Agent Name


CAS Number




Major Category



(+-)-Trichlorfon; (2,2,2-Trichloro-1-hydroxyethyl)-phosphonic acid dimethyl; ester; 1-Hydroxy-2,2,2-trichloro-ethyle phosphonate de dimethyle; 1-Hydroxy-2,2,2-trichloro-ethyle phosphonate de dimethyle; [French]; 1-Hydroxy-2,2,2-trichloroethylphosphonic acid dimethyl ester; Aerol 1; Aerol 1 (pesticide); Agroforotox; Anthon; BAY 15922; BAY-L 1359; BAY-a 9826; Bayer 15922; Bayer L 13/59; Bayer L 1359; Bilarcil; Bovinox; Briten; Briton; Britten; Cekufon; Chlorak; Chlorfos; Chlorofos; Chloroftalm; Chlorophos; Chlorophosciclosom; Chlorophthalm; Chloroxyphos; Chlorphos; Ciclosom; Clorofos; Clorofos [Russian]; Combot; Combot equine; DEP (VAN); DEP (pesticide); DETF; Danex; Denkaphon; Depthon; Dicontal Fort; Dimethoxy-2,2,2-trichloro-1-hydroxy-ethyl phosphine oxide; Dimethoxy-2,2,2-trichloro-1-hydroxy-ethyl-phosphine oxide; Dimethyl (1-hydroxy-2,2,2-trichloroethyl)phosphonate; Dimethyl (2,2,2-trichloro-1-hydroxyethyl)phosphonate; Dimethyl 1-hydroxy-2,2,2-trichloroethyl phosphonate; Dimethyl 2,2,2-trichloro-1-hydroxyethylphosphonate; Dimethyltrichlorohydroxyethyl phosphonate; Dimetox; Dioxaphos; Dipterex; Dipterex 50; Dipterex SL; Dipterex WP 80; Diptevur; Ditrifon; Ditriphon 50; Dylox; Dyrex; Dyvon; ENT 19,763; Equino-aid; Flibol E; Fliegenteller; Forotox; Foschlor; Foschlor 25; Foschlor R; Foschlor R-50; Foschlor R-50 (VAN); Foschlorem [Polish]; Hypodermacid; Khloroftalm; Leivasom; Loisol; Masoten; Mazoten; Methyl chlorophos; Metrifonate; Metrifonato [INN-Spanish]; Metrifonatum [INN-Latin]; Metriphonate; Metriphonatum; Neguvon; O,O Dimetil 2,2,2-trichloro 1 hidroxietil fosfonato (Portugese); O,O-Dimethyl (1-hydroxy-2,2,2-trichloroethyl)phosphonate; O,O-Dimethyl (1-oxy-2,2,2-trichloroethyl)phosphonate; O,O-Dimethyl (2,2,2-trichloro-1-hydroxyethyl)phosphonate; O,O-Dimethyl (2,2,2-trichloro-1-hydroxyethyl)phosponate; O,O-Dimethyl-(1-hydroxy-2,2,2-trichloraethyl)phosphonsaeure ester [German]; O,O-Dimethyl-(1-hydroxy-2,2,2-trichloraethyl)phosphosaeure ester; O,O-Dimethyl-(1-hydroxy-2,2,2-trichlorathyl)-phosphat [German]; O,O-Dimethyl-(2,2,2-trichloor-1-hydroxy-ethyl)-fosfonaat [Dutch]; O,O-Dimethyl-(2,2,2-trichlor-1-hydroxy-aethyl)phosphonat [German]; O,O-Dimethyl-1-hydroxy-2,2,2-trichloroethylphosphonate; O,O-Dimethyl-1-oxy-2,2,2-trichloroethyl phosphonate; O,O-Dimetil-(2,2,2-tricloro-1-idrossi-etil)-fosfonato [Italian]; OMS 800; Phoschlor; Phoschlor R50; Phosphonic acid, (1-hydroxy-2,2,2-trichloroethyl)-, dimethyl ester; Phosphonic acid, (2,2,2-trichloro-1-hydroxyethyl)-, dimethyl ester; Polfoschlor; Proxol; Ricifon; Ritsifon; Satox 20WSC; Soldep; Sotipox; Trichloorfon [Dutch]; Trichlorfon [BSI:ISO]; Trichlorfon [German]; Trichlorofon; Trichlorophon; Trichlorphon; Trichlorphon FN; Trichlorphon [ISO]; Trinex; Tugon; Tugon fly bait; Tugon stable spray; Vermicide bayer 2349; Volfartol; Votexit; WEC 50; Wotexit; [ChemIDplus] UN2783


Organophosphate Insecticides


White solid; [Merck Index] White solid; Formulated as soluble powder and granular products; [Reference #2]


Applied to crops, livestock, shrubs, and trees to kill cockroaches, crickets, silverfish, bedbugs, fleas, cattle grubs, flies, ticks, leafminers, and leaf-hoppers; also used to kill fish and domestic animal parasites; [EXTOXNET] Also used as therapeutic anthelmintic (schistosoma); [Merck Index] A general purpose non-agricultural systemic insecticide; Used mostly for home and golf course turf, but also used for ornamentals, food and meat processing facilities (non-food contact surfaces), and ornamental and bait fish ponds; Used in other countries as pour-on cattle treatment; [Reference #2] Used in the EU on fruit trees, vegetables, field crops, and greenhouse crops; [EFSA]


Trichlorfon is classified as "moderately toxic" with an LD50 of 450-650 mg/kg in rats. Skin sensitivity has been reported. Delayed polyneuropathy has occurred in patients who ingested large amounts. [EXTOXNET] A small number of the organophosphates (OPs) can Induce Delayed Neuropathy (OPIDN). OPIDN usually occurs after ingestion and is usually nonoccupational. [Levy, p. 431] A slow release cholinesterase inhibitor; Non-enzymatically transformed into dichlorvos, the active compound; [Merck Index] A cholinesterase inhibitor that may cause nervous system effects (convulsions, respiratory failure, and death); May cause skin sensitization; Can be absorbed through skin; [ICSC] Reports of delayed neuropathy and skin sensitivity in humans; [HSDB] Produces the OP pesticide dichlorvos (DDVP) on degradation; In a study to evaluate use for treatment of Alzheimers disease, the LOEL (plasma and erythrocyte cholinesterase inhibition) was 5.0 mg/kg/day for a single oral dose in humans; [Reference #2] 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] See "Dichlorvos."

Reference Link

EXTOXNET - Trichlorfon

Exposure Assessment

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)

Insufficient data


1 mg/m3, inhalable fraction

Vapor Pressure

7.8E-6 mm Hg

Lethal Concentration

LC50 (rat) = 533 mg/m3

Explanatory Notes

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

Reference Link

EPA Pesticide Chemical Search

Adverse Effects
Skin Sensitizer



Motor Neuropathy

Other Poison


IARC Carcinogen

Not Classifiable

ACGIH Carcinogen

Not Classifiable

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information


Chemical Information

Search ChemIDplus

Biomedical References

Search PubMed

Related Information in HazMap

Occupational diseases associated with exposure to this agent:


Industrial Processes with risk of exposure: