-90/07

11 Toxicity

11.1 Toxicological Information

11.1.1 Toxicity Summary

IDENTIFICATION AND USE: Methyl chloride is a colorless compressed gas or liquid. Most methyl chloride is used as an intermediate feedstock in silicone fluids, elastomers, and resins. Methyl chloride has been used in timber products processing, as a blowing agent for some polystyrene foams, and as a refrigerant. It was formerly used as an aerosol propellant. As a pesticide, methyl chloride is not registered for current use in the U.S.; but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses. HUMAN EXPOSURE AND TOXICITY: The many symptoms of acute exposure include headache, nausea, irritation of the skin and eyes, central nervous system depression, pulmonary edema, hemolysis, chronic intoxication, paresthesia, narcosis, increased risk of spontaneous abortion, intravascular hemolysis, unconsciousness, rapid followed by slow respiration, painful joints, swelling of the extremities, diabetes, aspiration pneumonia, gross hematuria, reduction of blood pH, gastrointestinal injury, upper respiratory tract irritation, depression, fatigue, vertigo, liver damage, blood dyscrasias, acceleration of the pulse, congestion in the head, neurasthenic disorders, digestive disturbances, acoustical and optical delusions, arrhythmias produced by catecholamines, faintness, loss of appetite, hyporeflexia, gross hemoglobinuria, metabolic acidosis, GI hemorrhage, diverticula, kidney damage, lung damage, corneal injury, abdominal pain, increase in salivary gland tumors, cyanosis, convulsions, coma, and death. Deaths have occurred following single severe or repeated prolonged moderate overexposure. Methyl chloride is poisonous intravenously; moderately toxic by ingestion, subcutaneous, and intraperitoneal routes; mildly toxic by inhalation. Most cases of intoxication by methyl chloride have involved concentrations above 500 ppm. After methyl chloride leakage from a refrigerator occurred on board an Icelandic fishing vessel in 1963, many of the crew members were hospitalized due to various neurological symptoms and signs. Follow-up showed increased mortality due to cardiovascular diseases after 47 years. The suicide cases had developed severe depression after the methyl chloride intoxication. Methyl chloride at an atmospheric concentration of 1% (10,000 ppm or 20,700 mg/cu m) was mutagenic to TK6 human lymphoid cells in vitro and caused an increased incidence of sister chromatid exchange and breakage of DNA strands. ANIMAL STUDIES: Exposure of a rabbit's eye to pure methyl chloride gas at room temperature for ninety seconds caused only slight conjunctival hyperemia. CNS depression occurs at 40,000 ppm in rabbits and at 108,600 ppm in cats. Rats and mice were exposed by inhalation to methyl chloride for 6 hr/day for up to 12 days. All male mice exposed to 2000 ppm were dead or moribund by day 2, and all mice in the remaining 2000 ppm groups were moribund by day 5. The principal clinical signs, which were confined to the 5000 and 3500 ppm groups, included severe diarrhea and incoordination of the forelimbs. In rats, lesions observed in tissues examined included vacuolar degeneration of the zona fasciculata of the adrenal glands and degenerative changes in the seminiferous tubules and epididymis. Three of four dogs and both of two monkeys died after 4 weeks and 16 weeks, respectively, after exposure to 500 ppm for 6 hr/day, 6 days/wk. Mice and rats of both sexes were exposed at methyl chloride concentrations of 0, 50, 225 or 1000 ppm for 6 hr/day, 5 days/week for 2 years. A statistically significant increase in both malignant and nonmalignant renal tumors occurred in only the male mice exposed at 1000 ppm. In another two-year inhalation study, male and female rats were exposed to 0, 51, 224 or 997 ppm methyl chloride for 6 hr per day, five days per week. No increase in tumor incidence was reported. Birth defects with retarded development have been observed in rodents. Pregnant mice were exposed via inhalation on days 6-18 of gestation. Exposure at 500 or 750 ppm caused a statistically significant increase in the numbers of cardiac malformations. Exposures at concentrations of 250 or 100 ppm were considered nonteratogenic. Offspring of rats exposed similarly to methyl chloride showed no terata. Methyl chloride is mutagenic to bacteria and induces chromosomal aberrations in plants. It induces DNA damage in mammalian cells in vitro but not in vivo. In cultured mammalian cells, it induces mutations and sister chromatid exchanges and enhances viral cell transformation. Reaction of methyl chloride with glutathione appears to constitute a mechanism of toxication, contrary to the role usually proposed for glutathione in detoxifying xenobiotics.

11.1.2 EPA IRIS Information

Toxicity Summary
EPA IRIS Summary PDF (Update: Jul-17-2001 )
Critical Effect Systems
Nervous
Reference Concentration (RfC), chronic
9 x 10 ^-2 mg/m^3

11.1.3 EPA Provisional Peer-Reviewed Toxicity Values

Chemical Substance
Reference Concentration (RfC), Subchronic
3 mg/m^3
PPRTV Assessment
Weight-Of-Evidence (WOE)
Inadequate information to assess carcinogenic potential
Last Revision
2012

11.1.4 RAIS Toxicity Values

Inhalation Unit Risk (IUR) (ug/m^3)^-1
1.8e-06
Inhalation Unit Risk Reference
HEAST Archive
Inhalation Acute Reference Concentration (RfCa) (mg/m^3)
1.03
Inhalation Acute Reference Concentration Reference
ATSDR Final
Inhalation Chronic Reference Concentration (RfC) (mg/m^3)
0.09
Inhalation Chronic Reference Concentration Reference
IRIS Current
Inhalation Subchronic Reference Concentration (RfCs) (mg/m^3)
3
Inhalation Subchronic Reference Concentration Reference
PPRTV Current
Inhalation Short-term Reference Concentration (RfCt) (mg/m^3)
0.62
Inhalation Short-term Reference Concentration Reference
ATSDR Final
Oral Slope Factor (CSFo)(mg/kg-day)^-1
0.013
Oral Slope Factor Reference
HEAST Archive

11.1.5 USGS Health-Based Screening Levels for Evaluating Water-Quality

Chemical
Chloromethane
Chemical Classes
Volatile Organic Compound (VOC)
Benchmark Remarks
Listed as methyl chloride
Reference
Smith, C.D. and Nowell, L.H., 2024. Health-Based Screening Levels for evaluating water-quality data (3rd ed.). DOI:10.5066/F71C1TWP

11.1.6 NIOSH Toxicity Data

11.1.7 Evidence for Carcinogenicity

The Human Health Assessment Group in EPA's Office of Health and Environmental Assessment has evaluated methyl chloride for carcinogenicity. According to their analysis, the weight-of-evidence for methyl chloride is group C, which is based on limited evidence in animals. No data are available for humans. As a group C chemical, methyl chloride is considered possibly carcinogenic to humans.
USEPA; Methodology for Evaluating Potential Carcinogenicity in Support of Reportable Quantity Adjustments Pursuant to Cercla Section 102 (Final) p.40 (1988) EPA/600/8-89/053
Evaluation: There is inadequate evidence for the carcinogenicity of methyl chloride in humans. There is inadequate evidence for the carcinogenicity of methyl chloride in experimental animals. Overall evaluation: Methyl chloride is not classifiable as to its carcinogenicity to humans (Group 3).
IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work). Available at: https://monographs.iarc.fr/ENG/Classification/index.php, p. V71 745 (1999)
A4: Not classifiable as a human carcinogen.
American Conference of Governmental Industrial Hygienists TLVs and BEIs. Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati, OH 2015, p. 40

11.1.8 Carcinogen Classification

IARC Carcinogenic Agent
Methyl chloride
IARC Carcinogenic Classes
Group 3: Not classifiable as to its carcinogenicity to humans
IARC Monographs

Volume 41: (1986) Some Halogenated Hydrocarbons and Pesticide Exposures

Volume Sup 7: Overall Evaluations of Carcinogenicity: An Updating of IARC Monographs Volumes 1 to 42, 1987; 440 pages; ISBN 92-832-1411-0 (out of print)

Volume 71: (1999) Re-evaluation of Some Organic Chemicals, Hydrazine and Hydrogen Peroxide (Part 1, Part 2, Part 3)

11.1.9 Exposure Routes

The substance can be absorbed into the body by inhalation and through the skin.
inhalation, skin and/or eye contact (liquid)

11.1.10 Symptoms

Inhalation Exposure
Staggering gait. Dizziness. Headache. Nausea. Vomiting. Convulsions. Unconsciousness.
Skin Exposure
MAY BE ABSORBED! ON CONTACT WITH LIQUID: FROSTBITE.
Eye Exposure
See Skin.
dizziness, nausea, vomiting; visual disturbance, stagger, slurred speech, convulsions, coma; liver, kidney damage; liquid: frostbite; reproductive, teratogenic effects; [potential occupational carcinogen]

11.1.11 Target Organs

Hepatic (Liver), Neurological (Nervous System), Renal (Urinary System or Kidneys), Reproductive (Producing Children)
Nervous
central nervous system, liver, kidneys, reproductive system

11.1.12 Cancer Sites

[in animals: lung, kidney &amp; forestomach tumors]

11.1.13 Adverse Effects

Neurotoxin - Acute solvent syndrome

Occupational hepatotoxin - Secondary hepatotoxins: the potential for toxic effect in the occupational setting is based on cases of poisoning by human ingestion or animal experimentation.

Nephrotoxin - The chemical is potentially toxic to the kidneys in the occupational setting.

Reproductive Toxin - A chemical that is toxic to the reproductive system, including defects in the progeny and injury to male or female reproductive function. Reproductive toxicity includes developmental effects. See Guidelines for Reproductive Toxicity Risk Assessment.

ACGIH Carcinogen - Not Classifiable.

