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Monosodium methanearsonate

PubChem CID
23664719
Structure
Monosodium methanearsonate_small.png
Molecular Formula
Synonyms
  • 2163-80-6
  • Sodium methylarsonate
  • Monosodium methanearsonate
  • Daconate
  • MSMA
Molecular Weight
161.952 g/mol
Computed by PubChem 2.2 (PubChem release 2024.11.20)
Dates
  • Create:
    2008-02-05
  • Modify:
    2025-01-11
Description
Methanearsonic acid, [sodium salt] appears as odorless colorless solid. Solution may be red or green. Solid may float or sink in water; solid and solution mix with water. (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.
Methylarsonic acid, monosodium salt is an organoarsenic compound formed from the methylation of inorganic arsenic by living organisms. AArsenic is a chemical element that has the symbol As and atomic number 33. It is a poisonous metalloid that has many allotropic forms: yellow (molecular non-metallic) and several black and grey forms (metalloids) are a few that are seen. Three metalloidal forms of arsenic with different crystal structures are found free in nature (the minerals arsenopyrite and the much rarer arsenolamprite and pararsenolamprite), but it is more commonly found as a compound with other elements. (T3, L389)
L389: Wikipedia. Organoarsenic chemistry. Last Updated 30 April 2009. http://en.wikipedia.org/wiki/Organoarsenic_compound
T3: Emsley, John (2001). Nature's Building Blocks: An A-Z Guide to the Elements. Oxford: Oxford University Press.

1 Structures

1.1 2D Structure

Chemical Structure Depiction
Monosodium methanearsonate.png

1.2 3D Status

Conformer generation is disallowed since MMFF94s unsupported element, mixture or salt

2 Names and Identifiers

2.1 Computed Descriptors

2.1.1 IUPAC Name

sodium;hydroxy(methyl)arsinate
Computed by Lexichem TK 2.7.0 (PubChem release 2024.11.20)

2.1.2 InChI

InChI=1S/CH5AsO3.Na/c1-2(3,4)5;/h1H3,(H2,3,4,5);/q;+1/p-1
Computed by InChI 1.07.0 (PubChem release 2024.11.20)

2.1.3 InChIKey

JITOKQVGRJSHHA-UHFFFAOYSA-M
Computed by InChI 1.07.0 (PubChem release 2024.11.20)

2.1.4 SMILES

C[As](=O)(O)[O-].[Na+]
Computed by OEChem 2.3.0 (PubChem release 2024.12.12)

2.2 Molecular Formula

CH4AsNaO3
Computed by PubChem 2.2 (PubChem release 2024.11.20)

2.3 Other Identifiers

2.3.1 CAS

2163-80-6

2.3.3 European Community (EC) Number

2.3.4 UNII

2.3.5 UN Number

2.3.6 DSSTox Substance ID

2.3.7 Nikkaji Number

2.3.8 Wikidata

2.4 Synonyms

2.4.1 MeSH Entry Terms

  • disodium methanearsonate
  • methanearsonic acid
  • methylarsonate
  • methylarsonic acid
  • methylarsonous acid
  • monomethylarsonic acid
  • monomethylarsonic acid, ammonium, iron (3+) salt
  • monomethylarsonic acid, calcium salt (2:1)
  • monomethylarsonic acid, dimercury (1+) salt
  • monomethylarsonic acid, dipotassium salt
  • monomethylarsonic acid, disodium salt
  • monomethylarsonic acid, iron (2+) salt (3:2)
  • monomethylarsonic acid, iron salt
  • monomethylarsonic acid, monoammonium salt
  • monomethylarsonic acid, monocalcium salt
  • monomethylarsonic acid, monosodium salt
  • monomethylarsonic acid, zinc salt
  • monosodium methanearsonate
  • MSMA
  • sodium methanearsonate

2.4.2 Depositor-Supplied Synonyms

3 Chemical and Physical Properties

3.1 Computed Properties

Property Name
Molecular Weight
Property Value
161.952 g/mol
Reference
Computed by PubChem 2.2 (PubChem release 2024.11.20)
Property Name
Hydrogen Bond Donor Count
Property Value
1
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2024.11.20)
Property Name
Hydrogen Bond Acceptor Count
Property Value
3
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2024.11.20)
Property Name
Rotatable Bond Count
Property Value
0
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2024.11.20)
Property Name
Exact Mass
Property Value
161.927408 Da
Reference
Computed by PubChem 2.2 (PubChem release 2024.11.20)
Property Name
Monoisotopic Mass
Property Value
161.927408 Da
Reference
Computed by PubChem 2.2 (PubChem release 2024.11.20)
Property Name
Topological Polar Surface Area
Property Value
60.4 Ų
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2024.11.20)
Property Name
Heavy Atom Count
Property Value
6
Reference
Computed by PubChem
Property Name
Formal Charge
Property Value
0
Reference
Computed by PubChem
Property Name
Complexity
Property Value
71.2
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2024.11.20)
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
2
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

Methanearsonic acid, [sodium salt] appears as odorless colorless solid. Solution may be red or green. Solid may float or sink in water; solid and solution mix with water. (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.
White solid; [Hawley] Colorless odorless solid; [CAMEO]

3.2.2 Color / Form

White solid
Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 13th ed. New York, NY: John Wiley & Sons, Inc. 1997., p. 1021

3.2.3 Odor

None
U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.

3.2.4 Boiling Point

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

3.2.5 Melting Point

235 to 241 °F (NTP, 1992)
National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
130-140 °C
Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 13th ed. New York, NY: John Wiley & Sons, Inc. 1997., p. 1021
Mp: 113-116 °C /Sodium methanearsonate sesquihydrate/
Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium, 11 th ed., British Crop Protection Council, Surrey, England 1997, p. 821
Mp: 132-139 °C /Sodium methanearsonate hexahydrate/
Verschueren, K. Handbook of Environmental Data on Organic Chemicals. Volumes 1-2. 4th ed. John Wiley & Sons. New York, NY. 2001, p. V2 1561

3.2.6 Solubility

greater than or equal to 100 mg/mL at 72 °F (NTP, 1992)
National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
16 g/100 ml in methanol @ 25 °C; 0.005 g/100 ml in hexane @ 25 °C
Farm Chemicals Handbook 2001. Willoughby, Ohio: Meister 2001., p. C 278
Insoluble in most organic solvents
Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium, 11 th ed., British Crop Protection Council, Surrey, England 1997, p. 821
In water, 5.8X10+5 mg/l @ 20 °C.
Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium, 11 th ed., British Crop Protection Council, Surrey, England 1997, p. 821

3.2.7 Density

(DSMA) 1.0 at 68.0 °F (MSMA solutions) 1.4-1.6 at 20 °C (liquid) (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.
1.535 /51% w/v aqueous technical/
Ahrens, W.H. Herbicide Handbook of the Weed Science Society of America. 7th ed. Champaign, IL: Weed Science Society of America, 1994., p. 210

3.2.8 Vapor Pressure

0.00000008 [mmHg]
1X10-5 Pa @ 25 °C (7.8X10-8 mm Hg)
Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium. 10th ed. Surrey, UK: The British Crop Protection Council, 1994., p. 684

3.2.9 LogP

log Kow= -3.10
Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants. Washington, DC: American Chemical Society., 1995., p. 3

3.2.10 Stability / Shelf Life

STABLE TO HYDROLYSIS
Spencer, E. Y. Guide to the Chemicals Used in Crop Protection. 7th ed. Publication 1093. Research Institute, Agriculture Canada, Ottawa, Canada: Information Canada, 1982., p. 407

3.2.11 Autoignition Temperature

Not flammable (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.

