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Mesityl oxide

PubChem CID
8858
Structure
Mesityl oxide_small.png
Mesityl oxide_3D_Structure.png
Molecular Formula
Synonyms
  • MESITYL OXIDE
  • 141-79-7
  • 4-Methylpent-3-en-2-one
  • 4-Methyl-3-penten-2-one
  • 3-Penten-2-one, 4-methyl-
Molecular Weight
98.14 g/mol
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Dates
  • Create:
    2005-03-26
  • Modify:
    2025-01-18
Description
Mesityl oxide appears as a colorless, oily liquid with a pungent honey-like odor. Flash point 87 °F. Less dense than water and slightly soluble in water. Vapors heavier than air. Used in paint removers, as a solvent for plastics, and as an insect repellent.
4-Methyl-3-penten-2-one, 9CI is an olefinic compound. It is functionally related to an acrylic acid.
Mesityl oxide has been reported in Bistorta manshuriensis, Tamarix aphylla, and other organisms with data available.

1 Structures

1.1 2D Structure

Chemical Structure Depiction
Mesityl oxide.png

1.2 3D Conformer

2 Names and Identifiers

2.1 Computed Descriptors

2.1.1 IUPAC Name

4-methylpent-3-en-2-one
Computed by Lexichem TK 2.7.0 (PubChem release 2021.10.14)

2.1.2 InChI

InChI=1S/C6H10O/c1-5(2)4-6(3)7/h4H,1-3H3
Computed by InChI 1.0.6 (PubChem release 2021.10.14)

2.1.3 InChIKey

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

2.1.4 SMILES

CC(=CC(=O)C)C
Computed by OEChem 2.3.0 (PubChem release 2024.12.12)

2.2 Molecular Formula

C6H10O
Computed by PubChem 2.2 (PubChem release 2021.10.14)

C6H10O

(CH3)2C=CH-COCH3

2.3 Other Identifiers

2.3.1 CAS

141-79-7

2.3.2 European Community (EC) Number

2.3.3 UNII

2.3.4 UN Number

2.3.5 ChEBI ID

2.3.6 ChEMBL ID

2.3.7 DSSTox Substance ID

2.3.8 FEMA Number

2.3.9 HMDB ID

2.3.10 ICSC Number

2.3.11 JECFA Number

1131

2.3.12 Lipid Maps ID (LM_ID)

2.3.13 Metabolomics Workbench ID

2.3.14 Nikkaji Number

2.3.15 NSC Number

2.3.16 RTECS Number

2.3.17 Wikidata

2.3.18 Wikipedia

2.4 Synonyms

2.4.1 MeSH Entry Terms

mesityl oxide

2.4.2 Depositor-Supplied Synonyms

3 Chemical and Physical Properties

3.1 Computed Properties

Property Name
Molecular Weight
Property Value
98.14 g/mol
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
XLogP3-AA
Property Value
1.4
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
1
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Rotatable Bond Count
Property Value
1
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Exact Mass
Property Value
98.073164938 Da
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Monoisotopic Mass
Property Value
98.073164938 Da
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Topological Polar Surface Area
Property Value
17.1 Ų
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Heavy Atom Count
Property Value
7
Reference
Computed by PubChem
Property Name
Formal Charge
Property Value
0
Reference
Computed by PubChem
Property Name
Complexity
Property Value
96.7
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

Mesityl oxide appears as a colorless, oily liquid with a pungent honey-like odor. Flash point 87 °F. Less dense than water and slightly soluble in water. Vapors heavier than air. Used in paint removers, as a solvent for plastics, and as an insect repellent.
Oily, colorless to light-yellow liquid with a peppermint- or honey-like odor; [NIOSH]
Liquid
COLOURLESS VISCOUS LIQUID WITH CHARACTERISTIC ODOUR. DARKENS ON STANDING.
Colourless oily liquid; unpleasant grassy-green or pungent, acrylic odour
Oily, colorless to light-yellow liquid with a peppermint- or honey-like odor.

3.2.2 Color / Form

Oily, colorless to light-yellow liquid
NIOSH. NIOSH Pocket Guide to Chemical Hazards & Other Databases CD-ROM. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2005-151 (2005)

3.2.3 Odor

... spearmint ...
Topping DC et al; Patty's Toxicology. (2005) NY, NY: John Wiley & Sons, Inc. Ketones of Six to Thirteen Carbons. On-line posting date: Apr 16, 2001.
COMMERCIAL GRADE EXHIBITS AN UNPLEASANT ODOR
Fenaroli's Handbook of Flavor Ingredients. Volume 2. Edited, translated, and revised by T.E. Furia and N. Bellanca. 2nd ed. Cleveland: The Chemical Rubber Co., 1975., p. 334
Peppermint- or honey-like odor
NIOSH. NIOSH Pocket Guide to Chemical Hazards & Other Databases CD-ROM. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2005-151 (2005)

3.2.4 Taste

OILY TASTE
Furia, T.E. (ed.). CRC Handbook of Food Additives. 2nd ed. Volume 2. Boca Raton, Florida: CRC Press, Inc., 1980., p. 289

3.2.5 Boiling Point

266 °F at 760 mmHg (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.
130 °C at 760 mm Hg
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. 13th Edition, Whitehouse Station, NJ: Merck and Co., Inc., 2001., p. 1056
130 °C
266 °F

3.2.6 Melting Point

-51 °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.
-59 °C
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. 13th Edition, Whitehouse Station, NJ: Merck and Co., Inc., 2001., p. V4: 3048
MP: -41.5 °C (also reported as -59 °C); can be made to crystallize at low temp in petroleum ether
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. 13th Edition, Whitehouse Station, NJ: Merck and Co., Inc., 2001., p. 1056
-41.5 °C
-52 °F

3.2.7 Flash Point

73 °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.
31 °C
87 °F (31 °C) (Closed cup)
Fire Protection Guide to Hazardous Materials. 13 ed. Quincy, MA: National Fire Protection Association, 2002., p. 325-79
25 °C c.c.
87 °F

3.2.8 Solubility

3 % (NIOSH, 2024)
Sol in about 30 parts water; miscible with most org liq
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. 13th Edition, Whitehouse Station, NJ: Merck and Co., Inc., 2001., p. 1056
Miscible in ethanol, ethyl ether
Lide, D.R., G.W.A. Milne (eds.). Handbook of Data on Organic Compounds. Volume I. 3rd ed. CRC Press, Inc. Boca Raton ,FL. 1994., p. V4: 3948
SLIGHTLY SOL IN PROPYLENE GLYCOL
Fenaroli's Handbook of Flavor Ingredients. Volume 2. Edited, translated, and revised by T.E. Furia and N. Bellanca. 2nd ed. Cleveland: The Chemical Rubber Co., 1975., p. 334
In water, 28,900 mg/L at 20 °C
Yalkowsky, S.H., He, Yan., Handbook of Aqueous Solubility Data: An Extensive Compilation of Aqueous Solubility Data for Organic Compounds Extracted from the AQUASOL dATAbASE. CRC Press LLC, Boca Raton, FL. 2003., p. 285
28.9 mg/mL at 20 °C
Solubility in water, g/100ml at 20 °C: 3.0 (moderate)
slightly soluble inwater; miscible in organic solvents
Miscible at room temperature (in ethanol)
3%

3.2.9 Density

0.853 at 68 °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.
0.8592 at 15 °C/4 °C
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. 13th Edition, Whitehouse Station, NJ: Merck and Co., Inc., 2001., p. 1056
Bulk density = 7.1 lb/gal at 20 °C
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 14th Edition. John Wiley & Sons, Inc. New York, NY 2001., p. 713
0.87 g/cm³
Relative density of the vapour/air-mixture at 20 °C (air = 1): 1.03
0.862-0.868
0.853 at 68 °F
(59 °F): 0.86

3.2.10 Vapor Density

3.4 (Air = 1)
Topping DC et al; Patty's Toxicology. (2005) NY, NY: John Wiley & Sons, Inc. Ketones of Six to Thirteen Carbons. On-line posting date: Apr 16, 2001.
Relative vapor density (air = 1): 3.4

3.2.11 Vapor Pressure

9 mmHg (NIOSH, 2024)
8.21 [mmHg]
8.21 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 20 °C: 1.2
9 mmHg

3.2.12 LogP

1.7

3.2.13 Autoignition Temperature

652 °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.
652 °F (344 °C)
340 °C

3.2.14 Decomposition

When heated to decomposition it emits acrid smoke and irritating fumes.
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 2323

3.2.15 Viscosity

0.0060 cP at 20 °C
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 14th Edition. John Wiley & Sons, Inc. New York, NY 2001., p. 713
0.75 mm²/s at 20 °C

3.2.16 Heat of Combustion

-14,400 BTU/LB= -8,000 CAL/G= -330X10+5 JOULES/KG
U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.

3.2.17 Heat of Vaporization

157 BTU/LB= 87 CAL/G= 3.7X10+5 JOULES/KG
U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.

3.2.18 Surface Tension

22.9 DYNES/CM= 0.0029 NEWTONS/M @ 20 °C
U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.

3.2.19 Ionization Potential

9.08 eV

3.2.20 Odor Threshold

Odor Threshold Low: 0.01 [mmHg]

Odor Threshold High: 12.0 [mmHg]

Detection odor threshold from AIHA (mean = 0.017 ppm)

Odor low: 0.068 mg/cu m; Odor high: 100 mg/cu m.
Ruth JH; Am Ind Hyg Assoc J 47: A-142-51 (1986)
Odor threshold values: 50% detection: 12 ppm; 100% detection: 25 ppm.
Verschueren, K. Handbook of Environmental Data on Organic Chemicals. Volumes 1-2. 4th ed. John Wiley & Sons. New York, NY. 2001, p. 1416
The absolute perception limit has been reported to be 0.017 ppm.
Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. 6:234

3.2.21 Refractive Index

Index of refraction: 1.4425 at 22 °C/D
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. 13th Edition, Whitehouse Station, NJ: Merck and Co., Inc., 2001., p. 1056
1.442-1.447

3.2.22 Dissociation Constants

3.2.23 Relative Evaporation Rate

8.4 (ETHER= 1)
Patty, F. (ed.). Industrial Hygiene and Toxicology: Volume II: Toxicology. 2nd ed. New York: Interscience Publishers, 1963., p. 1722

3.2.24 Kovats Retention Index

Standard non-polar
778 , 782 , 778.4 , 783 , 780 , 783 , 787
Semi-standard non-polar
771 , 798 , 798 , 804 , 782 , 797 , 798 , 798 , 801.1 , 778 , 802 , 798 , 798 , 804.6 , 792 , 800 , 804 , 792
Standard polar
1118 , 1125 , 1159 , 1131 , 1136 , 1118 , 1131 , 1140 , 1111 , 1127 , 1128 , 1114 , 1152 , 1129 , 1125 , 1137 , 1113 , 1110 , 1110 , 1127 , 1127

3.2.25 Other Experimental Properties

May darken upon standing
Topping DC et al; Patty's Toxicology. (2005) NY, NY: John Wiley & Sons, Inc. Ketones of Six to Thirteen Carbons. On-line posting date: Apr 16, 2001.
Max vapor concn: 12,3000 ppm at 20 °C
Topping DC et al; Patty's Toxicology. (2005) NY, NY: John Wiley & Sons, Inc. Ketones of Six to Thirteen Carbons. On-line posting date: Apr 16, 2001.
Conversion factors: 1 ppm = 4.02 mg/cu m; 1 mg/L = 249 ppm
Topping DC et al; Patty's Toxicology. (2005) NY, NY: John Wiley & Sons, Inc. Ketones of Six to Thirteen Carbons. On-line posting date: Apr 16, 2001.