11.1.14 Acute Effects

11.1.15 Toxicity Data

LC50 (rat) = 5,300 mg/m3/4H

11.1.16 Interactions

Lethargy may be more pronounced in patients also taking a benzodiazepine.
Lelkin, J.B., Paloucek, F.P., Poisoning & Toxicology Compendium. LEXI-COMP Inc. & American Pharmaceutical Association, Hudson, OH 1998., p. 664
Human behavioral effects resulting from the ingestion of an average dose of diazepam and from 3 h of inhaling either 100 ppm or 200 ppm of methyl chloride (MeCl) were studied in the laboratory. Each of 56 volunteers was randomly assigned to one of six groups comprising the combinations of diazepam and placebo and one of the two levels of MeCl plus control. Each individual was tested in an environmental room on three tasks involving components of eye-hand coordination, mental alertness, and time discrimination. Both pretreatment and treatment data were obtained. Diazepam produced a significant 10% impairment in task performance, whereas the effect of 200 ppm of MeCl was marginally significant (average performance impairment of 4.5%). When the two agents were combined, total impairment was equal to the sum of the individually induced losses. Large interindividual differences in breath and blood levels were found for MeCl.
Putz-Anderson V et al; Scand J Work Environ Health 7 (1): 8-13 (1981)
The effectiveness of the cyclooxygenase/lipoxygenase inhibitor, BW755C in preventing the toxicity induced in male F-344 rats by methyl chloride was examined; BW755C (10 mg/kg ip, 1 hr pre and postexposure) prevented both lethality (0/6 vs 8/12 in controls) and epididymal granuloma formation (0/6 vs 4/4 in control) in rats exposed to 7500 ppm methyl chloride 6 hr/day for 2 days. Additionally rats were exposed to 5000 ppm methyl chloride 6 hr/day for 5 days, with and without BW755C treatment as described above. The rats were killed on day 5 and tissues processed for light microscopic examination. Methyl chloride exposed rats showed hepatocellular cloudy swelling, degradation of renal proximal convoluted tubules, vacuolar degeneration in the adrenal cortex, necrosis of the internal granular layer of the cerebellum, and degenerative changes in the testis and epidermis, including formation of epididymal sperm granulomas. With the exception of the adrenal, tissues examined in rats of the methyl chloride/BW755C treatment group showed virtually no histological evidence of lesions. BW755C did not significantly alter metabolism of (14)C methyl chloride to (14)carbon dioxide or (14)carbon in urine, not did it affect the distribution to various organs of radioactivity derived from (14) methyl chloride. Therefore, BW755C protection against methyl chloride toxicity did not appear to result from altered methyl chloride metabolism or disposition. Instead, the protection was apparently related to the pharmacological activity of BW755C as an inhibitor of leukotriene and prostaglandin synthesis.
Chellman GJ et al; Toxicol Appl Pharmacol 85 (3): 367-79 (1986)
Inhalation of (14)C-labeled methyl chloride by rats ... at ... 6 hr exposure to 500 or 1500 ppm. ... Pretreatment of rats with cycloheximide reduced the amt of methyl chloride-derived radioactivity associated with tissue protein by 42-58%, whereas (3H)leucine incorporation was inhibited by 75-85%, indicating that most, but not necessarily all, of the uptake of (14)C-methyl chloride into protein was dependent on normal protein synthesis. Pretreatment with methotrexate inhibited the uptake of (14)C-methyl chloride into lipid, acid-insoluble material, RNA, and DNA by 47, 64, 65, and 93%, respectively. Pretreatment with methanol inhibited (14)C-methyl chloride uptake into acid-insoluble material by 66%. Most of the (14)carbon appearing in macromolecules following inhalation of (14)C-methyl chloride arose through metabolic incorporation, stemming from metabolism of methyl chloride via the 1-C pool. Methanol apparently competed with methyl chloride for entry into this pool, although the failure of ethanol, 4-methylpyrazole, or 3-amino-1,2,4-triazole to inhibit (14)C-methyl chloride incorporation indicated that methyl chloride was not metabolized to methanol per se. Methanol pretreatment also inhibited (14)CO2 evolution from (14)C-methyl chloride, indicating that metabolism of methyl chloride via 1-C pathways may be of major quantitative significance.
Kornbrust DJ et al; Toxicol Appl Pharmocol 65 (1): 122-34 (1982)
For more Interactions (Complete) data for METHYL CHLORIDE (6 total), please visit the HSDB record page.

11.1.17 Antidote and Emergency Treatment

Flush eyes with water, and hospitalize. Treat with oxygen against shock, and, if indicated administer stimulants. Treat burns of skin in the usual way.
ITII. Toxic and Hazardous Industrial Chemicals Safety Manual. Tokyo, Japan: The International Technical Information Institute, 1988., p. 332
Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Halogenated Aliphatic Hydrocarbons and Related Compounds/
Currance, P.L. Clements, B., Bronstein, A.C. (Eds).; Emergency Care For Hazardous Materials Exposure. 3rd revised edition, Elsevier Mosby, St. Louis, MO 2007, p. 217-18
Basic treatment: Establish a patent airway (oropharyngeal or nasophayrngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . Cover skin burns with sterile dressings after decontamination ... . /Halogenated Aliphatic Hydrocarbons and Related Compounds/
Currance, P.L. Clements, B., Bronstein, A.C. (Eds).; Emergency Care For Hazardous Materials Exposure. 3rd revised edition, Elsevier Mosby, St. Louis, MO 2007, p. 218
Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W TKO. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Consider vasopressors if patient is hypotensive with a normal fluid volume. Watch for signs of cardiac irritability and fluid overload ... . Treat seizures with diazepam (Valium) or lorasepam (Ativan) ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Halogenated Aliphatic Hydrocarbons and Related Compounds/
Currance, P.L. Clements, B., Bronstein, A.C. (Eds).; Emergency Care For Hazardous Materials Exposure. 3rd revised edition, Elsevier Mosby, St. Louis, MO 2007, p. 218

11.1.18 Human Toxicity Excerpts

/HUMAN EXPOSURE STUDIES/ Industrial workers are frequently exposed to organic solvents such as methyl chloride and also voluntarily ingest quantities of alcohol or caffeine, which affect the nervous system. Behavioral effects of such substances alone and when combined were assessed. Volunteers (84) were randomly assigned to 1 of 6 treatment groups. Each individual was then tested before and during the treatment or control procedures on three performance tasks. An alcohol dose sufficient to register blood levels of 0.08% produced a significant impairment of 10% on all three tests, which included eye-hand coordination and alertness. A caffeine dose equivalent to two cups of coffee (200 mg) produced a small but significant impairment on only the eye-hand coordination test. Participants who were exposed to methyl chloride for 3.5 hr at levels equivalent to the current legal standard did not experience any significant impairments on the tests. When the solvent was combined with each drug individually, the effect was essentially equivalent to the sum to the separate effects; no behavioral interaction was found.
Putz-Anderson V et al; Psychol Rep 48 (3): 715-25 (1981)
/SIGNS AND SYMPTOMS/ The complaints during mild cases /of intoxication with methyl chloride/ include dizziness, difficulty in walking, headache, nausea, and vomiting. The most frequent objective symptoms are a staggering gait, nystagmus, speech disorders, arterial hypotension, and reduced and disturbed cerebral electrical activity. Mild prolonged intoxication is liable to cause permanent injury of the heart muscle and the central nervous system, with a change of personality, depression, irritability and occasionally visual and auditory hallucinations.
International Labour Office. Encyclopaedia of Occupational Health and Safety. 4th edition, Volumes 1-4 1998. Geneva, Switzerland: International Labour Office, 1998., p. 104.243
/SIGNS AND SYMPTOMS/ Symptoms may include headache, elevated blood concentrations of carboxyhemoglobin, nausea, and irritation of the skin and eyes. Central nervous system depression, pulmonary edema, hemolysis, chronic intoxication, and paresthesia may also occur. Other symptoms include narcosis, temporary neurobehavioral effects, increase in serum bilirubin, increased urinary formic acid concentrations, and increased risk of spontaneous abortion. In addition, intravascular hemolysis, unconsciousness, lack of response to painful stimuli, rapid followed by slow respiration, erythema, blistering, toxic encephalopathy, painful joints, swelling of the extremities, mental impairment, diabetes, skin rash, aspiration pneumonia, gross hematuria, reduction of blood pH, gastrointestinal injury, and narrowing of the intestinal lumen may also occur. Symptoms may include upper respiratory tract irritation, giddiness, stupor, irritability, numbness, tingling in the limbs, and hallucinations. A dry, scaly, and fissured dermatitis, skin burns, comma and death may also result. Other symptoms may include dizziness sense of fullness in the head, sense of heat, dullness, lethargy and drunkenness. In addition, mental confusion, light-headedness, vomiting, weakness, somnolence, lassitude, anorexia, depression, fatigue, vertigo, liver damage, nose and throat irritation, anesthetic effects, smarting and reddening of the skin, blood dyscrasias, acceleration of the pulse, and congestion in the head may result. Staggering may also occur. Symptoms of exposure may include neurasthenic disorders, digestive disturbances and acoustical and optical delusions. Arrhythmias produced by catecholamines may also result. Additional symptoms include edema, faintness, loss of appetite, and apathy. Hyporeflexia, gross hemoglobinuria, epiglottal edema, metabolic acidosis, GI hemorrhage, ulceration of the duodenojejunal junction, and diverticula may also occur. Other symptoms may include kidney damage, lung damage, corneal injury, abdominal pain, and an increase in salivary gland tumors. Cyanosis may also occur. Exposure may also cause altered sleep time, convulsions, euphoria, and a change in cardiac rate.
Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. V5 9
/SIGNS AND SYMPTOMS/ Symptoms observed are ataxia, staggering gait, weakness, tremors, vertigo, drowsiness, confusion, personality changes, loss of memory, difficulty in speech, and blurred vision. In severe acute poisoning, GI disturbances such as nausea, vomiting, abdominal pain, and diarrhea may be observed.
Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. V5 4
For more Human Toxicity Excerpts (Complete) data for METHYL CHLORIDE (23 total), please visit the HSDB record page.

