Disodium methyl arsonate

Disodium methyl arsonate
Names
	IUPAC name Disodium methyl-dioxido-oxoarsorane
	Other names Disodium methanearsonate; disodium methylarsonate
Identifiers
CAS Number	144-21-8 ;
3D model (JSmol)	Interactive image;
Abbreviations	DSMA
ChemSpider	8603 ;
ECHA InfoCard	100.005.110
PubChem CID	8947;
UNII	7NK4BV40VN ;
CompTox Dashboard (EPA)	DTXSID4032665 ;
	InChI InChI=1S/CH5AsO3.2Na/c1-2(3,4)5;;/h1H3,(H2,3,4,5);;/q;2+1/p-2 Key: SDIXRDNYIMOKSG-UHFFFAOYSA-L ; 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). verify (what is ?) Infobox references

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. Tradenames include Metharsinat, Arrhenal, Disomear, Metharsan, Stenosine, Tonarsan, Tonarsin, Arsinyl, Arsynal, and Diarsen.

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. Arsenic is classified as a Group-A carcinogen. The EPA states 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.