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CAS Number: 141-66-2
Synonyms: Bidrin, Carbicron, Diapadrin, Dicron, Ektafos
Contaminant Type: Chemical

Dicrotophos is an organophosphate insecticide used to control insects in cotton. Dicrotophos can also be applied by tree injection to control insects on ornamental and non food bearing trees[1813].

Annual domestic use of dicrotophos in the U.S. is approximately 550,000 pounds. The bulk of this use is on cotton in the southeast, Texas, and Arkanssas [1813].

Its IUPAC name is (E)-2-dimethylcarbamoyl-1-methylvinyl dimethyl phosphate.  It is amixture of (E) and (Z) isomers with the (E) isomer being pesticidally active. 

Hydrolysis of dicrotophos in soil and water is pH dependent with half lives near 117days at pH 5 and near 28 days at pH 9.  Hydrolysis degradates are N,N-dimethylacetoacetamide and O-desmethyldicrotophos.  It can be aerobically and anaerobically microbially degraded with N,N-dimethylacetoacetamide as the major degradate.  Dicrotophos is not volatile or photodegradable.    

Dicrotophos is highly toxic and causes cholinesterase inhibition in animals [1813].  Dicrotophos is an inhibitor of plasma and red blood cell cholinesterase activity in humans [1811]. It can overstimulate the nervous system causing nausea, dizziness, confusion, and at very high exposures (e.g., accidents or major spills), respiratory paralysis and death.  No carcinogenic effects have been noted.

Dicrotophos in drinking water is not regulated by USEPA.  It is on the Contaminant Candidate List 3.

Date of Literature Search: September 2010

1811 National Institute for Occupational Safety and Health; 1995; Occupational safety and health guidelines for dicrotophos; www.cdc.gov/niosh/docs/81-123/pdfs/0203.pdf; As posted on 1995, NIOSH, Department of Health and Human Services
1813 USEPA; 2002; Dicrotophos facts; http://www.epa.gov/oppsrrd1/REDs/factsheets/dicrotophos_fs.htm; As posted on June 20, 2008. USEPA, Washington, DC.