11.1.19 Non-Human Toxicity Excerpts

/LABORATORY ANIMALS: Acute Exposure/ Exposure of a rabbit's eye to pure methyl chloride gas at room temperature for ninety seconds caused only slight conjunctival hyperemia. ... In ... two rabbits exposed for five days to concentrations from 250 to 465 ppm in air. There were no changes in the corneas, nor in pupillary reactions to light.
Grant, W.M. Toxicology of the Eye. 3rd ed. Springfield, IL: Charles C. Thomas Publisher, 1986., p. 613
/LABORATORY ANIMALS: Acute Exposure/ F344 rats were exposed /by inhalation/ to methyl chloride concentrations of 1500, 500 or 100 ppm. A 6 hr exposure to 1500 ppm decresed the nonprotein sulfhydryl (NPSH) content of liver, kidney and lungs to 17, 27 and 30% of control values, respectively, while 500 ppm methyl chloride lowered the liver, kidney and lung nonprotein sulfhydryl to 41, 59 and 55% of control values, respectively, demonstrating a concentration-related effect. Blood nonprotein sulfhydryl did not differ from controls in either group.
Dodd DE et al; Toxicol Appl Pharmacol 62 (6): 228-36 (1982)
/LABORATORY ANIMALS: Acute Exposure/ Sprague Dawley rats were exposed /by inhalation/ to 99.5% chloromethane at 0, 200, 500, 1000, or 2000 ppm for 48 or 72 hr. At 2000 ppm at 48 hr, rats were either lethargic, moribund, or dead. At 2000 ppm rats were all dead or moribund. The cause of death was thought to be kidney failure.
Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. V5 5
/LABORATORY ANIMALS: Acute Exposure/ The following effects have been reported in guinea pigs and other unspecified animals after acute inhalation exposures: death in a short time at 150,000-300,000 ppm; serious effects in 30-60 min at 20,000-40,000 ppm; no serious effects for up to 60 min at 7,000 ppm; no effect for up to 8 hr at 500-1000 ppm. /CNS depression/ occurs at 40,000 ppm in rabbits and at 108,600 ppm in cats.
USEPA; Chemical Hazard Information Profile: Chloromethane (Draft) p.V-7 (1978) EPA-560/10-78-001
For more Non-Human Toxicity Excerpts (Complete) data for METHYL CHLORIDE (32 total), please visit the HSDB record page.

11.1.20 Non-Human Toxicity Values

LC50 Mouse inhalation 6300 mg/cu m/7 hr
IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work). Available at: https://monographs.iarc.fr/ENG/Classification/index.php, p. V41 (1986)
LC50 Mouse (male) inhalation 4600 mg/cu m/6 hr
IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work). Available at: https://monographs.iarc.fr/ENG/Classification/index.php, p. V41 (1986)
LC50 Mouse (female) inhalation 17,500 mg/cu m/6 hr
IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work). Available at: https://monographs.iarc.fr/ENG/Classification/index.php, p. V41 (1986)
LC50 Rat ihl 5300 mg/cu m/4 hr
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 2408
For more Non-Human Toxicity Values (Complete) data for METHYL CHLORIDE (6 total), please visit the HSDB record page.

11.1.21 TSCA Test Submissions

In a two-generation reproduction study methyl chloride was administered via inhalation to male and female Fischer 344 rats (40 males and 80 females/group) at nominal concentrations of 0, 150, 475 or 1500 ppm for 6 hrs/day, 5 days/week for 10 weeks. Body weight gain was decreased relative to controls for animals dosed at 1500 ppm after 2 weeks exposure and for all F0 animals after day 57. The exposure schedule was then changed to 6 hrs/day, 7 days/week and each male was mated for 2 weeks with 2 females after which 10 males/group were necropsied and the remaining 30 males/group were mated with 2 unexposed females each. Treatment related lesions found in the necropsied high-dose males were severe testicular degeneration and granulomas in the epididymis. Exposure of females was continued after the start of mating to gestation day 18 (6 hrs/day, 7 days/week) and exposure resumed at the same concentrations from postnatal day 4-28. There were no significant differences between groups in the number of females that mated, but no litters were born to exposed or unexposed females mated to high-dose males, and significantly fewer litters were born to mid-dose females. No differences in the following were observed in litters born to mid- and low-dose and control animals: litter size, sex ratio, pup viability or pup growth. Ten weeks after exposure ceased, 5 of 20 F0 males had regained the ability to sire normal litters versus 15 of 20 of F0 mid-dose and control males. A trend towards decreased fertility was observed in F1 pups from the mid-dose group relative to low-dose and control group F1 pups exposed to the same concentrations of methyl chloride for 10 weeks and then mated.
Chemical Industry Institute of Toxicology; Reproduction in Fischer-344 Rats Exposed to Methyl Chloride by Inhalation for Two Generations. (1984), EPA Document No. 878214238, Fiche No. OTS0206500
Teratogenicity was evaluated in female Fischer 344 rats with copulation plugs (25/group) exposed to methyl chloride by inhalation at nominal concentrations of 0, 100, 500 or 1500 ppm from gestation day (GD) 7 to gd 20. Females were sacrificed at this time and 22 females were pregnant in the 0 ppm group, 23 at 100 ppm, 20 at 500 ppm, and 21 at 1500 ppm. Maternal food consumption and body weight were significantly depressed in dams exposed to 1500 ppm on GD 15 and 20. Weight gain was depressed in dams at 500 or 1500 ppm on gd 7-15, and the weight at sacrifice was significantly depressed for the 1500 ppm group. No other maternal or reproductive parameters were affected in any of the exposure groups. A significant reduction relative to controls in fetal male and female body weights and female crown-rump length were indicative of fetal toxicity. There were no methyl chloride-induced external, skeletal, or visceral abnormalities observed in the 50% of the fetuses from each litter examined for defects. In the fetal skeletal preparations from the 1500 ppm exposure group, statistically significant retardation in ossification was observed in the metacarpals and phalanges of the anterior limbs, thoracic vertebral centra, sternebrae, pubes of the pelvic girdle, and metatarsal of the hind limbs.
Chemical Industry Institute of Toxicology; Structural Teratogenicity Evaluation of Methyl Chloride in Rats and Mice After Inhalation Exposure, Final Report. (1981), EPA Document No. FYI-OTS-1281-0149, Fiche No. 0000194-0
Teratogenicity was evaluated in female C57BL/6 mice (33/group, with copulation plugs from C3H males) exposed to methyl chloride by inhalation at nominal concentrations of 0, 100, 500 or 1500 ppm from gestation day (GD) 6-18. Females in the 1500 ppm group exhibited urogenital bleeding commencing the 4th day of exposure (GD 10) and exhibited tremors, difficulty righting after falling over in their cages during exposure and a pronounced hunched-back and disheveled appearance, each of which worsened as exposures progressed. Exposure to the entire 1500 ppm group was terminated on GD 10-14, the dams were sacrificed, and 15 females of this group were pregnant. Selective necrosis of neurons in the internal granule cell layer of the cerebellum was observed in all high-dose females. Females from all other groups were sacrificed on GD 18 and 24 were pregnant in the 0 ppm group, 20 at 100 ppm, and 17 at 500 ppm. No significant differences relative to controls were observed in the dams of these groups with respect to body weight, weight gain, or reproductive parameters. Live male fetuses exhibited an increase in crown-rump length relative to controls. A small, but statistically significant increase in incidence of heart defects was observed in the litters of the 500 ppm group which consisted of a reduction or absence of the atrioventricular valve, chordae tendineae and papillary muscle on either the left or right side of the fetal hearts. Ossification in fetuses from exposed groups was equivalent to, or accelerated, relative to controls with acceleration of ossification in the tarsal and metatarsals of the hind limbs in fetuses from the 100 and 500 ppm groups which also exhibited more caudal centra per fetus versus controls.
Chemical Industry Institute of Toxicology; Structural Teratogenicity Evaluation of Methyl Chloride in Rats and Mice After Inhalation Exposure, Final Report. (1981), EPA Document No. FYI-OTS-1281-0149, Fiche No. 0000194-0
Teratogenicity was evaluated in a one-generation reproduction study using female C57BL/6 mice (74-77/group, impregnated by C3H males to produce B6C3F1 fetuses) which were exposed to methyl chloride by inhalation at nominal concentrations of 0, 250, 500 or 750 ppm for 6 hrs/day, from gestation day (GD) 6-18. Females exposed to 750 ppm exhibited ataxia commencing on GD 12 and these females also exhibited hypersensitivity to touch or sound, tremors and convulsions, as well as a statistically significant increase in mortality, and decrease in body weight, weight gain and absolute weight gain versus controls. On GD 18, all other females were sacrificed and 65 females were found to be pregnant in the 0 ppm group, 65 at 250 ppm, 67 at 500 ppm, and 62 at 750 ppm group. There were no significant differences between treated groups and controls in the following: pregnancy rate, gravid uterine weight, maternal liver weight, numbers or percentages of implantation, resorption, incidence of dead fetuses or non-live fetuses per litter, sex-ratio, or mean fetal body weight per litter. There were significant differences between treated groups and controls in the following: increased number and percentage of affected (non-live and malformed) fetuses per litter (750 ppm), increase in heart defects (500 and 750 ppm), increased number and percentage of malformed fetuses (750 ppm), and number of malformed fetuses (500 ppm). Heart defects included absent or abnormal tricuspid valve, reduced number of papillary muscles and/or chordae tendineae on the right side, small right ventricle, globular heart, and white spots in the left ventricular wall.
Research Triangle Institute; Methyl Chloride Structural Teratogenicity Evaluation in B6C3F1 Mice, Final Report. (1981), EPA Document No. FYI-OTS-1281-0149, Fiche No. 0000149-0
For more TSCA Test Submissions (Complete) data for METHYL CHLORIDE (21 total), please visit the HSDB record page.

11.1.22 Populations at Special Risk

Uniquely, human erythrocytes contain a glutathione transferase isoenzyme that catalyzes the conjugation of glutathione with methyl chloride. There are two distinct human subpopulations based on the amount or forms of this transferase. They are known as "fast metabolizers" and "slow metabolizers" or conjugators and nonconjugators. There is considerable variation among ethnic groups and this aspect has significant effect on toxicity.
Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. V5 12
There are two discreet groups of humans in regard to the rate of chloromethane metabolism; one rapid (capable of clearing 3460 mL of blood /minute), the other slow (capable of clearing 795 mL of blood/minute).
USEPA/ODW; Drinking Water Health Advisories for 15 Volatile Organic Chemicals p. A-5 (1990)
Elimination of chloromethane from the blood follows second-order kinetics and is rapid once inhalation exposure ceases with a half-life of 15 minutes in the rat, 50 minutes in the dog and in humans that are rapid metabolizers, and 90 minutes in humans that are slow metabolizers.
USEPA/ODW; Drinking Water Health Advisories for 15 Volatile Organic Chemicals p. A-5 (1990)
People who smoke cigarettes and those exposed passively to the smoke have a higher exposure to chloromethane.
HHS/ATSDR; Addendum to the Toxicological Profile for Chloromethane p.6 (June 24, 2009). Available from, as of January 26, 2016: https://www.atsdr.cdc.gov/toxprofiles/index.asp
/Protect/ from exposure those individual with diseases of kidneys, liver, and CNS. Physical exam of exposed personnel every 6 months incl studies of liver and kidney function.
ITII. Toxic and Hazarous Industrial Chemicals Safety Manual. Tokyo, Japan: The International Technical Information Institute, 1982., p. 332

11.2 Ecological Information

11.2.1 Ecotoxicity Values

Toxicity Threshold (Cell Multiplication Inhibition Test) Entosiphon sulcatum (protozoa) 8000 mg/L
Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983., p. 839
Toxicity Threshold (Cell Multiplication Inhibition Test) Scenedesmus quadricauda (green algae) 1450 mg/L
Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983., p. 839
Toxicity Threshold (Cell Multiplication Inhibition Test) Microcystis aeruginosa (algae) 550 mg/L
Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983., p. 839
LC50; Species: Lepomis macrochirus (/Bluegill)/; Conditions: static bioassay in fresh water at 23 °C, mild aeration applied after 24 hr; Concentration: 550 ppm for 96 hr
Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983., p. 839
For more Ecotoxicity Values (Complete) data for METHYL CHLORIDE (6 total), please visit the HSDB record page.

