Basic information
- Standard SMILES
COP(=O)(OC)C(O)C(Cl)(Cl)Cl- InChIKey
NFACJZMKEDPNKN-UHFFFAOYSA-N- Molecular formula
- C4H8Cl3O4P
- Average molar mass
- 257.43 g/mol
- Monoisotopic mass
- 255.92257841
Overview
Trichlorfon is a white crystalline solid. It is a wettable powder. It can cause illness by inhalation, skin absorption and/or ingestion. It is used as a pesticide.
Names & identifiers
- Preferred name
- Trichlorfon
- IUPAC
- 2,2,2-trichloro-1-dimethoxyphosphorylethanol
- English name
- Trichlorfon
- Molecular formula
- C4H8Cl3O4P
- Molecular weight
- 257.44
Names & synonyms
Show more names
Database identifiers
- CAS
52-68-6、56042-26-3、56042-27-4- PubChem CID
- 5853
- DTXSID
DTXSID0021389- ChEMBL
CHEMBL167150- ChEBI
CHEBI:6908- UNII
- 1MVY4KU98F、37VCQ9C0OG、DBF2DG4G2K
- EC Number
- 200-149-3
- Nikkaji
- J2.309D
Properties
Computed structural properties
- XLogP
- 0.5
- Topological polar surface area
- 55.8 Ų
- Hydrogen bond donors
- 1
- Hydrogen bond acceptors
- 4
- Rotatable bonds
- 3
- Heavy atoms
- 12
- Formal charge
- 0
- Complexity
- 183
Experimental & physicochemical properties
Pesticides
Insecticides
Active substance -> EU Pesticides database: Not approved
Pesticides -> Organophosphate Insecticides
Environmental transformation -> Pesticides (parent, predecessor)
Insecticides
Pesticide (Trichlorfon) -> USDA PDB
LogP
log Kow = 0.51
0.48
1.7
Odor
Ethyl ether-like
Weak, characteristic odor
Density
1.73 at 68 °F (USCG, 1999) - Denser than water; will sink
1.73 g/cu cm at 20 °C
Relative density (water = 1): 1.73
1.73
1.73 @ 20°C
Color/Form
White crystals
White, crystalline solid
Colorless crystals
Solubility
10 to 50 mg/mL at 70 °F (NTP, 1992)
In water, 1.20X10+5 mg/L at 25 °C
Soluble in benzene, ethanol; sparsely soluble in diethyl ether and petroleum ether
Solubility: 152 g/kg in benzene; 299 g/kg in dichloromethane; 200 g/kg in isopropanol; 30 g/kg in toluene
Soluble in benzene, chloroform, ether; insoluble in oils
Very soluble in methylene chloride; freely soluble in acetone, alcohol, chloroform, ether; soluble in benzene; very slightly soluble in hexane, pentane, carbon tetrachloride, diethyl ether
Boiling Point
212 °F at 0.1 mmHg (NTP, 1992)
BP: 100 °C at 0.1 mm Hg
212 °F at 0.1 mmHg
Physicochemical properties
- Melting point
- 77 · 77-81 °C
- Boiling point
- 100 °C · 100°C
- Density
- 1.73 · 1.73
- vapor pressure
- 2.1 · 2.1×10-4Pa (20 °C)
- refractive index
- 1.3439 · 1.3439
- storage temp.
- 2 · 2-8°C
- solubility
- Freely soluble in water, very soluble in methylene chloride, freely soluble in acetone and in ethanol (96 per cent).
- pka
- 6 · 6 (est.)
- form
- solid
- color
- Crystals
- Water Solubility
- 1 · Slightly soluble. 1-5 g/100 mL at 21 ºC
- Merck
- 13 · 13,9696
- BRN
- 1709434 · 1709434
- Henry's Law Constant
- 5.5 · 5.5×101 mol/(m3Pa) at 25℃, Chao et al. (2017)
- Exposure limits
- 0.5 mg/m3; · PC-TWA: 0.5 mg/m3; PC-STEL: 1 mg/m3
- Stability
- Light Sensitive
- Major Application
- agricultureenvironmental
- InChI
- 1S/C4H8Cl3O4P/c1-10-12(9,11-2)3(8)4(5,6)7/h3,8H,1-2H3
- InChIKey
- NFACJZMKEDPNKN-UHFFFAOYSA-N
- SMILES
- COP(=O)(OC)C(O)C(Cl)(Cl)Cl
- Toxicology and Carcinogenesis
- Trichlorfon (CASRN 52-68-6) - No report issued.
- EWG's Food Scores
- 9 · 9
- FDA UNII
- 2 DG4G2K · DBF2DG4G2K
- ATC code
- 2 BB01 · P02BB01
- IARC
- 3 · 3 (Vol. 30, Sup 7) 1987
- NIST Chemistry Reference
- Metrifonate(52-68-6)
- EPA Substance Registry System
- Trichlorfon (52-68-6)
- Pesticides Freedom of Information Act (FOIA)
- Trichlorfon
- UNSPSC Code
- 41116107 · 41116107
- NACRES
- 24 · NA.24
- Symbol(GHS)
- 7 · GHS07,GHS09
- Signal word
- Warning
- Hazard statements
- 302 · H302-H317-H400-H410
- Precautionary statements
- 264 · P264-P270-P261-P272-P280-P273-P301+P312-P330-P302+P352-P333+P313-P362+P364-P391-P501
- PPE
- 95 · dust mask type N95 (US), Eyeshields, Faceshields, Gloves
- Hazard Codes
- Xn,N
- Risk Statements
- 22 · 22-43-50/53
- Safety Statements
- 24 · 24-37-60-61-2
- RIDADR
- 3077 · UN 3077 9/PG 3
- WGK Germany
- 3 · 3
- RTECS
- 700000 · TA0700000
- HazardClass
- 6.1 · 6.1(b)
- PackingGroup
- III
- HS Code
- 29319090 · 29319090
- Storage Class
- 11 · 11 - Combustible Solids
- Hazard Classifications
- 4 DermalAcute · Acute Tox. 4 DermalAcute Tox. 4 OralAquatic Acute 1Aquatic Chronic 1Resp. Sens. 1Skin Sens. 1
- Hazardous Substances Data
- 52 · 52-68-6(Hazardous Substances Data)
- Toxicity
- 50 in · LD50 in male, female rats (mg/kg): 630, 560 orally (Gaines)
Safety & regulation
GHS classification
GHS Classification
Warning
H302: Harmful if swallowed [Warning Acute toxicity, oral]
P261, P264, P270, P272, P273, P280, P301+P317, P302+P352, P321, P330, P333+P317, P362+P364, P391, and P501 (click each P-code to see the statement)
Danger
H301 (29.6%): Toxic if swallowed [Danger Acute toxicity, oral]
P233, P260, P261, P264, P270, P271, P272, P273, P280, P284, P301+P316, P301+P317, P302+P352, P304+P340, P317, P321, P330, P333+P317, P342+P316, P362+P364, P391, P403, P405, and P501 (click each P-code to see the statement)
Hazard information
Regulatory Information
Chemical: Phosphonic acid, P-(2,2,2-trichloro-1-hydroxyethyl)-, dimethyl ester
Commission Regulation (EC) No 451/2000
Trichlorfon is listed in the dataset of EPA Human Health Benchmarks for Pesticides under the Safe Drinking Water Act (40 eCFR 141)
2007/356
Trichlorfon: Does not have an individual approval but may be used under an appropriate group standard
The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)
Fire Hazards
Excerpt from ERG Guide 152 [Substances - Toxic (Combustible)]:
Combustible.
