Dichlorvos

Hazardous Air Pollutants (HAPs)

Carcinogens

Pesticides

Pesticide -> EPA IRIS

Acaricides, Insecticides

Active substance -> EU Pesticides database: Not approved

Pesticides -> Organophosphate Insecticides

Environmental transformation -> Pesticides (parent, predecessor)

log Kow = 1.43

1.43

1.47

1.4

Aromatic odor

Mild, chemical odor

1.415 at 77 °F (EPA, 1998) - Denser than water; will sink

1.415 g/cu cm at 25 °C/D

Relative density (water = 1): 1.4

1.42

1.42 @25 °C

(77 °F): 1.42

Colorless liquid

Colorless to amber liquid [Note: Insecticide that may be absorbed on a dry carrier]

10 to 50 mg/mL at 68 °F (NTP, 1992)

In water, 8.00X10+3 mg/L at 20 °C

In water, about 1g/100 mL

Slightly soluble in glycerin; miscible with aromatic and chlorinated hydrocarbon solvents and alcohols.

Miscible in dichloromethane, 2-propanol, toluene. Barely soluble in kerosene.

For more Solubility (Complete) data for Dichlorvos (6 total), please visit the HSDB record page.

Greater than 175F (EPA, 1998)

100 °C (212 °F) - closed cup

350 °F (177 °C) - open cup

170 °C

>175 °F

>175 °F

Danger

H301: Toxic if swallowed [Danger Acute toxicity, oral]

P260, P261, P262, P264, P270, P271, P272, P273, P280, P284, P301+P316, P302+P352, P304+P340, P316, P320, P321, P330, P333+P317, P361+P364, P362+P364, P391, P403+P233, P405, and P501 (click each P-code to see the statement)

Danger

H300 (52.7%): Fatal if swallowed [Danger Acute toxicity, oral]

P260, P261, P262, P264, P270, P271, P272, P273, P280, P284, P301+P316, P302+P352, P304+P340, P316, P320, P321, P330, P333+P317, P361+P364, P362+P364, P391, P403+P233, P405, and P501 (click each P-code to see the statement)

Hazard Traits - Carcinogenicity; Developmental Toxicity; Environmental tox; Neurotoxicity

Commission Regulation (EC) No 451/2000

Dichlorvos is listed in the dataset of EPA Human Health Benchmarks for Pesticides under the Safe Drinking Water Act (40 eCFR 141)

2007/387

Dichlorvos: HSNO Approval: HSR002838 Approved with controls

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.)

Toxic chloride fumes and phosgene formed if heated to decomposition or on contact with acid or acid fumes. Corrosive to iron and mild steel, acids or acid fumes. Hydrolyzes in water. (EPA, 1998)

Combustible. Gives off irritating or toxic fumes (or gases) in a fire. Liquid formulations containing organic solvents may be flammable. Risk of fire and explosion if formulations contain flammable/explosive solvents.

This chemical is a combustible liquid.

Practically non-flammable.

Dichlorvos is a very toxic compound with a probable lethal oral dose in humans between 50 and 500 mg/kg, or between 1 teaspoonful and 1 oz. for a 70 kg (150 lb.) person. However, brief exposure (30-60 minutes) to vapor concentrations as high as 6.9 mg/liter did not result in clinical signs or depressed serum cholinesterase levels. Toxic changes are typical of organophosphate insecticide poisoning with progression to respiratory distress, respiratory paralysis, and death if there is no clinical intervention. (EPA, 1998)

Dichlorvos is an insecticide that is a dense colorless liquid. It has a sweetish smell and readily mixes with water. Dichlorvos used in pest control is diluted with other chemicals and used as a spray. It can also be incorporated into plastic that slowly releases the chemical. Dichlorvos is used for insect control in food storage areas, green houses, and barns, and control of insects on livestock. It is not generally used on outdoor crops. Dichlorvos is sometimes used for insect control in workplaces and in the home. Veterinarians use it to control parasites on pets.

Dichlorvos is an insecticide used on crops, animals, and in pest-strips. Acute (short-term) and chronic (long-term) exposures of humans to dichlorvos results in the inhibition of an enzyme, acetylcholinesterase, with neurotoxic effects including perspiration, vomiting, diarrhea, drowsiness, fatigue, headache, and at high concentrations, convulsions, and coma. No information is available on the reproductive, developmental, or carcinogenic effects of dichlorvos on humans. A study by the National Toxicology Program (NTP) reported an increased incidence of tumors of the pancreas, mammary glands, and forestomach in animals. EPA has classified dichlorvos as a Group B2, probable human carcinogen.