3.3 SpringerMaterials Properties

3.4 Chemical Classes

Other Classes -> Aliphatic Ketones, Other

3.4.1 Endocrine Disruptors

Potential endocrine disrupting compound
S109 | PARCEDC | List of 7074 potential endocrine disrupting compounds (EDCs) by PARC T4.2 | DOI:10.5281/zenodo.10944198

3.4.2 Food Additives

FLAVORING AGENT OR ADJUVANT -> FDA Substance added to food

3.4.3 Fragrances

Fragrance Ingredient (4-Methyl-3-penten-2-one) -> IFRA transparency List

3.4.4 Lipids

Fatty Acyls [FA] -> Oxygenated hydrocarbons [FA12]

4 Spectral Information

4.1 1D NMR Spectra

1D NMR Spectra

4.1.1 1H NMR Spectra

1 of 3
View All
Spectra ID
Instrument Type
JEOL
Frequency
90 MHz
Solvent
CDCl3
Shifts [ppm]:Intensity
2.14:479.00, 6.11:70.00, 2.13:478.00, 6.06:37.00, 6.10:72.00, 6.09:94.00, 6.12:36.00, 6.08:74.00, 1.88:459.00, 1.89:447.00, 2.16:1000.00
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Instrument Name
BRUKER AC-300
Source of Sample
Fluka AG, Buchs, Switzerland
Copyright
Copyright © 1991-2024 John Wiley & Sons, Inc. All Rights Reserved.
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4.1.2 13C NMR Spectra

1 of 3
View All
Spectra ID
Instrument Type
Varian
Frequency
25.16 MHz
Solvent
CDCl3
Shifts [ppm]:Intensity
20.57:557.00, 154.83:766.00, 27.55:786.00, 124.30:1000.00, 31.58:582.00, 198.35:582.00
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Source of Sample
Chem Service, Inc., West Chester, Pennsylvania
Copyright
Copyright © 1980, 1981-2024 John Wiley & Sons, Inc. All Rights Reserved.
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4.1.3 17O NMR Spectra

1 of 2
Copyright
Copyright © 2016-2024 W. Robien, Inst. of Org. Chem., Univ. of Vienna. All Rights Reserved.
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2 of 2
Copyright
Copyright © 2016-2024 W. Robien, Inst. of Org. Chem., Univ. of Vienna. All Rights Reserved.
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4.2 Mass Spectrometry

4.2.1 GC-MS

1 of 12
View All
Spectra ID
Instrument Type
EI-B
Ionization Mode
positive
Top 5 Peaks

55.0 99.99

83.0 94.59

43.0 46.64

98.0 40.98

29.0 34.19

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Notes
instrument=HITACHI RMU-7M
2 of 12
View All
Spectra ID
Instrument Type
EI-B
Ionization Mode
positive
Top 5 Peaks

55.0 99.99

83.0 97.83

43.0 59.31

98.0 42.53

39.0 39.76

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Notes
instrument=HITACHI M-80B

4.2.2 Other MS

1 of 3
View All
Other MS
MASS: 63797 (NIST/EPA/MSDC Mass Spectral Database, 1990 version)
2 of 3
View All
Authors
TAJIMA S, GUNMA COLLEGE OF TECHNOLOGY
Instrument
HITACHI RMU-7M
Instrument Type
EI-B
MS Level
MS
Ionization Mode
POSITIVE
Ionization
ENERGY 70 eV
Top 5 Peaks

55 999

83 946

43 466

98 410

29 342

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License
CC BY-NC-SA

4.3 UV Spectra

MAX ABSORPTION: 227.5 NM (LOG E= 3.87); 253 NM (LOG E= 3.88); 295 NM (LOG E= 3.59); SADTLER REF NUMBER: 109 (IR, PRISM)
Weast, R.C. (ed.). Handbook of Chemistry and Physics. 60th ed. Boca Raton, Florida: CRC Press Inc., 1979., p. C-423
UV: 41 (Sadtler Research Laboratories Spectral Collection)
Lide, D.R., G.W.A. Milne (eds.). Handbook of Data on Organic Compounds. Volume I. 3rd ed. CRC Press, Inc. Boca Raton ,FL. 1994., p. V4: 3948

4.4 IR Spectra

IR Spectra
IR: 18001 (Sadtler Research Laboratories IR Grating Collection)

4.4.1 FTIR Spectra

1 of 2
Technique
CAPILLARY CELL: NEAT
Source of Sample
Union Carbide Corporation, New York, New York
Copyright
Copyright © 1980, 1981-2024 John Wiley & Sons, Inc. All Rights Reserved.
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2 of 2
Instrument Name
Bruker Tensor 27 FT-IR
Technique
Neat
Source of Spectrum
Bio-Rad Laboratories, Inc.
Source of Sample
TCI Chemicals India Pvt. Ltd.
Catalog Number
M0069
Lot Number
PQL8I-CA
Copyright
Copyright © 2016-2024 John Wiley & Sons, Inc. All Rights Reserved.
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4.4.2 ATR-IR Spectra

1 of 2
Technique
ATR-Neat
Copyright
Copyright © 1980, 1981-2024 John Wiley & Sons, Inc. All Rights Reserved.
Thumbnail
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2 of 2
Instrument Name
Bruker Tensor 27 FT-IR
Technique
ATR-Neat (DuraSamplIR II)
Source of Spectrum
Bio-Rad Laboratories, Inc.
Source of Sample
TCI Chemicals India Pvt. Ltd.
Catalog Number
M0069
Lot Number
PQL8I-CA
Copyright
Copyright © 2016-2024 John Wiley & Sons, Inc. All Rights Reserved.
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4.4.3 Near IR Spectra

1 of 2
Instrument Name
INSTRUMENT PARAMETERS=INST=BRUKER,RSN=7717,REO=2,CNM=HEI,ZFF=2
Technique
NIR Spectrometer= BRUKER IFS 88
Source of Spectrum
Prof. Buback, University of Goettingen, Germany
Copyright
Copyright © 1989, 1990-2024 Wiley-VCH Verlag GmbH & Co. KGaA. All Rights Reserved.
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2 of 2
Instrument Name
INSTRUMENT PARAMETERS=INST=BRUKER,RSN=7717,REO=2,CNM=HEI,ZFF=2
Technique
NIR Spectrometer= BRUKER IFS 88
Source of Spectrum
Prof. Buback, University of Goettingen, Germany
Copyright
Copyright © 1989, 1990-2024 Wiley-VCH Verlag GmbH & Co. KGaA. All Rights Reserved.
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4.4.4 Vapor Phase IR Spectra

1 of 2
Instrument Name
DIGILAB FTS-14
Technique
Vapor Phase
Copyright
Copyright © 1980, 1981-2024 John Wiley & Sons, Inc. All Rights Reserved.
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2 of 2
Instrument Name
Bruker IFS 85
Technique
Gas-GC
Copyright
Copyright © 1989, 1990-2024 Wiley-VCH Verlag GmbH & Co. KGaA. All Rights Reserved.
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4.5 Raman Spectra

Instrument Name
Bruker MultiRAM Stand Alone FT-Raman Spectrometer
Technique
FT-Raman
Source of Spectrum
Bio-Rad Laboratories, Inc.
Source of Sample
TCI Chemicals India Pvt. Ltd.
Catalog Number
M0069
Lot Number
PQL8I-CA
Copyright
Copyright © 2016-2024 John Wiley & Sons, Inc. All Rights Reserved.
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4.6 Other Spectra

% IN SATURATED AIR 1.25
Patty, F. (ed.). Industrial Hygiene and Toxicology: Volume II: Toxicology. 2nd ed. New York: Interscience Publishers, 1963., p. 1722

6 Chemical Vendors

7 Food Additives and Ingredients

7.1 Food Additive Classes

Flavoring Agents
JECFA Functional Classes
Flavouring Agent -> FLAVOURING_AGENT;

7.2 FDA Substances Added to Food

Used for (Technical Effect)
FLAVORING AGENT OR ADJUVANT
FEMA Number
3368
GRAS Number
6
JECFA Flavor Number
1131

7.3 Associated Foods

7.4 Evaluations of the Joint FAO / WHO Expert Committee on Food Additives - JECFA

1 of 4
Chemical Name
4-METHYL-3-PENTEN-2-ONE
Evaluation Year
2002
ADI
No safety concern at current levels of intake when used as a flavouring agent
Tox Monograph
2 of 4
Chemical Name
METHYL ISOBUTENYL KETONE
Evaluation Year
2002
ADI
No safety concern at current levels of intake when used as a flavouring agent
Tox Monograph
3 of 4
Chemical Name
ISOPROPYLIDENE ACETONE
Evaluation Year
2002
ADI
No safety concern at current levels of intake when used as a flavouring agent
Tox Monograph
4 of 4
Chemical Name
MESITYL OXIDE
Evaluation Year
2002
ADI
No safety concern at current levels of intake when used as a flavouring agent
Tox Monograph

8 Pharmacology and Biochemistry

8.1 Absorption, Distribution and Excretion

Mesityl oxide ... reduced in body to apprecialbe extent. ... Shown to increase glucuronic output in rabbits. ... Repeated exposure of animals to non-lethal concentrations, suggests that it is probably not rapidly eliminated, and that with frequent exposures, blood concentration reaches anesthetic level.
Browning, E. Toxicity and Metabolism of Industrial Solvents. New York: American Elsevier, 1965., p. 441
It is readily absorbed through the intact skin.
International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983., p. 1172
... /Mesityl oxide/ can be absorbed into the body by inhalation of its vapor, through the skin and by ingestion.
IPCS, CEC; International Chemical Safety Card on Mesityl oxide. (March 1998). Available from, as of November 01, 2006: https://www.inchem.org/documents/icsc/icsc/eics0814.htm

8.2 Metabolism / Metabolites

Some mesityl oxide remains unchanged, some reduction and conjugation occurs. Metabolite is believed to be a glucuronide, but has not been demonstrated. /From table/
Casarett, L.J., and J. Doull. Toxicology: The Basic Science of Poisons. New York: MacMillan Publishing Co., 1975., p. 81
... Mesityl oxide reacts with certain sulfur-containing compounds in body, probably sulfhydryls and that this forms odorous product which ... /is/ believed to be sulfur substituted ketone.
Browning, E. Toxicity and Metabolism of Industrial Solvents. New York: American Elsevier, 1965., p. 441

8.3 Human Metabolite Information

8.3.1 Cellular Locations

  • Cytoplasm
  • Extracellular

9 Use and Manufacturing

9.1 Uses

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
Mesityl oxide has many uses as an industrial solvent. It is used as a paint remover and insect repellent. [ACGIH] Used as a solvent for resins, lacquers, enamels, rubber, inks, and oils; [HSDB]
ACGIH - Documentation of the TLVs and BEIs, 7th Ed. Cincinnati: ACGIH Worldwide, 2020.
Industrial Processes with risk of exposure

Painting (Solvents) [Category: Paint]

Plastic Composites Manufacturing [Category: Industry]

Solvent for nitrocellulose, many gums and resins, particularly vinyl resins. In lacquers, varnishes and enamels. In making methyl isobutyl ketone.
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. 13th Edition, Whitehouse Station, NJ: Merck and Co., Inc., 2001., p. 1056
IN LEATHER INDUSTRIES, IN ORE FLOTATION, AS ORGANIC INTERMEDIATE
Browning, E. Toxicity and Metabolism of Industrial Solvents. New York: American Elsevier, 1965., p. 440
SYNTHETIC FLAVOR INGREDIENT
Fenaroli's Handbook of Flavor Ingredients. Volume 2. Edited, translated, and revised by T.E. Furia and N. Bellanca. 2nd ed. Cleveland: The Chemical Rubber Co., 1975., p. 334
SOLVENT FOR RUBBERS, VINYL CHLORIDE-VINYL ACETATE COPOLYMERS, CELLULOSE RESINS, OILS, GUMS, INK, & LACQUERS; COMPONENT OF PAINT AND VARNISH REMOVERS; CHEM INTERMEDIATE FOR METHYL ISOBUTYL KETONE
SRI
For more Uses (Complete) data for MESITYL OXIDE (9 total), please visit the HSDB record page.