3.2.12 Decomposition

When heated to decomposition it emits toxic fumes of /arsenic and sodium oxide/.
Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996., p. 2353
Decomposed by strong oxidizing and reducing agents.
Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium. 10th ed. Surrey, UK: The British Crop Protection Council, 1994., p. 684

3.2.13 Corrosivity

NON-CORROSIVE TO IRON, RUBBER, & MOST PLASTICS
Worthing, C. R. (ed.). Pesticide Manual. 6th ed. Worcestershire, England: British Crop Protection Council, l979., p. 352

3.2.14 Dissociation Constants

pKa1= 4.1; pKa2 = 9.02
Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium, 11 th ed., British Crop Protection Council, Surrey, England 1997, p. 821

3.2.15 Other Experimental Properties

Soln may contain red or green dyes. /Methanearsonic acid, sodium salts/
U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.
Colorless crystals /Sodium methanearsonate hydrate/
Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium, 11 th ed., British Crop Protection Council, Surrey, England 1997, p. 821
Clear liquid /Target MSMA/
Farm Chemicals Handbook 2001. Willoughby, Ohio: Meister 2001., p. C 278
Clear liquid; bp: 110 °C; density: 1.55 g/ml @ 20 °C /Ansar 6.6/
Farm Chemicals Handbook 2001. Willoughby, Ohio: Meister 2001., p. C 278

3.3 Chemical Classes

Metals -> Arsenic Compounds, Organic

3.3.1 Pesticides

Herbicides
Active substance -> EU Pesticides database: Not approved

4 Spectral Information

4.1 IR Spectra

4.1.1 FTIR Spectra

Technique
BETWEEN SALTS
Source of Sample
U.S. Epa Repository, Research Triangle Park, North Carolina
Copyright
Copyright © 1980, 1981-2024 John Wiley & Sons, Inc. All Rights Reserved.
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6 Chemical Vendors

7 Agrochemical Information

7.1 Agrochemical Category

Herbicide
Pesticide active substances -> Herbicides

7.2 EU Pesticides Data

Active Substance
msma (methyl arsonic acid)
Status
Not approved [Reg. (EC) No 1107/2009]
Legislation
2002/2076

8 Pharmacology and Biochemistry

8.1 MeSH Pharmacological Classification

Herbicides
Pesticides used to destroy unwanted vegetation, especially various types of weeds, grasses (POACEAE), and woody plants. Some plants develop HERBICIDE RESISTANCE. (See all compounds classified as Herbicides.)
Teratogens
An agent that causes the production of physical defects in the developing embryo. (See all compounds classified as Teratogens.)

8.2 Absorption, Distribution and Excretion

MSMA ... TRANSLOCATED MORE RAPIDLY THAN CACODYLIC ACID TO ROOT SYSTEM & PROBABLY ... SHOOT TIP, YET IT WAS NOT MORE PHYTOTOXIC. RADIOACTIVE MSMA WAS FOUND ABOVE, BELOW & IN NUTRIENT SOLN WHEN BLACK VALENTINE BEANS WERE TREATED WITH (14)C MSMA. ... NUTSEDGE TUBERS ACCUM ARSENIC & SMALLER TUBERS CONTAINED HIGHEST CONCN.
Kearney, P.C., and D. D. Kaufman (eds.) Herbicides: Chemistry, Degredation and Mode of Action. Volumes 1 and 2. 2nd ed. New York: Marcel Dekker, Inc., 1975., p. 765
/IN COTTON/ ... (14)C MSMA TRANSLOCATED OUT OF COTYLEDONS FASTER WHEN TREATED @ 20 °C THAN @ 29 °C. MAX ABSORPTION ... OCCURRED @ 29 °C.
Kearney, P.C., and D. D. Kaufman (eds.) Herbicides: Chemistry, Degredation and Mode of Action. Volumes 1 and 2. 2nd ed. New York: Marcel Dekker, Inc., 1975., p. 766
... 10 MG/KG/DAY ... PROVED FATAL TO CATTLE IN 10 DAYS; ARSENIC CONTENT OF KIDNEY & LIVER BEING IN RANGE 27-64 PPM.
Clarke, M. L., D. G. Harvey and D. J. Humphreys. Veterinary Toxicology. 2nd ed. London: Bailliere Tindall, 1981., p. 30
No significant arsenic residues are found in cottonseed when the sodium & disodium salts of methanearsonic acid are applied after the cotton has reached a height of 7.6 cm and before early bloom.
IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work). Available at: https://monographs.iarc.fr/ENG/Classification/index.php, p. V23 72 (1980)
For more Absorption, Distribution and Excretion (Complete) data for SODIUM METHANEARSONATE (7 total), please visit the HSDB record page.

8.3 Metabolism / Metabolites

... DEGRADATION OF MONOSODIUM METHANEARSONATE IN BEANS ... 3-5% OF ARSENIC RECOVERED IN EXTRACT REMAINED BOUND TO INSOL RESIDUE. ... OF REMAINING RESIDUE ... ABOUT 60% WAS ASSOCIATED WITH A NINHYDRIN-POS SUBSTANCE (RF= 0.69) WHILE 40% WAS UNCOMPLEXED MSMA (RF= 0.35). ... MONOSODIUM METHANEARSONATE ON COTTON. LITTLE OR NO METAB...DURING 72 HR PLANT EXPOSURE. ... COTTON APPARENTLY FORMS NO COMPLEX, @ LEAST WITHIN 72 HR AFTER TREATMENT. /HISTIDINE COMPLEX PROPOSED, BUT NOT PROVEN, IN OTHER PLANTS/
Kearney, P.C., and D. D. Kaufman (eds.) Herbicides: Chemistry, Degredation and Mode of Action. Volumes 1 and 2. 2nd ed. New York: Marcel Dekker, Inc., 1975., p. 754
RESISTANCE TO ENTRY OF PINUS PONDEROSA WAS SUBSTANTIALLY MORE PROLONGED FOR MONOSODIUM METHANEARSONATE THAN FOR CACODYLIC ACID WHICH MAY BE RESULT OF ADDED METABOLIC STEP NECESSARY TO CONVERT MONOSODIUM METHANEARSONATE TO CACODYLIC ACID. ... NO PROOF OF METHYLATION ... OFFERED.
Kearney, P.C., and D. D. Kaufman (eds.) Herbicides: Chemistry, Degredation and Mode of Action. Volumes 1 and 2. 2nd ed. New York: Marcel Dekker, Inc., 1975., p. 755
VOLUNTEERS INGESTED A SINGLE ORAL DOSE OF 500 MG ARSENIC AS DISODIUM METHANEARSONATE. AFTER 4 DAYS, 78% OF INGESTED ARSENIC WAS EXCRETED IN URINE. METHANEARSONATE IS 13% METHYLATED INTO DIMETHYLARSINATE. /METHANEARSONIC ACID, DISODIUM SALT/
BUCHET ET AL; INT ARCH OCCUP ENVIRON HEALTH 48 (1): 71-9 (1981)
REACTION OF ... DSMA ... EXAMINED IN ... PLANTS ... SINGLE RADIOACTIVE CMPD ... FOUND /IN PURPLE NUTSEDGE (CYPERUS ROTUNDUS LEGUMINOSAE)/ IN HOT 80% ETHANOL EXTRACT. CHEM ANALYSIS REVEALED THAT C-AS BOND REMAINED INTACT. /METHANEARSONIC ACID, DISODIUM SALT/
Kearney, P.C., and D. D. Kaufman (eds.) Herbicides: Chemistry, Degredation and Mode of Action. Volumes 1 and 2. 2nd ed. New York: Marcel Dekker, Inc., 1975., p. 754
For more Metabolism/Metabolites (Complete) data for SODIUM METHANEARSONATE (7 total), please visit the HSDB record page.
Arsenic is absorbed mainly by inhalation or ingestion, as to a lesser extent, dermal exposure. It is then distributed throughout the body, where it is reduced into arsenite if necessary, then methylated into monomethylarsenic (MMA) and dimethylarsenic acid (DMA) by arsenite methyltransferase. Arsenic and its metabolites are primarily excreted in the urine. Arsenic is known to induce the metal-binding protein metallothionein, which decreases the toxic effects of arsenic and other metals by binding them and making them biologically inactive, as well as acting as an antioxidant. (L20)
L20: Wikipedia. Arsenic toxicity. Last Updated 22 February 2009. http://en.wikipedia.org/wiki/Arsenic_toxicity