A small number of the organophosphates (Ops) can Induce Delayed Neuropathy (OPIDN). OPIDN usually occurs after ingestion and is usually nonoccupational. [Levy, p. 431] Allergic contact dermatitis reported in flower growers and horticulturists; [Kanerva, p. 1780] Because of its relatively high vapor pressure, confined space exposure can cause significant poisoning. [AHLS, p. 237] 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]

The major hazards encountered in the use and handling of dichlorvos stem from its toxicologic properties as an organophosphate pesticide. Direct contact with dichlorvos may cause burns to the skin and eyes. Systemic effects from skin absorption, ingestion, or inhalation range from depression of blood cholinesterase, dizziness, and confusion, to convulsions, coma, and death. The airborne level of dichlorvos reported by NIOSH to be immediately dangerous to life and health (IDLH) is 200 mg/cu m. The OSHA PEL and ACGIH TLV are both set at 1 mg/cu m, with an indication that skin contact be avoided. To avoid skin exposure, wear overalls made of tight fabric or polyvinyl chloride, gloves, rubber boots (some forms of rubber are attacked by dichlorvos), and a face shield or splash-proof goggles. To avoid inhalation wear a full facepiece supplied-air respirator or self-contained breathing apparatus. Clothing that becomes contaminated with dichlorvos should be promptly removed and any contaminated skin immediately washed with soap and water. Protect from exposure persons under 18 yr of age, expectant or nursing mothers, alcoholics, or those having diseases of the CNS, respiratory system, liver, kidney, or eyes. Dichlorvos will not ignite easily (flashpoint > 175 °C open cup), but will burn with the possible release of toxic gases and vapors such as hydrogen chloride, phosphoric acid mist, and carbon monoxide. For small fires involving dichlorvos, extinguish with dry chemical, CO2, water spray, foam, and for large fires, use water spray, fog, or foam. Runoff from fire control water may give off poisonous gases or cause water polution and should, therefore, be diked for later disposal. Dichlorvos should be stored in a cool (< 80 °F) and dry place (to avoid hydrolysis); away from strong acids and alkalis. In choosing an appropriate storage container, the fact that dichlorvos is corrosive to iron and mild steel should be considered. Containers of dichlorvos may be shipped by air, rail, road, water, and for both domestic and international compliance, should should be affixed with labels stating, "Keep Away From Food", and "Poison". For small spills of dichlorvos, absorb in vermiculite, dry sand or earth and collect for reclamation. Large land spills should be deposited in excavated pits, ponds, or other holding areas and the bulk material absorbed with fly ash or cement powder. Surface flow should be diked with sand bags or soil. Spills of dichlorvos in bodies of water, first may need to be treated with activated carbon, then the immobilized masses removed with mechanical dredges or lifts. Before permanent land disposal of dichlorvos, consult with environmental regulatory agencies.

Oral dosage form new animal drugs. ... Conditions of use in swine. (1) It is recommended for the removal and control of sexually mature (adult), sexually immature and/or 4th stage larvae of the whipworm (Trichuris suis), nodular worms (Oesophagostomum spp.), large round-worm (Ascaris suum), and the mature thick stomach worm (Ascarops strongylina) occurring in the lumen of the gastrointestinal tract of pigs, boars, and open or bred gilts and sows. ... Conditions of use in dogs. (1) For removal of Toxocara canis and Toxascaris leonina (roundworms), Ancylostoma caninum and Uncinaria stenocephala (hookworms), and Trichuris vulpis (whipworm) residing in the lumen of the gastrointestinal tract. ... Conditions of use in horses when administered in grain. (1) It is recommended for the removal and control of bots (Gastrophilus intestinalis, G. nasalis), large strongyles (Strongylus vulgaris, S. equinus, S. edentatus), small strongyles (of the genera Cyathostomum, Cylicocercus, Cylicocyclus, Cylicodontophorus, Triodontophorus, Poteriostomum, Gyalocephalus), pinworms (Oxyuris equi), and large roundworm (Parascaris equorum) in horses including ponies and mules. Not for use in foals (sucklings and young weanlings). ... Conditions of use in horses when administered orally by syringe. (1) It is recommended for the removal and control of first, second, and third instar bots (Gastrophilus intestinalis and G. nasalis), sexually mature and sexually immature (4th stage) ascarids (Parascaris equorum) in horses and foals. ... Conditions of use in dogs, cats, puppies, and kittens. ... Dogs and puppies: Removal and control of intestinal roundworms (Toxocara canis and Toxascaris leonina) and hookworms (Ancylostoma caninum and Uncinaria stenocephala). ... Cats and kittens: Removal and control of intestinal roundworms (Toxocara cati and Toxascaris leonina) and hookworms (Ancylostoma tubaeforme and Uncinaria stenocephala).