9.1.1 Use Classification

Food additives -> Flavoring Agents
Fragrance Ingredients
Flavouring Agent -> FLAVOURING_AGENT; -> JECFA Functional Classes
Flavoring Agents -> JECFA Flavorings Index
Hazard Classes and Categories -> Flammable - 3rd degree, Reactive - 1st degree

9.2 Methods of Manufacturing

Dehydration of acetone or diacetone alcohol.
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 14th Edition. John Wiley & Sons, Inc. New York, NY 2001., p. 713
Made by distilling diacetone alcohol with a small amount of iodine; ... condensation of acetone to mesityl oxide using sulfonated polystyrene-divinylbenzene resin as ion exchange catalyst.
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. 13th Edition, Whitehouse Station, NJ: Merck and Co., Inc., 2001., p. 1056

9.3 Impurities

4-Methyl-4-penten-2-one is the precursor of methyl isobutyl ketone ... and can be produced from acetone in a single- or a two-step process. Pure mesityl oxide is obtained by azeotropic distillation of the crude water-containing product. Subsequent purification by removal of the accompanying impurities, such as mesitylene and phorone ... is effected by distillation.
Ullmann's Encyclopedia of Industrial Chemistry. 6th ed.Vol 1: Federal Republic of Germany: Wiley-VCH Verlag GmbH & Co. 2003 to Present, p. V18 745 (2003)

9.4 Formulations / Preparations

Grade: Technical
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 14th Edition. John Wiley & Sons, Inc. New York, NY 2001., p. 713
Grades of purity: 97+%
U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.

9.5 U.S. Production

Aggregated Product Volume

2017: 63,000 lb

2016: 189,824 lb

This chemical is listed as a High Production Volume (HPV) (65FR81686). Chemicals listed as HPV were produced in or imported into the U.S. in >1 million pounds in 1990 and/or 1994. The HPV list is based on the 1990 Inventory Update Rule. (IUR) (40 CFR part 710 subpart B; 51FR21438).
EPA/Office of Pollution Prevention and Toxics; High Production Volume (HPV) Challenge Program on Mesityl Oxide (141-79-7). Available from, as of October 12, 2006: https://www.epa.gov/hpv/pubs/general/opptsrch.htm
(1973) 1.23X10+10 GRAMS (ACETONE USED IN MFR)
SRI
(1975) 2.07X10+10 GRAMS
SRI
Production volumes for non-confidential chemicals reported under the Inventory Update Rule.
Year
1986
Production Range (pounds)
>10 million-50 million
Year
1990
Production Range (pounds)
>10 million-50 million
Year
1994
Production Range (pounds)
>10 million-50 million
Year
1998
Production Range (pounds)
>10 million-50 million
Year
2002
Production Range (pounds)
>10 million-50 million
US EPA; Non-confidential Production Volume Information Submitted by Companies for Chemicals Under the 1986-2002 Inventory Update Rule (IUR). 3-Penten-2-one, 4-methyl (141-79-7). Available from, as of November 8, 2006: https://www.epa.gov/oppt/iur/tools/data/2002-vol.html

9.6 General Manufacturing Information

EPA TSCA Commercial Activity Status
3-Penten-2-one, 4-methyl-: ACTIVE
FLAVORS USEFUL IN PEPPERMINT AND SPEARMINT.
Furia, T.E. (ed.). CRC Handbook of Food Additives. 2nd ed. Volume 2. Boca Raton, Florida: CRC Press, Inc., 1980., p. 289

9.7 Sampling Procedures

NIOSH Method 1301. Analyte: Mesityl oxide. Matrix: Air. Sampler: Solid sorbent tube (coconut shell charcoal, 100 mg/50 mg). Flow Rate: 0.01 to 0.2 liters/min: Shipment: Normal. Sample Stability: Unknown.
U.S. Department of Health and Human Services, Public Health Service. Centers for Disease Control, National Institute for Occupational Safety and Health. NIOSH Manual of Analytical Methods, 3rd ed. Volumes 1 and 2 with 1985 supplement, and revisions. Washington, DC: U.S. Government Printing Office, February 1984., p. 1301-1

10 Identification

10.1 Analytic Laboratory Methods

OPTIMUM CONDITIONS FOR ABSORPTION & GAS CHROMATOGRAPHIC DETERMINATION OF MESITYL OXIDE & DIACETONE ALC WERE DETERMINED. ISOPROPYL ALC WAS MOST SUITABLE FOR ABSORPTION OF THE 2 CMPD FROM AIR. GAS CHROMATOGRAPHIC DETERMINATIONS WERE DONE ON COLUMNS WITH CARBOWAX 20 M DEPOSITED ON CHROMOSORB W-AW-DMCS (80-100 MESH) WITH FLAME-IONIZATION DETECTION. THE LOWER LIMIT OF DETERMINATION WAS 7.2 MG/CU M OF AIR FOR MESITYL OXIDE.
MIAZEK-KULA M; PR CENT INST OCHR PR 30 (104): 3 (1980)
NIOSH Method 1301. Analyte: Mesityl oxide. Matrix: Air. Procedure: Gas chromatography, flame ionization detector. For mesityl oxide this method has an estimated detection limit of 0.05 mg/sample. The precision/RSD is 0.014 and the recovery is not given. Applicability: The working range is 0.10 to 3.0 mg/sample. Interferences: None reported.
U.S. Department of Health and Human Services, Public Health Service. Centers for Disease Control, National Institute for Occupational Safety and Health. NIOSH Manual of Analytical Methods, 3rd ed. Volumes 1 and 2 with 1985 supplement, and revisions. Washington, DC: U.S. Government Printing Office, February 1984., p. 1301-1

10.2 NIOSH Analytical Methods

11 Safety and Hazards

11.1 Hazards Identification

11.1.1 GHS Classification

1 of 5
View All
Pictogram(s)
Flammable
Acute Toxic
Irritant
Signal
Danger
GHS Hazard Statements

H226 (100%): Flammable liquid and vapor [Warning Flammable liquids]

H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]

H312 (99.6%): Harmful in contact with skin [Warning Acute toxicity, dermal]

H315 (11.3%): Causes skin irritation [Warning Skin corrosion/irritation]

H319 (11.3%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]

H331 (14.3%): Toxic if inhaled [Danger Acute toxicity, inhalation]

H332 (85.5%): Harmful if inhaled [Warning Acute toxicity, inhalation]

H335 (11.3%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]

Precautionary Statement Codes

P210, P233, P240, P241, P242, P243, P261, P264, P264+P265, P270, P271, P280, P301+P317, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P316, P317, P319, P321, P330, P332+P317, P337+P317, P362+P364, P370+P378, P403+P233, P403+P235, P405, 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 1694 reports by companies from 15 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.

11.1.2 Hazard Classes and Categories

Flam. Liq. 3 (100%)

Acute Tox. 4 (100%)

Acute Tox. 4 (99.6%)

Skin Irrit. 2 (11.3%)

Eye Irrit. 2A (11.3%)

Acute Tox. 3 (14.3%)

Acute Tox. 4 (85.5%)

STOT SE 3 (11.3%)

Flammable liquid - category 3

Acute toxicity - category 4

Acute toxicity - category 4

Acute toxicity - category 4

11.1.3 NFPA Hazard Classification

1 of 2
View All
NFPA 704 Diamond
3-3-1
NFPA Health Rating
3 - Materials that, under emergency conditions, can cause serious or permanent injury.
NFPA Fire Rating
3 - Liquids and solids that can be ignited under almost all ambient temperature conditions. Materials produce hazardous atmospheres with air under almost all ambient temperatures or, though unaffected by ambient temperatures, are readily ignited under almost all conditions.
NFPA Instability Rating
1 - Materials that in themselves are normally stable but that can become unstable at elevated temperatures and pressures.

11.1.4 Health Hazards

Inhalation causes irritation of nose and throat, headache, dizziness, difficult breathing. Contact with liquid or concentrated vapor causes severe eye irritation. Liquid irritates skin. Ingestion causes irritation of mouth and stomach. (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 129 (Mesityl oxide)

· May cause toxic effects if inhaled or absorbed through skin.

· Inhalation or contact with material may irritate or burn skin and eyes.

· Fire will produce irritating, corrosive and/or toxic gases.

· Vapors may cause dizziness or asphyxiation, especially when in closed or confined areas.

· Runoff from fire control or dilution water may cause environmental contamination.

11.1.5 Fire Hazards

Behavior in Fire: Vapor is heavier than air and may travel a considerable distance to a source of ignition and flash back. (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 129 (Mesityl oxide)

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

· Vapors may form explosive mixtures with air.

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

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

· Vapor explosion hazard indoors, outdoors or in sewers.

· Those substances designated with a (P) may polymerize explosively when heated or involved in a fire.

· Runoff to sewer may create fire or explosion hazard.

· Containers may explode when heated.

· Many liquids will float on water.

Flammable. Above 25 °C explosive vapour/air mixtures may be formed.

11.1.6 Hazards Summary

Liquid causes first degree burns on short exposure. [CHRIS] Narcosis is induced in acute inhalation studies, and animals develop renal tubular degeneration and hepatic necrosis in subchronic studies. [ACGIH] A lachrymator; [CHEMINFO] A skin irritant and severe eye irritant; [CAMEO]
ACGIH - Documentation of the TLVs and BEIs, 7th Ed. Cincinnati: ACGIH Worldwide, 2020.

11.1.7 Fire Potential

Flammable liquid.
Fire Protection Guide to Hazardous Materials. 13 ed. Quincy, MA: National Fire Protection Association, 2002., p. 49-94
Dangerous, when exposed to heat or flame; can react with oxidizing materials
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 2323

11.1.8 Skin, Eye, and Respiratory Irritations

Vapor irritating to eyes, nose and throat.
U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.
May be harmful if absorbed through skin or inhaled. Irritating to skin, eyes, and respiratory system.
Fire Protection Guide to Hazardous Materials. 13 ed. Quincy, MA: National Fire Protection Association, 2002., p. 49-94

11.2 Safety and Hazard Properties

11.2.1 Flammable Limits

Lower flammable limit: 1.4% by volume; Upper flammable limit: 7.2% by volume
Fire Protection Guide to Hazardous Materials. 13 ed. Quincy, MA: National Fire Protection Association, 2002., p. 325-79
Flammability
Class IC Flammable Liquid: Fl.P. at or above 73 °F and below 100 °F.