Health Hazards
INHALATION, INGESTION, AND SKIN ABSORPTION. Inhibits cholinesterase. Headache, depressed appetite, nausea, miosis are symptoms of light exposures. Moderate effects are peritoneal paralysis, diarrhea, salivation, lacrimation, sweating, dyspnea, substernal tightness, slow pulse, tremors, muscular cramps and ataxia. Severe symptoms are: pyrexia, cyanosis, pulmonary edema, areflexia, loss of sphincter control, paralysis, coma, heart block, shock and respiratory failure. EYES: Increases permeability of blood vessels in anterior eye. Reduces corneal sensitivity with glaucoma, abnormalities in intraocular tension or decreased visual acuity. (USCG, 1999)
Hazards Summary
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 Alzheimer's 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.
FDA Requirements
Oral dosage form new animal drugs. Mebendazole and trichlorfon powder. ... Indications for use: It is used in horses for the treatment of infections of bots (Gastrophilus intestinalis and G. nasalis), large roundworms (Parascaris equorum), large strongyles (Strongylus edentatus, S. equinus, S. vulgaris), small strongyles, and pinworms (Oxyuris equi.)
Oral dosage form new animal drugs. Mebendazole and trichlorfon paste. ... Indications for use: It is used in horses for the treatment of infections of bots (Gastrophilus intestinalis and G. nasalis), large roundworms (Parascaris equorum), large strongyles (Strongylus edentatus, S. equinus, S. vulgaris), small strongyles, and pinworms (Oxyuris equi.)
Oral dosage form new animal drugs. Oxfendazole and trichlorfon paste. ... Indications for use: The drug is used in horses for removal of bots (Gasterophilus intestinalis, 2nd and 3rd instars; G. nasalis, 3rd instar) and the following gastrointestinal worms: Large roundworms (Parascaris equorum), pinworms (Oxyuris equi), adult and 4th stage larvae; large strongyles (Strongylus edentatus, S. vulgaris, and S. equinus); and small strongyles.
Oral dosage form new animal drugs. Thiabendazole with trichlorfon. ... Indications for use /in horses/. For the treatment and control of bots (Gasterophilus spp.), large strongyles (Strongylus spp.), small strongyles (genera Cyathostomum, Cylicobrachytus, Craterostomum, Oesophagodontus, Poteriostomum), pinworms (Oxyuris spp., Strongyloides spp.), and ascarids (Parascaris spp.).
For more FDA Requirements (Complete) data for Trichlorfon (7 total), please visit the HSDB record page.
Special Reports
WHO; Environmental Health Criteria 132: Trichlorfon (1992)[Available from, as of May 24, 2017: http://www.inchem.org/documents/ehc/ehc/ehc132.htm]
USEPA/Office of Prevention, Pesticides and Toxic Substances; Report of the Food Quality Protection Act (FQPA) Tolerance Reassessment Progress and Risk Management Decision (TRED) for Trichlorfon EPA 738-R-01-009 (September 2001). EPA issues a TRED for a pesticide that requires tolerance reassessment decisions, but does not require a reregistration eligibility decision at present because: the pesticide was initially registered after November 1, 1984, and by law is not included within the scope of the reregistration program; EPA completed a RED for the pesticide before FQPA was enacted on August 3, 1996; or the pesticide is not registered for use in the U.S. but tolerances are established that allow crops treated with the pesticide to be imported from other countries.[Available from, as of June 20, 2017: http://www.epa.gov/pesticides/reregistration/status.htm]
USEPA/Office of Prevention, Pesticides and Toxic Substances; Reregistration Eligibility Decision Document for Trichlorfon EPA 738-R-96-017 (January 1997). The RED summarizes the risk assessment conclusions and outlines any risk reduction measures necessary for the pesticide to continue to be registered in the USA.[Available from, as of June 20, 2017: http://www.epa.gov/pesticides/reregistration/status.htm]
Safety & protection
Fire Fighting
Excerpt from ERG Guide 152 [Substances - Toxic (Combustible)]:
In case of fire in the surroundings, use appropriate extinguishing media.
First Aid Measures
Fresh air, rest. Refer for medical attention.
Remove contaminated clothes. Rinse and then wash skin with water and soap. Refer for medical attention .
First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.
Induce vomiting (ONLY IN CONSCIOUS PERSONS!). Rest. Refer for medical attention .
First Aid
EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.
Exposure Control and Personal Protection
Biological Exposure Indices (BEI) [ACGIH] - 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]
Fire Fighting Procedures
Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
Advice for firefighters: Wear self-contained breathing apparatus for firefighting if necessary.
If material involved in fire: Extinguish fire using agent suitable for type surrounding fire. (Material itself does not burn, or burns with difficulty.)
For small fires, use dry chemical, carbon dioxide, water spray, or foam. For large fires, use water spray, fog, or foam. ... If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters. Notify local health and fire officials and pollution control agencies. From a secure, explosion-proof location, use water pray to cool exposed containers. If cooling streams are ineffective (venting sound increases in volume and pitch, tank discolors, or shows any signs of deforming), withdraw immediately to a secure position. ... The only respirators recommended for firefighting are self-contained breathing apparatuses that have full face-pieces and are operated in a pressure-demand or other positive-pressure mode.
Storage Conditions
Keep container tightly closed in a dry and well-ventilated place. Storage class (TRGS 510): Non Combustible Solids.
Store in a secure poison location. ... Store in tightly closed containers in a cool, well-ventilated area away from alkaline materials. Where possible, automatically transfer material from other storage containers to process containers.
Cleanup Methods
ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid dust formation. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. Avoid breathing dust. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided. Methods and materials for containment and cleaning up: Pick up and arrange disposal without creating dust. Sweep up and shovel. Keep in suitable, closed containers for disposal.
Environmental considerations - Land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. Cover solids with a plastic sheet to prevent dissolving in rain or fire fighting water. Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete.
Environmental considerations - Water spill: Use natural barriers or oil control booms to limit spill travel. Use natural deep water pockets, excavated lagoons, or sand bag barriers to trap material at bottom. Remove trapped material with suction hoses.