11.2.2 US EPA Regional Screening Levels for Chemical Contaminants

1 of 2
Resident Soil (mg/kg)
3.20e-01
Industrial Soil (mg/kg)
1.40e+00
Resident Air (ug/m3)
1.20e-01
Industrial Air (ug/m3)
5.30e-01
Tapwater (ug/L)
2.20e-01
MCL (ug/L)
8.0E+01(G)
Risk-based SSL (mg/kg)
6.1e-05
MCL-based SSL (mg/kg)
2.20e-02
Oral Slope Factor (mg/kg-day)-1
3.10e-02
Inhalation Unit Risk (ug/m3)-1
2.3e-05
Chronic Oral Reference Dose (mg/kg-day)
1.00e-02
Chronic Inhalation Reference Concentration (mg/m3)
1.95e-03
Volatile
Volatile
Mutagen
Mutagen
Fraction of Contaminant Absorbed in Gastrointestinal Tract
1
Soil Saturation Concentration (mg/kg)
2.54e+03
2 of 2
Resident Soil (mg/kg)
1.10e+02
Industrial Soil (mg/kg)
4.60e+02
Resident Air (ug/m3)
9.40e+01
Industrial Air (ug/m3)
3.90e+02
Tapwater (ug/L)
1.90e+02
MCL (ug/L)
8.0E+01(G)
Risk-based SSL (mg/kg)
4.90e-02
Chronic Inhalation Reference Concentration (mg/m3)
9.00e-02
Volatile
Volatile
Mutagen
Mutagen
Fraction of Contaminant Absorbed in Gastrointestinal Tract
1
Soil Saturation Concentration (mg/kg)
1.32e+03

11.2.3 US EPA Regional Removal Management Levels for Chemical Contaminants

1 of 2
Resident Soil (mg/kg)
1.60e+01
Industrial Soil (mg/kg)
6.70e+01
Resident Air (ug/m3)
6.10e+00
Industrial Air (ug/m3)
2.60e+01
Tapwater (ug/L)
1.20e+01
MCL (ug/L)
8.0E+01 (G)
Oral Slope Factor (mg/kg-day)-1
3.10e-02
Inhalation Unit Risk (ug/m3)-1
2.3e-05
Chronic Oral Reference Dose (mg/kg-day)
1.00e-02
Chronic Inhalation Reference Concentration (mg/m3)
1.95e-03
Volatile
Volatile
Mutagen
Mutagen
Fraction of Contaminant Absorbed in Gastrointestinal Tract
1
Soil Saturation Concentration (mg/kg)
2.54e+03
2 of 2
Resident Soil (mg/kg)
3.30e+02
Industrial Soil (mg/kg)
1.40e+03
Resident Air (ug/m3)
2.80e+02
Industrial Air (ug/m3)
1.20e+03
Tapwater (ug/L)
5.60e+02
MCL (ug/L)
8.0E+01 (G)
Chronic Inhalation Reference Concentration (mg/m3)
9.00e-02
Volatile
Volatile
Mutagen
Mutagen
Fraction of Contaminant Absorbed in Gastrointestinal Tract
1
Soil Saturation Concentration (mg/kg)
1.32e+03

11.2.4 Environmental Fate / Exposure Summary

Methyl chloride's production and use as chemical intermediate may result in its release to the environment through various waste streams. It is estimated that up to 99% of methyl chloride released to the environment is from natural sources, such as the oceans or from combustion of grass, wood, charcoal, and coal. If released to air, a vapor pressure of 4,300 mm Hg at 25 °C indicates methyl chloride will exist solely as a vapor in the atmosphere. Gas-phase methyl chloride will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 445 days. Methyl chloride does not absorb at wavelengths >290 nm and, therefore, is not expected to be susceptible to direct photolysis by sunlight. If released to soil, methyl chloride is expected to have very high mobility based upon an estimated Koc of 13. Volatilization from moist soil surfaces is expected to be an important fate process based upon a Henry's Law constant of 8.82X10-3 atm-cu m/mole. Methyl chloride is expected to volatilize from dry soil surfaces based upon its vapor pressure. Utilizing the Japanese MITI test, 1% of the Theoretical BOD was reached in 4 weeks, indicating that biodegradation is not an important environmental fate process in soil or water. However, a 77% biodegradation in 28 days using OECD Guideline 301D suggests methyl chloride can biodegrade readily under certain conditions. Overall, methyl chloride is not considered readily biodegradable, but it can be degraded by adapted bacteria and under anaerobic conditions. If released into water, methyl chloride is not expected to adsorb to suspended solids and sediment in water based upon the estimated Koc. Methyl chloride has been shown to biodegrade in environmental waters. Volatilization from water surfaces is expected to be an important fate process based upon this compound's Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 2.1 hours and 2.8 days, respectively. An estimated BCF of 3 suggests the potential for bioconcentration in aquatic organisms is low. The hydrolysis half-life is 0.93 yr at pH 7 and 25 °C. Occupational exposure to methyl chloride may occur through inhalation and dermal contact with this compound at workplaces where methyl chloride is produced or used. Monitoring data indicate that the general population may be exposed to methyl chloride via inhalation of ambient air and tobacco smoke, ingestion of contaminated drinking water, and dermal contact with seawater containing methyl chloride. (SRC)

11.2.5 Natural Pollution Sources

Methyl chloride is a natural and ubiquitous constituent of the oceans and atmosphere(1). Major sources of release of methyl chloride to the air include tropical plants, wood-rotting fungi, and soil from wood-rotting fungi(1). It is estimated that up to 99% of methyl chloride released to the environment is from natural sources, such as chemical reactions that occur in the oceans or chemical reactions that occur from combustion of grass, wood, charcoal, and coal(1,2). Millions of kilograms of methyl chloride are produced naturally every day, primarily in the oceans(3). Methyl chloride is produced in seawater by the reaction of methyl iodide, which is produced photosynthetically by several marine organisms, with chloride ions(4). For the eastern Pacific, the mean ocean air flux of 13X10-7 g/sq cm-yr when extrapolated to global waters provide an adequate source to explain the atmospheric reservoir of methyl chloride(5). Methyl chloride is released to the atmosphere from forest fires, brush fires, back yard burning and volcanoes(6-8). Agricultural slash burning is believed to be a source of high levels of methyl chloride in the Amazon and China, the latter specifically from rice agriculture(9). The estimated 0.6 g of methyl chloride per kg vegetation burned is believed to have an impact on the global burden of methyl chloride(6). Plant volatiles from cedar and cypress include methyl chloride(10). Methyl chloride has been identified as a chemical component of tobacco plants(11). Various species of Antarctic macroalgae have been found to produce and release methyl chloride at levels of 1.98 pmol/g (wet wt) per day(2).
(1) Reid JB, Muianga CV; Halogenated One-Carbon Compounds. Patty's Toxicology. 6th ed. (1999-2015). New York, NY: John Wiley & Sons, Inc. On-line Posting Date: Aug 17, 2012.
(2) OECD; SIDS Initial Assessment Report For SIAM 15. Chloromethane (CAS 74-87-3). Available from, as of Jan 19, 2016: https://www.chem.unep.ch/irptc/sids/OECDSIDS/CLMETHANE.pdf
(3) Holbrook MT; Methyl Chloride. Kirk-Othmer Encyclopedia of Chemical Technology. (1999-2015). New York, NY: John Wiley & Sons. Online Posting Date: Aug 15, 2003.
(4) Zafiriou, OC; J Mar Res 33: 75-81 (1975)
(5) Singh HB et al; J Geophys Res 88: 3684-90 (1983)
(6) Tassios S, Packham DR; J Air Pollution Control Association 33: 41-2 (1985)
(7) Graedel TE; Chemical Compounds in the Atmosphere. New York, NY: Academic Press, pp. 324 (1978)
(8) Edgerton SA et al; J Air Pollut Control Assoc 34: 661-4 (1984)
(9) Khalil MAK, Rasmussen RA; J Air Waste Manage Assoc 40: 1143-6 (1990)
(10) Isidorov VA et al; Atmos Environ 19: 1-8 (1985)
(11) Rodgman A, Perfetti TA; The Chemical Components of Tobacco and Tobacco Smoke, Second Edition. Boca Raton, FL: CRC Press, p. 2069 (2013)

11.2.6 Artificial Pollution Sources

Methyl chloride's production and use as an chemical intermediate(1) may result in its release to the environment through various waste streams(SRC). It is released in tobacco smoke and turbine exhaust(2) and can be released from very old refrigeration equipment that used methyl chloride as a refrigerant(3). Coal combustion is thought to contribute to high levels of methyl chloride in parts of China(4). Methyl chloride may be formed in the chlorination of drinking water and sewage effluent(5).
(1) Reid JB, Muianga CV; Halogenated One-Carbon Compounds. Patty's Toxicology. 6th ed. (1999-2015). New York, NY: John Wiley & Sons, Inc. On-line Posting Date: Aug 17, 2012.
(2) Graedel TE; Chemical Compounds in the Atmos. New York, NY: Academic Press pp. 324 (1978)
(3) ATSDR; Toxicological Profile for Chloromethane. Atlanta, GA: Agency for Toxic Substances and Disease Registry, US Public Health Service (1998). Available from, as of Jan 27, 2016: https://www.atsdr.cdc.gov/toxprofiles/index.asp
(4) Khalil MAK, Rasmussen RA; J Air Waste Manage Assoc 40: 143-6 (1990)
(5) Abrams EF et al; Identification of Org Compounds in Effluents from Industrial Sources. USEPA-560/3-75-002. Washington, DC: US Environ Protect Agency. (1975)