11.2.2 Lower Explosive Limit (LEL)

1.4 % (NIOSH, 2024)
1.4%

11.2.3 Upper Explosive Limit (UEL)

7.2 % (NIOSH, 2024)
7.2%

11.2.4 Explosive Limits and Potential

Above 25 °C explosive vapor/air mixtures may be formed ... /Mesityl oxide/ can presumably form explosive peroxides.
IPCS, CEC; International Chemical Safety Card on Mesityl oxide. (March 1998). Available from, as of November 01, 2006: https://www.inchem.org/documents/icsc/icsc/eics0814.htm
MAY EXPLODE IF IGNITED IN AN ENCLOSED AREA. CONTAINERS MAY EXPLODE IN FIRE.
U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5., p. 49-177
Explosive limits , vol% in air: 1.4-10.1

11.2.5 OSHA Standards

Permissible Exposure Limit: Table Z-1 8-hr Time Weighted Avg: 25 ppm (100 mg/cu m).
29 CFR 1910.1000; U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of August 30, 2006: https://www.ecfr.gov
Vacated 1989 OSHA PEL TWA 15 ppm (60 mg/cu m); STEL 25 ppn (100 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

11.2.6 NIOSH Recommendations

Recommended Exposure Limit: 10 Hr Time-Weighted Avg: 10 ppm (40 mg/cu m).
NIOSH. NIOSH Pocket Guide to Chemical Hazards & Other Databases CD-ROM. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2005-151 (2005)

11.3 First Aid Measures

Inhalation First Aid
Fresh air, rest. Artificial respiration may be needed. Refer immediately for medical attention.
Skin First Aid
Remove contaminated clothes. Rinse and then wash skin with water and soap. Refer for medical attention .
Eye First Aid
First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.
Ingestion First Aid
Rinse mouth. Do NOT induce vomiting. Refer immediately for medical attention.

11.3.1 First Aid

Excerpt from NIOSH Pocket Guide for Mesityl oxide:

Eye: IRRIGATE IMMEDIATELY - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.

Skin: WATER FLUSH IMMEDIATELY - If this chemical contacts the skin, immediately flush the contaminated skin with water. If this chemical penetrates the clothing, immediately remove the clothing and flush the skin with water. Get medical attention promptly.

Breathing: RESPIRATORY SUPPORT - If a person breathes large amounts of this chemical, move the exposed person to fresh air at once. If breathing has stopped, perform artificial respiration. Keep the affected person warm and at rest. Get medical attention as soon as possible.

Swallow: MEDICAL ATTENTION IMMEDIATELY - If this chemical has been swallowed, get medical attention immediately. (NIOSH, 2024)

ERG 2024, Guide 129 (Mesityl oxide)

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:

· Wash skin with soap and water.

· 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: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.

Skin: Water flush immediately - If this chemical contacts the skin, immediately flush the contaminated skin with water. If this chemical penetrates the clothing, immediately remove the clothing and flush the skin with water. Get medical attention promptly.

Breathing: Respiratory support

Swallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately.

11.4 Fire Fighting

Excerpt from ERG Guide 129 [Flammable Liquids (Water-Miscible / Noxious)]:

CAUTION: The majority of these products have a very low flash point. Use of water spray when fighting fire may be inefficient.

SMALL FIRE: Dry chemical, CO2, water spray or alcohol-resistant foam. Do not use dry chemical extinguishers to control fires involving nitromethane (UN1261) or nitroethane (UN2842).

LARGE FIRE: Water spray, fog or alcohol-resistant foam. Avoid aiming straight or solid streams directly onto the product. If it can be done safely, move undamaged containers away from the area around the fire.

FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY 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. 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)

Use alcohol-resistant foam, powder, carbon dioxide. In case of fire: keep drums, etc., cool by spraying with water.

11.4.1 Fire Fighting Procedures

Use dry chemical, foam, carbon dioxide, or water spray. Water may be ineffective. Use water spray to keep fire-exposed containers cool.
Fire Protection Guide to Hazardous Materials. 13 ed. Quincy, MA: National Fire Protection Association, 2002., p. 49-94
If material /is/ on fire or involved in fire: Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Solid streams of water may spread fire. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Use "alcohol" foam, dry chemical or carbon dioxide.
Association of American Railroads; Bureau of Explosives. Emergency Handling of Hazardous Materials in Surface Transportation. Association of American Railroads, Pueblo, CO. 2005, p. 556
Aqueous film-forming foam (AFFF), alcohol-resistant foam, powder, carbon dioxide.
IPCS, CEC; International Chemical Safety Card on Mesityl oxide. (March 1998). Available from, as of November 01, 2006: https://www.inchem.org/documents/icsc/icsc/eics0814.htm

11.4.2 Firefighting Hazards

A harmful contamination of the air can be reached rather quickly on evaporation of this substance at 20 °C.
IPCS, CEC; International Chemical Safety Card on Mesityl oxide. (March 1998). Available from, as of November 01, 2006: https://www.inchem.org/documents/icsc/icsc/eics0814.htm
Vapors are heavier than air (vapor-air density at 100 °F, 1.1) and may travel to a source of ignition and flash back.
Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997., p. 49-84

11.5 Accidental Release Measures

Public Safety: ERG 2024, Guide 129 (Mesityl oxide)

· 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.

· Ventilate closed spaces before entering, but only if properly trained and equipped.

Spill or Leak: ERG 2024, Guide 129 (Mesityl oxide)

· 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.

· Prevent entry into waterways, sewers, basements or confined areas.

· A vapor-suppressing foam may be used to reduce vapors.

· Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers.

· Use clean, non-sparking tools to collect absorbed material.

Large Spill

· Dike far ahead of liquid spill for later disposal.

· Water spray may reduce vapor, but may not prevent ignition in closed spaces.

11.5.1 Isolation and Evacuation

Excerpt from ERG Guide 129 [Flammable Liquids (Water-Miscible / Noxious)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 50 meters (150 feet) in all directions.

LARGE SPILL: Consider initial downwind evacuation for at least 300 meters (1000 feet).

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)

Evacuation: ERG 2024, Guide 129 (Mesityl oxide)

Immediate precautionary measure

· Isolate spill or leak area for at least 50 meters (150 feet) in all directions.

Large Spill

· Consider initial downwind evacuation for at least 300 meters (1000 feet).

Fire

· If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions.

11.5.2 Spillage Disposal

Personal protection: self-contained breathing apparatus. Ventilation. Do NOT let this chemical enter the environment. Collect leaking liquid in sealable containers. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations.

11.5.3 Cleanup Methods

Eliminate all ignition sources. Stop or control the leak, if it can be done without undue risk. Use appropriate foam to blanket release and suppress vapors. Approach release from upwind. Absorb in noncombustible material for proper disposal.
Fire Protection Guide to Hazardous Materials. 13 ed. Quincy, MA: National Fire Protection Association, 2002., p. 49-94
Absorb on paper. Evaporate on a glass or iron dish in hood. Burn the paper.
ITII. Toxic and Hazardous Industrial Chemicals Safety Manual. Tokyo, Japan: The International Technical Information Institute, 1988., p. 317
Ventilation. Collect leaking liquid in sealable containers. Absorb remaining liquid in sand or inert absorbent and remove to safe place. Do NOT wash away into sewer. (Extra personal protection: self-contained breathing apparatus).
IPCS, CEC; International Chemical Safety Card on Mesityl oxide. (March 1998). Available from, as of November 01, 2006: https://www.inchem.org/documents/icsc/icsc/eics0814.htm

11.5.4 Disposal Methods

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

11.5.5 Preventive Measures

If mesityl oxide gets into the eyes, flush them immediately with large amounts of water for 15 minutes, lifting the lower and upper lids occasionally. Get medical attention as soon as possible. Contact lenses should not be worn when working with this chemical.
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.
If mesityl oxide gets on the skin, wash it immediately with soap and water. If mesityl oxide penetrates the clothing, remove the clothing immediately and wash the skin with soap and water. Get medical attention promptly.
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.
If a worker has been incapacitated, move the affected worker from the hazardous exposure. Put into effect the established emergency rescue procedures. Do not become a casualty. Understand the facility's emergency rescue procedures and know the locations of rescue equipment before the need arises.
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.
SRP: Local exhaust ventilation should be applied wherever there is an incidence of point source emissions or dispersion of regulated contaminants in the work area. Ventilation control of the contaminant as close to its point of generation is both the most economical and safest method to minimize personnel exposure to airborne contaminants.
For more Preventive Measures (Complete) data for MESITYL OXIDE (13 total), please visit the HSDB record page.

11.6 Handling and Storage

11.6.1 Nonfire Spill Response

Excerpt from ERG Guide 129 [Flammable Liquids (Water-Miscible / Noxious)]:

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. Prevent entry into waterways, sewers, basements or confined areas. A vapor-suppressing foam may be used to reduce vapors. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. Use clean, non-sparking tools to collect absorbed material.

LARGE SPILL: Dike far ahead of liquid spill for later disposal. Water spray may reduce vapor, but may not prevent ignition in closed spaces. (ERG, 2024)

11.6.2 Safe Storage

Fireproof. Separated from strong oxidants and acids. Do NOT store or transport in containers made from plastic or copper. Cool. Keep in the dark. Store in an area without drain or sewer access.

11.6.3 Storage Conditions

Fireproof. Separated from strong oxidants. Cool. Keep in the dark.
IPCS, CEC; International Chemical Safety Card on Mesityl oxide. (March 1998). Available from, as of November 01, 2006: https://www.inchem.org/documents/icsc/icsc/eics0814.htm
Protect containers against physical damage. Store well-ventilated cool place, isolating from oxidizing materials. Outdoor or isolated place from inhabitants is preferable. In case of outdoor storage, use standard combustible liquid storage room or cabinet.
ITII. Toxic and Hazardous Industrial Chemicals Safety Manual. Tokyo, Japan: The International Technical Information Institute, 1988., p. 317

11.7 Exposure Control and Personal Protection

Protective Clothing: ERG 2024, Guide 129 (Mesityl oxide)

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

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

Maximum Allowable Concentration (MAK)
2.0 [ppm]

11.7.2 Permissible Exposure Limit (PEL)

25.0 [ppm]
PEL-TWA (8-Hour Time Weighted Average)
25 ppm (100 mg/m³)
TWA 25 ppm (100 mg/m3) See Appendix G

11.7.3 Immediately Dangerous to Life or Health (IDLH)

1400 ppm ; Based on 10% of the lower explosive limit. (NIOSH, 2024)

1400.0 [ppm]

Excerpts from Documentation for IDLHs: Human data: The probable response to 100 ppm was predicted to be eye and mucous membrane irritation, difficulty breathing, headache, and vertigo [Shell 1957]. It has been stated that 5,000 ppm might be dangerous to life in 30 to 60 minutes [Smyth et al. 1942].