A tolerance of 0.1 part per million is established for negligible residues of dichlorvos (2,2-dichlorovinyl dimethyl phosphate) in the edible tissues of swine.

New animal drugs for use in animal feeds. ... Conditions of use: It is used in feed for swine as follows: ... For the removal and control of mature, immature, and/or fourth-stage larvae of the whipworm (Trichuris suis), nodular worm (Oesophagostomum sp.), large roundworm (Ascaris suum) and the thick stomach worm (Ascarops strongylina) of the gastrointestinal tract. ... An aid in improving litter production efficiency by increasing pigs born alive, birth weights, survival to market, and rate of weight gain. Treatment also removes and controls mature, immature and/or fourth stage larvae of whipworm (Trichuris suis), nodular worm (Oesophagostomum supp. ) large roundworm (Ascaris suum), and the thick stomach worm (Ascarops strongylina) occurring in the gastrointestinal tract of the sow or gilt.

Use self-contained breathing apparatus with a full face piece operated on pressure-demand or other positive pressure mode. Prevent skin contact with protective clothing. Isolate area and deny entry. Fight fire from maximum distance. Dike fire control water for future disposal.

Use water spray, foam, powder, carbon dioxide. In case of fire: keep drums, etc., cool by spraying with water.

Fresh air, rest. Refer immediately for medical attention.

Remove contaminated clothes. Rinse and then wash skin with water and soap. Refer immediately for medical attention.

Rinse with plenty of water (remove contact lenses if easily possible). Refer for medical attention.

Rinse mouth. Do NOT induce vomiting. Refer immediately for medical attention.

Warning: Effects may be delayed up to 12 hours. Caution is advised.

(General first aid procedures)

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]

1.0 [mg/m3]

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.

Use dry chemical, carbon dioxide, or foam extinguishers. Use self-contained breathing apparatus with a full face-piece operated on pressure-demand or other positive-pressure mode. Prevent skin contact with protective clothing. Isolate area and deny entry. Fight fire from maximum distance. Dike fire control water for future disposal. ... 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 spray 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.

Do not use water; smother with foam, /carbon dioxide/, dry.

For more Fire Fighting Procedures (Complete) data for Dichlorvos (6 total), please visit the HSDB record page.

Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. Recommended storage temperature -20 °C.

Store in a secure poison location. ... Store in tightly closed containers in a cool, well-ventilated area away from strong acids; strong alkalis. Dichlorvos will attack some forms of mild iron, plastics, rubber, and coatings.

Store in tightly sealed container, protected from light, and at room temperature. Stability of compounded formulations has not been evaluated.

Store Atgard swine wormer at less than 80 °F. Dichlorvos feed additives should not be stored at temperatures below freezing. Dichlorvos is sensitive to hydrolysis if exposed to moisture or oxidizing agents.

PRECAUTIONS FOR "CARCINOGENS": Storage site should be as close as practical to lab in which carcinogens are to be used, so that only small quantities required for ... expt need to be carried. Carcinogens should be kept in only one section of cupboard, an explosion-proof refrigerator or freezer (depending on chemicophysical properties ...) that bears appropriate label. An inventory ... should be kept, showing quantity of carcinogen & date it was acquired ... Facilities for dispensing ... should be contiguous to storage area. /Chemical Carcinogens/

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Wear respiratory protection. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. 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: Soak up with inert absorbent material and dispose of as hazardous waste. Keep in suitable, closed containers for disposal.

Evacuate and restrict persons not wearing protective equipment from area of spill or leak until cleanup is complete. Remove all ignition sources. Ventilate area of spill or leak. Remove and isolate contaminated clothing at the site. Do not touch spilled material; stop leaks if you can do it without risk. Reduce vapors with water spray. Take up small spills with sand or other noncombustible absorbent material for later disposal in canisters. Dike large spills far ahead of spill for later disposal. Keep this chemical out of a confined space, such as a sewer, because of the possibility of an explosion, unless the sewer is designed to prevent the buildup of explosive concentrations. 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.

Environmental consideration: Land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Absorb bulk liquid with fly ash, or cement powder.

Environmental considerations: Water spill: If dissolved in region of 10 ppm or greater concentration, apply activated carbon at ten times the spilled amount. ...