As for other organophosphorus pesticides, stay upwind; keep out of low areas. Ventilate closed spaced before entering them. Wear positive-pressure breathing apparatus and special protective clothing. Do not touch spilled material; stop leak if you can do so without risk. Use water spray to reduce vapors. Small spills: Absorb with sand or other noncombustible absorbent material and place into containers for later disposal. Small dry spills: With clean shovel place material into clean dry containers and cover; move containers from spill area. Large spills: Dike far ahead of spill for later disposal. Ventilate area after cleanup is complete. It may be necessary to contain and dispose of this chemical as a hazardous waste. If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters.
Disposal Methods
SRP: Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.
SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.
Product: Offer surplus and non-recyclable solutions to a licensed disposal company. Contact a licensed professional waste disposal service to dispose of this material. Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber; Contaminated packaging: Dispose of as unused product.
Add a combustible solvent and burn in a furnace equipped with an afterburner and an alkali scrubber. In accordance with 40CFR165, follow recommendations for the disposal of pesticides and pesticide containers. Must be disposed properly by following package label directions or by contacting your local or federal environmental control agency, or by contacting your regional EPA office.
Trichlorofon initially hydrolyzes to the more toxic compound dichlorvos at pH 8 and 37.5 °C, but is essentially 100% hydrolyzed in approximately 24 hr to nontoxic products which can be mixed with a portion of soil rich in organic matter and buried. Recommendable methods: Incineration, hydrolysis, and landfill. Peer-review: Large amount of trichlorofon should be incinerated at high temperature in a unit with effluent gas scrubbing. (Peer-review conclusions of a IRPTC expert consultation (May 1985))
Spillage Disposal
Personal protection: filter respirator for organic gases and particulates adapted to the airborne concentration of the substance. Do NOT let this chemical enter the environment. Do NOT wash away into sewer. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Then store and dispose of according to local regulations.
Toxicology
Treatment
If the compound has been ingested, rapid gastric lavage should be performed using 5% sodium bicarbonate. For skin contact, the skin should be washed with soap and water. If the compound has entered the eyes, they should be washed with large quantities of isotonic saline or water. In serious cases, atropine and/or pralidoxime should be administered. Anti-cholinergic drugs work to counteract the effects of excess acetylcholine and reactivate AChE. Atropine can be used as an antidote in conjunction with pralidoxime or other pyridinium oximes (such as trimedoxime or obidoxime), though the use of '-oximes' has been found to be of no benefit, or possibly harmful, in at least two meta-analyses. Atropine is a muscarinic antagonist, and thus blocks the action of acetylcholine peripherally.
Interactions
The aim of this study is to determine the effect of levamisole and levamisole-trichlorfon combination on isolated sheep trachea. Contraction was achieved with levamisole concentrations (10(-8)-10(-3) M) on tracheal strips of adult sheep (> 1 year of age). Pretreatment with trichlorfon (10(-7) M)-levamisole (10(-7) M) decreased the pD2 and E(max) of Ach when compared to levamisole pretreatment (p < or = 0.01). Pretreatment with levamisole (10(-7) M), decreased the E(max) (p < or = 0.01) and pD2 (p < 0.05) of bethanechol concentrations (10(-8)-10(-3) M) significantly. Pretreatment with atropine (10(-6) M) decreased the E(max) of levamisole (10(-4) M) significantly (p < 0.05). To conclude, levamisole acted mainly on the muscarinic receptors of the sheep trachea and this effect was partly inhibited by atropine. Adverse interaction was present between levamisole and trichlorfon.
In the forward mutation test system ade6 of the yeast Saccharomyces pombe, trichlorfon in combination with azinphos-methyl produced clearly synergistic effects for toxicity and mutagenicity. The addition of S9 microsomal liver fraction decreased the efficiency of single and combined treatments.
12 organophosphorus insecticides were tested for toxicity and mutagenicity in the forward mutation test system ade6 of the yeast Schizosaccharomyces pombe. EMS and MMS were selected as positive controls. 3 compounds, dichlorvos, trichlorfon and paraoxon, showed a linear dose-response relationship. Among the other compounds investigated, methyl derivatives, though in general more toxic than ethyl derivatives, did not significantly increase the mutation frequency. Trichlorfon, tested in combination with malathion, methylparathion or methylazinphos (guthion), produced clearly synergistic effects for both toxicity and mutagenicity. The addition of S9 microsomal liver fraction decreased the efficiency of both single and combined treatments only where a dose-response relationship or a synergistic effect was obtained.
Two randomized crossover studies were conducted to examine the effects of a combination of aluminum hydroxide (aluminium hydroxide) and magnesium hydroxide (Maalox TC), cimetidine, and ranitidine on the pharmacokinetics of trichlorfon (metrifonate) and its metabolite in a total of 34 healthy subjects (ages 45-75 yr) who received a single oral tablet of 50 mg trichlorfon alone, with or 90 min before a suspension of Maalox TC, or with or after pretreatment with oral tablets of 400 mg cimetidine or 150 mg ranitidine. The ratios and 90% confidence intervals (trichlorfon with comedication/trichlorfon alone) of AUC and Cmax of the drug and its metabolites fulfilled the criteria defined for showing lack of relevant interaction for all treatment comparisons in both studies. Trichlorfon was well tolerated.
For more Interactions (Complete) data for Trichlorfon (6 total), please visit the HSDB record page.
Health Effects
Acute exposure to cholinesterase inhibitors can cause a cholinergic crisis characterized by severe nausea/vomiting, salivation, sweating, bradycardia, hypotension, collapse, and convulsions. Increasing muscle weakness is a possibility and may result in death if respiratory muscles are involved. Accumulation of ACh at motor nerves causes overstimulation of nicotinic expression at the neuromuscular junction. When this occurs symptoms such as muscle weakness, fatigue, muscle cramps, fasciculation, and paralysis can be seen. When there is an accumulation of ACh at autonomic ganglia this causes overstimulation of nicotinic expression in the sympathetic system. Symptoms associated with this are hypertension, and hypoglycemia. Overstimulation of nicotinic acetylcholine receptors in the central nervous system, due to accumulation of ACh, results in anxiety, headache, convulsions, ataxia, depression of respiration and circulation, tremor, general weakness, and potentially coma. When there is expression of muscarinic overstimulation due to excess acetylcholine at muscarinic acetylcholine receptors symptoms of visual disturbances, tightness in chest, wheezing due to bronchoconstriction, increased bronchial secretions, increased salivation, lacrimation, sweating, peristalsis, and urination can occur. Certain reproductive effects in fertility, growth, and development for males and females have been linked specifically to organophosphate pesticide exposure. Most of the research on reproductive effects has been conducted on farmers working with pesticides and insecticdes in rural areas. In females menstrual cycle disturbances, longer pregnancies, spontaneous abortions, stillbirths, and some developmental effects in offspring have been linked to organophosphate pesticide exposure. Prenatal exposure has been linked to impaired fetal growth and development. Neurotoxic effects have also been linked to poisoning with OP pesticides causing four neurotoxic effects in humans: cholinergic syndrome, intermediate syndrome, organophosphate-induced delayed polyneuropathy (OPIDP), and chronic organophosphate-induced neuropsychiatric disorder (COPIND). These syndromes result after acute and chronic exposure to OP pesticides.