1400 ppm [Based on 10% of the lower explosive limit for safety considerations even though the relevant toxicological data indicated that irreversible health effects or impairment of escape existed only at higher concentrations.]
NIOSH. NIOSH Pocket Guide to Chemical Hazards & Other Databases CD-ROM. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2005-151 (2005)
1400 ppm

1400 ppm [10%LEL]

See: 141797

11.7.4 Threshold Limit Values (TLV)

15.0 [ppm]
TLV-STEL
25.0 [ppm]
8 hr Time Weighted Avg (TWA): 15 ppm; 15 min Short Term Exposure Limit (STEL): 25 ppm.
American Conference of Governmental Industrial Hygienists TLVs and BEIs. Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati, OH, 2008, p. 38
15 ppm as TWA; 25 ppm as STEL.
TLV-TWA (Time Weighted Average)
15 ppm [1992]
TLV-STEL (Short Term Exposure Limit)
25 ppm [1992]

11.7.5 Occupational Exposure Limits (OEL)

MAK (Maximale Arbeitsplatz Konzentration)
8.1 mg/m

11.7.6 Emergency Response Planning Guidelines

Emergency Response: ERG 2024, Guide 129 (Mesityl oxide)

CAUTION: The majority of these products have a very low flash point. Use of water spray when fighting fire may be inefficient.

Small Fire

· Dry chemical, CO2, water spray or alcohol-resistant foam.

· Do not use dry chemical extinguishers to control fires involving nitromethane (UN1261) or nitroethane (UN2842).

Large Fire

· Water spray, fog or alcohol-resistant foam.

· Avoid aiming straight or solid streams directly onto the product.

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

Fire Involving Tanks, Rail Tank Cars or Highway 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.

· 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.

11.7.7 Other Standards Regulations and Guidelines

USSR (1976): 0.25 ppm
American Conference of Governmental Industrial Hygienists. Documentation of the Threshold Limit Values and Biological Exposure Indices. 5th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, 1986., p. 361

11.7.8 Inhalation Risk

A harmful contamination of the air can be reached rather quickly on evaporation of this substance at 20 °C.

11.7.9 Effects of Short Term Exposure

The substance is irritating to the eyes, skin and respiratory tract. Exposure far above the OEL could cause unconsciousness. If swallowed the substance may cause vomiting and could result in aspiration pneumonitis.

11.7.10 Effects of Long Term Exposure

The substance defats the skin, which may cause dryness or cracking. The substance may have effects on the liver, kidneys and lungs.

11.7.11 Allowable Tolerances

Mesityl oxide is exempted from the requirement of a tolerance when used as a plant nutrient, cosolvent or solvent in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to growing crops only. Limit: Not for use after edible parts of plant begin to form. Do not graze livestock in treated areas within 48 hr after application.
40 CFR 180.920; U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of August 30, 2006: https://www.ecfr.gov

11.7.12 Personal Protective Equipment (PPE)

Excerpt from NIOSH Pocket Guide for Mesityl oxide:

Skin: PREVENT SKIN CONTACT - Wear appropriate personal protective clothing to prevent skin contact.

Eyes: PREVENT EYE CONTACT - Wear appropriate eye protection to prevent eye contact.

Wash skin: WHEN CONTAMINATED - The worker should immediately wash the skin when it becomes contaminated.

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: QUICK DRENCH - Facilities for quickly drenching the body should be provided within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.] (NIOSH, 2024)

Wear full protective clothing and positive pressure self-contained breathing apparatus.
Fire Protection Guide to Hazardous Materials. 13 ed. Quincy, MA: National Fire Protection Association, 2002., p. 49-94
Wear appropriate personal protective clothing to prevent skin contact.
NIOSH. NIOSH Pocket Guide to Chemical Hazards & Other Databases CD-ROM. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2005-151 (2005)
Wear appropriate eye protection to prevent eye contact.
NIOSH. NIOSH Pocket Guide to Chemical Hazards & Other Databases CD-ROM. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2005-151 (2005)
Facilities for quickly drenching the body should be provided within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.]
NIOSH. NIOSH Pocket Guide to Chemical Hazards & Other Databases CD-ROM. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2005-151 (2005)
For more Personal Protective Equipment (PPE) (Complete) data for MESITYL OXIDE (10 total), please visit the HSDB record page.

(See personal protection and sanitation codes)

Skin: Prevent skin contact - Wear appropriate personal protective clothing to prevent skin contact.

Eyes: Prevent eye contact - Wear appropriate eye protection to prevent eye contact.

Wash skin: When contaminated

Remove: When wet (flammable)

Change: No recommendation

Provide: Quick drench - Facilities for quickly drenching the body should be provided within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.]

11.7.13 Respirator Recommendations

NIOSH

Up to 250 ppm:

(APF = 25) Any supplied-air respirator operated in a continuous-flow mode

(APF = 25) Any powered, air-purifying respirator with organic vapor cartridge(s)

Up to 500 ppm:

(APF = 50) Any chemical cartridge respirator with a full facepiece and organic vapor cartridge(s)

(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister

(APF = 50) Any powered, air-purifying respirator with a tight-fitting facepiece and organic vapor cartridge(s)

(APF = 50) Any self-contained breathing apparatus with a full facepiece

(APF = 50) Any supplied-air respirator with a full facepiece

Up to 1400 ppm:

(APF = 2000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode

Emergency or planned entry into unknown concentrations or IDLH conditions:

(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:

(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister

Any appropriate escape-type, self-contained breathing apparatus

Important additional information about respirator selection

11.7.14 Preventions

Fire Prevention
NO open flames, NO sparks and NO smoking. Above 25 °C use a closed system, ventilation and explosion-proof electrical equipment.
Exposure Prevention
STRICT HYGIENE!
Inhalation Prevention
Use ventilation, local exhaust or breathing protection.
Skin Prevention
Protective gloves. Protective clothing.
Eye Prevention
Wear face shield or eye protection in combination with breathing protection.
Ingestion Prevention
Do not eat, drink, or smoke during work.

11.8 Stability and Reactivity

11.8.1 Air and Water Reactions

Highly flammable. Slightly soluble in water

11.8.2 Reactive Group

Ketones

Hydrocarbons, Aliphatic Unsaturated

11.8.3 Reactivity Alerts

Highly Flammable

11.8.4 Reactivity Profile

Mixing MESITYL OXIDE in equal molar proportions with any of the following substances in a closed container caused the temperature and pressure to increase: 2-aminoethanol, chlorosulfonic acid, ethylene diamine, nitric acid, oleum, or sulfuric acid [NFPA 1991].

11.8.5 Hazardous Reactivities and Incompatibilities

Mixing mesityl oxide and 2-aminoethanol /or chlorosulfonic acid or ethylene diamine or nitric acid or oleum or sulfuric acid/ in closed container caused temp and pressure to incr.
Fire Protection Guide to Hazardous Materials. 13 ed. Quincy, MA: National Fire Protection Association, 2002., p. 491-119
Oxidizers, acids.
NIOSH. NIOSH Pocket Guide to Chemical Hazards & Other Databases CD-ROM. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2005-151 (2005)
... Attacks many plastics.
IPCS, CEC; International Chemical Safety Card on Mesityl oxide. (March 1998). Available from, as of November 01, 2006: https://www.inchem.org/documents/icsc/icsc/eics0814.htm

11.9 Transport Information

11.9.1 DOT Emergency Guidelines

/GUIDE 129: FLAMMABLE LIQUIDS (Polar/Water-Miscible/Noxious)/ Fire or Explosion: HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion hazard indoors, outdoors or in sewers. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water.
U.S. Department of Transportation. 2012 Emergency Response Guidebook. Washington, D.C. 2012
/GUIDE 129: FLAMMABLE LIQUIDS (Polar/Water-Miscible/Noxious)/ Health: May cause toxic effects if inhaled or absorbed through skin. Inhalation or contact with material may irritate or burn skin and eyes. Fire will produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or suffocation. Runoff from fire control or dilution water may cause pollution.
U.S. Department of Transportation. 2012 Emergency Response Guidebook. Washington, D.C. 2012
/GUIDE 129: FLAMMABLE LIQUIDS (Polar/Water-Miscible/Noxious)/ 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 50 meters (150 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. Ventilate closed spaces before entering.
U.S. Department of Transportation. 2012 Emergency Response Guidebook. Washington, D.C. 2012
/GUIDE 129: FLAMMABLE LIQUIDS (Polar/Water-Miscible/Noxious)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection.
U.S. Department of Transportation. 2012 Emergency Response Guidebook. Washington, D.C. 2012
For more DOT Emergency Guidelines (Complete) data for MESITYL OXIDE (8 total), please visit the HSDB record page.

11.9.2 DOT ID and Guide

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

UN 1229; Mesityl oxide
IMO 3.3; Mesityl oxide

11.9.4 Standard Transportation Number

49 092 23; Mesityl oxide

11.9.5 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; U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of February 15, 2006: 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.
International Air Transport Association. Dangerous Goods Regulations. 47th Edition. Montreal, Quebec Canada. 2006., p. 216
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.
International Maritime Organization. International Maritime Dangerous Goods Code. London, UK. 2004., p. 52

11.9.6 DOT Label

Flammable Liquid

11.9.7 EC Classification

Symbol: Xn; R: 10-20/21/22; S: (2)-25

11.9.8 UN Classification

UN Hazard Class: 3; UN Pack Group: III

11.10 Regulatory Information

The Australian Inventory of Industrial Chemicals
Chemical: 3-Penten-2-one, 4-methyl-
REACH Registered Substance
New Zealand EPA Inventory of Chemical Status
3-Penten-2-one, 4-methyl-: HSNO Approval: HSR001185 Approved with controls

11.10.1 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. Mesityl oxide is produced, as an intermediate or a final product, by process units covered under this subpart.
40 CFR 60.489; U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of August 30, 2006: https://www.ecfr.gov

11.10.2 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. Mesityl oxide is included on this list.
40 CFR 716.120; U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of August 30, 2006: https://www.ecfr.gov
EPA is withdrawing the final test rule for mesityl oxide (MO; CAS No. 141-79-7). EPA has determined that, since testing of MO has been completed according to the terms of an enforceable consent agreement, testing required under the test rule would be duplicative and therefore, the test rule is no longer needed.
61 FR 33375 6/27/1996
A testing consent order is in effect for mesityl oxide for health effects testing, FR publication date: September 1991.
40 CFR 799.5000; U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of August 30, 2006: https://www.ecfr.gov

11.10.3 FIFRA Requirements

Mesityl oxide is exempted from the requirement of a tolerance when used as a plant nutrient, cosolvent or solvent in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to growing crops only. Limit: Not for use after edible parts of plant begin to form. Do not graze livestock in treated areas within 48 hr after application.
40 CFR 180.920; U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of August 30, 2006: https://www.ecfr.gov

11.11 Other Safety Information

11.11.1 Toxic Combustion Products

Combustion may produce irritants and toxic gases.
Fire Protection Guide to Hazardous Materials. 13 ed. Quincy, MA: National Fire Protection Association, 2002., p. 49-94

12 Toxicity

12.1 Toxicological Information

12.1.1 NIOSH Toxicity Data

12.1.2 Carcinogen Classification

Carcinogen Classification
No indication of carcinogenicity to humans (not listed by IARC).

12.1.3 Exposure Routes

The substance can be absorbed into the body by inhalation of its vapour and by ingestion.
inhalation, ingestion, skin and/or eye contact

12.1.4 Symptoms

Inhalation Exposure
Cough. Sore throat. Shortness of breath. Headache. Dizziness. Drowsiness. Unconsciousness. Respiratory and cardiac arrest.
Skin Exposure
Dry skin. Redness. Pain.
Eye Exposure
Redness. Pain.
Ingestion Exposure
Abdominal cramps. Further see Inhalation.
irritation eyes, skin, mucous membrane; narcosis, coma; In Animals: liver, kidney damage; central nervous system effects

12.1.5 Target Organs

Eyes, skin, respiratory system, central nervous system, liver, kidneys

12.1.6 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.