For more Cleanup Methods (Complete) data for Dichlorvos (7 total), please visit the HSDB record page.

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.

Fifty percent hydrolysis is obtained in pure water in 25 min at 70 °C and in 61.5 days at 20 °C. A buffered solution yields 50% hydrolysis (37.5 °C) in 301 min at pH 8, 462 min at pH 7, 620 min at pH 5.4. Hydrolysis yields no toxic residues. Incineration in a furnace equipped with an afterburner and alkaline scrubber is recommended as is alkaline hydrolysis followed by soil burial. 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.

For more Disposal Methods (Complete) data for Dichlorvos (11 total), please visit the HSDB record page.

Evacuate danger area! Consult an expert! Personal protection: chemical protection suit including self-contained breathing apparatus. Do NOT let this chemical enter the environment. Do NOT wash away into sewer. Ventilation. Collect leaking liquid in sealable containers. Absorb liquid in sand or inert absorbent. Then store and dispose of according to local regulations.

The mean and maximum alkyl phosphate levels in urine of pest control operators using dichlorvos in Japan were 0.099 and 0.22 ug/mg creatinine, respectively(1). Dichlorvos was not detected in human adipose tissue samples collected April 2008 to June 2009 from three regions (Nantong, Hexian, Dachang) of Southeast China(2). Dichlorvos was detected in one breast milk sample collected 1974-1975 in Taiwan at 0.1 ppm(3).

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.

/The study objective was/ to evaluate the reproduction toxicity of the mixture composed of dichlorvos, dimethoate and malathion synergistic effect on male mice, and further explore its possible mechanisms. The 105 male mice were divided into 7 groups, including control (0 mg/kg), mix low (10.8 mg/kg), mix medium (21.5 mg/kg), mix high dose (43.0 mg/kg), dichlorvos (5.1 mg/kg), dimethoate (12.6 mg/kg) and malathion (25.3 mg/kg) group. The oral gavage for successive 35 days, and the mice were sacrificed on the 36(th) day. The body weight, and the quantity, activity and morphology of sperms were examined. The levels of sexual hormone were measured, including testosterone (T), follicle stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E(2)). Pathological changes of testicle and epididymis were observed by morphology, pathology and electron microscope. After 14 days exposure, the body weights of the mice were lower in the mix-high dose group ((22.40 +/- 3.07) g) than those in control group ((26.73 +/- 2.82) g) (P < 0.05). After 28 days exposure, the body weights of the mice were also lower in the mix-medium dose group ((30.00 +/- 4.93) g) than those in control group ((33.13 +/- 3.29) g) (P < 0.05). The sperm counts and sperm motility decreased significantly as the toxic concentration arised. Comparing to control group ((373.33 +/- 14.65)x10(6)/g weight of epididymis and (75.17 +/- 7.68)%), the spermatozoa count and sperm motility had decreased in mix-medium and mix-high dose groups ((321.17 +/- 18.19)x10(6)/g weight of epididymis, (225.00 +/- 19.67)x10(6)/g weight of epididymis, and (64.67 +/- 9.91)%, (57.83 +/- 9.66)%), and the sperm abnormality rates were higher in mix-medium and mix-high groups ((43.33 +/- 8.66) per mil and (55.00 +/- 13.80) per mil) comparing to those in control group ((32.67 +/- 8.17) per mil). Compared to those in control group (FSH (1.41 +/- 0.20), E(2)(17.32 +/- 2.72), LH (8.75 +/- 1.32) and T (3.45 +/- 0.80) nmol/L), the serum level of FSH (3.14 +/- 0.62) and (3.85 +/- 0.37) nmol/L, E(2) (36.81 +/- 6.68) and (43.76 +/- 9.82) nmol/L in mix-medium and mix-high dose group increased (P < 0.01), while the level of LH (5.21 +/- 1.23) and (4.27 +/- 1.09) nmol/L and T (1.37 +/- 0.38) and (0.73 +/- 0.18) nmol/L decreased (P < 0.01). The morphological and ultramicrostructure results of testicle and epididymis indicated that the mature sperm numbers were decreased, and the cacoplastic sperm head and the tail of spermatozoon were observed in mix-high dose groups. The dichlorvos, dimethoate and malathion mixture had synergistic reproductive toxicity to the testicle and epididymis structure and function, and thus leading to the process of generation cell cytopoiesis abnormalities, simultaneously the hypothalamus-pituitary-gonad axis were also affected and thus resulted in parasecretion.