Ecotoxicity Values
LC50; Species: Gammarus fasciatus (/Scud/) mature; Conditions: static bioassay without aeration, 21 °C, pH 7.2-7.5, water hardness 40-50 mg/L as calcium carbonate and alkalinity of 30-35 mg/L; Concentration: 40 ug/L for 96 hr (95% confidence limit: 26-60 ug/L) /Technical material 98%/
LC50; Species: Procambarus (Crayfish) mature; Conditions: static bioassay without aeration, 12 °C, pH 7.2-7.5, water hardness 40-50 mg/L as calcium carbonate and alkalinity of 30-35 mg/L; Concentration: 7800 ug/L for 96 hr (95% confidence limit: 6520-9330 ug/L) /Technical material 98%/
LC50; Species: Pteronarcella badia (/Stonefly/) naiads; Conditions: static bioassay without aeration, pH 7.2-7.5, water hardness 40-50 mg/L as calcium carbonate and alkalinty of 30-35 mg/L; Concentration: 11 ug/L for 96 hr (95% confidence limit: 7.6-16 ug/L) /Technical material 98%/
LC50; Species: Pteronarcys california (/Stonefly/) second year class; Conditions: static bioassay without aeration, 16 °C, pH 7.2-7.5, water hardness 40-50 mg/L as calcium carbonate and alkalinity of 30-35 mg/L; Concentration: 35 ug/L/96 hr (95% confidence limit: 22-55 ug/L) /Technical material 98%/
For more Ecotoxicity Values (Complete) data for Trichlorfon (85 total), please visit the HSDB record page.
Environmental Fate
TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of 6-79(2-3) indicate that trichlorfon is expected to have high to very high mobility in soil(SRC). Volatilization of trichlorfon from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.2X10-11 atm-cu m/mole(SRC), based upon its vapor pressure, 7.8X10-6 mm Hg(4), and water solubility, 1.2X10+5 mg/L(5). Trichlorfon is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(4). Trichlorfon, at an initial concentration of 2 ppm in soil, degraded 100% in 1.5 months at pH values of 3-4.6 and in 0.5 months at pH values of 8.7-9.05(6). Half-lives in clay (pH 7.9) and calcerous (pH 8.1) soils have been determined to be 1.15 and 1.05 days, respectively(7). Persistence of trichlorfon in soils has been reported as 2 weeks or less and is degraded by ammonifying microorganisms(8). Trichlorfon degrades rapidly in aerobic soils with reported half-lives of approximately 1-27 days under non-sterile conditions(9). The dissipation half-life of trichlorfon from plants has been estimated to be 2.36-3.10 days(10).
TERRESTRIAL FATE: The reported half-life for trichlorfon in aerobic soils was reported as 3-27 days. Using standard practices for application of pesticides to golf greens, trichlorfon dissipation half-lives were found to be 1.1 and 6 days in 1996 and 1997, respectively(1). Loss of trichlorfon due to volatilization, clipping removal and leaching from the greens was minimal(1). Dissipation of trichlorfon in individual components of the greens were as follows(1):[Table#2326]
AQUATIC FATE: Based on a classification scheme(1), Koc values of 6-79(2-3) indicate that trichlorfon may adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(4) based upon an estimated Henry's Law constant of 2.2X10-11 atm-cu m/mole(SRC), derived from its vapor pressure, 7.8X10-6 mm Hg(5), and water solubility, 1.2X10+5 mg/L(6). Trichlorfon is subject to hydrolysis and decomposition proceeds more rapidly with heating, and above pH 6(7). Hydrolysis half-lives (22 °C) of trichlorfon were reported as 510 days (pH 4), 46 hours (pH 7), and <30 minutes (pH 9)(7). According to a classification scheme(8), an estimated BCF of 3(SRC), from its log Kow of 0.51(9) and a regression-derived equation(10), suggests the potential for bioconcentration in aquatic organisms is low. Complete biodegradation of trichlorfon in river water occurred within 5 days at 10 mg/L, 13 days at 20 mg/L, and 20 days at 30 mg/L(11). In screening studies carried out at 20 °C using activated sludge inoculum, the aerobic biodegradation rate of trichlorfon was determined to be 0.28/day with a half-life of 2.5 days(12). Trichlorfon underwent photochemical conversion to dichlorvos when irradiated under UV light in an aqueous solution(13).
ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), dichlorvos, which has a vapor pressure of 0.0158 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase dichlorvos is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals, ozone and nitrate radicals; the half-life for these reactions in air is estimated to be 11-19 hours, 70 days and 3.2 hours(SRC), calculated from respective rate constants of 2.0X10-11 to 3.5X10-11(3-5), 1.7X10-19(5) and 2.5X10-13(5) cu cm/molecule-sec. Dichlorvos absorbs light in the UV range with a maximum absorbance of 295-305 nm and was found to have a photodegradation rate constant of 2.652X10-9 L/sec, giving it a photodegradation half-life of about 7.25 hours(6).
Food Survey Values
Trichlorfon was detected in 1 of 13,980 food samples collected by state food laboratories in 10 states (California, Florida, Indiana, Massachusetts, Michigan, New York, North Carolina, Oregon, Virginia, Wisconsin) during fiscal year 1988; it was not detected in 13,085 food samples collected during a similar study conducted in fiscal year 1989(1). In a study of grapes, 60% of trichlorfon residues were found in the skin; levels were higher in grape juice concentrate, raisins, and wine than in grapes, and trichlorfon accumulated in wine(2). Trichlorfon applied as a veterinary medicine can produce residues in meat(3). Trichlorfon was not detected (detection limit 9.35 ng/g) in 278 honey samples collected in 2003-2004 from 33 locations throughout Turkey(4).