8.4 Mechanism of Action

ARSONIC ACID HERBICIDES ARE NOT GROWTH REGULATORS IN SENSE OF PLANT HORMONES. THEY ... ACT THROUGH ENZYME SYSTEMS TO INHIBIT GROWTH. THEY KILL ... SLOWLY; FIRST SYMPTOMS ARE ... CHLOROSIS, CESSATION OF GROWTH, & GRADUAL YELLOWING, THEN BROWNING FOLLOWED BY DEHYDRATION & DEATH. /ORGANOARSENICAL HERBICIDES/
Kearney, P.C., and D. D. Kaufman (eds.) Herbicides: Chemistry, Degredation and Mode of Action. Volumes 1 and 2. 2nd ed. New York: Marcel Dekker, Inc., 1975., p. 763

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
Used as post-emergence herbicide for turf, cotton, and non-cropland; [HSDB]
Industrial Processes with risk of exposure
Farming (Pesticides) [Category: Industry]
For Sodium methanearsonate (USEPA/OPP Pesticide Code: 013803) ACTIVE products with label matches. /SRP: Registered for use in the U.S. but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./
U.S. Environmental Protection Agency/Office of Pesticide Program's Chemical Ingredients Database on Sodium methanearsonate (2163-80-6). Available from, as of May 24, 2001: https://npirspublic.ceris.purdue.edu/ppis/
Post-emergence herbicide for grassy weeds.
Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 13th ed. New York, NY: John Wiley & Sons, Inc. 1997., p. 1021
ONE OF THE FIRST MAJOR USES WAS AS A SELECTIVE HERBICIDE FOR POSTEMERGENCE CONTROL OF CRABGRASS, DALLISGRASS, & OTHER WEEDY GRASSES IN TURF. CURRENTLY IT IS USED...AS SELECTIVE POSTEMERGENT HERBICIDE IN COTTON & NONCROP AREAS FOR CONTROL OF JOHNSONGRASS, NUTSEDGE, WATERGRASS, SANDBUR, FOXTAIL, COCKLEBUR, PIGWEED, & OTHER WEEDS. IT IS WIDELY USED...FOR CONTROLLING WEEDS & GRASSES IN NONCROP AREAS. NOT FOR USE ON ST AUGUSTINE OR CENTIPEDEGRASS WHERE ITS USE AS TURF IS DESIRABLE. ALSO MIXED WITH 2,4-D/2,4,5-T BRUSHKILLERS ON NONCROPPED AREAS TO INCREASE CONIFER & OTHER BRUSH SPECIES KILL OR DIEBACK. /MONO AND SODIUM SALTS/
Weed Science Society of America. Herbicide Handbook. 4th ed. Champaign, IL: Weed Science Society of America, 1979. of America, 1979., p. 253
Methylarsonic acid, monosodium salt is used as an herbicide and pesticide. (L389)
L389: Wikipedia. Organoarsenic chemistry. Last Updated 30 April 2009. http://en.wikipedia.org/wiki/Organoarsenic_compound

9.1.1 Use Classification

Hazard Classes and Categories -> Carcinogens
HERBICIDES

9.1.2 Household Products

Household & Commercial/Institutional Products

Information on 5 consumer products that contain Monosodium acid methanearsonate in the following categories is provided:

• Pesticides

9.2 Methods of Manufacturing

MSMA is produced by the reaction of diarsenic trioxide with methyl chloride and aq sodium hydroxide or by the methylation of sodium arsenite by dimethyl sulfate
Worthing, C. R. (ed.). Pesticide Manual. 6th ed. Worcestershire, England: British Crop Protection Council, l979., p. 352
MSMA ... formed from DSMA at pH 6-7.
Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium, 11 th ed., British Crop Protection Council, Surrey, England 1997, p. 822
Ashford, R.D. Ashford's Dictionary of Industrial Chemicals. London, England: Wavelength Publications Ltd., 1994., p. 606

9.3 Formulations / Preparations

USEPA/OPP Pesticide Code 013803; Trade Names: Weed-broom (Use 3 code Nos. 012301,013803 & 030001) mixt, (DSMA, Bromacil & 2,4-D); Ansar 529; Ansar 170; Target MSMA; Phyban H.C.; Deconate; Mesamate; Bueno; Monate Merge 823; Dal-e-rad; Weed-s-rad; Arsanote liquid; Silvisar 550.
U.S. Environmental Protection Agency/Office of Pesticide Program's Chemical Ingredients Database on Sodium methanearsonate (2163-80-6). Available from, as of May 24, 2001: https://npirspublic.ceris.purdue.edu/ppis/
Methylarsonic acid, monosodium salt is avail for farm applications as a tech grade in combination with a surfactant, or in combination with sodium cacodylate, dimethylarsinic acid and a surfactant.
IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work). Available at: https://monographs.iarc.fr/ENG/Classification/index.php, p. V23 47 (1980)
MSMA CONTENT, IN LB/GAL: WEED-HOE 120, 6.67; ANSAR 170, 6.67; ANSAR 170 HC, 8.0; WEED-HOE-2X, 8.0; ANSAR 529 (SURFACTANT), 4.0; WEED-E-RAD +W, 4.02 (SURFACTANT); DAL-E-RAD 70 +W, 4.02 (SURFACTANT); WEED-HOE 100 +W, 5.56 (SURFACTANT); ANSAR 529 HC, 6.0 (SURFACTANT); MONEX 3, 6.0; PHYBAN HC, 6.0; BROADSIDE, 3.0; CHEX-MATE, 3.00 (SURFACTANT). /FROM TABLE/
Kearney, P.C., and D. D. Kaufman (eds.) Herbicides: Chemistry, Degredation and Mode of Action. Volumes 1 and 2. 2nd ed. New York: Marcel Dekker, Inc., 1975., p. 753
Liq (8 lb/gal) ... Silvisar 550 (tree killer for forestry use). Target MSMA 8 (8lb/gal); Target MSMA 6.6 (6.6 lb/gal); Target MSMA 6 (6 lb/gal) + surfactant: Target MSMA 4 (4 lb/gal) + surfactant ... .
Farm Chemicals Handbook 1984. Willoughby, Ohio: Meister Publishing Co., 1984., p. C-158
For more Formulations/Preparations (Complete) data for SODIUM METHANEARSONATE (10 total), please visit the HSDB record page.