11.2.7 Environmental Fate

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 13(SRC), determined from a structure estimation method(2), indicates that methyl chloride is expected to have very high mobility in soil(SRC). Volatilization of methyl chloride from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 8.82X10-3 atm-cu m/mole(3). Methyl chloride is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 4300 mm Hg at 25 °C(4). Utilizing the Japanese MITI test, 1% of the Theoretical BOD was reached in 4 weeks(5) indicating that biodegradation is not an important environmental fate process in soil(SRC). However, a 77% biodegradation in 28 days using OECD Guideline 301D(6) suggests methyl chloride can biodegrade readily under certain conditions. Methyl chloride has been shown to biodegrade in soil microcosms(8) and in environmental waters(6,7). Overall, methyl chloride is not considered readily biodegradable, but it can be degraded by adapted bacteria and under anaerobic conditions(7).
(1) Swann RL et al; Res Rev 85: 17-28 (1983)
(2) US EPA; Estimation Program Interface (EPI) Suite. Ver. 4.11. Nov, 2012. Available from, as of Jan 19, 2016: https://www2.epa.gov/tsca-screening-tools
(3) Gossett JM; Environ Sci Technol 21: 202-8 (1987)
(4) Daubert TE, Danner RP; Physical and thermodynamic properties of pure chemicals: data compilation. Design Inst Phys Prop Data, Amer Inst Chem Eng. New York, NY: Hemisphere Pub. Corp 4 Vol (1989)
(5) NITE; Chemical Risk Information Platform (CHRIP). Biodegradation and Bioconcentration. Tokyo, Japan: Natl Inst Tech Eval. Available from, as of Jan 19, 2016: https://www.safe.nite.go.jp/english/db.html
(6) ECHA; Search for Chemicals. Chloromethane (CAS 74-87-3) Registered Substances Dossier. European Chemical Agency. Available from, as of Jan 19, 2016: https://echa.europa.eu/
(7) OECD; SIDS Initial Assessment Report For SIAM 15. Chloromethane (CAS 74-87-3). Available from, as of Jan 19, 2016: https://www.chem.unep.ch/irptc/sids/OECDSIDS/CLMETHANE.pdf
(8) Miller LG et al; Geochim et Cosmochim Acta 68: 3271-3283 (2004)
AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 13(SRC), determined from an estimation method(2), indicates that methyl chloride is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon a Henry's Law constant of 8.82X10-3 atm-cu m/mole(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 2.1 hours and 2.8 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 3(SRC), from its log Kow of 0.91(6) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low. Utilizing the Japanese MITI test, 1% of the Theoretical BOD was reached in 4 weeks(5) indicating that biodegradation is not an important environmental fate process in water(SRC). However, a 77% biodegradation in 28 days using OECD Guideline 301D(8) suggests methyl chloride can biodegrade readily under certain conditions. Methyl chloride has been shown to biodegrade in environmental waters(8,9). Overall, methyl chloride is not considered readily biodegradable, but it can be degraded by adapted bacteria and under anaerobic conditions(9). The half-life for the hydrolysis of methyl chloride is 0.93 yr at pH 7 and 25 °C(10); the rate is independent of pH below pH 10(10).
(1) Swann RL et al; Res Rev 85: 17-28 (1983)
(2) US EPA; Estimation Program Interface (EPI) Suite. Ver. 4.11. Nov, 2012. Available from, as of Jan 19, 2016: https://www2.epa.gov/tsca-screening-tools
(3) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 15-1 to 15-29 (1990)
(4) Gossett JM; Environ Sci Technol 21: 202-8 (1987)
(5) Franke C et al; Chemosphere 29: 1501-14 (1994)
(6) Hansch C et al; Exploring QSAR. Hydrophobic, Electronic, and Steric Constants. ACS Prof Ref Book. Heller SR, consult. ed., Washington, DC: Amer Chem Soc p. 3 (1995)
(7) NITE; Chemical Risk Information Platform (CHRIP). Biodegradation and Bioconcentration. Tokyo, Japan: Natl Inst Tech Eval. Available from, as of Jan 19, 2016: https://www.safe.nite.go.jp/english/db.html
(8) ECHA; Search for Chemicals. Chloromethane (CAS 74-87-3) Registered Substances Dossier. European Chemical Agency. Available from, as of Jan 19, 2016: https://echa.europa.eu/
(9) OECD; SIDS Initial Assessment Report For SIAM 15. Chloromethane (CAS 74-87-3). Available from, as of Jan 19, 2016: https://www.chem.unep.ch/irptc/sids/OECDSIDS/CLMETHANE.pdf
(10) Mabey W, Mill T; J Phys Chem Ref Data 7: 383-415 (1978)
ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), methyl chloride, which has a vapor pressure of 4300 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Gas-phase methyl chloride is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 445 days(SRC), calculated from its rate constant of 3.6X10-14 cu cm/molecule-sec at 25 °C(3). Methyl chloride does not absorb at wavelengths >290 nm(4) and, therefore, is not expected to be susceptible to direct photolysis by sunlight in the troposphere(SRC). The dominant loss mechanism for methyl chloride in the troposphere may be upward diffusion although washout by rain may have some importance(5). From the tropopause to about 30 km, both upward diffusion and reaction with hydroxyl radicals may have approximately equal importance, and above 30 km in the stratosphere diffusion, reaction with hydroxyl radicals, and direct photolysis may have approximately equal weight(5). The surface half-life resulting from upward diffusion is about 80 days(5).
(1) Bidleman TF; Environ Sci Technol 22: 361-367 (1988)
(2) Daubert TE, Danner RP; Physical and thermodynamic properties of pure chemicals: data compilation. Design Inst Phys Prop Data, Amer Inst Chem Eng. New York, NY: Hemisphere Pub. Corp 4 Vol (1989)
(3) Atkinson R et al; Atmos Chem Phys 8: 4141-96 (2008). Available from, as of Jan 19, 2015: https://www.atmos-chem-phys.net/special_issue8.html
(4) OECD; SIDS Initial Assessment Report For SIAM 15. Chloromethane (CAS 74-87-3). Available from, as of Jan 19, 2016: https://www.chem.unep.ch/irptc/sids/OECDSIDS/CLMETHANE.pdf
(5) Robbins DE; Geophys Res Lett 3: 213-6 (1976)

11.2.8 Environmental Biodegradation

AEROBIC: Methyl chloride, present at 3.79-19.2 mg/L, reached 1% of its theoretical BOD in 4 weeks using an activated sludge inoculum concentration of 1 drop/L in the Japanese MITI test(1). Using OECD Guideline 301D (Ready Biodegradability: Closed Bottle Test) with an activated sludge inoculum, methyl chloride (at 3 mg/L) reached 77% degradation after 28 days of incubation(2). Direct measurements of methyl chloride degradation in coastal seawater from Nova Scotia indicated that loss of methyl chloride was due to microbial activity(3). Strains of bacteria isolated from terrestrial, freshwater, estuarine and marine environments have been shown to be capable of biodegrading methyl chloride(2,4). Methyl chloride was biodegraded in a soil microcosm(5).
(1) NITE; Chemical Risk Information Platform (CHRIP). Biodegradation and Bioconcentration. Tokyo, Japan: Natl Inst Tech Eval. Available from, as of Jan 19, 2016: https://www.safe.nite.go.jp/english/db.html
(2) ECHA; Search for Chemicals. Chloromethane (CAS 74-87-3) Registered Substances Dossier. European Chemical Agency. Available from, as of Jan 19, 2016: https://echa.europa.eu/
(3) Tokarczyk R et al; Global Biogeochemical Cycles 17: 1057-1062 (2003)
(4) OECD; SIDS Initial Assessment Report For SIAM 15. Chloromethane (CAS 74-87-3). Available from, as of Jan 19, 2016: https://www.chem.unep.ch/irptc/sids/OECDSIDS/CLMETHANE.pdf
(5) Miller LG et al; Geochim et Cosmochim Acta 68: 3271-3283 (2004)
ANAEROBIC: Chlorinated methanes released 50-70% of bound Cl when incubated anaerobically for 4-5 days with arable soil or sewage sludge(1). A half-life of <11 days in groundwater was reported using a simulated spill site laboratory test(2). Municipal landfill leachate was collected from a site in Guelph, Ontario, Canada and stored at ambient temperature(3); over a period of four months, methyl chloride decreased from an initial concentration of 60 ug/L to 9 ug/L(3). In lysimeter studies using this same leachate, 3 ug/L methyl chloride was added and none was detected in a 14-day breakthrough effluent(3).
(1) Haider K; pp. 200-4 in Comm Eur Communities, Rep Eur 1980 Eur 6388, Environ Res Programme (1980)
(2) Wood PR et al; pp. 493-511 in Groundwater Quality. Ward CH et al, eds. New York, NY: John Wiley and Sons (1985)
(3) Lesage S et al; pp. 88-97 in Proc Ont Minist Environ Technol Transfer Conf Toronto, Ontario, Canada. Vol 2. (1989)

11.2.9 Environmental Abiotic Degradation

The rate constant for the vapor-phase reaction of methyl chloride with photochemically-produced hydroxyl radicals is 3.6X10-14 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 445 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(2). Aliphatic halides hydrolyze in water by neutral and base catalyzed reactions to give the corresponding alcohol(3). The half-life for the hydrolysis of methyl chloride, extrapolated from data obtained at higher temperatures, is 0.93 yr at pH 7 and 25 °C(3); the rate is independent of pH below pH 10(3). Calculated values of the half-life of methyl chloride in water have been reported to be 88, 14, and 2.5 yr at 0, 10, and 20 °C, respectively(4). Methyl chloride was reported to hydrolyze (9X10-5/hr) in less than 6 months at 25 °C(5). In the stratosphere, photodissociation will occur at a rate approximately equal to its reaction with hydroxyl radicals(6).
(1) Atkinson R et al; Atmos. Chem Phys 8: 4141-4496 (2008). Available from, as of Jan 19, 2015: https://www.atmos-chem-phys.net/special_issue8.html
(2) US EPA; Estimation Program Interface (EPI) Suite. Ver. 4.11. Nov, 2012. Available from, as of Jan 19, 2016: https://www2.epa.gov/tsca-screening-tools
(3) Mabey W, Mill T; J Phys Chem Ref Data 7: 383-415 (1978)
(4) Zafiriou OC; J Mar Res 33: 75-81 (1975)
(5) Wolfe NL; Screening Hydrolytic Reactivity of OSW Chemicals. Athens, GA: USEPA Environ Res Lab (NA--)
(6) Robbins DE; Geophys Res Lett 3: 213-6 (1976)