Trichlorfon was not detected in the following food products(1-4):[Table#2328]
Toxicity Summary
IDENTIFICATION AND USE: Trichlorfon is a white, crystalline solid. It is used as anthelmintic drug and systemic insecticide. HUMAN STUDIES: Trichlorfon, an organophosphate, has a moderately potent anticholinesterase activity. 379 cases of trichlorfon poisoning were reviewed, and in some cases (3%), acute poisonings were accompanied by loss of memory and problem-solving ability, delirium, depression and anxiety, psychomotor stimulation, hallucinations, and paranoid delusions; in other cases (21%), poisoning was accompanied by a delayed type polyneuropathy. Of 15 live births in one Hungarian village in 1989-90, 11 (73%) were affected by congenital abnormalities and six were twins. Of the 11, four had Down's syndrome. The likely causes of such clusters were excluded. A case control study and environmental investigations revealed the excessive use of trichlorfon at local fish farms. Trichlorfon content was very high in fish (100 mg/kg) and several pregnant women, including all mothers of babies with Down syndrome, had consumed contaminated fish in the critical period for the congenital abnormalities observed. Trichlorfon demonstrated clastogenic, mutagenic, and DNA damaging effects in human lymphocytes in vitro. Significant and persistent increases (lasting at least 180 days after exposure) in aneuploidy in lymphocytes of individuals who attempted suicide by using trichlorfon were reported. ANIMAL STUDIES: Trichlorfon was a moderate contact allergen in the skin. When applied to the eyes of rabbits it has short lasting miotic effect and produces little or no irritation. In rats given daily oral doses of 300 mg/kg body weight technical trichlorfon for 5 days, brain edema, congestion of organs, fatty degeneration, and glycogen depletion of the liver, glycogen depletion of the heart muscle and emphysema and local inflammation in the lungs were observed. Significant cholinesterase depression was noted at 300 mg/kg in rats. The dietary level of 500 ppm (about 10.5 mg/kg/day) inhibited RBC cholinesterase activity in dogs. Trichlorfon does not have a cumulative effect. There was no significant difference in the incidence of tumors between treated and control groups in mice or hamsters. A single 80 mg/kg body weight dose administered to rats orally by gavage on day 13 of pregnancy caused an increased number of embryonic deaths, a decreased number of live fetuses and increased fetal anomalies, such as exencephaly and failure of eyelids to close; administration of 8 mg/kg body weight throughout pregnancy produced no teratogenic manifestations. Trichlorfon did not induce mutation in Drosophila melanogaster, but because of high toxicity, only low doses could be tested. Trichlorfon induces gene mutation in Salmonella typhimurium and Escherichia coli and in Saccharomyces cerevisiae. It also induces a mitotic crossing over, gene conversion, and mitotic recombination. The positive results in microorganisms indicate that trichlorfon induces mainly base-pair substitution or mutation in the absence of metabolic activation. Trichlorfon also induces a chlorophyll mutation and chromosomal damage in plants. ECOTOXICITY STUDIES: Trichlorfon is moderately toxic for fish and moderately to highly toxic for aquatic arthropods. Trichlorfon applied to ponds at the rate of 1 mg/liter water destroyed the food invertebrates for fish. Large numbers of zooplankton, rotifers, and crustacea died in the first 24 hours after treatment, whereas benthos died during the first week. The affected fauna community recovered slowly. Trichlorfon treatment deprived the fish of valuable foods, such as crustacean and bottom fauna, for as long as 1 month after treatment. No effects on numbers, breeding pairs, nesting success, or mortality of forest songbirds were seen following aerial application of trichlorfon. An observed reduction in singing and increased feeding activity may have been the result of a reduction in food organisms. Trichlorfon was teratogenic for zebrafish embryos leading to anomalies in the absorption of the yolk sac, spine bending and pericardial edemas. Immunological responses and immune gene expressions of prawn exposed to trichlorfon at 0.4 mg/L for 24 hr were perturbed, thus causing a deficiency in immunity and subsequent increased susceptibility to pathogen infections. Trichlorfon influenced fish plasma antioxidative status, caused lipid peroxidation then resulted in hepatocytes apoptosis.
Trichlorfon is a cholinesterase or acetylcholinesterase (AChE) inhibitor. A cholinesterase inhibitor (or 'anticholinesterase') suppresses the action of acetylcholinesterase. Because of its essential function, chemicals that interfere with the action of acetylcholinesterase are potent neurotoxins, causing excessive salivation and eye-watering in low doses, followed by muscle spasms and ultimately death. Nerve gases and many substances used in insecticides have been shown to act by binding a serine in the active site of acetylcholine esterase, inhibiting the enzyme completely. Acetylcholine esterase breaks down the neurotransmitter acetylcholine, which is released at nerve and muscle junctions, in order to allow the muscle or organ to relax. The result of acetylcholine esterase inhibition is that acetylcholine builds up and continues to act so that any nerve impulses are continually transmitted and muscle contractions do not stop. Among the most common acetylcholinesterase inhibitors are phosphorus-based compounds, which are designed to bind to the active site of the enzyme. The structural requirements are a phosphorus atom bearing two lipophilic groups, a leaving group (such as a halide or thiocyanate), and a terminal oxygen.
Ecotoxicity Excerpts
/BIRDS and MAMMALS/ Japanese quail /Coturnix japonica/ were given trichlorfon daily for 20 days at an oral dose of 5 mg/kg body weight. Hematological examinations were made on the 5th, 10th, 15th, and 20th day of treatment and on the 5th, 10th, 15th, and 30th day after stopping treatment. The number of erythrocytes dropped on the 5th and 10th days, and the values of the hematocrit and hemoglobin fell on the 5th day. A significant increase in erythroblast contents was found on the 5th and 10th day. No other significant changes of the above parameters were observed up to the 30th day after treatment. The numbers of leukocytes, lymphocytes, neutrophils, and monocytes sharply increased from the 5th to 15th day of treatment, and quikly dropped to normal ranges on the 10th day after stopping treatment.
/AQUATIC SPECIES/ The cardio-respiratory function, oxidative stress and fish antioxidants were analyzed in juvenile Nile tilapia exposed for 96 hr to a sublethal trichlorfon concentration of 0.5 mg/L. The exposure to TRC induced oxidative stress in the heart, as manifested by the glutathione S-transferase depletion and hydroperoxide elevation, and was the most sensitive organ when compared to the liver and gills, in which the antioxidant mechanisms against TRC exposure were sufficient to remove reactive oxygen species (ROS), preventing the increase of lipid peroxidation. TRC exposure also reduced O(2) uptake (V O(2)) and increased the critical oxygen tension (PcO(2)), reducing the species capacity to survive prolonged hypoxic conditions. The heart rate and force contraction were significantly impaired, making the heart the most sensitive organ when exposed to the TRC.