9.4 General Manufacturing Information

May be formed by decomp of DSMA /disodium methanearsonate/ at pH 6-7.
Spencer, E. Y. Guide to the Chemicals Used in Crop Protection. 7th ed. Publication 1093. Research Institute, Agriculture Canada, Ottawa, Canada: Information Canada, 1982., p. 407
... MSMA /HAS BEEN USED/ IN CONJUNCTION WITH TRIFLURALIN TO CONTROL JOHNSONGRASS ... PREPLANT APPLICATION OF TRIFLURALIN REDUCED NUMBER OF MSMA APPLICATIONS NEEDED FOR COMPLETE WEED CONTROL BEFORE COTTON BLOOMED.
Kearney, P.C., and D. D. Kaufman (eds.) Herbicides: Chemistry, Degredation and Mode of Action. Volumes 1 and 2. 2nd ed. New York: Marcel Dekker, Inc., 1975., p. 743
/IN MSMA TREATMENT/ ... ATRAZINE ... FACILITATES UPTAKE OF ARSENIC BY /GRAPE/ PLANT.
Kearney, P.C., and D. D. Kaufman (eds.) Herbicides: Chemistry, Degredation and Mode of Action. Volumes 1 and 2. 2nd ed. New York: Marcel Dekker, Inc., 1975., p. 765
Incompatabilities: water with high calcium, magnesium, and iron may cause precipitate; these cations form insoluble methane arsonate salts.
Ahrens, W.H. Herbicide Handbook of the Weed Science Society of America. 7th ed. Champaign, IL: Weed Science Society of America, 1994., p. 210
For more General Manufacturing Information (Complete) data for SODIUM METHANEARSONATE (7 total), please visit the HSDB record page.

10 Safety and Hazards

10.1 Hazards Identification

10.1.1 GHS Classification

Pictogram(s)
Acute Toxic
Environmental Hazard
Signal
Danger
GHS Hazard Statements

H301 (90.5%): Toxic if swallowed [Danger Acute toxicity, oral]

H331 (90.5%): Toxic if inhaled [Danger Acute toxicity, inhalation]

H400 (90.5%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410 (90.5%): Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

Precautionary Statement Codes

P261, P264, P270, P271, P273, P301+P316, P304+P340, P316, P321, P330, P391, P403+P233, 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 42 reports by companies from 2 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

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

10.1.2 Hazard Classes and Categories

Acute Tox. 3 (90.5%)

Acute Tox. 3 (90.5%)

Aquatic Acute 1 (90.5%)

Aquatic Chronic 1 (90.5%)

Carcinogens

10.1.3 Health Hazards

Subacute poisoning by arsenicals causes salty taste, burning in throat and stomach, and intestinal pain. Acute toxicity indicated by headache, vomiting, stupor, convulsions, paralysis. About 1 ounce to 1 pound must be taken to cause these symptoms. (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.

10.1.4 Fire Hazards

Special Hazards of Combustion Products: Toxic gases may be generated in fires. (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.

10.1.5 Hazards Summary

A skin and eye irritant; [HSDB] Most excreted unchanged; [Rosenstock, p. 947] For MSMA and DSMA, developmental studies of rats and rabbits along with a two-generation reproductive study show no indication of increased susceptibility; No evidence of carcinogenicity; Target organs are large intestines and kidneys; [Reference #1]
Rosenstock - Rosenstock L, Cullen MR, Brodkin CA, Redlich CA (eds). Textbook of Clinical Occupational and Environmental Medicine, 2nd Ed. Philadelphia: Elsevier Saunders, 2004., p. 947

10.1.6 Fire Potential

NON-FLAMMABLE.
Spencer, E. Y. Guide to the Chemicals Used in Crop Protection. 7th ed. Publication 1093. Research Institute, Agriculture Canada, Ottawa, Canada: Information Canada, 1982., p. 407

10.1.7 Skin, Eye, and Respiratory Irritations

EYE & SKIN IRRITATION.
PEOPLES ET AL; VET HUM TOXICOL 21 (6): 417-21 (1979)

10.1.8 EPA Hazardous Waste Number

D004; A waste containing arsenic may or may not be characterized as a hazardous waste following testing by the Toxicity Characteristic Leaching Procedure as prescribed by the Resource Conservation and Recovery Act (RCRA) regulations. /Arsenic/

10.2 Safety and Hazard Properties

10.2.1 OSHA Standards

Permissible Exposure Limit: Table Z-1 8-Hr Time Weighted Avg: 0.5 mg/cu m. /Arsenic, organic cmpd (as As)/
29 CFR 1910.1000 (7/1/2001)

10.3 First Aid Measures

10.3.1 First Aid

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

SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, IMMEDIATELY call a physician and be prepared to transport the victim to a hospital for treatment.

INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. IMMEDIATELY call a physician and be prepared to transport the victim to a hospital even if no symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.

INGESTION: Some heavy metals are VERY TOXIC POISONS, especially if their salts are very soluble in water (e.g., lead, chromium, mercury, bismuth, osmium, and arsenic). IMMEDIATELY call a hospital or poison control center and locate activated charcoal, egg whites, or milk in case the medical advisor recommends administering one of them. Also locate Ipecac syrup or a glass of salt water in case the medical advisor recommends inducing vomiting. Usually, this is NOT RECOMMENDED outside of a physician's care. If advice from a physician is not readily available and the victim is conscious and not convulsing, give the victim a glass of activated charcoal slurry in water or, if this is not available, a glass of milk, or beaten egg whites and IMMEDIATELY transport victim to a hospital. If the victim is convulsing or unconscious, do not give anything by mouth, assure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital.

OTHER: Since this chemical is a known or suspected carcinogen you should contact a physician for advice regarding the possible long term health effects and potential recommendation for medical monitoring. Recommendations from the physician will depend upon the specific compound, its chemical, physical and toxicity properties, the exposure level, length of exposure, and the route of exposure. (NTP, 1992)

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

10.4 Fire Fighting

Fires involving this compound should be controlled with a dry chemical, carbon dioxide or Halon extinguisher. (NTP, 1992)
National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.

10.5 Accidental Release Measures

10.5.1 Isolation and Evacuation

Excerpt from ERG Guide 151 [Substances - Toxic (Non-Combustible)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary.

