Metam sodium

Metam sodium

Names
Preferred IUPAC name Sodium methylcarbamodithioate
Other names Metham sodium Carbathion Carbathione Carbothion Metamsodium Metam-sodium
Identifiers
CAS Number	137-42-8 Y
3D model (JSmol)	Interactive image
ChemSpider	2273119 Y
ECHA InfoCard	100.004.812
PubChem CID	5366415
UNII	3CD7UKN224 Y
CompTox Dashboard (EPA)	DTXSID2029167
InChI InChI=1S/C2H5NS2.Na/c1-3-2(4)5;/h1H3,(H2,3,4,5);/q;+1/p-1 Y Key: AFCCDDWKHLHPDF-UHFFFAOYSA-M Y
SMILES [Na+].[S-]C(=S)NC
Properties
Chemical formula	C2H4NNaS2
Molar mass	129.18 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Metam sodium is an organosulfur compound with the formula CH₃NHCS₂Na. The compound is a sodium salt of a dithiocarbamate. The compound exists as a colorless dihydrate, but most commonly it is encountered as an aqueous solution. It is used as a soil fumigant, pesticide, herbicide, and fungicide. It is one of the most widely used pesticides in the United States, with approximately 60 million pounds used in 2001.

Preparation and properties

Metam sodium is prepared by combining methylamine, carbon disulfide, and sodium hydroxide:

CH₃NH₂ + CS₂ + NaOH → CH₃NHCS₂Na + H₂O

It also arises from the reaction of methyl isothiocyanate and sodium thiolate.

Upon exposure to the environment, metam sodium decomposes to methyl isothiocyanate.

Safety and environmental considerations

Metam sodium is nonpersistent in the environment since it is prone to hydrolysis. The degradation products, carbon disulfide and methyl amine are however toxic. In 1991 a tank car with 19,000 gallons of metam sodium spilled into Sacramento River above Lake Shasta. This killed all fish in a 41-mile stretch of the river. By 20 years later the rainbow trout population had recovered.

See also

• Zineb - A related dithiocarbamate salt which is also used as a fungicide

External links

• Metam sodium in the Pesticide Properties DataBase (PPDB)