11.2.10 Environmental Bioconcentration

An estimated BCF of 3 was calculated for methyl chloride in fish(SRC), using a log Kow of 0.91(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).
(1) Hansch C et al; Exploring QSAR. Hydrophobic, Electronic, and Steric Constants. ACS Prof Ref Book. Heller SR, consult. ed., Washington, DC: Amer Chem Soc p. 3 (1995)
(2) US EPA; Estimation Program Interface (EPI) Suite. Ver. 4.11. Nov, 2012. Available from, as of Jan 19, 2016: https://www2.epa.gov/tsca-screening-tools
(3) Franke C et al; Chemosphere 29: 1501-14 (1994)

11.2.11 Soil Adsorption / Mobility

Using a structure estimation method based on molecular connectivity indices(1), the Koc for methyl chloride can be estimated to be 13(SRC). According to a classification scheme(2), this estimated Koc value suggests that methyl chloride is expected to have very high mobility in soil.
(1) US EPA; Estimation Program Interface (EPI) Suite. Ver. 4.11. Nov, 2012. Available from, as of Jan 19, 2016: https://www2.epa.gov/tsca-screening-tools
(2) Swann RL et al; Res Rev 85: 17-28 (1983)

11.2.12 Volatilization from Water / Soil

The Henry's Law constant for methyl chloride is 8.82X10-3 atm-cu m/mole(1). This Henry's Law constant indicates that methyl chloride is expected to volatilize rapidly from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 2.1 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 2.8 days(SRC). Methyl chloride's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Methyl chloride is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 4,300 mm Hg at 25 °C(3).
(1) Gossett JM; Environ Sci Technol 21: 202-8 (1987)
(2) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 15-1 to 15-29 (1990)
(3) Daubert TE, Danner RP; Physical and thermodynamic properties of pure chemicals: data compilation. Design Inst Phys Prop Data, Amer Inst Chem Eng. NY,NY: Hemisphere Pub. Corp 4 Vol (1989)
The volatilization half-life for 1 ppm methyl chloride from a stirred beaker 6.5 cm deep is 27.6 min(1) which converts to a half-life at a 1 m depth of 7.1 hr(SRC). According to a mathematical model, the cumulative volatilization loss of methyl chloride during the first year after placement 1 m beneath the ground, assuming no water evaporation, is 66.9% and 22.3% for sandy and clay soil, respectively(2). When the buried methyl chloride is subject to 0.1 cm/day of steady upward water flow (water evaporation) the cumulative loss at the end of a year is 77.0% for sandy soil and 42.7% for clay soil(SRC).
(1) Dilling WL; Environ Sci Technol (1977)
(2) Jury WA et al; Water Resources Res 26: 13-20 (1990)

11.2.13 Environmental Water Concentrations

GROUNDWATER: Methyl chloride was detected, not quantified, in 11 of 20 groundwaters underlying municipal solid waste landfills in MN(1). Methyl chloride was detected in groundwater from 2 of 9 sites in Managua, Nicaragua (1990, 1992 dates) at levels of 513 and 72.1 ug/L (detection limit of 3.6 ug/L)(2). Samples of an alluvial aquifer collected beneath Denver CO in 1993 had positive methyl chloride detections in about 7% of all samples with a maximum level of 0.6 ug/L(3). Methyl chloride was detected in 4% of 214 groundwater samples collected in industrial areas of Taiwan between 1994-1994(4). A US Geological Survey analysis for VOCs in drinking water from domestic wells sampled during 1985-2002 detected methyl chloride in 117 of 1207 total well samples(5). As part of the National Water-Quality Assessment Program of the USGS, groundwater samples collected from 2948 wells between 1985 and 1995 were analyzed for VOCs(6); methyl chloride was detected in 1.1% of urban wells at levels of 0.2-0.8 ug/L(6); methyl chloride was detected in 0.4% of rural wells at levels of 0.2-20 ug/L(6). Monitoring wells sampled between 1996-1998 in southern New Jersey (95 total wells) had about 14% positive methyl chloride detections (0.254 ug/L method reporting level)(7).
(1) Sabel GV, Clark TP; Waste Manag Res 2: 119-30 (1984)
(2) Bethune DN et al; Ground Water 34: 699-708 (1996)
(3) Bruce BW, McMahon PB; Journal of Hydrology 186: 129-151 (1996)
(4) Kuo MCT et al; Bull Environ Contam Toxicol 65: 654-659 (2000)
(5) Rowe BL et al; Environ Health Perspect 115(11): 1539-1546 (2007)
(6) Squillance PJ et al; Environ Sci Technol 33: 4176-4187 (1999)
(7) Stackelberg PE et al; Environ Toxicol Chem 20(4): 853-865 (2001)
DRINKING WATER: Treated water from 30 Canadian potable water treatment facilities was analyzed and 2 samples were positive for methyl chloride with a mean concentration of 5 ppb(1). A drinking water well in Maine reported in a Council on Environmental Quality survey of contaminated drinking water from groundwater sources reported a maximum methyl chloride level of 44 ppb(2); highest reported concentration of methyl chloride in surface water derived drinking water was 12 ppb(2). Methyl chloride was identified, but not quantified in drinking water in New Orleans, Cincinnati, Miami, Philadelphia, and Ottumwa, IA of 10 cities surveyed(3). Methyl chloride was not detected (detection limit = 0.1 ppb) in treated water at 10 water treatment plants (42 samples) using Great Lakes water(4).
(1) Otson R et al; J Assoc Offic Analyst Chem 65: 1370-4 (1982)
(2) Burmaster DE; Environ 24: 6-13, 33-36 (1982)
(3) Abrams EF et al; Identification of Organic Cmpds in Effluents from Industrial Sources USEPA-560/3-75-002. Washington, DC: US Environ Protect Agency (1975)
(4) Otson R; Intern J Environ Anal Chem 31: 41-53 (1987)
DRINKING WATER: The USEPA Unregulated Contaminant Monitoring Rule (UCMR3) program monitors for 30 contaminants (including methyl chloride) in PWSs (public water systems)(1). All PWSs serving more than 10,000 people and 800 representative PWSs serving 10,000 or fewer people were monitored beginning in January 2013. The April 2016 Data Summary reports that 4,850 systems contained methyl chloride, one of which was at or above the minimum reporting level of 0.2 ug/L(2).
(1) USEPA; Monitoring the Occurrence of Unregulated Drinking Water Contaminants. Available from, as of Jan 28, 2016: https://www.epa.gov/dwucmr
(2) USEPA; The Third Unregulated Contaminant Monitoring Rule (UCMR 3): Data Summary April 2016. Available from, as of May 27, 2016: https://www.epa.gov/sites/production/files/2016-05/documents/ucmr3-data-summary-april-2016.pdf
SURFACE WATER: 895 stations in the USEPA STORET data base had 1.4% positive methyl chloride detections with a median concentration of <10 ppb(1). Raw water from 30 Canadian potable water treatment facilities had 1 sample positive, mean concentration <5 ppb(2). Methyl Chloride was detected in the Niagara River and the open water of Lake Ontario(3). It was not detected (detection limit= 0.1 ppb) in raw water at 10 water treatment plants (42 samples) using Great Lakes water(4).
(1) Staples CA et al; Environ Toxicol Chem 4: 131-42 (1985)
(2) Otson R et al; J Assoc Offic Analyt Chem 65: 1370-4 (1982)
(3) Great Lakes Water Quality Board; Report to the Great Lakes Water Quality Board, Windsor Ontario, Canada 1: 195 (1982)
(4) Otson R; Intern J Environ Anal Chem 31: 41-53 (1987)
SEAWATER: Seawater has been found to contain 5.9-21X10-9 mL methyl chloride gas/mL seawater(1). Methyl chloride was detected in the Pacific Ocean at 26.8 parts per trillion at surface, 3.3 parts per trillion at 300 m depth(2). Methyl chloride was detected at Point Reyes, CA (nearshore) at 1200 parts per trillion(3). Methyl chloride was detected in the Eastern Pacific surface water (latitude 29 deg N to -29 deg S) at 6.3-42 parts per trillion, 11.5 parts per trillion mean(4).
(1) Rossberg M et al; Chloromethanes. Ullmann's Encyclopedia of Industrial Chemistry. 7th ed. (1999-2015). New York, NY: John Wiley & Sons. Online Posting Date: Oct 15, 2011
(2) Singh HB et al; Atmos Distributions, Sources and Sinks of Selected Halocarbon, Hydrocarbons, SF6 + N2O. Washington, DC: US EPA, EPA-600/3-79-107. pp.134 (1979)
(3) Singh HB et al; J Air Pollut Control Assoc 27: 332-6 (1977)
(4) Singh HB et al; J Geophys Res 88: 3684-90 (1983)

11.2.14 Effluent Concentrations

1298 stations in the USEPA STORET data base had 3.5% positive detections for methyl chloride with a median concentration of <10 ppb(1). Methyl chloride was detected in 1 of 5 leachates from municipal waste landfills in Wisconsin at 170 ppb and detected, not quantified in 4 of 6 leachates from municipal landfills in Minnesota(2). Methyl chloride has been detected in treated wastewater from the following industries (industry (mean concentration)): pharmaceutical manufacturing (2000 ppb), organic chemical manufacturing/plastics (0.1 ppb), timber products processing (140 ppb) and raw wastewater from metal finishing (610 ppb)(3). Ratios of methyl chloride (ppmv) to carbon dioxide (1X10-6 ppmv) in wood smoke ranged from 0.66 to 2.63(4). In a comprehensive survey of wastewater from 4000 industrial and publicly owned treatment works (POTWs) sponsored by the Effluent Guidelines Div of the US EPA, methyl chloride was identified in discharges of the following industrial categories (frequency of occurrence, median concentration in ppb): nonferrous metals (1; 21.6), paint and ink (2; 4128.7), printing and publishing (1; 6.0), organics and plastics (1; 156.7), pharmaceuticals (1; 2558.3), organic chemicals (3; 49.0)(5); the highest effluent concentration was 4194 ppb in the paint and ink industry(5). Methyl chloride has been detected in anhydrous volcanic gases from various locations at levels ranging from 0.61 to 84 ppbv(6). Field studies conducted between June 1998 and June 1999 at two southern California coastal salt marshes reported a daily flux release of methyl chloride of up to 570 umol/sq m-day(7).
(1) Staples CA et al; Environ Toxicol Chem 4: 131-42 (1985)
(2) Sabel GV, Clark TP; Waste Manag Res 2: 119-30 (1984)
(3) USEPA; Treatability Manual pp. I.12.1-I.12.5 USEPA-600/282-001a (1981)
(4) Edgerton SA et al; Environ Sci Technol 20: 803-807 (1986)
(5) Shackelford WM et al; Analyt Chim Acta 146: 15-27 (1983)
(6) Jordan A et al; Environ Sci Technol 34: 1122-1124 (2000)
(7) Rhew RC et al; Nature 403: 292-295 (2000)