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)

10.5.2 Disposal Methods

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number D004, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.
40 CFR 240-280, 300-306, 702-799 (7/1/91)

10.5.3 Preventive Measures

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

10.6 Handling and Storage

10.6.1 Nonfire Spill Response

SMALL SPILLS AND LEAKAGE: If you spill this chemical, you should dampen the solid spill material with water, then transfer the dampened material to a suitable container. Use absorbent paper dampened with water to pick up any remaining material. Seal your contaminated clothing and the absorbent paper in a vapor-tight plastic bag for eventual disposal. Wash all contaminated surfaces with a strong soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.

STORAGE PRECAUTIONS: You should store this material in a refrigerator away from oxidizing and reducing agents. (NTP, 1992)

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

10.6.2 Storage Conditions

SOLID FORMULATIONS ARE SOMEWHAT HYGROSCOPIC & SHOULD BE STORED IN DRY PLACE. /METHANEARSONIC ACID/
Weed Science Society of America. Herbicide Handbook. 5th ed. Champaign, Illinois: Weed Science Society of America, 1983., p. 291

10.7 Exposure Control and Personal Protection

10.7.1 Permissible Exposure Limit (PEL)

0.5 [mg/m3], as As

10.7.2 Other Standards Regulations and Guidelines

... The following countries had adopted the ... TLV of 0.5 mg/cu m: Austria, Belgium, Finland, Japan, and Holland. Czechoslavakia, East Germany, Hungary and Poland ... USSR ... 0.3 mg/cu m; Romania and Switzerland, 0.2 mg/cu m; Sweden 0.05 mg/cu m; and Italy 0.25 mg/cu m. /Arsenic and sol cmpd/
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. 37

10.7.3 Allowable Tolerances

Tolerances are established for residues of the herbicide methanearsonic acid (calculated as As2O3) from application of the disodium and monosodium salts of methanearsonic acid in or on raw agricultural commodities as follows: citrus fruit, 0.35 ppm; cottonseed, 0.7 ppm; and cottonseed hulls, 0.9 ppm.
40 CFR 180.289 (4/1/2000)
Tolerances for total residues of combined arsenic (calculated as As) in food are established as follows: (a) In edible tissues & in eggs of chickens & turkeys: 0.5 ppm in uncooked muscle tissue; 2 ppm in uncooked edible by-products; & 0.5 ppm in eggs. (b) In edible tissues of swine: 2 ppm in uncooked liver & kidney; 0.5 ppm in uncooked muscle tissue & by-products other than liver & kidney. /Arsenic/
21 CFR 556.60 (4/1/2001)

10.7.4 Personal Protective Equipment (PPE)

Protective clothing to prevent contact with skin; chemical goggles. (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.
Protective gloves rubber or neoprene, goggles, or face shield for eye protection, rubber apron.
Farm Chemicals Handbook 1984. Willoughby, Ohio: Meister Publishing Co., 1984., p. C-158
Long pants, long-sleeved shirt, impermeable gloves, boots for handling or applying. Mixer-loaders should wear an apron and full-face shield for handling, mixing concentrate. Flagmen should be fully protected during spray operations or use mechanical flagmen. Pilots and ground spray rig applicators should wear a mask or approved respirator.
Farm Chemicals Handbook 1993. Willoughby, OH: Meister Publishing Co., 1993., p. C-237

10.8 Stability and Reactivity

10.8.1 Air and Water Reactions

Water soluble.

10.8.2 Reactive Group

Salts, Basic

10.8.3 Reactivity Profile

METHANEARSONIC ACID, [SODIUM SALT] is decomposed by strong oxidizers and reducers. (NTP, 1992)
National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.

10.9 Transport Information

10.9.1 DOT Label

Poison

10.10 Regulatory Information

Status Regulation (EC)
2002/2076
REACH Restricted Substance

Restricted substance: Sodium methylarsonate

EC: 218-495-9

Restriction condition document: PDF link

10.10.1 Atmospheric Standards

Listed as a hazardous air pollutant (HAP) generally known or suspected to cause serious health problems. The Clean Air Act, as amended in 1990, directs EPA to set standards requiring major sources to sharply reduce routine emissions of toxic pollutants. EPA is required to establish and phase in specific performance based standards for all air emission sources that emit one or more of the listed pollutants. Sodium methanearsonate is included on this list.
Clean Air Act as amended in 1990, Sect. 112 (b) (1) Public Law 101-549 Nov. 15, 1990
(a) The owner or operator of an existing glass melting furnace subject to the provisions of this subpart shall comply with either paragraph (a)(1) or (a)(2) of this section ... (1) Uncontrolled total arsenic emissions from the glass melting furnace shall be less than 2.5 Mg (2.7 ton) per year, or ... (2) Total arsenic emissions from glass melting furnace shall be conveyed to a control device and reduced by at least 85%. /Total arsenic/
40 CFR 61.162(a) (7/1/2001)
(b) The owner or operator of a new or modified glass melting furnace subject to the provisions of this subpart shall comply with either paragraph (b)(1) or (b)(2) of this section ... (1) Uncontrolled total arsenic emissions from the glass melting furnace shall be less than 0.4 Mg (0.44 ton) per year, or ... (2) Total arsenic emissions from glass melting furnace shall be conveyed to a control device and reduced by at least 85%. /Total arsenic/
40 CFR 61.162(b) (7/1/2001)
The owner or operator of each copper converter subject to the provisions of this subpart shall reduce inorganic arsenic emissions to the atmosphere by meeting the following design, equipment, work practice, and operational requirements: (1) Install, operate, and maintain a secondary hood system on each copper converter. Each secondary hood system shall consist of a hood enclosure, air curtain fan(s), exhaust system fan(s), and ductwork that conveys the captured emission to a control device ... (2) Optimize the capture of secondary inorganic arsenic emission by operating the copper converter and secondary hood systems at all times ... . /Inorganic arsenic/
40 CFR 61.172(b) (7/1/2001)

10.10.2 Federal Drinking Water Standards

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

10.10.3 State Drinking Water Guidelines

(AZ) ARIZONA 10 ug/L /Arsenic/
USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93) To Present
(CT) CONNECTICUT 10 ug/l /Arsenic/
USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93) To Present

10.10.4 Clean Water Act Requirements

Toxic pollutant designated pursuant to section 307(a)(1) of the Federal Water Pollution Control Act and is subject to effluent limitations. /Arsenic & cmpd/
40 CFR 401.15 (7/1/2001)
For the maximum protection of human health from the potential carcinogenic effects due to exposure of arsenic through ingestion of contaminated water & contaminated aquatic organisms, the ambient water concn should be zero based on the nonthreshold assumption for this chemical. However, zero level may not be attainable at the present time. Therefore, the levels which may result in incremental increase of cancer risk over the lifetime are estimated at 1X10-5, 1X10-6, & 1X10-7. The corresponding criteria are 22 ng/l, 2.2 ng/l, & .22 ng/l, respectively .... For consumption of aquatic organisms only, excluding consumption of water, the levels are 175 ng/ml, 17.5 ng/l, & 1.75 ng/l, respectively. /Arsenic/
USEPA; Quality Criteria for Water 1986: Arsenic: Human Health Criteria (May 1, 1986) EPA 440/5-86-001
D004; A solid waste containing arsenic may or may not become characterized as a hazardous waste when subjected to the Toxicity Characteristic Leaching Procedure listed in 40 CFR 261.24, and if so characterized, must be managed as a hazardous waste.
40 CFR 261.24 (7/1/2001)

