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Trichlorfon is a moderately toxic organophosphate insecticide which is registered as a General Use Pesticide by the EPA but the primary manufacture, Bayer Corporation, has voluntarily canceled its production of most products containing the chemical (#INCHEM and #EXTOXNET). It is used to control insects on numerous crops (see #Uses below).


  1. #Chemical Description
  2. #Uses
  3. #Health Effects
  4. #Environmental Effects
  5. #Precautions
  6. #Regulation
  7. #External Links
  8. #References

    Just the facts

    Physical Information

    Name: Trichlorfon

    Use: organophosphate insecticide

    Formula: C 4 H 8 Cl 3 O 4 P

    Synonyms: chlorofos, DEP, DETF, dipterex, dimethyl 1-hydroxy- 2,2,2-trichloro ethanephosphonate, O, O-dimethyl (2,2,2-trichloro-1-hydroxyethyl), phosphonate, metrifonate, foschlor, trichlorofon, trichlorphon

    Trade Names: Anthon, Bovinos, Briten, Chlorophos, Ciclosom, Dipterex, Ditrifon, Dylox, Dyrex, Equino-Aid, Foschlor, Leivasom, Neguvon, Masoten, Pronto, Phoschlor, Proxol, Totalene, Trichlorophene, Trichlorophon, Trinex, Tugon and Vermicide Bayer 2349

    Source: synthetic chemistry

    Recommended daily intake: none

    Absorption: dermal, inhalation, ingestion

    Sensitive individuals: workers

    Toxicity/symptoms: moderately toxic

    Regulatory facts: registered as a General Use Pesticide (GUP)

    Chemical Structure

    Structure retrieved from #INCHEM.

Chemical Description

Trichlorfon is a colorless powder at room temperature.


Trichlorfon is produced and used in dust, emulsifiable concentrate, granular, fly bait, and soluble powder formulations and the concentration of trichlorfon in the product ranges from around 40-98% (#EXTOXNET). It has been used since the early 1950s in a number of settings. It was used on a variety of crops to control insects such as cockroaches, crickets, silverfish, bedbugs, fleas, cattle grubs, flies, ticks, leafminers, and leaf-hoppers (#EXTOXNET). It was also used on livestock, domestic settings, greenhouses, and aquatic environments (#EXTOXNET). During the height of its use, 500,000-1,000,000 were applied annually (#EPA).

Health Effects

Main Article: Cholinesterase Inhibitor
The undesirable health effects associated with trichlorfon, and all Organophosphates for that matter, is its cholinesterase inhibiting properties. It is a moderately toxic organophosphate absorbed easily dermally but also can have negative effects when its's fumes are inhaled or it is ingested (#EXTOXNET).

It is "Suspected" (but not listed as definitively) the following long-term health problems (#Scorecard):
* Carcinogen
* Neurotoxicant
* Immunotoxicant
* Devlopmental Toxicant
* Gastrointestinal or Liver Toxicant
* Reproductive Toxicant

Cases of occupational and accidental exposure have been documented with some cases resulting in fatalaties (#INCHEM).

Environmental Effects

Trichlorfon breaks down and degrades very rapidly in soil with a half-life of anywhere from 3-27 days and usually only negligible amounts are left in the soil a month after treatment (#INCHEM and #EXTOXNET). Because it does not bind strongly to soil particles it is likely to leach into groundwater sources where tt is stable in water below 5.5 pH but at higher pH level's, it is converted to dichlorvos (#INCHEM and #EXTOXNET). Though it leeched into groundwater easily, it has little prospect of causing lasting damage to groundwater supplies because it evaporates easily, often with the majority being evaporated after oly two hours (#EXTOXNET).

In laboratory settings, Trichlorfon is highly toxic to most aquatic organisms, but in practice the amount of trichlorfon rarely reached levels considered high enough to cause real harm to fish and therefore it probably had negligible effects on populations (#INCHEM). The same scenerio is observed in relation to birds: highly toxic in labaratory settings but a negligible effect on overall populations (#INCHEM).


Trichlorfon is classified by the EPA) as a General Use Pesticide (GUP) and is in toxicity class II (Moderately Toxic) with products containing trichlorfon bear the Signal Word WARNING (#EXTOXNET). But, the main producer, Bayer, voluntarily canceled production of most products containing trichlorfan in 1995 (#EPA). Additionally it is on three federal regulatory lists: Hazardous Substances (Superfund), Registered Pesticides (Federal Insecticide, Fungicide, and Rodenticide Act), and Toxic Release Inventory Chemicals (#Scorecard).



United States Environmental Protection Agency (EPA). "Reregistration Eligibility Decision (RED) Trichlorfon". January 1997.

Extension Toxicology Network. "Pesticide Information Profile -Trichlorvos". Revised June 1996. Accessed 10-11-07.

World Health Organization (WHO) - International Programme on Chemical Safety (INCHEM). "ENVIRONMENTAL HEALTH CRITERIA 132 - TRICHLORFON. 1992.

Scorecard. "Chemical Profiles - Trichlorfon". Accessed 10-11-07.

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