Trichlorfon

Trichlorfon

敌百虫

dimethyl (RS)-2,2,2-trichloro-1-hydroxyethylphosphonate
or
(RS)-2,2,2-trichloro-1-(dimethoxyphosphinoyl)ethanol

dimethyl (2,2,2-trichloro-1-hydroxyethyl)phosphonate

52-68-6

C₄H₈Cl₃O₄P

Insecticides > Organophosphorus insecticides

Insecticide

Trichlorfon+Rotenone
Trichlorfon+malathion
Trichlorfon+fenvalerate
Trichlorfon+beta-cypermethrin
Parathion-methyl+trichlorfon
Parathion+trichlorfon
Diazinon+Trichlorfon
Dusting powder, emulsifiable concentrate, granules, soluble powder, suspension concentrate, wettable powder. Premix Parters: epoxiconazole; tebuconazole; triadimenol;

Molecular weight:257.4; Physical form:Colourless crystals, with a weak, characteristic odour. Density:1.73 (20 °C); Composition:Racemate, i.e. 1:1 mixture of the (1R)- and (1S)- enantiomers. Melting point:78.5 °C; delayed melting to 84 °C; Vapour pressure:0.21 mPa (20 °C); 0.5 mPa (25 °C); Henry constant:4.4 × 10-7 Pa m3 mol-1 (20 °C); Partition coefficient(n-octanol and water):logP = 0.43 (20 °C); Solubility:In water 120 g/l (20 °C). Readily soluble in common organic solvents (with the exception of aliphatic hydrocarbons and petroleum oils), e.g. hexane 0.1-1, dichloromethane, isopropanol >200, toluene 20-50 (all in g/l, 20 °C).; Stability:Subject to hydrolysis and dehydrochlorination. Decomposition proceeds more rapidly with heating, and above pH 6. Rapidly converted by alkalis to dichlorvos ( q.v.), which is then hydrolysed: DT50;

Oral:Acute oral LD₅₀ for male and female rats c. 250 mg/kg. Percutaneous:Acute percutaneous LD₅₀ (24 h) for male and female rats >5000 mg/kg. Not irritating to skin and eye (rabbits). Inhalation:LC₅₀ (4 h) for male and female rats >2.3 mg/l air (aerosol). ADI:0.001 mg/kg b.w.

Ecotoxicology: 
Algae: E_rC₅₀ for Scenedesmus subspicatus >10 mg/l.Bees:Low toxicity to bees and other beneficial insects.Daphnia:LC₅₀ (48 h) 0.00096 mg/l.Fish: LC₅₀ (96 h) for rainbow trout 0.7, golden orfe 0.52 mg/l. 

Environmental fate: 
EHC 132 notes that trichlorfon is moderately toxic to fish and birds, and moderately to highly toxic to aquatic arthropods, and concludes it should not be sprayed over areas of water.Animals:In animals, trichlorfon is rapidly absorbed and metabolised. Excretion of the radioactivity in the urine is more or less complete within 6 hours. The major metabolites are dimethylphosphoric acid, monomethylphosphoric acid and conjugates of dichloroaceticSoil:Trichlorfon has a relatively high mobility in soil, but it is rapidly metabolised to CO₂. Intermediates are dichloroethanol, dichloroacetic acid and trichloroacetic acid. K_oc 20 .Plant:In plants, trichlorfon is rapidly hydrolysed. The main metabolites are dimethyl- and monomethyl- phosphoric acid and conjugates of dichloroacetic acid and dichloroethanol.

Hazard Class:II(Moderately hazardous)