10.10.5 FIFRA Requirements

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their future use. Under this pesticide reregistration program, EPA examines health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether they are eligible for reregistration. In addition, all pesticides must meet the new safety standard of the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA, as amended in 1988, were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern and List D pesticides of less concern. Monosodium methanearsonate is found on List B. Case No: 2395; Pesticide type: insecticide, herbicide, rodenticide; Case Status: OPP is reviewing data from the pesticide's producers regarding its human health and/or environmental effects, or OPP is determining the pesticide's eligibility for reregistration and developing the Reregistration Eligibility Decision (RED) document.; Active ingredient (AI): Monosodium methanearsonate; Data Call-in (DCI) Date(s): 06/14/91, 03/03/95, 10/13/95; AI Status: The producers of the pesticide has made commitments to conduct the studies and pay the fees required for reregistration, and are meeting those commitments in a timely manner.
USEPA/OPP; Status of Pesticides in Registration, Reregistration and Special Review p.190 (Spring, 1998) EPA 738-R-98-002
Tolerances are established for residues of the herbicide methanearsonic acid (calculated as As2O3) from application of the disodium and monosodium salts of methanearsonic acid in or on raw agricultural commodities as follows: citrus fruit; cottonseed; and cottonseed hulls.
40 CFR 180.289 (4/1/2000)
If material involved in fire: Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) Use water in flooding quantities as fog. Use foam, dry chemical, or carbon dioxide. /Arsenical cmpd, liquid, NOS/
Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994., p. 104
If material involved in fire: Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) Use water in flooding quantities as fog. Use foam, dry chemical, or carbon dioxide. /Arsenical cmpd, solid, NOS/
Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994., p. 105

10.11 Other Safety Information

Chemical Assessment

IMAP assessments - Arsonic acid, methyl-, monosodium salt: Environment tier I assessment

IMAP assessments - Arsonic acid, methyl-, monosodium salt: Human health tier I assessment

10.11.1 Toxic Combustion Products

Toxic gases may be generated in fires. /Methanearsonic acid, sodium salts/
U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.

10.11.2 Special Reports

Shah PV et al; Comparison of the Penetration of 14 Pesticides (Including Disodium Methanearsonate and Monosodium Methanearsonate) Through the Skin of Young and Adult rats. J Toxicol Environ Health 21 (3): 353-66 (1987).

11 Toxicity

11.1 Toxicological Information

11.1.1 Toxicity Summary

Arsenic and its metabolites disrupt ATP production through several mechanisms. At the level of the citric acid cycle, arsenic inhibits pyruvate dehydrogenase and by competing with phosphate it uncouples oxidative phosphorylation, thus inhibiting energy-linked reduction of NAD+, mitochondrial respiration, and ATP synthesis. Hydrogen peroxide production is also increased, which might form reactive oxygen species and oxidative stress. Arsenic's carginogenicity is influenced by the arsenical binding of tubulin, which results in aneuploidy, polyploidy and mitotic arrests. The binding of other arsenic protein targets may also cause altered DNA repair enzyme activity, altered DNA methylation patterns and cell proliferation. (T1, A17)
A17: Kitchin KT, Wallace K: The role of protein binding of trivalent arsenicals in arsenic carcinogenesis and toxicity. J Inorg Biochem. 2008 Mar;102(3):532-9. doi: 10.1016/j.jinorgbio.2007.10.021. Epub 2007 Nov 22. PMID:18164070
T1: Klaassen C and Watkins J (2003). Casarett and Doull's Essentials of Toxicology. New York, NY: McGraw-Hill.

11.1.2 RAIS Toxicity Values

Oral Acute Reference Dose (RfDoa)(mg/kg-day)
0.1
Oral Acute Reference Dose Reference
OPP
Oral Chronic Reference Dose (RfDoc) (mg/kg-day)
0.03
Oral Chronic Reference Dose Reference
OPP

11.1.3 EPA Human Health Benchmarks for Pesticides

Acute or One Day PAD (RfD) [mg/kg/day]
0.1
Acute or One Day HHBPs [ppb]
700
Acute HHBP Sensitive Lifestage/Population
Children
Chronic or One Day PAD (RfD) [mg/kg/day]
0.03
Chronic or One Day HHBPs [ppb]
200
Chronic HHBP Sensitive Lifestage/Population
General Population

11.1.4 Evidence for Carcinogenicity

Cancer Classification: Not Likely to be Carcinogenic to Humans
USEPA Office of Pesticide Programs, Health Effects Division, Science Information Management Branch: "Chemicals Evaluated for Carcinogenic Potential" (April 2006)

11.1.5 Carcinogen Classification

Carcinogen Classification
3, not classifiable as to its carcinogenicity to humans. (L135)

11.1.6 Health Effects

Arsenic poisoning can lead to death from multi-system organ failure, probably from necrotic cell death, not apoptosis. Arsenic is also a known carcinogen, esepcially in skin, liver, bladder and lung cancers. (T1, L20)
L20: Wikipedia. Arsenic toxicity. Last Updated 22 February 2009. http://en.wikipedia.org/wiki/Arsenic_toxicity
T1: Klaassen C and Watkins J (2003). Casarett and Doull's Essentials of Toxicology. New York, NY: McGraw-Hill.

11.1.7 Exposure Routes

Oral (L2) ; inhalation (L2); dermal (L2)
L2: ATSDR - Agency for Toxic Substances and Disease Registry (2007). Toxicological profile for arsenic. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). http://www.atsdr.cdc.gov/toxprofiles/tp2.html

11.1.8 Symptoms

Exposure to lower levels of arsenic can cause nausea and vomiting, decreased production of red and white blood cells, abnormal heart rhythm, damage to blood vessels, and a sensation of burn (T1).
T1: Klaassen C and Watkins J (2003). Casarett and Doull's Essentials of Toxicology. New York, NY: McGraw-Hill.

11.1.10 Acute Effects

11.1.11 Toxicity Data

LC50 (rat) > 2,200 mg/m3

11.1.12 Minimum Risk Level

Acute Oral: 0.005 mg/kg/day (L134) Chronic Oral: 0.0003 mg/kg/day (L134) Chronic Inhalation: 0.01 mg/m3 (L134)
L134: ATSDR - Agency for Toxic Substances and Disease Registry (2001). Minimal Risk Levels (MRLs) for Hazardous Substances. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). http://www.atsdr.cdc.gov/mrls/

11.1.13 Treatment

Arsenic poisoning can be treated by chelation therapy, using chelating agents such as dimercaprol, EDTA or DMSA. Charcoal tablets may also be used for less severe cases. In addition, maintaining a diet high in sulfur helps eliminate arsenic from the body. (L20)
L20: Wikipedia. Arsenic toxicity. Last Updated 22 February 2009. http://en.wikipedia.org/wiki/Arsenic_toxicity

