Disodium methyl arsonate

Disodium methyl arsenate (DSMA) is the organoarsenic compound with the formula CH3AsO3Na2. It is a colorless, water-soluble solid derived from methanearsonic acid. It is used as a herbicide.^[1] Tradenames include Metharsinat, Arrhenal, Disomear, Metharsan, Stenosine, Tonarsan, Tonarsin, Arsinyl, Arsynal, and Diarsen.

Disodium methyl arsonate

Names
IUPAC name Disodium methyl-dioxido-oxoarsorane
Other names Disodium methanearsonate; disodium methylarsonate
Identifiers
CAS Number	144-21-8 Y
3D model (JSmol)	Interactive image
Abbreviations	DSMA
ChemSpider	8603 N
ECHA InfoCard	100.005.110
PubChem CID	8947
UNII	7NK4BV40VN Y
CompTox Dashboard (EPA)	DTXSID4032665
InChI InChI=1S/CH5AsO3.2Na/c1-2(3,4)5;;/h1H3,(H2,3,4,5);;/q;2*+1/p-2 N Key: SDIXRDNYIMOKSG-UHFFFAOYSA-L N InChI=1/CH5AsO3.2Na/c1-2(3,4)5;;/h1H3,(H2,3,4,5);;/q;2*+1/p-2 Key: SDIXRDNYIMOKSG-NUQVWONBAA
SMILES C[As](=O)([O-])[O-].[Na+].[Na+]
Properties
Chemical formula	CH3AsNa2O3
Molar mass	183.93 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

The EPA states that all forms of arsenic are a serious risk to human health and the United States' Agency for Toxic Substances and Disease Registry ranked arsenic as number 1 in its 2001 Priority List of Hazardous Substances at Superfund sites.^[2] Arsenic is classified as a Group-A carcinogen.^[2] The EPA states^[3] that:

Arsenate (AsV) is the oxidized form and occurs in well-aerated soils, whereas in chemically-reduced soil environments, arsenite (AsIII) is the prevalent As form. Although arsenite is more toxic than arsenate, arsenate can also have deleterious effects on humans, plants, and microorganisms. Arsenic-contaminated soils pose serious risk to human health.

The EPA also states that, while contaminated soil poses a serious risk to health, arsenic frequently mobilizes from soils and other sources, ending up in water where it is even more of a toxicity issue.^[2]

See also

• Cacodylic acid
• Monosodium methyl arsenate