Agent Name

Demeton-S-methyl

CAS Number

919-86-8

Formula

C6-H15-O3-P-S2

Major Category

Pesticides

Synonyms

2-Ethylthioethyl dimethyl phosphorothioate; Demeton-S-methyl; Demeton-S-metile [Italian]; Demetox; Dimethyl S-(2-eththioethyl)thiophosphate; Duratox; Ethanethiol, 2-(ethylthio)-, S-ester with O,O-dimethyl phosphorothioate; Metaisoseptox; Metaisosystox; Metasystox (I); Metasystox 55; Metasystox J; Methyl demeton thioester; Methyl isosystox; Methyl thionodemeton; Methyl-mercaptofos teolovy (USSR); Methylmercaptofostiol (USSR); Mifatox; O,O-Dimethyl 2-ethylmercaptoethyl thiophosphate, thiolo isomer; O,O-Dimethyl S-(2-(ethylthio)ethyl)phosphorothioate; O,O-Dimethyl S-(2-eththioethyl)phosphorothioate; O,O-Dimethyl S-ethylmercaptoethyl thiophosphate; O,O-Dimethyl-S-(2-aethylthio-aethyl)-monothiophosphat [German]; O,O-Dimethyl-S-(2-ethylthio-ethyl)-monothiofosfaat [Dutch]; O,O-Dimethyl-S-(3-thia-pentyl)-monothiophosphat [German]; O,O-Dimetil-S-(2-etiltio-etil)-monotiofosfato [Italian]; Phosphorothioic acid, O,O-dimethyl S-(2-(ethylthio)ethyl) ester; S-(2-(Ethylthio)ethyl) O,O-dimethyl phosphorothioate; S-(2-(Ethylthio)ethyl) O,O-dimethyl thiophosphate; S-(2-(Ethylthio)ethyl) dimethyl phosphorothiolate; Thiometon oxon; Thiophosphate de O,O-dimethyle et de S-2-ethylthio-ethyle [French]; [ChemIDplus] UN3018

Category

Organophosphate Insecticides

Description

Oily, colorless to pale yellow liquid with an unpleasant odor; [ACGIH]

Sources/Uses

Used as an insecticide and acaricide to control aphids, red spider mites, whiteflies, leaf hoppers, and sawflies on vegetables, fruits, and hops; [ACGIH]

Comments

A cholinesterase inhibitor that may cause CNS effects (cardiac disorders, convulsions, cyanosis, and respiratory failure); Can be absorbed through skin; [ICSC] A dermal sensitizer (positive sensitization testing in guinea pigs); [ACGIH] 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]

Restricted

No longer registered for use in the USA; [ACGIH]

Exposure Assessment
BEI

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]

Skin Designation (ACGIH)

Yes

TLV (ACGIH)

0.05 mg/m3, inhalable fraction and vapor

Lethal Concentration

LC50 (rat) = 500 mg/m3/4hr

Explanatory Notes

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

Adverse Effects
Skin Sensitizer

Yes

Other Poison

Organophosphate

ACGIH Carcinogen

Not Classifiable

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Related Information in HazMap
Diseases

Occupational diseases associated with exposure to this agent:

Processes

Industrial Processes with risk of exposure: