3079. Dichlorvos

Nomenclature

CAS number: 62-73-7
Phosphoric acid 2,2-dichloroethenyl dimethyl ester; phosphoric acid 2,2-dichlorovinyl dimethyl ester; O,O-dimethyl O-(2,2-dichlorovinyl) phosphate; dichlorophos; dichlorovos; DDVP; SD-1750; Atgard (Boehringer, Ing.); Dedevap (Bayer CropSci.); Divipan (Makhteshim-Agan); Doom (United Phosphorus); Nuvan (Syngenta); Task (Boehringer, Ing.); Vapona (Boehringer, Ing.).
C4H7Cl2O4P; mol wt 220.98.
C 21.74%, H 3.19%, Cl 32.09%, O 28.96%, P 14.02%.

Description and references

Organophosphate insecticide; cholinesterase inhibitor. Prepn: Whetstone, Harman, US 2956073 (1960 to Shell). Toxicity: T. B. Gaines, Toxicol. Appl. Pharmacol. 14, 515 (1969) DOI PubMed. Determn in wheat: F. Longobardi et al., J. Agric. Food Chem. 53, 9389 (2005) DOI PubMed. Review of carcinogenicity studies: M. D. Reuber, Clin. Toxicol. 18, 47-84 (1981) PubMed; of toxicology and human exposure: Toxicological Profile for Dichlorvos (PB98-101124, 1997) 248 pp.

Chemical structure

Properties

Liquid. Poisonous. Practically non-flammable. d425 1.415. bp20 140°; bp1.0 84°; bp0.5 72°; bp0.01 30°. nD25 1.451. Vapor pressure at 20°: 1.2 × 10-2 mm Hg. Misc with alcohol and most non-polar solvents. Soly in water: about 1 g/100 ml; in glycerol: about 0.5 g/100 ml. LD50 orally in male, female rats: 80, 56 mg/kg (Gaines).

Caution

Potential symptoms of overexposure are miosis, aching eyes; rhinorrhea; headache; chest tightening, wheezing, laryngeal spasms and salivation; cyanosis; anorexia, nausea, vomiting and diarrhea; sweating; muscle fasciculation, paralysis, giddiness and ataxia; convulsions; low blood pressure, cardiac irregularities; irritation of eyes and skin. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 102.

Use

Insecticide; fumigant.

Therapeutic Category (Veterinary)

Anthelmintic; ectoparasiticide.