The present study was designed to assess the possible protective effects of Quercetin (QUER), a flavonoid with well-known pharmacological effects, against Dichlorvos (DDVP)-induced toxicity in vitro using HCT116 cells. The cytotoxicity was monitored by cell viability, reactive oxygen species (ROS) generation, anti-oxidant enzyme activities, malondialdehyde (MDA) production, and DNA fragmentation. The apoptosis was assessed through the measurement of the mitochondrial transmembrane potential (delta-psi-m) and caspase activation. The results indicated that pretreatment of HCT116 cells with QUER, 2 hr prior to DDVP exposure, significantly decreased the DDVP-induced cell death, inhibited the ROS generation, modulated the activities of catalase (CAT) and superoxide dismutase (SOD), and reduced the MDA level. The reductions in mitochondrial membrane potential, DNA fragmentation, and caspase activation were also attenuated by QUER. These findings suggest that dietary QUER can protect HCT116 cells against DDVP-induced oxidative stress and apoptosis.

A previous study of ours has reported that chronic exposure to low-level dichlorvos (DDVP, 7.2 mg per kg bw) damages the liver, interferes with fatty acid metabolism, and disturbs the antioxidant defense system in rats. This study aims to investigate whether or not quercetin can protect against DDVP-induced toxicity through metabonomics and to elucidate the mechanism underlying this protective effect. Rats were randomly assigned into the control group, DDVP-treated group, quercetin-treated group, and quercetin plus DDVP-treated group. DDVP and quercetin were administered to the rats daily via drinking water and gavage, respectively, continuously for 90 d. The metabonomic profiles of rat plasma were analyzed using ultra-performance liquid chromatography-mass spectrometry. Finally, 11 metabolites were identified, including those of quercetin, isorhamnetin, and quercetin-3-glucuronide. The 11 metabolites showed significant changes in some treatment groups compared with the control group. Arachidonic acid, phytosphingosine, and C16 sphinganine significantly decreased while p-cresol, lysoPE (16:0/0:0), lysoPC (15:0/0:0), lysoPC (16:0/0:0), lysoPC (0:0/18:0), and tryptophan significantly increased in the DDVP-treated group compared with the control group. The tendency of the aforementioned metabolites to change was significantly ameliorated in the high-dose quercetin (50 mg per kg bw per day) plus DDVP-treated group compared with the DDVP-treated group. However, the levels of these metabolites in the high-dose quercetin plus DDVP-treated group were still significantly different from those in the control group. The results indicate that high-dose quercetin (50 mg per kg bw per day) elicits a partial protective effect on DDVP-induced toxicity. The histopathology of the liver tissues was consistent with the above results. Quercetin demonstrated regulatory effects on the metabolism of lipids and amino acids, the antioxidant defense system, etc. Therefore, increasing the daily intake of quercetin can ameliorate the toxicity induced by chronic exposure to low-level DDVP residue in food and/or water.

/The study objective was/ to provide toxicokinetic and clinical evidence of the hydrolytic effect of paraoxonase-1 (PON1) on acute organophosphate poisoning in rats. 40 male Wistar rats were randomized into four equal groups. Dichlorvos administration group (A group) underwent dichlorvos injection (dissolved in corn oil) using intraperitoneal (ip) dose of 10 mg/kg. PON1 pretreatment group (B group) was injected with PON1 in the tail vein (intravenous), dose 9600 U/kg, 30 min prior to dichlorvos administration. In the treatment group (C group), atropine 0.05 mg/kg and pyraloxime chloride (PAM-CI) 120 mg/kg were injected intravenously within 2 min after dichlorvos administration. Finally, in the co-treatment group (D group), PON1 was injected intravenously with a dose of 9000 U/kg 30 min prior to dichlorvos administration; atropine 0.05 mg/kg and PAM-CI 120 mg/kg were injected intravenously within 2 min after dichlorvos administration. Blood was collected after administration. Plasma dichlorvos concentration was detected by liquid chromatography-mass spectra (LC-MS) method and clinical signs were observed. Toxicokinetic parameters were calculated in a statistical moment model. AUC (0 to infinity) in group B was statistically different from that in groups A and C (p<0.05), while it was not different from group D (p>0.05); there was no statistical difference between group A and group C (p>0.05). The statistical results of Cmax were the same as those of AUC (0 to infinity). There were no differences of MRT between four groups (p>0.05). Clinical signs can be improved by PON1 and atropine + PAM-CI, and co-treatment can relieve signs more effectively. PON1 can decrease the amount of dichlorvos that entered the blood, lowered the peak concentration and relieved clinical signs.