Dermatotoxin - Skin burns.

Lacrimator (Lachrymator) - A substance that irritates the eyes and induces the flow of tears.

12.1.7 Acute Effects

12.1.8 Toxicity Data

LC50 (rat) = 9,000 mg/m3/4H

12.1.9 Interactions

Use of alcoholic beverages enhances the harmful effect.
IPCS, CEC; International Chemical Safety Card on Mesityl oxide. (March 1998). Available from, as of November 01, 2006: https://www.inchem.org/documents/icsc/icsc/eics0814.htm

12.1.10 Antidote and Emergency Treatment

Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal 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 ... 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. /Turpentine, terpenes, and related compounds/
Currance, P.L. Clements, B., Bronstein, A.C. (Eds).; Emergency Care For Hazardous Materials Exposure. 3Rd edition, Elsevier Mosby, St. Louis, MO 2005, p. 244
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 /SRP: "To keep open", minimal flow rate/. 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. Watch for signs of fluid overload ...Treat seizures with diazepam or lorazepam ... Use proparacaine hydrochloride to assist eye irrigation ... /Turpentine, Terpenes, and related compounds/
Currance, P.L. Clements, B., Bronstein, A.C. (Eds).; Emergency Care For Hazardous Materials Exposure. 3Rd edition, Elsevier Mosby, St. Louis, MO 2005, p. 245
Irrigate eyes with water. Wash contaminated areas of body with soap and water. Give oxygen if indicated.
ITII. Toxic and Hazardous Industrial Chemicals Safety Manual. Tokyo, Japan: The International Technical Information Institute, 1988., p. 317
/If ingested/ ... Rinse mouth. Give a slurry of activated charcoal in water to drink. Refer for medical attention.
IPCS, CEC; International Chemical Safety Card on Mesityl oxide. (March 1998). Available from, as of November 01, 2006: https://www.inchem.org/documents/icsc/icsc/eics0814.htm

12.1.11 Human Toxicity Excerpts

/HUMAN EXPOSURE STUDIES/ A majority of individuals experienced eye irritation after 3 to 5 minutes of exposure at 25 ppm mesityl oxide with the addition of nasal irritation at 50 ppm. On the basis of an unpleasant taste that persisted in some cases for 3 to 6 hours after exposure and the nasal irritation experienced at 50 ppm, these workers suggested 25 ppm as the highest concentration, which would be satisfactory for an 8-hour day. The probable human response to 100 ppm of mesityl oxide was predicted to be eye and mucous membrane irritation accompanied by difficulty in breathing, headache, and vertigo.
American Conference of Governmental Industrial Hygienists. Documentation of the TLV's and BEI's with Other World Wide Occupational Exposure Values. CD-ROM Cincinnati, OH 45240-1634 2005., p. 2
/HUMAN EXPOSURE STUDIES/ Exposure to 50 to 100 ppm caused eye irritation and half of the test subjects experienced nasal irritation and pulmonary discomfort at 25 ppm.
Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. 6:238
/SIGNS AND SYMPTOMS/ Mesityl oxide (MO) can produce marked irritation and transient corneal injury to the eye. Occasional skin contact may produce some irritation; prolonged contact may produce dermatitis and, if the dose is high enough, systemic injury. MO ... can produce ... /CNS depression/ via inhalation exposure. Sublethal concentrations of the vapors may result in vascular congestion, which has been reported to occur primarily in the kidneys. The liver and lung are affected to a lesser degree. Death is generally attributed to its ... /CNS depressant/ action ... The penetrating odor and eye and nose irritation that occurs following exposure at low levels should prevent overexposure.
Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. 6:234
/SIGNS AND SYMPTOMS/ Mesityl oxide is a strong irritant both on contact with the liquid and in the vapor phase and can cause necrosis of the cornea. Short exposure /may cause CNS depression/ ...
International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983., p. 1172
For more Human Toxicity Excerpts (Complete) data for MESITYL OXIDE (11 total), please visit the HSDB record page.

12.1.12 Non-Human Toxicity Excerpts

/LABORATORY ANIMALS: Acute Exposure/ When doses of 0.5 mL were dropped on the skin of mice, marked irritation occurred within a few minutes and the animals became ataxic and narcotized within 15 min. This dose killed all ten animals in 3 to 9 hr. Applications of 0.1 mL to the backs of mice produced local irritation and excitement within 5 min; one of 10 animals died in 12 hr, but the others recovered.
Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. 6:236
/LABORATORY ANIMALS: Acute Exposure/ ... /It was foundthat / 12,000 ppm mesityl oxide (MO) killed rats and guinea pigs after 1 hr of exposure. Eight-hour exposures of rats to 2500, 1000, and 500 ppm killed 100, 68, and 30% of the test animals, respectively.
Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. 6:236
/LABORATORY ANIMALS: Acute Exposure/ ... Mice /were exposed/ to concentrations of 6,000 to 24,000 ppm mesityl oxide in air. Clinical signs of toxicity were ocular and nasal irritation, labored breathing, convulsions, /CNS depression/, vasodilation, cyanosis, and death. The time to death was concentration dependent, and ranged from 23 to 135 min.
Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. 6:236
/LABORATORY ANIMALS: Acute Exposure/ ... Groups of six male or female rats /were exposed/ to acute 4-hr exposures of increasing concentrations of mesityl oxide until two to four of the animals died within a 14-days observation period. They found that a concentration of 1,000 ppm was necessary to produce this mortality.
Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. 6:236
For more Non-Human Toxicity Excerpts (Complete) data for MESITYL OXIDE (29 total), please visit the HSDB record page.

12.1.13 Non-Human Toxicity Values

LD50 Rat oral 655 mg/kg
Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. 6:235
LC50 Rat inhalation 1130 ppm/4 hr
Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. 6:236
LC50 Rat inhalation 9 g/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. 2323
LD50 Mouse ip 354 mg/kg
ITII. Toxic and Hazardous Industrial Chemicals Safety Manual. Tokyo, Japan: The International Technical Information Institute, 1988., p. 316
For more Non-Human Toxicity Values (Complete) data for MESITYL OXIDE (12 total), please visit the HSDB record page.

12.1.14 TSCA Test Submissions

Mesityl Oxide (CAS RN 141-79-7) was evaluated for repeated dose and reproductive effects in Sprague-Dawley rats in a study consisting of 4 phases: pre-mating (14 days), mating (1-14 days), gestation (21-22 days), and early lactation(4 days). Groups of 12 male and 12 female rats were exposed to target vapor concentrations of 0, 30, 100, or 300 ppm (mean chamber vapor concentrations: 0, 31, 103, or 302 ppm, respectively) for 6 hours/day, 7 days/ week. Females received a total of 36 to 49 exposures (through Day 20 of gestation) and males received 49 exposures. No mortality was observed in the adults. Clinical signs of toxicity were observed during exposure, including partially closed eyes (high-exposure) and temporary reduction in activity (high- and mid-exposure). All exposed animals exhibited an increased incidence of porphyrin nasal discharge post-exposure, and 3 high-exposure males exhibited sialorrhea. A treatment-related decrease in feed consumption, with a corresponding decrease in body weight and body weight gain were observed during pre-mating in all exposed males and females. Females exposed to 103 and 302 ppm (mid- and high-exposure) continued to exhibit these trends in feed consumption and body weight gain during the first week of gestation. Mating was confirmed in 12/12 control females and 12/12 high-exposure females, while 11/12 confirmed matings were noted in the low- and mid-exposure females. High-exposure females exhibited a significant reduction in the number of litters produced (7/12; p<=0.05). A second mating between high-exposure males (receiving 42 exposures) and unexposed females resulted in 10/12 dams producing litters, which was comparable to controls. No treatment-related changes were noted upon necropsy in any exposed animals. Histological examination of the reproductive organs revealed no treatment-related lesions in any exposed animals, however examination of the nasal passages revealed chronic focal inflamation and focal metaplasia of the respiratory and olfactory epithelium, and sero-cellular exudates. Differences in the length of gestation, number of pups per litter, ratio of males to females and mean pup weights were considered biologically insignificant. The lowest-observed-adverse-effect-level (NOAEL) based on feed consumption, body weights, body weight gain, and nasal passage histology was determined to be 31 ppm. The NOEL for reproductive toxicity under the test conditions was 103 ppm.
Eastman Kodak Co.; Mesityl Oxide (MO), Synonym: 4-Methyl-3-penten-2-one, Combined Repeated Dose and Reproductive/Developmental Toxicity Screening Test in the Rat (1992); EPA Doc. 8EHQ-1092-1712; Fiche OTS0534809
This submission contains a preliminary report from a study evaluating mesityl oxide (CAS RN 141-79-7) for repeated dose and reproductive effects in Sprague-Dawley rats. Groups of 12 male and 12 female rats were exposed to target vapor concentrations of 0, 30, 100, or 300 ppm (mean chamber vapor concentrations: 0, 31, 103, or 302 ppm, respectively) for 6 hours/day, 7 days/ week. Females received a total of 36 to 49 exposures (through Day 20 of gestation) and males received 49 exposures. No mortality was observed in the adults. Clinical signs of toxicity were not discussed. Mating, confirmed by the presence of a vaginal plug and/or the presence of sperm, was deemed successful in 12/12 control females and 12/12 high-exposure (300 ppm) females, while 11/12 confirmed matings were noted in the low- and mid-exposure females (30, and 100 ppm, respectively). The pregnancy index (number of litters delivered/number mated) for females exposed to 300 ppm was 7/12, or 58%. A second mating of high-exposure males (after 42 exposures) to unexposed females was conducted to further evaluate reproductive effects. As of this notification, the females of that second mating were in the third week of gestation. The males were euthanized on the day following the last exposure. Necropsy revealed no gross changes in the testes or epididymides or in testicular or epididymal weights. Histopathological evaluation was ongoing at the time this notice was filed.
Eastman Kodak Co.; Mesityl Oxide (MO), Synonym: 4-Methyl-3-penten-2-one, Combined Repeated Dose and Reproductive/Developmental Toxicity Screening Test in the Rat (1992); EPA Doc. 8EHQ-1291-1712; Fiche OTS0534809
Mesityl oxide (CAS RN 141-79-7) was evaluated for genetic toxicity in a mouse micronucleus assay, however, this submission contains only information concerning dose selection for the primary micronucleus assay. In the first of 3 studies, groups of male and female mice (3/sex/group; species and strain not reported) were administered 125, 250, or 500 mg/kg of the test substance in corn oil by intraperitoneal injection and were observed for a recovery period of up to 3 days. Mice in the 500 mg/kg group exhibited ataxia at 15 minutes post-dosing (females) and 30 minutes post-dosing (males). Lethargy was noted in all test groups (male and female). Recovery was complete at 7 hours post-dosing, and all animals survived a 3-day recovery period. Two additional studies were conducted in which groups (3/sex/group) were injected with 750 mg/kg (second study) and 875 or 1000 mg/kg (third study)and observed for up to 3 days. In study 2, 1 mortality occurred (female), while all animals exhibited ataxia and lethargy. At 7 hours, all survivors appeared normal, and all survived the 3-day observation period. At 1000 mg/kg, mortality was 100% within 40 minutes, and at 875 mg/kg, 2 males and females each were found dead within 48 hours. The remaining animals survived through the 3-day observation period. The LD50 under the conditions of this study was determined to be 850 mg/kg.
Union Carbide Corp.; Mouse Micronucleus Assay of Mesityl Oxide (study date not reported); EPA Doc. No. 8EHQ-0492-3243; Fiche No. OTS0539339
Mesityl oxide (CAS 141-79-7) was evaluated for the ability to induce micronuclei in mouse bone marrow polychromatic erythrocytes (PCE). The test material was administered to groups of Swiss CD-1 mice by intraperitoneal injection at 0, 170, 340, or 680 mg/kg, and groups (10/sex/group) at each dose level were sacrificed at 24, 48, and 72 hours after treatment. Negative control groups at each harvest time received corn oil only, while a positive control group received 40 mg cyclophosphamide/kg and were sacrificed at the 24 hour point only. Mortalities occurred in females receiving 680 mg/kg at the 24-hour harvest (1), the 48-hour harvest (2), and the 72-hour harvest (1) times. A statistically significant decrease in bone marrow was noted for male mice receiving 680 mg/kg of the test article. The test material did not induce a significant increase of micronucleated polychromatic erythrocytes (MNPCE) at any dose level compared to concurrent negative controls. It was concluded that the test material was negative for inducing the production of MNPCEs at dose levels causing mortalities among female mice and statistically significant bone marrow depression in male mice.
Chemical Mfgs Assoc.; In Vivo Mammalian Bone Marrow Mouse Micronucleus Assay: Mesityl Oxide Final Report (1992); EPA Doc. No. 42030 L2-2 44588; Fiche No. OTS0572975