/AQUATIC SPECIES/ Trichlorfon (TCF) is one of the most used veterinary pharmaceuticals not only to fight infestations but also as a preventive measure worldwide. The high concentrations used generate concerns about environmental and human health. ...The acute toxicity of this compound to non-target organisms belonging to different trophic levels /was assessed/: Danio rerio (early life stages and adults), Daphnia magna and algae (Pseudokirchneriella subcapitata and Chlorella vulgaris), and studied the potential of the biomarkers cholinesterase (ChE), glutathione-S-transferase (GST), lactate dehydrogenase (LDH) and catalase (CAT) to assess sub-lethal effects of trichlorfon in zebrafish and daphnids. The fish embryo test followed the OECD draft guideline FET and was based on the exposure of newly fertilized eggs to 0, 2.5, 5.0, 10, 20, 40, 80 and 160 mg/L of TCF for 5 days; the fish acute test followed the OECD guideline 203 and was based on the exposure of adult fish to 0, 2.5, 5, 10, 20, 40, 60 and 80 mg/L of TCF for 4 days; Daphnia sp. immobilization assay followed the OECD guideline 202 and was based on the exposure of juvenile daphnids to 0, 0.1, 0.3, 0.5, 0.7, 0.9, 1 and 2 ug/L of TCF for 2 days and the algae growth inhibition assay followed the OECD guideline 201 and was based on the exposure of the two species to 0, 1, 3.2, 10, 32, 100 and 300 mg/L of TCF for 4 days. Biomarker levels were measured after 96 hr exposure to TCF in zebrafish early life stages and adults and after 48 hr exposure in D. magna. Tested organisms seem to have dissimilar sensitivities towards TCF exposure. D. magna (48 hr-LC(50)=0.29 ug/L) was the most sensitive organism, followed by early life stages and adults of zebrafish (96 hr-LC(50)=25.4 and 28.8 mg/L, respectively) and finally by the algae P. subcapitata (96 hr-LC(50)=274.5 mg/L) and C. vulgaris (no effect observed). As daphnids are a source of food for organisms of higher trophic levels, the impairment on its population is prone to have consequences in the entire ecosystem. The biomarker activities measured in daphnids and fish seemed to be useful tools in the assessment of trichlorfon effects, especially ChE activity which was the most sensitive biomarker tested for all organisms. Trichlorfon was teratogenic for zebrafish embryos leading to anomalies in the absorption of the yolk sac, spine bending and pericardial oedemas. The present research suggests that further work is urgently needed in order to monitor environmental concentrations of trichlorfon and to test the long term effects of environmentally realistic concentrations of this compound.
/AQUATIC SPECIES/ Trichlorfon (TRC) is the most common organophosphorous insecticide used in aquaculture practices in Southeast Asian countries. Indiscriminate use of TRC can either damage or alter the enzymatic and hormonal activities in the living organisms. In this present study, therefore, toxicogenomic analyses using real time PCR was used to characterize expression levels of various genes in Pangasianodon hypophthalmus after exposure to three concentrations, the 96 hr 1/100(LC(50)) (0.01 mg/L), the 96 hr 1/10(LC(50)) (0.1 mg/L) and the 96 hr 1/2(LC(50)) (0.5 mg/L) of TRC for 6 hr, 24 hr, 96 hr, 7 days, 14 days, 28 days and 56 days respectively. The expression kinetics of stress and other cellular toxicity representative genes such as heat shock protein70 (HSP70), growth hormone, acetylcholinesterase (AChE), trypsinogen, cytochrome P4501B (CYP1B) and cytochrome oxidase subunit 1 (COI) were investigated in liver and gills. TRC at a level of 0.1 mg/L and 0.5 mg/L induced a time and dose-dependent increase in the expression of the HSP70, COI and CYPIB while the transcript level of AChE, growth hormone and trypsinogen were significantly down-regulated. These results could permit to develop a "molecular biomarker system" which can be applied as a first-tier method of identifying contaminant exposure before effects at population level occur.
For more Ecotoxicity Excerpts (Complete) data for Trichlorfon (23 total), please visit the HSDB record page.
Regulatory information
FDA Requirements
Oral dosage form new animal drugs. Mebendazole and trichlorfon powder. ... Indications for use: It is used in horses for the treatment of infections of bots (Gastrophilus intestinalis and G. nasalis), large roundworms (Parascaris equorum), large strongyles (Strongylus edentatus, S. equinus, S. vulgaris), small strongyles, and pinworms (Oxyuris equi.)
Oral dosage form new animal drugs. Mebendazole and trichlorfon paste. ... Indications for use: It is used in horses for the treatment of infections of bots (Gastrophilus intestinalis and G. nasalis), large roundworms (Parascaris equorum), large strongyles (Strongylus edentatus, S. equinus, S. vulgaris), small strongyles, and pinworms (Oxyuris equi.)
Oral dosage form new animal drugs. Oxfendazole and trichlorfon paste. ... Indications for use: The drug is used in horses for removal of bots (Gasterophilus intestinalis, 2nd and 3rd instars; G. nasalis, 3rd instar) and the following gastrointestinal worms: Large roundworms (Parascaris equorum), pinworms (Oxyuris equi), adult and 4th stage larvae; large strongyles (Strongylus edentatus, S. vulgaris, and S. equinus); and small strongyles.
Oral dosage form new animal drugs. Thiabendazole with trichlorfon. ... Indications for use /in horses/. For the treatment and control of bots (Gasterophilus spp.), large strongyles (Strongylus spp.), small strongyles (genera Cyathostomum, Cylicobrachytus, Craterostomum, Oesophagodontus, Poteriostomum), pinworms (Oxyuris spp., Strongyloides spp.), and ascarids (Parascaris spp.).
For more FDA Requirements (Complete) data for Trichlorfon (7 total), please visit the HSDB record page.
FIFRA Requirements
Tolerances are established for residues of the insecticide trichlorfon (dimethyl (2,2,2-trichloro-1-hydroxyethyl) phosphonate) in or on the following food commodities:[Table#2327]
EPA has concluded, after completing its assessment of the cumulative risks associated with exposures to all of the OPs /including trichlorfon/, that: (1) the pesticides covered by the IREDs that were pending the results of the OP cumulative assessment (listed in Attachment A) are indeed eligible for reregistration; and (2) the pesticide tolerances covered by the IREDs and TREDs that were pending the results of the OP cumulative assessment (listed in Attachment A) meet the safety standard under Section 408(b)(2) of the FFDCA. Thus, with regard to the OPs, EPA has fulfilled its obligations as to FFDCA tolerance reassessment and FIFRA reregistration, other than product-specific reregistration.
Based on a review of generic data and public comments on the Agency's revised risk assessments for the active ingredient trichlorfon, the Agency has sufficient information on the human health effects of trichlorfon to make an interim decision as part of the tolerance reassessment process under FQPA. Because the Agency has not yet completed its cumulative risk assessment for the OPs, this interim decision does not fully address tolerance reassessment as required by Section 408(q) of the FQPA; however, the Agency has completed its assessment of risk from dietary exposure to trichlorfon alone. When the cumulative assessment is considered, the FQPA tolerance reassessment requirement will be completed. Nothing in this report precludes the Agency from making further FQPA determinations and tolerance-related rulemaking that may be required on this pesticide or any other in the future. The Agency has also not considered risks associated with exposure to DDVP resulting from trichlorfon use. DDVP, although a trichlorfon degradate, is a registered OP pesticide that is currently undergoing reregistration. Once the DDVP IRED is complete, the Agency will determine whether the DDVP exposure resulting from trichlorfon use poses risk concerns. The Agency may determine that further action is necessary after assessing the cumulative risk of the organophosphate class. At that time, the Agency may also address any other risk concerns that may arise including risks associated with DDVP exposure. ... The Agency has determined that aggregate dietary risk from exposure to trichlorfon may exceed the Agency's level of concern for children 1-6 years when the source of drinking water is surface water. Therefore, mitigation measures are needed at this time to address this concern.