For more Interactions (Complete) data for Dichlorvos (20 total), please visit the HSDB record page.

Cancer, Gastrointestinal (Stomach and Intestines, part of the digestive system), Neurological (Nervous System)

Nervous

Eyes, skin, respiratory system, cardiovascular system, central nervous system, blood cholinesterase

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.

LC50; Species: /Pimephales promelas/ (Fathead minnow) weight 0.7 g; Conditions: static bioassay, 17 °C; Concentration: 11,600 ug/L for 96 hr (95% confidence limit: 7,830-17,200 ug/L) /Technical material, 93%/

LC50; Species: /Lepomis macrochirus/ (Bluegill) weight 1.5 g; Conditions: static bioassay, 18 °C; Concentration: 869 ug/L for 96 hr (95% confidence limit: 700-1,080 ug/L) /Technical material, 100%/

LC50; Species: /Gambusia affinis/ (Mosquitofish) weight 0.2 g; Conditions: static bioassay, 17 °C; Concentration: 5,270 ug/L for 96 hr (95% confidence limit: 2,660-10,400 ug/L) /Technical material, 100%/

LC50; Species: /Oncorhynchus clarki/ (Cutthroat trout) weight 2.5 g; Conditions: static bioassay, 12 °C; Concentration: 170 ug/L for 96 hr (95% confidence limit: 143-203 ug/L) /Technical material, 100%/

For more Ecotoxicity Values (Complete) data for Dichlorvos (80 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of 27.5-151(2-4) indicate that dichlorvos is expected to have very high to moderate mobility in soil. Volatilization of dichlorvos from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 5.7X10-7 atm-cu m/mole(SRC), derived from its vapor pressure, 0.0158 mm Hg(5), and water solubility, 8000 mg/L(6). Dichlorvos is not expected to volatilize from dry soil surfaces(SRC) based on its vapor pressure(5). Dichlorvos had a field dissipation half-life of 1 day(4). Dichlorvos, added to Houston black clay, degraded 71% (49.7% hydrolysis, 21.3% biodegradation) in 10 days(7). The presence of active microorganisms reduced the half-life of dichlorvos in clay and calcareous soil from 0.9 to 0.75 days and 0.85 to 0.70 days, respectively(8). The average first-order rate constants of dichlorvos in an acidic silty clay soil and a neutral sandy clay soil were 0.0423 and 0.04443 L/day, respectively; the half-life in both soils was 16 days(9).

AQUATIC FATE: Based on a classification scheme(1), Koc values of 27.5-151(2-4) indicate that dichlorvos may adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(5) based upon an estimated Henry's Law constant of 5.7X10-7 atm-cu m/mole(SRC) derived from its vapor pressure, 0.0158 mm Hg(6), and water solubility, 8000 mg/L(7). Using this Henry's Law constant and an estimation method(5), volatilization half-lives for a model river and model lake are 95 days and 1.9 years, respectively(SRC). Dichlorvos has been reported to undergo hydrolysis in environmental aqueous systems in <1-70 days depending on the temperature, pH and other environmental conditions(6,8-10). According to a classification scheme(11), BCFs of <0.5-0.8 in fish(12-13), suggest bioconcentration in aquatic organisms is low. In aquatic environments, dichlorvos has been reported as having half-lives of <1 days(6) to 3.5 days with an activated sludge inoculum(3) and has reached 8-14% of theoretical BOD in 8 days using a sewage inoculum(14).

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 265.2X10-7 L/sec, giving it a photodegradation half-life of about 7.25 hours(6).

Dichlorvos was detected in <1% and <2% of 49,877 and 49,055 commodity samples in FDA's Residue Monitoring studies conducted 1978-1982 and 1982-1986, respectively(1-2). Dichlorvos was detected at 0.01 ug/g in one of 234 ready-to-eat foods that were tested 37 times each over a 10 year period (1982-1991) in an FDA study(3). In FDA's Total Diet Study (1986-1991) in which foods prepared for consumption from different regions of the country are analyzed, <2% of the 4914 items of food analyzed contained dichlorvos(4). A pesticide residue screen program conducted 1989-1991 in the US analyzing 6970 produce samples found only one sample of radishes containing dichlorvos above the detection limit of 0.25 ppm(5). The FDA found no dichlorvos residues in a targeted 1992-1993 study of 1219 domestic and 144 imported samples of tomato(6). In a 1993-1994 FDA study of domestic and imported apples (1831 samples) and rice (1210 samples), dichlorvos was only found in one sample of domestic rice at 0.08 ppm(7).