12.2 Ecological Information

12.2.1 Ecotoxicity Values

LD50 Carassius auratus (goldfish) 540 mg/L/24 hr /Conditions of bioassay not specified in source examined/
Verschueren, K. Handbook of Environmental Data on Organic Chemicals. Volumes 1-2. 4th ed. John Wiley & Sons. New York, NY. 2001, p. 1417

12.2.2 ICSC Environmental Data

The substance is harmful to aquatic organisms.

12.2.3 Environmental Fate / Exposure Summary

Mesityl oxide's production and use in manufacturing methyl isobutyl ketone, and its use as an intermediate, solvent for nitrocellulose and vinyl chloride-vinyl acetate resins, additive, or mineral extractant may result in its release to the environment through various waste streams. Mesityl oxide's use as an insect repellent will result in its direct release to the environment. If released to air, a vapor pressure of 8.21 mm Hg at 25 °C indicates mesityl oxide will exist solely as a vapor in the atmosphere. Vapor-phase mesityl oxide will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals and ozone; the half-life for these reactions in air are estimated to be 4.9 hours and 1.4 hours, respectively. Mesityl oxide will also react with atmospheric nitrate with a half-life of 3.9 hours. Vapor-phase mesityl oxide undergoes direct photolysis with an experimental half-life and rate constant of 76.8 hrs and 8.75X10-3/hr, respectively. If released to soil, mesityl oxide is expected to have very high mobility based upon an estimated Koc of 15. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 3.67X10-5 atm-cu m/mole. Mesityl oxide may volatilize from dry soil surfaces based upon its vapor pressure. Theoretical %BOD values of 74 and 30 from studies done with sewage inoculum suggest that biodegradation may be an important environmental fate process. If released into water, mesityl oxide is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is expected to be an important fate process based upon this compound's estimated Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 17 hours and 11 days, respectively. An estimated BCF of 1.9 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions. Occupational exposure to mesityl oxide may occur through inhalation and dermal contact with this compound at workplaces where mesityl oxide is produced or used. Monitoring data indicate that the general population may be exposed to mesityl oxide via inhalation of ambient air, ingestion of food and drinking water, and dermal contact with insect repellents and other products containing mesityl oxide. (SRC)

12.2.4 Natural Pollution Sources

Mesityl oxide was qualitatively identified in nectarines obtained from a local orchard in Winters, CA(1).
(1) Takeoka GR et al; J Agric Food Chem 36: 553-60 (1988)

12.2.5 Artificial Pollution Sources

Mesityl oxide's production and use in manufacturing methyl isobutyl ketone(1), and its use as an intermediate(2), solvent for nitrocellulose(2) and vinyl chloride-vinyl acetate resins(2-3), additive(3), or mineral extractant(3) may result in its release to the environment through various waste streams(SRC). Mesityl oxide's use as an insect repellent(4) will result in its direct release to the environment(SRC).
(1) O'Neil MJ, ed; The Merck Index. 13th ed, Whitehouse Station, NJ: Merck and Co., Inc., p. 1056 (2001)
(2) Lande SS et al; Investigation of Selected Potential Environmental Contaminants: Ketonic Solvents USEPA-560/2-76-003 (1976)
(3) Papa AJ, Sherman PDJR; Kirk-Othmer Encycl Chem Tech 3rd ed. NY: Wiley 13: p. 918 (1981)
(4) Lewis RJ SR; Hawley's Condensed Chemical Dictionary 14th ed p.713 (2001)

12.2.6 Environmental Fate

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 15(SRC), determined from a water solubility of 28,900 mg/L(2) and a regression-derived equation(3), indicates that mesityl oxide is expected to have very high mobility in soil(SRC). Volatilization of mesityl oxide from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 3.67X10-5 atm-cu m/mole(SRC), derived from its vapor pressure, 8.21 mm Hg(4), and water solubility(2). Mesityl oxide is expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(4). Theoretical %BOD values of 74(5) and 30(6) from studies done with sewage inoculum suggest that biodegradation may be an important environmental fate process in soil(SRC).
(1) Swann RL et al; Res Rev 85: 17-28 (1983)
(2) Yalkowsky SH, He Y; Handbook of Aqueous Solubility Data. CRC Press LLC, Boca Raton, FL. p. 285 (2003)
(3) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 4-5 (1990)
(4) Daubert TE, Danner DP; Physical & Thermodynamic Properties of Pure Chemicals Vol. 3 NY: Hemisphere Pub Corp (1989)
(5) Bridie AL et al; Water Res 13: 627-30 (1979)
(6) Sasaki S; pp. 283-98 in Aquatic Pollutants. Hutzinger O et al, eds. Oxford: Pergamon Press (1978)
AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 15(SRC), determined from a water solubility of 28,900 mg/L(2) and a regression-derived equation(3), indicates that mesityl oxide is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 3.67X10-5 atm-cu m/mole(SRC), derived from its vapor pressure, 8.21 mm Hg(4), and its water solubility(2). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 17 hours and 11 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 1.9(SRC), using a water solubility of 28,900 mg/L(2) and a regression-derived equation(6), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Theoretical %BOD values of 74(7) and 30(8) from studies done with sewage inoculum suggest that biodegradation may be an important environmental fate process in water(SRC).
(1) Swann RL et al; Res Rev 85: 17-28 (1983)
(2) Yalkowsky SH, He Y; Handbook of Aqueous Solubility Data. CRC Press LLC, Boca Raton, FL. p. 285 (2003)
(3) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 4-5, 15-1 to 15-29 (1990)
(4) Daubert TE, Danner DP; Physical & Thermodynamic Properties of Pure Chemicals Vol. 3 NY: Hemisphere Pub Corp (1989)
(5) Franke C et al; Chemosphere 29: 1501-14 (1994)
(6) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 5-5 (1990)
(7) Bridie AL et al; Water Res 13: 627-30 (1979)
(8) Sasaki S; pp. 283-98 in Aquatic Pollutants: Transformation and Biological Effects. Hutzinger O et al (eds) Oxford:Pergamon Press (1978)
ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), mesityl oxide, which has a vapor pressure of 8.21 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase mesityl oxide 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 4.9 hours(SRC), calculated from its rate constant of 7.86X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). The rate constant for the vapor-phase reaction of mesityl oxide with ozone has been estimated as 2X10-16 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). This corresponds to an atmospheric half-life of about 1.4 hours at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(4). The rate constant for the vapor-phase reaction of mesityl oxide with nitrate has been estimated as 2.04X10-13 cu cm/molecule-sec at 25 °C(5). This corresponds to an atmospheric half-life of about 3.9 hours at an atmospheric concentration of 2.4X10+8 nitrate molecules per cu cm(6). Vapor-phase mesityl oxide undergoes direct photolysis with an experimental half-life and rate constant of 76.8 hrs and 8.75X10-3/hr, respectively(7).
(1) Bidleman TF; Environ Sci Technol 22: 361-367 (1988)
(2) Lyman WJ; p. 31 in Environmental Exposure From Chemicals Vol I, Neely WB, Blau GE, eds, Boca Raton, FL: CRC Press (1985)
(3) Meylan WM, Howard PH; Chemosphere 26: 2293-99 (1993)
(4) Atkinson R, Carter WPL; Chem Rev 84: 437-70 (1984)
(5) Grosjean D, Williams EL II; Atmos Environ 26A;1395-405 (1992)
(6) Mill T et al; Environmental Fate and Exposure Studies Development of a PC-SAR for Hydrolysis: Esters, Alkyl Halides and Epoxides. EPA Contract No. 68-02-4254. Menlo Park, CA: SRI International (1987)
(7) Mill T, Davenport J; ACS Div Environ Chem 192nd Natl Mtg 26: 59-63 (1986)

12.2.7 Environmental Biodegradation

AEROBIC: Using a standard BOD technique with sewage inoculum, a theoretical BOD of 74% was determined for mesityl oxide over a 5-day incubation period (1). Using a standard BOD technique with activated sewage sludge inoculum, a theoretical BOD of at least 30% was measured for mesityl oxide over a 14-day incubation period(2).
(1) Bridie AL et al; Water Res 13: 627-30 (1979)
(2) Sasaki S; pp. 283-98 in Aquatic Pollutants. Hutzinger O et al, eds. Oxford: Pergamon Press (1978)

12.2.8 Environmental Abiotic Degradation

The rate constant for the vapor-phase reaction of mesityl oxide with photochemically-produced hydroxyl radicals has been estimated as 7.86X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 4.9 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The rate constant for the vapor-phase reaction of mesityl oxide with ozone has been estimated as 2X10-16 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(1). This corresponds to an atmospheric half-life of about 1.4 hours at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(2). The rate constant for the vapor-phase reaction of mesityl oxide with nitrate has been estimated as 2.04X10-13 cu cm/molecule-sec at 25 °C(3). This corresponds to an atmospheric half-life of about 3.9 hours at an atmospheric concentration of 2.4X10+8 nitrate molecules per cu cm(4). Mesityl oxide is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(5). Vapor-phase mesityl oxide undergoes direct photolysis with an experimental half-life and rate constant of 76.8 hrs and 8.75X10-3/hr, respectively(6).
(1) Meylan WM, Howard PH; Chemosphere 26: 2293-99 (1993)
(2) Atkinson R, Carter WPL; Chem Rev 84: 437-70 (1984)
(3) Grosjean D, Williams EL II; Atmos Environ 26A;1395-405 (1992)
(4) Mill T et al; Environmental Fate and Exposure Studies Development of a PC-SAR for Hydrolysis: Esters, Alkyl Halides and Epoxides. EPA Contract No. 68-02-4254. Menlo Park, CA: SRI International (1987)
(5) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 7-4, 7-5, 8-12 (1990)
(6) Mill T, Davenport J; ACS Div Environ Chem 192nd Natl Mtg 26: 59-63 (1986)

12.2.9 Environmental Bioconcentration

An estimated BCF of 1.9 was calculated in fish for mesityl oxide(SRC), using a water solubility of 28,900 mg/L(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) Yalkowsky SH, He Y; Handbook of Aqueous Solubility Data. CRC Press LLC, Boca Raton, FL. p. 285 (2003)
(2) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 5-5 (1990)
(3) Franke C et al; Chemosphere 29: 1501-14 (1994)