Based on the reviews of the generic data for the active ingredient Trichlorfon, the Agency has sufficient information on the health effects of Trichlorfon and on its potential for causing adverse effects in fish and wildlife and the environment. Where the potential for adverse effects was identified, the Agency and the registrant agreed upon risk mitigation measures. The Agency has determined that all Trichlorfon products, labeled for non-food uses as specified in this Reregistration Eligibility Decision, will not pose unreasonable risks or adverse effects to humans or the environment. Therefore, the Agency concludes that products containing Trichlorfon are eligible for reregistration if labeing and other changes specified in this document are implemented.
As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their continued use. Under this pesticide reregistration program, EPA examines newer health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether the use of the pesticide does not pose unreasonable risk in accordance to newer safety standards, such as those described in the Food Quality Protection Act of 1996. Trichlorfon is found on List A, which contains most pesticides that are used on foods and, hence, have a high potential for human exposure. List A consists of the 194 chemical cases (or 350 individual active ingredients) for which EPA issued registration standards prior to FIFRA '88. Case No: 0104; Pesticide type: insecticide; Registration Standard Date: 06/30/84; Case Status: RED Approved 09/95; OPP has made a decision that some/all uses of the pesticide are eligible for reregistration, as reflected in a Reregistration Eligibility Decision (RED) document.; Active ingredient (AI): trichlorfon; Data Call-in (DCI) Date(s): 09/10/91, 03/03/95, 02/14/97; AI Status: OPP has completed a Reregistration Eligibility Decision (RED) document for the case/AI.
CERCLA Reportable Quantities
Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 100 lb or 45.4 kg. The toll free number of the NRC is (800) 424-8802. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b).
Clean Water Act Requirements
Trichlorfon is designated as a hazardous substance under section 311(b)(2)(A) of the Federal Water Pollution Control Act and further regulated by the Clean Water Act Amendments of 1977 and 1978. These regulations apply to discharges of this substance. This designation includes any isomers and hydrates, as well as any solutions and mixtures containing this substance.
Safety data
- PPE
- dust mask type N95 (US), Eyeshields, Faceshields, Gloves
- wgk
- 3
- rtecs
- TA0700000
- ridadr
- UN 3077 9/PG 3
- hs_code
- 29319090
- Toxicity
- LD50 in male, female rats (mg/kg): 630, 560 orally (Gaines)
- risk_code
- 22-43-50/53
- Signal word
- Warning
- Symbol(GHS)
- GHS07,GHS09
- hazard_code
- Xn,N
- safety_code
- 24-37-60-61-2
- hazard_class
- 6.1(b)
- Storage Class
- 11 - Combustible Solids
- packing_group
- III
- Hazard statements
- H302-H317-H400-H410
- Hazard Classifications
- Acute Tox. 4 DermalAcute Tox. 4 OralAquatic Acute 1Aquatic Chronic 1Resp. Sens. 1Skin Sens. 1
- Precautionary statements
- P264-P270-P261-P272-P280-P273-P301+P312-P330-P302+P352-P333+P313-P362+P364-P391-P501
- Hazardous Substances Data
- 52-68-6(Hazardous Substances Data)
Chemistry & industry
Pharmacology
ATC Code
P - Antiparasitic products, insecticides and repellents
QP - Antiparasitic products, insecticides and repellents
QP - Antiparasitic products, insecticides and repellents
Biological Half-Life
...The half-time of trichlorfon in human plasma is approximately 2 hours.
The biological half-life of trichlorfon was 80 min /in mice/.
... Following a 133 mg/kg oral dose, trichlorfon was not detected ... Calculated half-lives /of dichlorvos (a nonenzymatic breakdown product of trichlorfon)/ in /rat/ blood, adipose tissue, muscle, and liver were 7, 11, 10, and 12 days, respectively.
After acute oral treatment of healthy male volunteers with a 2, 5, 7.5, or 12 mg/kg dose of trichlorfon (metrifonate) ... the half-life of ... dichlorvos /in blood/ was about 3.8 hr ...
Metabolism/Metabolites
Trichlorfon and dichlorvos levels were followed in plasma and RBCs of 7 individuals given single oral doses of 7.5-10 mg/kg trichlorfon repeated after 2 wk for treating schistosomiases. The relationship of dichlorvos to trichlorfon in plasma and RBCs was about 1%. A biphasic curve for the elimination of trichlorfon in plasma developed; the first phase had a half-life of 0.4 to 0.6 hr, and the second phase had a half-life of about 3 hr. Clearance of trichlorfon was primarily due to formation of dichlorvos.
... Trichlorfon (and its /metabolic/ product dichlorvos) is very rapidly absorbed and cleared in humans. After acute oral treatment of healthy male volunteers with a 2, 5, 7.5, or 12 mg/kg dose of trichlorfon (metrifonate), the maximum blood concentration of trichlorfon was obtained between 12 min and 2 hr and the half-life in blood was about 2 hr. The concentrations of dichlorvos ... closely followed those of trichlorphon at a constant ratio of about 1 to 100. The concentrations of trichlorfon were detectable up to 8 hr, but those of dichlorvos had fallen bellow the level of detection by then. Both plasma and RBC cholinesterases were readily inhibited and were still low after 24 hr - none of the volunteers complained of side effects (and the half-life of ... dichlorvos was about 3.8 hr).
The predominant metabolic pathway that involves cleavage of the P-C phosphonate bond that generates trichloroethanol and dimethyl phosphate which are then excreted in urine. Quantitatively minor pathways of metabolism include demethylation ... and (nonenzymatic) dehydrochlorination of dichlorvos which is rapidly metabolized to dichloroethanol and dimethyl phosphate which are then excreted in urine.
Dichlorvos was detected in the brain of mice after ip injection of trichlorfon. Following dermal and intragastric application of trichlorfon to cows, the parent compound and dichlorvos were detected in the milk up to 22 days after application.
For more Metabolism/Metabolites (Complete) data for Trichlorfon (13 total), please visit the HSDB record page.
Metabolism of organophosphates occurs principally by oxidation, by hydrolysis via esterases and by reaction with glutathione. Demethylation and glucuronidation may also occur. Oxidation of organophosphorus pesticides may result in moderately toxic products. In general, phosphorothioates are not directly toxic but require oxidative metabolism to the proximal toxin. The glutathione transferase reactions produce products that are, in most cases, of low toxicity. Paraoxonase (PON1) is a key enzyme in the metabolism of organophosphates. PON1 can inactivate some organophosphates through hydrolysis. PON1 hydrolyzes the active metabolites in several organophosphates insecticides as well as, nerve agents such as soman, sarin, and VX. The presence of PON1 polymorphisms causes there to be different enzyme levels and catalytic efficiency of this esterase, which in turn suggests that different individuals may be more susceptible to the toxic effect of organophosphate exposure.