Dichlorvos was detected in 5.3% of various fruits and vegetables produced in 1975 in Gifu Prefecture, Japan(1). Four (strawberry) of 478 domestic commodity samples monitored in Prefecture, Japan from April 1995 to March 2000 were found to contain dichlorvos at <0.1 ug/g; it was not detected in 287 imported agricultural products sampled(2). Of 173 agricultural products analyzed in 2006 in Japan, two were reported to contain dichlorvos at 10.4 and 81.3 ng/g(3). Dichlorvos was not detected in 327, 79, 16, 2 or 3 wheat samples collected from UK, North America, Spain, Germany and Denmark, respectively, but was detected in 1 of 47 wheat samples from France at a concentration of 0.2 mg/kg, all samples were collected Feb 1987-Dec 1988(4). Dichlorvos was not detected (detection limit 3.60 ng/g) in 278 honey samples collected in 2003-2004 from 33 locations throughout Turkey(5).

The substance can be absorbed into the body by inhalation, through the skin and by ingestion.

inhalation, skin absorption, ingestion, skin and/or eye contact

Oral (L1171) ; inhalation (L1171) ; dermal (L1171)

Oral dosage form new animal drugs. ... Conditions of use in swine. (1) It is recommended for the removal and control of sexually mature (adult), sexually immature and/or 4th stage larvae of the whipworm (Trichuris suis), nodular worms (Oesophagostomum spp.), large round-worm (Ascaris suum), and the mature thick stomach worm (Ascarops strongylina) occurring in the lumen of the gastrointestinal tract of pigs, boars, and open or bred gilts and sows. ... Conditions of use in dogs. (1) For removal of Toxocara canis and Toxascaris leonina (roundworms), Ancylostoma caninum and Uncinaria stenocephala (hookworms), and Trichuris vulpis (whipworm) residing in the lumen of the gastrointestinal tract. ... Conditions of use in horses when administered in grain. (1) It is recommended for the removal and control of bots (Gastrophilus intestinalis, G. nasalis), large strongyles (Strongylus vulgaris, S. equinus, S. edentatus), small strongyles (of the genera Cyathostomum, Cylicocercus, Cylicocyclus, Cylicodontophorus, Triodontophorus, Poteriostomum, Gyalocephalus), pinworms (Oxyuris equi), and large roundworm (Parascaris equorum) in horses including ponies and mules. Not for use in foals (sucklings and young weanlings). ... Conditions of use in horses when administered orally by syringe. (1) It is recommended for the removal and control of first, second, and third instar bots (Gastrophilus intestinalis and G. nasalis), sexually mature and sexually immature (4th stage) ascarids (Parascaris equorum) in horses and foals. ... Conditions of use in dogs, cats, puppies, and kittens. ... Dogs and puppies: Removal and control of intestinal roundworms (Toxocara canis and Toxascaris leonina) and hookworms (Ancylostoma caninum and Uncinaria stenocephala). ... Cats and kittens: Removal and control of intestinal roundworms (Toxocara cati and Toxascaris leonina) and hookworms (Ancylostoma tubaeforme and Uncinaria stenocephala).

A tolerance of 0.1 part per million is established for negligible residues of dichlorvos (2,2-dichlorovinyl dimethyl phosphate) in the edible tissues of swine.

New animal drugs for use in animal feeds. ... Conditions of use: It is used in feed for swine as follows: ... For the removal and control of mature, immature, and/or fourth-stage larvae of the whipworm (Trichuris suis), nodular worm (Oesophagostomum sp.), large roundworm (Ascaris suum) and the thick stomach worm (Ascarops strongylina) of the gastrointestinal tract. ... An aid in improving litter production efficiency by increasing pigs born alive, birth weights, survival to market, and rate of weight gain. Treatment also removes and controls mature, immature and/or fourth stage larvae of whipworm (Trichuris suis), nodular worm (Oesophagostomum supp. ) large roundworm (Ascaris suum), and the thick stomach worm (Ascarops strongylina) occurring in the gastrointestinal tract of the sow or gilt.

Tolerances for residues of the insecticide 2,2-dichlorovinyl dimethyl phosphate are established as follows:[Table#1039]

The tolerance of 0.1 part per million prescribed by 21 CFR 556.180 for negligible residues of 2,2-dichlorovinyl dimethyl phosphate in hog, fat; hog, meat; hog, meat byproducts; and hog, skin covers both its use as an anthelmintic in swine feed and as an insecticide applied directly to swine.