12.2.10 Soil Adsorption / Mobility

The Koc of mesityl oxide is estimated as 15(SRC), using a water solubility of 28,900 mg/L(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that mesityl oxide is expected to have very high mobility in soil.
(1) Yalkowsky SH, He Y; Handbook of Aqueous Solubility Data. CRC Press LLC, Boca Raton, FL. p. 285 (2003)
(2) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 4-5 (1990)
(3) Swann RL et al; Res Rev 85: 17-28 (1983)

12.2.11 Volatilization from Water / Soil

The Henry's Law constant for mesityl oxide is estimated as 3.67X10-5 atm-cu m/mole(SRC) derived from its vapor pressure, 8.21 mm Hg(1), and water solubility, 28,900 mg/L(2). This Henry's Law constant indicates that mesityl oxide is expected to volatilize from water surfaces(3). 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)(3) is estimated as 17 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)(3) is estimated as 11 days(SRC). Mesityl oxide's estimated Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). The potential for volatilization of mesityl oxide from dry soil surfaces may exist(SRC) based upon its vapor pressure(1).
(1) Daubert TE, Danner DP; Physical & Thermodynamic Properties of Pure Chemicals Vol. 3 NY: Hemisphere Pub Corp (1989)
(2) Yalkowsky SH, He Y; Handbook of Aqueous Solubility Data. CRC Press LLC, Boca Raton, FL. p. 285 (2003)
(3) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 15-1 to 15-29 (1990)

12.2.12 Environmental Water Concentrations

DRINKING WATER: Mesityl oxide was qualitatively detected in samples of drinking water taken from Cincinnati, OH waterworks on 10/17/78 and 1/14/80(1-3).
(1) Lucas SV; GC/MS Analysis of Organics in Drinking Water Concentrates and Advanced Waste Treatment Concentrates. Vol 1 USEPA-600/1-84-020a (1984)
(2) Lucas SV; GC/MS Analysis of Organics in Drinking Water Concentrates and Advanced Waste Treatment Concentrates. Vol 2 USEPA-600/1-84-020b (1984)
(3) Lucas SV; GC/MS Analysis of Organics in Drinking Water Concentrates and Advanced Waste Treatment Concentrates. Vol 3 USEPA-600/1-84-020c (1984)
SURFACE WATER: Mesityl oxide was qualitatively detected in the Glatt River in Switzerland(1).
(1) Zuercher F, Giger W; Vom Wasser 47: 37-55 (1976)

12.2.13 Effluent Concentrations

Exhaust from an automobile using various hydrocarbon fuels under simulated city conditions yielded concentrations of <0.1-1.5 ppm of mesityl oxide(1). Qualitatively detected in Lockport, IL oil refinery final effluent(2) and in advanced waste water treatment concentrates from Orange County and Lake Tahoe, CA(3-5). In a comprehensive survey of 46 industrial and publicly owned treatment works, mesityl oxide was qualitatively identified in effluents from various organic chemical manufacturing sites(6).
(1) Seizinger DE, Dimitriades B; J Air Pollut Control Assoc 22: 47-51 (1972)
(2) Ellis DD et al; Arch Environ Contam Toxicol 11: 373-82 (1982)
(3) Lucas SV; GC/MS Analysis of Organics in Drinking Water Concentrates and Advanced Waste Treatment Concentrates. Vol 1 USEPA-600/1-84-020a (1984)
(4) Lucas SV; GC/MS Analysis of Organics in Drinking Water Concentrates and Advanced Waste Treatment Concentrates. Vol 2 USEPA-600/1-84-020b (1984)
(5) Lucas SV; GC/MS Analysis of Organics in Drinking Water Concentrates and Advanced Waste Treatment Concentrates. Vol 3 USEPA-600/1-84-020c (1984)
(6) Bursey JT, Pellizzari ED; Analysis of Industrial Waste Water for Organic Pollutants in Consent Decree Survey USEPA-68-03-2867 (1982)

12.2.14 Food Survey Values

Mesityl oxide was qualitatively identified in Idaho Russet Burbank baked potatoes(1).
(1) Coleman EC et al; J Agric Food Chem 29: 42-8 (1981)

12.2.15 Plant Concentrations

Mesityl oxide was qualitatively identified in nectarines obtained from a local orchard in Winters, CA(1).
(1) Takeoka GR et al; J Agric Food Chem 36: 553-60 (1988)

12.2.16 Probable Routes of Human Exposure

NIOSH (NOES Survey 1981-1983) has statistically estimated that 362 workers (34 of these are female) are potentially exposed to mesityl oxide in the US(1). Occupational exposure to mesityl oxide may occur through inhalation and dermal contact with this compound at workplaces where mesityl oxide is produced or used(SRC). Monitoring data indicate that the general population may be exposed to mesityl oxide via inhalation of ambient air, ingestion of food and drinking water, and dermal contact with insect repellents and other products containing mesityl oxide(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 at https://www.cdc.gov/noes/ as of Oct 18, 2006.

13 Associated Disorders and Diseases

Associated Occupational Diseases with Exposure to the Compound

Encephalopathy, chronic solvent [Category: Chronic Poisoning]

Solvents, acute toxic effect [Category: Acute Poisoning]

14 Literature

14.1 Consolidated References

14.2 NLM Curated PubMed Citations

14.3 Springer Nature References

14.4 Thieme References

14.5 Wiley References

14.6 Chemical Co-Occurrences in Literature

14.7 Chemical-Gene Co-Occurrences in Literature

14.8 Chemical-Disease Co-Occurrences in Literature

15 Patents

15.1 Depositor-Supplied Patent Identifiers

15.2 WIPO PATENTSCOPE

15.3 Chemical Co-Occurrences in Patents

15.4 Chemical-Disease Co-Occurrences in Patents

15.5 Chemical-Gene Co-Occurrences in Patents

16 Interactions and Pathways

16.1 Chemical-Target Interactions

17 Biological Test Results

17.1 BioAssay Results

18 Taxonomy

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

19 Classification

19.1 MeSH Tree

19.2 ChEBI Ontology

19.3 LIPID MAPS Classification

19.4 ChemIDplus

19.5 CAMEO Chemicals

19.6 UN GHS Classification

19.7 EPA CPDat Classification

19.8 NORMAN Suspect List Exchange Classification

19.9 EPA DSSTox Classification

19.10 EPA TSCA and CDR Classification

19.11 LOTUS Tree

19.12 EPA Substance Registry Services Tree

19.13 MolGenie Organic Chemistry Ontology

20 Information Sources

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  24. Toxin and Toxin Target Database (T3DB)
    LICENSE
    T3DB is offered to the public as a freely available resource. Use and re-distribution of the data, in whole or in part, for commercial purposes requires explicit permission of the authors and explicit acknowledgment of the source material (T3DB) and the original publication.
    http://www.t3db.ca/downloads
    4-Methyl-3-penten-2-one, 9CI
    http://www.t3db.ca/toxins/T3D4894
  25. ChEMBL
    LICENSE
    Access to the web interface of ChEMBL is made under the EBI's Terms of Use (http://www.ebi.ac.uk/Information/termsofuse.html). The ChEMBL data is made available on a Creative Commons Attribution-Share Alike 3.0 Unported License (http://creativecommons.org/licenses/by-sa/3.0/).
    http://www.ebi.ac.uk/Information/termsofuse.html
  26. Comparative Toxicogenomics Database (CTD)
    LICENSE
    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
  27. EPA Chemical and Products Database (CPDat)
  28. EU Food Improvement Agents
  29. Hazardous Chemical Information System (HCIS), Safe Work Australia
  30. NITE-CMC
    3-Penten-2-one, 4-methyl- (Mesityl oxide) - FY2006 (New/original classication)
    https://www.chem-info.nite.go.jp/chem/english/ghs/06-imcg-0734e.html
    Mesityloxid (Mesityl oxide) - FY2014 (Revised classification)
    https://www.chem-info.nite.go.jp/chem/english/ghs/14-mhlw-2112e.html
  31. Regulation (EC) No 1272/2008 of the European Parliament and of the Council
    LICENSE
    The copyright for the editorial content of this source, the summaries of EU legislation and the consolidated texts, which is owned by the EU, is licensed under the Creative Commons Attribution 4.0 International licence.
    https://eur-lex.europa.eu/content/legal-notice/legal-notice.html
    4-methylpent-3-en-2-one; mesityl oxide
    https://eur-lex.europa.eu/eli/reg/2008/1272/oj
  32. FDA Substances Added to Food
    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
  33. Flavor and Extract Manufacturers Association (FEMA)
  34. FooDB
    LICENSE
    FooDB is offered to the public as a freely available resource. Use and re-distribution of the data, in whole or in part, for commercial purposes requires explicit permission of the authors and explicit acknowledgment of the source material (FooDB) and the original publication.
    https://foodb.ca/about
    4-Methyl-3-penten-2-one, 9CI
    https://foodb.ca/compounds/FDB008178
  35. MassBank Europe
  36. MassBank of North America (MoNA)
    LICENSE
    The content of the MoNA database is licensed under CC BY 4.0.
    https://mona.fiehnlab.ucdavis.edu/documentation/license
  37. NIST Mass Spectrometry Data Center
    LICENSE
    Data covered by the Standard Reference Data Act of 1968 as amended.
    https://www.nist.gov/srd/public-law
    3-Penten-2-one, 4-methyl-
    http://www.nist.gov/srd/nist1a.cfm
  38. SpectraBase
    4-METHYL-3-PENTEN-2-ONE;MESITYLOXID
    https://spectrabase.com/spectrum/5NIrSFs8Rzc
  39. IUPAC Digitized pKa Dataset
  40. Japan Chemical Substance Dictionary (Nikkaji)
  41. KNApSAcK Species-Metabolite Database
  42. Natural Product Activity and Species Source (NPASS)
  43. LIPID MAPS
    Lipid Classification
    https://www.lipidmaps.org/
  44. Metabolomics Workbench
  45. NIOSH Manual of Analytical Methods
    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
  46. NMRShiftDB
  47. NORMAN Suspect List Exchange
    LICENSE
    Data: CC-BY 4.0; Code (hosted by ECI, LCSB): Artistic-2.0
    https://creativecommons.org/licenses/by/4.0/
    NORMAN Suspect List Exchange Classification
    https://www.norman-network.com/nds/SLE/
  48. Springer Nature
  49. SpringerMaterials
  50. Thieme Chemistry
    LICENSE
    The Thieme Chemistry contribution within PubChem is provided under a CC-BY-NC-ND 4.0 license, unless otherwise stated.
    https://creativecommons.org/licenses/by-nc-nd/4.0/
  51. Wikidata
  52. Wikipedia
  53. Wiley
  54. PubChem
  55. Medical Subject Headings (MeSH)
    LICENSE
    Works produced by the U.S. government are not subject to copyright protection in the United States. Any such works found on National Library of Medicine (NLM) Web sites may be freely used or reproduced without permission in the U.S.
    https://www.nlm.nih.gov/copyright.html
  56. GHS Classification (UNECE)
  57. EPA Substance Registry Services
  58. MolGenie
    MolGenie Organic Chemistry Ontology
    https://github.com/MolGenie/ontology/
  59. PATENTSCOPE (WIPO)
CONTENTS