11.2.15 Sediment / Soil Concentrations

Of 345 stations in the USEPA STORET data base 0.3% were positive for methyl chloride with a median concentration of <5 ppb(1).
(1) Staples CA et al; Environ Toxicol Chem 4: 131-42 (1985)

11.2.16 Atmospheric Concentrations

URBAN/SUBURBAN: Monitoring at 12 sites in the US (389 samples) detected methyl chloride at 570-5700 parts per trillion with a 1000 parts per trillion median(1). Samples collected in Delft, The Netherlands (densely populated area of the country) detected methyl chloride at 3000 parts per trillion mean with a 7000 parts per trillion max(2). A suburban site in Hillsboro, OR had peak methyl chloride concentrations in December and May of 680 and 700 parts per trillion, respectively, that was attributed to wood burning and backyard burning(3). 37 Ambient air samples from 1434 US locations contained methyl chloride at an average concentration of 1.3 ug/cu m(4). Average concentrations of methyl chloride were reported in four US cities as follows: Downey CA in February 1984, at 792 parts per trillion; in San Jose CA in April and December 1985 at 1060 and 1118 parts per trillion, respectively; in Houston TX in March 1984 at 961 parts per trillion; and Denver CO in April 1984 at 7 parts per trillion(5). Air monitoring at a Los Angeles CA community with a high traffic density between Nov 1999 and Jan 2000 found a mean daily methyl chloride concentration of 0.580 ppb(6). Air measurements in downtown Porto Alegre, Brazil between 1996 and 1997 found an average methyl chloride level of 0.150 ppb(7). Monitoring at 27 locations in Perth, Australia in 2000 detected an average level of 0.6 ppb(8). Air samples collected at 13 urban locations in the US during Sept 1996 to Aug 1997 detected methyl chloride at all locations(9).
(1) Brodzinsky R, Singh HB; Volatile Organic Chemicals in the Atmos, An Assess of Available Data, Menlo Park, CA pp.198 No 68-02-3452 (1982)
(2) Guicherit R, Schulting FL; Sci Total Environ 43: 193-219 (1985)
(3) Edgerton SA et al; J Air Pollut Control Assoc 34: 661-4 (1984)
(4) Kelly TJ et al; Environ Sci Technol 28: 378-87 (1994)
(5) Singh HB et al; Atmos Environ 26A: 2929-46 (1992)
(6) Delfino RJ et al; Environ Health Perspect 111(4): 647-656 (2003)
(7) Grosjean E et al; Environ Sci Technol 33: 1970-1978 (1999)
(8) Hinwood AL et al; Chemosphere 63: 421-429 (2006)
(9) Mohamed MF et al; Chemosphere 47: 863-882 (2002)
INDOOR AIR: Methyl chloride concentrations are elevated due to biomass combustion(1). In rural Nepal, where stoves are used for cooking and heating, methyl chloride levels in one house were 6950 parts per trillion(1). Indoor samples collected from residences, offices, restaurants and nightclubs in Perth Australia in 2000 contained an average methyl chloride level of 0.6 ppb(2). Indoor air was sampled in 100 homes in suburban and rural areas of New Jersey during 2003-2006(3); methyl chloride was detected in 81 homes at mean and maximum concentrations of 1.49 and 6.2 ug/cu m, respectively(3). Residential air samples from Massachusetts between 2004-2005 had a mean methyl chloride level of 1.22 ug/cu m(3). Air sampled in NY homes during 1997-2003, that heated with fuel oil, had a mean methyl chloride level of 0.5 ug/cu m(3).
(1) Davidson CI et al; Environ Sci Technol 20: 561-7 (1986)
(2) Hinwood AL et al; Chemosphere 63: 421-429 (2006)
(3) Weisel CP et al; Environ Sci Technol 42: 8231-8238 (2008)
RURAL/REMOTE: Methyl chloride was detected in samples collected in southwest Washington at 530 parts per trillion(1). Monitoring at four US sites (191 samples) detected methyl chloride at 590-1300 parts per trillion with a 1300 parts per trillion median(2). Sampling at 8 background locations in 1980 (time series over seasons) detected 564-687 parts per trillion methyl chloride(3); concentration highest in spring and lowest in fall and highest in the tropics; however there is no significant difference between hemispheres(3). Two rural coastal sites (192 samples) near San Francisco had 953 parts per trillion(4). Mean concentration of methyl chloride over the eastern Pacific between 40 deg N and 32 deg S latitudes was 630 parts per trillion, and contrary to other results, the methyl chloride concentration was independent of latitude(5). The concentration of methyl chloride decreases with altitude, declining to 50 parts per trillion at 29 km(6). The island of Terschelling, The Netherlands (least populated area of country) had a mean concentration of 700 parts per trillion(7). From the coast to the forest in Guyana had methyl chloride concentrations of 630-730 parts per trillion volume(8). The atmospheric background level of methyl chloride is reported to be around 1.2 ug/cu m (0.6 ppb)(9). Air samples collected over the western Pacific Ocean region in 1991 and 1994 contained median methyl chloride concentrations ranging from 464 to 594 parts per trillion(10). The average atmospheric global concentration of methyl chloride between 1985 and 1996 ranged from 573 to 612 parts per trillion volume depending on latitude(11). Air sampling at a remote island (Okinawa, Japan) in 1996 detected levels of 574-766 parts per trillion volume(12).
(1) Grimsrud EP, Rasmussen RA; Atmos Environ 9: 1014-7 (1975)
(2) Brodzinsky R, Singh HB; Volatile Organic Chemicals in the Atmos, An Assess of Available Data, Menlo Park, CA pp.198 No 68-02-3452 (1982)
(3) Khalil MAK, Rasmussen RA; Chemosphere 10: 1019-23 (1981)
(4) Singh HB et al; J Air Pollut Control Assoc 27: 332-6 (1977)
(5) Singh HB et al; J Geophys Res 88: 3684-90 (1983)
(6) Fabian P, Goemer D; Fresenius' Z Anal Chem 319: 890-7 (1984)
(7) Guicherit R, Schulting FL; Sci Total Environ 43: 193-219 (1985)
(8) Gregory G et al; J Geophys Res 91: 8603-12 (1986)
(9) Reid JB, Muianga CV; Halogenated One-Carbon Compounds. Patty's Toxicology. 6th ed. (1999-2015). New York, NY: John Wiley & Sons, Inc. On-line Posting Date: Aug 17, 2012.
(10) Blake NJ et al; J Geophys Researc 102: 28315-31 (1997)
(11) Khalil MAK, Rasmussen RA; Atmos Environ 33: 1305-1321 (1999)
(12) Li HJ et al; Atmos Environ 33: 1881-1887 (1999)

11.2.17 Plant Concentrations

Methyl chloride has been identified as a chemical component of tobacco plants(1). Various species of Antarctic macroalgae have been found to produce and release methyl chloride at levels of 1.98 pmol/g (wet wt) per day(2).
(1) Rodgman A, Perfetti TA; The Chemical Components of Tobacco and Tobacco Smoke, Second Edition. Boca Raton, FL: CRC Press, p. 2069 (2013)
(2) Laturnus F et al; Geophys Research Letters 25(6): 773-776 (1998)

11.2.18 Fish / Seafood Concentrations

Of 84 samples in the USEPA STORET data base, only 1% were positive for methyl chloride, median concentration <50 ppb(1).
(1) Staples, CA et al; Environ Toxicol Chem 4: 131-42 (1985)

11.2.19 Milk Concentrations

In mother's milk from 4 urban areas of the US, methyl chloride was detected not quantified in 2 of 8 samples(1).
(1) Pellizzari ED et al; Bull Environ Contam Toxicol 28: 322-8 (1982)

11.2.20 Other Environmental Concentrations

Methyl chloride has been identified as a chemical component of tobacco smoke(1). The methyl chloride concentration in tobacco smoke collected in canisters was about 30-500 ppmv (1.5-5.3 mg/cigarette) compared with about 500 parts per trillion volume in typical urban air(2). Methyl chloride was detected in smoke emissions from smoldering incense at average levels of 205-226 ug/g(3). The compound is also present in chlorinated swimming pools(4).
(1) Rodgman A, Perfetti TA; The Chemical Components of Tobacco and Tobacco Smoke, Second Edition. Boca Raton, FL: CRC Press, p. 2069 (2013)
(2) Reid JB, Muianga CV; Halogenated One-Carbon Compounds. Patty's Toxicology. 6th ed. (1999-2015). New York, NY: John Wiley & Sons, Inc. On-line Posting Date: Aug 17, 2012.
(3) Yang TT et al; Bull Environ Contam Toxicol 78: 308-313 (2007)
(4) ATSDR Tox Profiles. Chloromethane (74-87-3). Available from, as of Jan 29, 2016: https://www.atsdr.cdc.gov/toxprofiles/index.asp

11.2.21 Probable Routes of Human Exposure

According to the 2012 TSCA Inventory Update Reporting data, 3 reporting facilities estimate the number of persons reasonably likely to be exposed during the manufacturing, processing, or use of methyl chloride in the United States may be as low as 25-49 workers and as high as 500-999 workers per plant; the data may be greatly underestimated due to confidential business information (CBI) or unknown values(1).
(1) US EPA; Chemical Data Reporting (CDR). Non-confidential 2012 Chemical Data Reporting information on chemical production and use in the United States. Available from, as of Jan 15, 2015: https://java.epa.gov/oppt_chemical_search/
NIOSH (NOES Survey 1981-1983) has statistically estimated that 10,003 workers (571 of these are female) are potentially exposed to methyl chloride in the US(1). Occupational exposure to methyl chloride may occur through inhalation and dermal contact with this compound at workplaces where methyl chloride is produced or used(SRC). Monitoring data indicate that the general population may be exposed to methyl chloride via inhalation of ambient air and tobacco smoke, ingestion of drinking water, and dermal contact with seawater containing methyl chloride(SRC).
(1) NIOSH; NOES. National Occupational Exposure Survey conducted from 1981-1983. Estimated numbers of employees potentially exposed to specific agents by 2-digit standard industrial classification (SIC). Available from, as of Jan 27, 2016: https://www.cdc.gov/noes/