11.1.14 Human Toxicity Excerpts

COMPOUNDS INCLUDED METHANEARSONIC ACID & ITS SODIUM SALTS; 9/34 CASES SHOWED SYSTEMIC SYMPTOMS & REMAINDER HAD EYE & SKIN IRRITATION.
PEOPLES ET AL; VET HUM TOXICOL 21 (6): 417-21 (1979)
ORGANIC ARSENICALS INCLUDE DISODIUM METHYLARSONATE ... AND AMINE METHYLARSONATE.TOXICITY OF THESE CMPD TO HUMANS IS CONSIDERABLY LESS THAN ... INORGANIC ARSENICALS; HOWEVER THEY ARE HARMFUL IF INHALED, SWALLOWED, OR IF THEY COME IN CONTACT WITH EYES OR SKIN. /DISODIUM METHYLARSONATE/
International Labour Office. Encyclopedia of Occupational Health and Safety. Volumes I and II. New York: McGraw-Hill Book Co., 1971., p. 664

11.1.15 Non-Human Toxicity Excerpts

... GAVE MONOSODIUM METHANEARSONATE TO CATTLE THROUGH RENAL TUBULES @ DOSE OF 10 MG/KG DAILY. FOUR OF 5 ... TREATED DIED AFTER 8-10 DAYS OF TREATMENT. CAUSE OF DEATH WAS APPARENT KIDNEY FAILURE. HIGH LEVELS OF ARSENIC WERE FOUND IN KIDNEY & LIVER. ... 100 & 1000 PPM BY WT OF ... MONOSODIUM METHANEARSONATE /IN 60% SUCROSE SYRUP/ WERE EXTREMELY TOXIC TO NEWLY EMERGED WORKER BEES ... NO DIFFERENCES IN TOXICITY WERE OBSERVED BETWEEN PURIFIED & COMMERCIALLY FORMULATED HERBICIDES.
Kearney, P.C., and D. D. Kaufman (eds.) Herbicides: Chemistry, Degredation and Mode of Action. Volumes 1 and 2. 2nd ed. New York: Marcel Dekker, Inc., 1975., p. 761
... EXAMINED EFFECTS OF MONOSODIUM METHANEARSONATE & CACODYLIC ACID ON INSECT MORTALITY IN TREATED PONDEROSA PINES ... DIFFERENCES OF INSECT SURVIVAL BETWEEN CMPD WERE NOTED.
Kearney, P.C., and D. D. Kaufman (eds.) Herbicides: Chemistry, Degredation and Mode of Action. Volumes 1 and 2. 2nd ed. New York: Marcel Dekker, Inc., 1975., p. 755
COTTON ... INJURED BY MONOSODIUM METHANEARSONATE APPLICATION 3.36 KG/HA ... @ 13 OR 20 °C. NO INJURY @ 31 °C.
Kearney, P.C., and D. D. Kaufman (eds.) Herbicides: Chemistry, Degredation and Mode of Action. Volumes 1 and 2. 2nd ed. New York: Marcel Dekker, Inc., 1975., p. 766
Long term feeding of 50 mg/kg of diet of methanearsonic acid, monosodium salt (1.5 mg/kg bw/day as arsenic) to rabbits produced toxic hepatitis.
IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work). Available at: https://monographs.iarc.fr/ENG/Classification/index.php, p. V23 90 (1980)
For more Non-Human Toxicity Excerpts (Complete) data for SODIUM METHANEARSONATE (11 total), please visit the HSDB record page.

11.1.16 Non-Human Toxicity Values

LD50 Rat oral 900 mg/kg (young, albino)
Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium. 10th ed. Surrey, UK: The British Crop Protection Council, 1994., p. 685
LD50 Mouse oral 1800 mg/kg (white)
Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983., p. 886
LD50 Rat oral 700 mg/kg
Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996., p. 2353
LD50 Rabbit oral 102 mg/kg
Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996., p. 2353
LC50 Rat inhalation >20 mg/l/4 hr
Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium. 10th ed. Surrey, UK: The British Crop Protection Council, 1994., p. 685

11.2 Ecological Information

11.2.1 EPA Ecotoxicity

Pesticide Ecotoxicity Data from EPA

11.2.2 Ecotoxicity Values

LC50 GAMMARUS FASCIATUS GREATER THAN 100 MG/L/96 HR @ 15 °C, MATURE. STATIC BIOASSAY WITHOUT AERATION, PH 7.2-7.5, WATER HARDNESS 40-50 MG/L AS CALCIUM CARBONATE AND ALKALINITY OF 30-35 MG/L. /LIQUID FORMULATION, 34.8%/
U.S. Department of Interior, Fish and Wildlife Service. Handbook of Acute Toxicity of Chemicals to Fish and Aquatic Invertebrates. Resource Publication No. 137. Washington, DC: U.S. Government Printing Office, 1980., p. 54
LC50 SALMO CLARKI (CUTTHROAT TROUT) GREATER THAN 100 MG/L/96 HR @ 10 °C, WT 0.6 G STATIC BIOASSAY WITHOUT AERATION, PH 7.2-7.5, WATER HARDNESS 40-50 MG/L ASCALCIUM CARBONATE AND ALKALINITY OF 30-35 MG/L. /LIQUID FORMULATION, 34.8%/
U.S. Department of Interior, Fish and Wildlife Service. Handbook of Acute Toxicity of Chemicals to Fish and Aquatic Invertebrates. Resource Publication No. 137. Washington, DC: U.S. Government Printing Office, 1980., p. 54
LC50 CARASSIUS AURATUS (GOLDFISH) 31.1 MG/L/96 HR @ 18 °C (95% CONFIDENCE LIMIT 24.4-38.8 MG/L), WT 0.9 G STATIC BIOASSAY WITHOUT AERATION, PH 7.2-7.5, WATER HARDNESS 40-50 MG/L AS CALCIUM CARBONATE AND ALKALINITY OF 30-35 MG/L. /LIQUID FORMULATION, 34.8%/
U.S. Department of Interior, Fish and Wildlife Service. Handbook of Acute Toxicity of Chemicals to Fish and Aquatic Invertebrates. Resource Publication No. 137. Washington, DC: U.S. Government Printing Office, 1980., p. 54
LC50 PIMEPHALES PROMELAS (FATHEAD MINNOW) 13.3 MG/L/96 HR @ 18 °C (95% CONFIDENCE LIMIT 5.1-35.8 MG/L), WT 0.9 G STATIC BIOASSAY WITHOUT AERATION, PH 7.2-7.5, WATER HARDNESS 40-50 MG/L AS CALCIUM CARBONATE AND ALKALINITY OF 30-35 MG/L. /LIQUID FORMULATION, 34.8%/
U.S. Department of Interior, Fish and Wildlife Service. Handbook of Acute Toxicity of Chemicals to Fish and Aquatic Invertebrates. Resource Publication No. 137. Washington, DC: U.S. Government Printing Office, 1980., p. 54
For more Ecotoxicity Values (Complete) data for SODIUM METHANEARSONATE (8 total), please visit the HSDB record page.

