Methyl parathion

Synonyms

8056HC; A-GRO; Azofos; Azophos; BAY 11405; BAY E-601; Bladan-M; Cekumethion; Dalf; Demethylfenitrothion; Devithion; Dimethyl 4-nitrophenyl phosphorothionate; Dimethyl p-nitrophenyl monothiophosphate; Dimethyl p-nitrophenyl phosphorothionate; Dimethyl p-nitrophenyl thiophosphate; Dimethyl parathion; Dimethyl-p-nitrophenyl thionphosphate; Drexel methyl parathion 4E; E 601; EPA Shaughnessy Code: 053501; Folidol 600; Folidol M; Folidol M 50; Folidol M-40; Folidol-80; Fosferno M 50; Kilex parathion; M-Parathion; M40 & 80; ME 605; Me 605SP; Me-parathion; Mepaton; Meptox; Metacid 50; Metacide; Metacide (insecticide); Metafos; Metafos (pesticide); Metaphos; Methyl 1605; Methyl fosferno; Methyl niran; Methyl-E 605; Methylparathion; Methylthiophos; Metilparation (Hungarian); Metron; Metron (pesticide); Metyloparation [Polish]; Metylparation [Czech]; Nitrox; Nitrox 80; O,O-Dimethyl O-(p-nitrophenyl) phosphorothioate; O,O-Dimethyl O-(p-nitrophenyl) thionophosphate; O,O-Dimethyl O-p-nitrophenyl thiophosphate; O,O-Dimethyl-O-(4-nitro-fenyl)-monothiofosfaat [Dutch]; O,O-Dimethyl-O-(4-nitro-phenyl)-monothiophosphat [German]; O,O-Dimethyl-O-(4-nitrophenyl) phosphorothioate; O,O-Dimethyl-O-(4-nitrophenyl)-thionophosphat [German]; O,O-Dimethyl-O-(p-nitrophenyl)-thionophosphat [German]; O,O-Dimethyl-O-p-nitrofenylester kyseliny thiofosforecne [Czech]; O,O-Dimethyl-O-p-nitrofenylthiofosfat [Czech]; O,O-Dimetil-O-(4-nitro-fenil)-monotiofosfato [Italian]; Oleovofotox; Parapest M-50; Parathion methyl; Parathion methyl homolog; Parathion-methyl; Parathion-metile [Italian]; Paratox; Paratuf; Parton-M; Partron M; Penncap MLS; Penncap-M; Phenol, p-nitro-, O-ester with O,O-dimethyl phosphorothioate; Phenol, p-nitro-, O-ester with O,O-dimethylphosphorothioate; Quinophos; Sinafid M-48; Tekwaisa; Thiophenit; Thiophosphate de O,O-dimethyle et de O-(4-nitrophenyle) [French]; Thylpar M-50; Vofatox; Wofatox; Wofatox 50 EC; Wofatox 80; Yphos; p-Nitrophenyldimethylthionophosphate; [ChemIDplus]

Category

Organophosphate Insecticides

Description

White to tan, crystalline solid or powder with a pungent, garlic-like odor. [pesticide]; [NIOSH]

Sources/Uses

Used to kill boll weevils on cotton; [EXTOXNET]

Comments

Classified as "highly toxic," and most formulations may be used only by certified applicators; [EXTOXNET] Allergic contact dermatitis reported in sprayers; [Kanerva, p. 1431] “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]

Reference Link #1

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]

Yes

0.02 mg/m3, inhalable fraction and vapor

3.5E-06 mm Hg

0.0012 ppm

LC50 (rat) = 34 mg/m3/4h

Explanatory Notes

Odor threshold from AIHA;

Reference Link #2

Yes

Not classifiable

Not Classifiable

Other Poison

Organophosphate

Diseases

Occupational diseases associated with exposure to this agent:

• Contact dermatitis, allergic
• Organophosphates & carbamates, acute poisoning

Processes

Industrial Processes with risk of exposure:

• Farming (Pesticides)