11.2.22 Body Burden

Methyl chloride was detected not quantified in 2 of 8 samples of mother's milk from 4 urban areas of the US(1). It was detected in expired air from a sample of 62 nonsmoking individuals(2).
(1) Pellizzari ED et al; Bull Environ Contam Toxicol 28: 322-8 (1982)
(2) Krotoszynski BK, O'Neill HJ; J Environ Sci Health A17: 855-83 (1982)

12 Associated Disorders and Diseases

Associated Occupational Diseases with Exposure to the Compound
Solvents, acute toxic effect [Category: Acute Poisoning]

13 Literature

13.1 Consolidated References

13.2 NLM Curated PubMed Citations

13.3 Springer Nature References

13.4 Thieme References

13.5 Wiley References

13.6 Chemical Co-Occurrences in Literature

13.7 Chemical-Gene Co-Occurrences in Literature

13.8 Chemical-Disease Co-Occurrences in Literature

14 Patents

14.1 Depositor-Supplied Patent Identifiers

14.2 WIPO PATENTSCOPE

14.3 Chemical Co-Occurrences in Patents

14.4 Chemical-Disease Co-Occurrences in Patents

14.5 Chemical-Gene Co-Occurrences in Patents

15 Interactions and Pathways

15.1 Protein Bound 3D Structures

15.1.1 Ligands from Protein Bound 3D Structures

PDBe Ligand Code
PDBe Structure Code
PDBe Conformer

15.2 Chemical-Target Interactions

15.3 Pathways

16 Biological Test Results

16.1 BioAssay Results

17 Taxonomy

The LOTUS Initiative for Open Natural Products Research: frozen dataset union wikidata (with metadata) | DOI:10.5281/zenodo.5794106

18 Classification

18.1 MeSH Tree

18.2 NCI Thesaurus Tree

18.3 ChEBI Ontology

18.4 ChemIDplus

18.5 CAMEO Chemicals

18.6 UN GHS Classification

18.7 EPA CPDat Classification

18.8 NORMAN Suspect List Exchange Classification

18.9 EPA DSSTox Classification

18.10 International Agency for Research on Cancer (IARC) Classification

18.11 Consumer Product Information Database Classification

18.12 EPA TSCA and CDR Classification

18.13 LOTUS Tree

18.14 EPA Substance Registry Services Tree

18.15 MolGenie Organic Chemistry Ontology

19 Information Sources

  1. Agency for Toxic Substances and Disease Registry (ATSDR)
    LICENSE
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    https://www.cdc.gov/Other/disclaimer.html
  2. EPA Integrated Risk Information System (IRIS)
  3. The National Institute for Occupational Safety and Health (NIOSH)
    LICENSE
    The information provided using CDC Web site is only intended to be general summary information to the public. It is not intended to take the place of either the written law or regulations.
    https://www.cdc.gov/Other/disclaimer.html
  4. EPA Air Toxics
  5. NJDOH RTK Hazardous Substance List
  6. Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
    LICENSE
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    https://haz-map.com/About
  7. California Office of Environmental Health Hazard Assessment (OEHHA)
  8. CAMEO Chemicals
    LICENSE
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    https://cameochemicals.noaa.gov/help/reference/terms_and_conditions.htm?d_f=false
    CAMEO Chemical Reactivity Classification
    https://cameochemicals.noaa.gov/browse/react
  9. ChEBI
  10. LOTUS - the natural products occurrence database
    LICENSE
    The code for LOTUS is released under the GNU General Public License v3.0.
    https://lotus.nprod.net/
  11. NCI Thesaurus (NCIt)
    LICENSE
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    https://www.cancer.gov/policies/copyright-reuse
  12. Australian Industrial Chemicals Introduction Scheme (AICIS)
  13. CAS Common Chemistry
    LICENSE
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    https://creativecommons.org/licenses/by-nc/4.0/
  14. ChemIDplus
    ChemIDplus Chemical Information Classification
    https://pubchem.ncbi.nlm.nih.gov/source/ChemIDplus
  15. DHS Chemical Facility Anti-Terrorism Standards (CFATS) Chemicals of Interest
  16. EPA Acute Exposure Guideline Levels (AEGLs)
  17. EPA Chemical Data Reporting (CDR)
    LICENSE
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    https://www.epa.gov/web-policies-and-procedures/epa-disclaimers#copyright
  18. EPA Chemicals under the TSCA
    EPA TSCA Classification
    https://www.epa.gov/tsca-inventory
  19. EPA DSSTox
    CompTox Chemicals Dashboard Chemical Lists
    https://comptox.epa.gov/dashboard/chemical-lists/
  20. EPA Provisional Peer-Reviewed Toxicity Values (PPRTVs)
  21. European Chemicals Agency (ECHA)
    LICENSE
    Use of the information, documents and data from the ECHA website is subject to the terms and conditions of this Legal Notice, and subject to other binding limitations provided for under applicable law, the information, documents and data made available on the ECHA website may be reproduced, distributed and/or used, totally or in part, for non-commercial purposes provided that ECHA is acknowledged as the source: "Source: European Chemicals Agency, http://echa.europa.eu/". Such acknowledgement must be included in each copy of the material. ECHA permits and encourages organisations and individuals to create links to the ECHA website under the following cumulative conditions: Links can only be made to webpages that provide a link to the Legal Notice page.
    https://echa.europa.eu/web/guest/legal-notice
    chloromethane; methyl chloride
    https://chem.echa.europa.eu/100.000.744
  22. FDA Global Substance Registration System (GSRS)
    LICENSE
    Unless otherwise noted, the contents of the FDA website (www.fda.gov), both text and graphics, are not copyrighted. They are in the public domain and may be republished, reprinted and otherwise used freely by anyone without the need to obtain permission from FDA. Credit to the U.S. Food and Drug Administration as the source is appreciated but not required.
    https://www.fda.gov/about-fda/about-website/website-policies#linking
  23. Hazardous Substances Data Bank (HSDB)
  24. ILO-WHO International Chemical Safety Cards (ICSCs)
  25. New Zealand Environmental Protection Authority (EPA)
    LICENSE
    This work is licensed under the Creative Commons Attribution-ShareAlike 4.0 International licence.
    https://www.epa.govt.nz/about-this-site/general-copyright-statement/
  26. Occupational Safety and Health Administration (OSHA)
    LICENSE
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    https://www.dol.gov/general/aboutdol/copyright
  27. Risk Assessment Information System (RAIS)
    LICENSE
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    https://rais.ornl.gov/
  28. California Safe Cosmetics Program (CSCP) Product Database
  29. Consumer Product Information Database (CPID)
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    https://www.whatsinproducts.com/contents/view/1/6
    Consumer Products Category Classification
    https://www.whatsinproducts.com/
  30. Emergency Response Guidebook (ERG)
  31. ChEMBL
    LICENSE
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    http://www.ebi.ac.uk/Information/termsofuse.html
  32. Comparative Toxicogenomics Database (CTD)
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    It is to be used only for research and educational purposes. Any reproduction or use for commercial purpose is prohibited without the prior express written permission of NC State University.
    http://ctdbase.org/about/legal.jsp
  33. Crystallography Open Database (COD)
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    https://creativecommons.org/publicdomain/zero/1.0/
  34. EPA Chemical and Products Database (CPDat)
  35. EPA Regional Screening Levels for Chemical Contaminants at Superfund Sites
  36. Hazardous Chemical Information System (HCIS), Safe Work Australia
  37. NITE-CMC
    Chloromethane, (alias Methyl chloride) - FY2009 (Revised classification)
    https://www.chem-info.nite.go.jp/chem/english/ghs/09-mhlw-2087e.html
    Chloromethane; Methyl chloride - FY2006 (New/original classication)
    https://www.chem-info.nite.go.jp/chem/english/ghs/06-imcg-0025e.html
    Chloromethane - FY2021 (Revised classification)
    https://www.chem-info.nite.go.jp/chem/english/ghs/21-moe-2096e.html
  38. Regulation (EC) No 1272/2008 of the European Parliament and of the Council
    LICENSE
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    https://eur-lex.europa.eu/content/legal-notice/legal-notice.html
  39. MassBank Europe
  40. NMRShiftDB
  41. Human Metabolome Database (HMDB)
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    http://www.hmdb.ca/citing
  42. International Agency for Research on Cancer (IARC)
    LICENSE
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    https://publications.iarc.fr/Terms-Of-Use
    IARC Classification
    https://www.iarc.fr/
  43. Japan Chemical Substance Dictionary (Nikkaji)
  44. KEGG
    LICENSE
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    https://www.kegg.jp/kegg/legal.html
  45. MassBank of North America (MoNA)
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    https://mona.fiehnlab.ucdavis.edu/documentation/license
  46. NIST Mass Spectrometry Data Center
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    Data covered by the Standard Reference Data Act of 1968 as amended.
    https://www.nist.gov/srd/public-law
  47. SpectraBase
  48. Metabolomics Workbench
  49. NIOSH Manual of Analytical Methods
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    https://www.cdc.gov/Other/disclaimer.html
  50. NORMAN Suspect List Exchange
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    Data: CC-BY 4.0; Code (hosted by ECI, LCSB): Artistic-2.0
    https://creativecommons.org/licenses/by/4.0/
    Methyl chloride
    NORMAN Suspect List Exchange Classification
    https://www.norman-network.com/nds/SLE/
  51. Protein Data Bank in Europe (PDBe)
  52. Rhea - Annotated Reactions Database
    LICENSE
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    https://www.rhea-db.org/help/license-disclaimer
  53. Springer Nature
  54. SpringerMaterials
  55. Thieme Chemistry
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    https://creativecommons.org/licenses/by-nc-nd/4.0/
  56. USGS Health-Based Screening Levels for Evaluating Water-Quality Data
  57. Wikidata
    Chloromethylstyrene-divinylbenzene-styrene copolymer
    https://www.wikidata.org/wiki/Q72455235
  58. Wikipedia
  59. Wiley
  60. Medical Subject Headings (MeSH)
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    https://www.nlm.nih.gov/copyright.html
  61. PubChem
  62. GHS Classification (UNECE)
  63. EPA Substance Registry Services
  64. MolGenie
    MolGenie Organic Chemistry Ontology
    https://github.com/MolGenie/ontology/
  65. PATENTSCOPE (WIPO)
  66. NCBI
CONTENTS