11.2.3 Environmental Biodegradation

... DEGRADATION OF MSMA ... /IN/ SOILS. ... SOIL MICROORGANISMS APPEARED TO PLAYSOME ROLE IN DECOMP PROCESS. A FUNGUS, SEVERAL ACTINOMYCETES, & SEVERAL BACTERIA WERE ISOLATED ... THE ORGANISMS DEGRADED 3, 13 OR 9, & 20% OF MSMA IN 11 DAYS, RESPECTIVELY. ... IN THE ABSENCE OF AN ENERGY SOURCE, MICROBIAL METAB ... WAS NONEXISTENT. THE PRODUCTS OF METAB WERE CO2 & ARSENATE. NO ARSENITE COULD BE DETECTED.
Kearney, P.C., and D. D. Kaufman (eds.) Herbicides: Chemistry, Degredation and Mode of Action. Volumes 1 and 2. 2nd ed. New York: Marcel Dekker, Inc., 1975., p. 757

11.2.4 Soil Adsorption / Mobility

Organoarsenicals, such as ... methanearsonic acid, monosodium ... salt ... are adsorbed by clay soils. After rapid initial adsorption, changes occur which result in the redistribution of dimethylarsinic acid into a less sol form assoc with aluminum in the soil. Downward leaching of the methanearsonic acid salts has also been reported. The ... salts are fixed by iron and aluminum in the soil, although not as strongly as inorg arsenate.
IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work). Available at: https://monographs.iarc.fr/ENG/Classification/index.php, p. V23 71 (1980)

11.2.5 Probable Routes of Human Exposure

... Urinary arsenic levels of up to 0.93 mg/l /were found/ in forestry workers using the monosodium salt of methanearsonic acid, compared with a level of up to 0.14 mg/l in the urine of nonexposed controls.
IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work). Available at: https://monographs.iarc.fr/ENG/Classification/index.php, p. V23 67 (1980)

12 Literature

12.1 Consolidated References

12.2 NLM Curated PubMed Citations

12.3 Springer Nature References

12.4 Chemical Co-Occurrences in Literature

12.5 Chemical-Gene Co-Occurrences in Literature

12.6 Chemical-Disease Co-Occurrences in Literature

13 Patents

13.1 Depositor-Supplied Patent Identifiers

13.2 WIPO PATENTSCOPE

13.3 Chemical Co-Occurrences in Patents

13.4 Chemical-Disease Co-Occurrences in Patents

13.5 Chemical-Gene Co-Occurrences in Patents

14 Interactions and Pathways

14.1 Chemical-Target Interactions

15 Biological Test Results

15.1 BioAssay Results

16 Classification

16.1 MeSH Tree

16.2 ChemIDplus

16.3 CAMEO Chemicals

16.4 UN GHS Classification

16.5 EPA CPDat Classification

16.6 NORMAN Suspect List Exchange Classification

16.7 EPA DSSTox Classification

16.8 Consumer Product Information Database Classification

16.9 EPA Substance Registry Services Tree

16.10 MolGenie Organic Chemistry Ontology

17 Information Sources

  1. Australian Industrial Chemicals Introduction Scheme (AICIS)
  2. CAMEO Chemicals
    LICENSE
    CAMEO Chemicals and all other CAMEO products are available at no charge to those organizations and individuals (recipients) responsible for the safe handling of chemicals. However, some of the chemical data itself is subject to the copyright restrictions of the companies or organizations that provided the data.
    https://cameochemicals.noaa.gov/help/reference/terms_and_conditions.htm?d_f=false
    METHANEARSONIC ACID, [SODIUM SALT]
    https://cameochemicals.noaa.gov/chemical/8824
    CAMEO Chemical Reactivity Classification
    https://cameochemicals.noaa.gov/browse/react
  3. ChemIDplus
    ChemIDplus Chemical Information Classification
    https://pubchem.ncbi.nlm.nih.gov/source/ChemIDplus
  4. EPA DSSTox
    CompTox Chemicals Dashboard Chemical Lists
    https://comptox.epa.gov/dashboard/chemical-lists/
  5. EPA Safe Drinking Water Act (SDWA)
  6. European Chemicals Agency (ECHA)
    LICENSE
    Use of the information, documents and data from the ECHA website is subject to the terms and conditions of this Legal Notice, and subject to other binding limitations provided for under applicable law, the information, documents and data made available on the ECHA website may be reproduced, distributed and/or used, totally or in part, for non-commercial purposes provided that ECHA is acknowledged as the source: "Source: European Chemicals Agency, http://echa.europa.eu/". Such acknowledgement must be included in each copy of the material. ECHA permits and encourages organisations and individuals to create links to the ECHA website under the following cumulative conditions: Links can only be made to webpages that provide a link to the Legal Notice page.
    https://echa.europa.eu/web/guest/legal-notice
  7. FDA Global Substance Registration System (GSRS)
    LICENSE
    Unless otherwise noted, the contents of the FDA website (www.fda.gov), both text and graphics, are not copyrighted. They are in the public domain and may be republished, reprinted and otherwise used freely by anyone without the need to obtain permission from FDA. Credit to the U.S. Food and Drug Administration as the source is appreciated but not required.
    https://www.fda.gov/about-fda/about-website/website-policies#linking
  8. Hazardous Substances Data Bank (HSDB)
  9. NJDOH RTK Hazardous Substance List
    methanearsonic acid, monosodium salt
    http://nj.gov/health/eoh/rtkweb/documents/fs/4105.pdf
  10. Risk Assessment Information System (RAIS)
    LICENSE
    This work has been sponsored by the U.S. Department of Energy (DOE), Office of Environmental Management, Oak Ridge Operations (ORO) Office through a joint collaboration between United Cleanup Oak Ridge LLC (UCOR), Oak Ridge National Laboratory (ORNL), and The University of Tennessee, Ecology and Evolutionary Biology, The Institute for Environmental Modeling (TIEM). All rights reserved.
    https://rais.ornl.gov/
  11. Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
    LICENSE
    Copyright (c) 2022 Haz-Map(R). All rights reserved. Unless otherwise indicated, all materials from Haz-Map are copyrighted by Haz-Map(R). No part of these materials, either text or image may be used for any purpose other than for personal use. Therefore, reproduction, modification, storage in a retrieval system or retransmission, in any form or by any means, electronic, mechanical or otherwise, for reasons other than personal use, is strictly prohibited without prior written permission.
    https://haz-map.com/About
    Monosodium methanearsonate
    https://haz-map.com/Agents/7136
  12. 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
    Methylarsonic acid, monosodium salt
    http://www.t3db.ca/toxins/T3D0309
  13. Consumer Product Information Database (CPID)
    LICENSE
    Copyright (c) 2024 DeLima Associates. All rights reserved. Unless otherwise indicated, all materials from CPID are copyrighted by DeLima Associates. No part of these materials, either text or image may be used for any purpose other than for personal use. Therefore, reproduction, modification, storage in a retrieval system or retransmission, in any form or by any means, electronic, mechanical or otherwise, for reasons other than personal use, is strictly prohibited without prior written permission.
    https://www.whatsinproducts.com/contents/view/1/6
    Consumer Products Category Classification
    https://www.whatsinproducts.com/
  14. EPA Chemical and Products Database (CPDat)
  15. EPA Pesticide Ecotoxicity Database
  16. EU Pesticides Database
  17. Japan Chemical Substance Dictionary (Nikkaji)
  18. USGS Columbia Environmental Research Center
  19. SpectraBase
  20. Springer Nature
  21. Wikidata
  22. PubChem
  23. 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
  24. GHS Classification (UNECE)
  25. 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/
  26. EPA Substance Registry Services
  27. MolGenie
    MolGenie Organic Chemistry Ontology
    https://github.com/MolGenie/ontology/
  28. PATENTSCOPE (WIPO)
CONTENTS