MeSH Pharmacological Classification
Agents that kill parasitic worms. They are used therapeutically in the treatment of HELMINTHIASIS in man and animal.
Drugs that inhibit cholinesterases. The neurotransmitter ACETYLCHOLINE is rapidly hydrolyzed, and thereby inactivated, by cholinesterases. When cholinesterases are inhibited, the action of endogenously released acetylcholine at cholinergic synapses is potentiated. Cholinesterase inhibitors are widely used clinically for their potentiation of cholinergic inputs to the gastrointestinal tract and urinary bladder, the eye, and skeletal muscles; they are also used for their effects on the heart and the central nervous system.
Pesticides designed to control insects that are harmful to man. The insects may be directly harmful, as those acting as disease vectors, or indirectly harmful, as destroyers of crops, food products, or textile fabrics.
Absorption, Distribution and Excretion
Absorbed by skin.
Trichlorfon ... is not readily absorbed by cotton leaves.
In cow, (32)P-labeled trichlorfon administered orally ... /was/ eliminated in urine, about 65% of administered dose ... /was/ excreted in 12 hr. ... 75% ... of compound of unknown structure. ... Less than 0.2% of administered dose ... in milk ... Blood contained ... max of 15.1 ug equivalent 2 hr after administration, decreased ... to about 1 ug equivalent after 24 hr.
The absorption, distribution, and excretion of trichlorfon in mammals is rapid: about 70-80% of a dose administered orally to mice was excreted during the first 12 hr after treatment. The biological half-life of trichlorfon was 80 min. ...3 hr after an iv injection of (14)CH3O-trichlorfon to rats, trace amounts of radioactivity were found in the liver, lungs, kidney, heart, spleen and blood.
For more Absorption, Distribution and Excretion (Complete) data for Trichlorfon (15 total), please visit the HSDB record page.
Uses & manufacturing
Uses
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]
Farming (Pesticides) [Category: Industry]
Anthelmintics; Cholinesterase Inhibitors; Insecticides.
For trichlorfon (USEPA/OPP Pesticide Code: 057901) ACTIVE products with label matches. /SRP: Registered for use in the U.S. but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./
MEDICATION (VET)
Non-systemic insecticide with contact and stomach action. Insecticidal control in agriculture, horticulture, forestry, food storage, gardening, households, and animal husbandry. In particular, control of Diptera, Lepidoptera, Hymenoptera, Hemiptera and Coleoptera on many crops. ...Also used to control household pests, such as flies, cockroaches, fleas, bed bugs, silverfish, ants, etc.; as a fly bait in farm buildings and animal houses; and for control of ectoparasites on domestic animals.
Impurities
... Impurities are 2,2-dichlorovonyl dimethyl phosphate: dichlorvos (0-0.2%), trichloroacetaldehyde (0-0.05%), dichloroacetaldehyde (0-0.03%), methyl hydrogen 2,2,2-trichloro-1-hydroxyethylphosphonate; demethyl trichlorfon (0-0.03%), and water (less than 0.3%). The technical product also contains phosphoric acid, 2,2,2-trichloro-1-hydroxyethylphosphoric acid, and dimethyl phosphite.
U.S. Production
(1977) NOT PRODUCED COMMERCIALLY IN US
(1982) NOT PRODUCED COMMERCIALLY IN US
Consumption Patterns
INSECTICIDE FOR NON-AGRICULTURAL USES EXCL FORESTS, 40%; FOREST, 30%; VEGETABLES, 20%; COTTON, 10% (1980)
Estimated US use of trichlorfon, 568,000 lb in 1989, 1,060,000 lbs in 1966.
Methods of Manufacturing
... Reaction of dimethyl hydrogen phosphite with trichloroacetaldehyde.
Prepn: W. Lorenz, United States of America patent 2701225 (1955 to Bayer).
Formulations/Preparations
Dipterex Technical Insecticide (Bayer Environmental Science): Active ingredient: trichlorfon 80%.
Dylox 80 Concentrate Insecticide (Bayer Environmental Science): Active ingredient: trichlorfon 80%.
Dylox 80 Turf and Ornamental Insecticide (Bayer Environmental Science): Active ingredient: trichlorfon 80%.
Dylox 6.2 Granular Insecticide (Bayer Environmental Science): Active ingredient: trichlorfon 6.2%.
For more Formulations/Preparations (Complete) data for Trichlorfon (14 total), please visit the HSDB record page.
Use Classification
Veterinary Drug -> INSECTICIDE -> JECFA Functional Classes
Veterinary Drug -> INSECTICIDE -> JECFA Functional Classes
Insecticides
Environmental transformation -> Pesticides (parent, predecessor)
INSECTICIDES
Applications
DescriptionTrichlorfon is a colorless crystalline powder. It is soluble in water (120 g/L) and most organic solvents, except aliphatic hydrocarbons. Log Kow = 0.43. Trichlorfon is rapidly converted to dichlorvos by alkalis (2) and then hydrolyzed; DT50 (22 C) values at pH 4, 7, and 9 are 510 d, 46 h, and
Usesanticholinergic, urinary incontenance therapy
UsesOne of the biologically active forms of nicotinic acid. Differs from NAD by an additional phosphate group at the 2position of the adenosine moiety. Serves as a coenzyme of hydrogenases and dehydrogenases. Present in living cells primarily in the r
UsesInsecticide used to control ies and roaches.
UsesTrichlorfon is an irreversible organophosophate acetylcholinesterase inhibitor and the prodrug of Dichlorvos (D435950). Trichlorfon have also shown potential actions to be utilized as an effective org anophosphorus pesticide.
UsesTrichlorfon is used to control a wide range of insects in many crops and to control household pests, flies in animal houses and ectoparasites in domestic animals.
General DescriptionMetrifonate is an organophosphate thatwas originally developed to treat schistosomiasis under thetrade name Bilarcil. It is an irreversible cholinesteraseinhibitor with some selectivity for BuChE over AChE. Itachieves sustained cholinesterase inhibition by its nonenzymaticmetabolite dichlorvos (DDVP), a long-actingorganophosphate. Its use in mild-to-moderate Alzheimerdisease was suspended recently because of adverse effectsexperienced by several patients during the clinical evaluationof this product. Toxicity at the neuromuscular junctionis probably attributable to the inhibition by the drug of neurotoxicesterase, a common feature of organophosphates.
General DescriptionChlorophos is a white crystalline solid. Soluble in water, benzene, chloroform, ether; insoluble in oils. Chlorophos is a wettable powder. Chlorophos can cause illness by inhalation, skin absorption and/or ingestion. Chlorophos is used as a pesticide.
Upstream & downstream products
Upstream raw materials
Downstream products
Suppliers50 total
Additional notes
DefinitionChEBI: A phosphonic ester that is dimethyl phosphonate in which the hydrogen atom attched to the phosphorous is substituted by a 2,2,2-trichloro-1-hydroxyethyl group.
Related reactions
Linked notes
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