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Metam sodium

Names
Preferred IUPAC name Sodium methylcarbamodithioate
Other names Metham sodium Carbathion Carbathione Carbothion Metamsodium Metam-sodium
Identifiers
CAS Number	137-42-8
3D model (JSmol)	Interactive image
ChemSpider	2273119
ECHA InfoCard	100.004.812
PubChem CID	5366415
UNII	3CD7UKN224
CompTox Dashboard (EPA)	DTXSID2029167
InChI InChI=1S/C2H5NS2.Na/c1-3-2(4)5;/h1H3,(H2,3,4,5);/q;+1/p-1Key: AFCCDDWKHLHPDF-UHFFFAOYSA-M
SMILES .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 , 100 kPa). Y verify (what is  ?) 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 and other sulfur compounds.

Safety and environmental considerations

Metam sodium is nonpersistent in the environment since it decomposes rather quickly to toxic methyl isothiocyanate and carbon disulfide. In 1991 a tank car with 19,000 gallons of a metam sodium based pesticide spilled into Sacramento River above Lake Shasta. This killed all fish in a 41-mile stretch of the river. 20 years later the rainbow trout population had recovered.

See also

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

References

1. ^ Merck Index, 11th Edition, 5860.
2. ^ Hartwig, Jürgen; Sommer, Herbert; Müller, Franz (2008). "Nematicides". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a17_125.pub2. ISBN 978-3527306732.
3. 2000-2001 Pesticide Market Estimates Archived 2009-02-07 at the Wayback Machine, U.S. Environmental Protection Agency
4. ^ Bretaudeau Deguigne M, Lagarce L, Boels D, Harry P (2011). "Metam sodium intoxication: the specific role of degradation products--methyl isothiocyanate and carbon disulphide--as a function of exposure". Clin Toxicol (Phila). 49 (5): 416–22. doi:10.3109/15563650.2011.585472. PMID 21740140.{{cite journal}}: CS1 maint: multiple names: authors list (link)
5. "Largest chemical spill in California history". dtsc.ca.gov. Retrieved 2017-12-11.

External links

• Metam sodium in the Pesticide Properties DataBase (PPDB)

• Pesticides
• Herbicides
• Fungicides
• Dithiocarbamates
• Organic sodium salts