Vamidothion

Synonyms

10465 RP; 2-(2-Dimethoxyphosphinoylthioethylthio)-N-methylpropionamide; American Cyanamid-43073; Dimethyl S-(2-(1-methylcarbamoylethylthio)ethyl) phosphorothiolate; ENT 26,613; Kilval; N-Methyl O,O-dimethylthiolophosphoryl-5-thia-3-methyl-2-valeramide; N-Methyl-3-thia-2-methyl-valeramid der O,O-dimethylthiolphosphorsaeure [German]; NPH 83; O,O-Dimethyl S-(2-((1-methyl-2-(methylamino)-2-oxoethyl)thio)ethyl) phosphorothioate (9CI); O,O-Dimethyl S-(2-(1-methylcarbamoylethylthio)ethyl) phosphorothioate; O,O-Dimethyl S-2-(1-N-methylcarbamoylethylmercapto)ethyl thiophosphate; O,O-Dimethyl phosphorothioate S-ester with 2-((2-mercaptoethyl)thio)-N-methylpropionamide; R.P. 10,465; RP-9895; Trucidor; Vamidoate; Phosphorothioic acid, O,O-dimethyl S-(2-((1-methyl-2-(methylamino)-2-oxoethyl)thio)ethyl) ester; Phosphorothioic acid, O,O-dimethyl ester, S-ester with 2-((2-mercaptoethyl)thio)-N-methylpropionamide; [ChemIDplus] UN2783

Category

Organophosphate Insecticides

Description

Colorless or white solid; [HSDB] Colorless solid; [MSDSonline]

Sources/Uses

Used as systemic acaricide and insecticide for fruit trees, vines, ornamentals, beets, potatoes, cotton, rice, and other crops; Registered for use in many other countries; [HSDB]

Comments

A cholinesterase inhibitor that may have nervous system effects causing convulsions and respiratory failure; Can be absorbed through skin; [ICSC] No adverse histopathological findings, increased tumors, or signs of developmental, delayed neurological, or teratogenic toxicity; [HSDB] “The average of two baseline respective cholinesterase activity determinations three days apart, with no exposures to enzyme inhibiting pesticides for at least 30 days, is recommended for each worker prior to exposure to cholinesterase inhibitors because of large inter-individual differences in published baseline values. To be established at least once a year. Removal from workplace exposures is recommended until the cholinesterase activity returns to within 20% of baseline.” [TLVs and BEIs]

No longer registered as a pesticide for use in the US; [HSDB] Banned in the EU for use as a biocide and agricultural insecticide; [eChemPortal: ESIS]

Biomedical References

Acetylcholinesterase activity in red blood cells = 70% of individual's baseline; Butylcholinesterase activity in serum or plasma = 60% of individual's baseline; Sample at end of shift; [TLVs and BEIs]

1.37E-06 mm Hg

LC50 (rat) = 1,730 mg/m3/4h

Explanatory Notes

The Guide in the Emergency Response Guidebook is for "Organophosphorus pesticide, solid, toxic."

Other Poison

Organophosphate

Diseases

Occupational diseases associated with exposure to this agent:

• Organophosphates & carbamates, acute poisoning

Processes

Industrial Processes with risk of exposure:

• Farming (Pesticides)