Dichlorvos may be present as a residue from application as an insecticide on packaged or bagged nonperishable processed food (see: 21 CFR 170.3(j)) in an amount in such food not in excess of 0.5 part per million (ppm). To assure safe use of the insecticide, its label and labeling shall conform to the label and labeling registered by the U.S. Environmental Protection Agency, and the usage employed shall conform with such label or labeling.

EPA has concluded, after completing its assessment of the cumulative risks associated with exposures to all of the OPs /including dichlorvos/, 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.

For more FIFRA Requirements (Complete) data for Dichlorvos (6 total), please visit the HSDB record page.

Listed as a hazardous air pollutant (HAP) generally known or suspected to cause serious health problems. The Clean Air Act, as amended in 1990, directs EPA to set standards requiring major sources to sharply reduce routine emissions of toxic pollutants. EPA is required to establish and phase in specific performance based standards for all air emission sources that emit one or more of the listed pollutants. Dichlorvos is included on this list.

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 10 lb or 4.54 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).

Releases of CERCLA hazardous substances are subject to the release reporting requirement of CERCLA section 103, codified at 40 CFR part 302, in addition to the requirements of 40 CFR part 355. Dichlorvos is an extremely hazardous substance (EHS) subject to reporting requirements when stored in amounts in excess of its threshold planning quantity (TPQ) of 1,000 lbs.

Dichlorvos 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.

QP - Antiparasitic products, insecticides and repellents

QP - Antiparasitic products, insecticides and repellents

Like other organophosphate agents, dichlorvos inhibits acetylcholinesterase interfering with neuromuscular transmission in susceptible parasites.

Dichlorvos is the active molecule of the pro-drug metrifonate used to revert the cognitive deficits associated with Alzheimer's disease. A few years ago it was reported that dichlorvos inhibits the enzyme acylpeptide hydrolase at lower doses than those necessary to inhibit acetylcholinesterase to the same extent. Therefore, the aim of our investigation was to test the hypothesis that dichlorvos can enhance synaptic efficacy through a mechanism that involves acylpeptide hydrolase instead of acetylcholinesterase inhibition. We used long-term potentiation induced in rat hippocampal slices as a model of synaptic plasticity. Our results indicate that short-term exposures (20 min) to 50 uM dichlorvos enhance long-term potentiation in about 200% compared to the control condition. This effect is correlated with approximately 60% inhibition of acylpeptide hydrolase activity, whereas acetylcholinesterase activity remains unaffected. Paired-pulse facilitation and inhibition experiments indicate that dichlorvos does not have any presynaptic effect in the CA3-->CA1 pathway nor affect gabaergic interneurons. Interestingly, the application of 100 nM methyllicaconitine, an alpha(7) nicotinic receptor antagonist, blocked the enhancing effect of dichlorvos on long-term potentiation. These results indicate that under the exposure conditions described above, dichlorvos enhances long-term potentiation through a postsynaptic mechanism that involves (a) the inhibition of the enzyme acylpeptide hydrolase and (b) the modulation of alpha(7) nicotinic receptors.

Exposure to dichlorvos (DDVP), an organophosphorus pesticide, is known to result in neurotoxicity as well as other metabolic perturbations. However, the molecular causes of DDVP toxicity are poorly understood, especially in cells other than neurons and muscle cells. To obtain a better understanding of the process of non-neuronal DDVP toxicity, we exposed zebrafish to different concentrations of DDVP, and investigated the resulting changes in liver histology and gene transcription. Functional enrichment analysis of genes affected by DDVP exposure identified a number of processes involved in energy utilization and stress response in the liver. The abundance of transcripts for proteins involved in glucose metabolism was profoundly affected, suggesting that carbon flux might be diverted toward the pentose phosphate pathway to compensate for an elevated demand for energy and reducing equivalents for detoxification. Strikingly, many transcripts for molecules involved in beta-oxidation and fatty acid synthesis were down-regulated. We found increases in message levels for molecules involved in reactive oxygen species responses as well as ubiquitination, proteasomal degradation, and autophagy. To ensure that the effects of DDVP on energy metabolism were not simply a consequence of poor feeding because of neuromuscular impairment, we fasted fish for 29 or 50 hr and analyzed liver gene expression in them. The patterns of gene expression for energy metabolism in fasted and DDVP-exposed fish were markedly different. We observed coordinated changes in the expression of a large number of genes involved in energy metabolism and responses to oxidative stress. These results argue that an appreciable part of the effect of DDVP is on energy metabolism and is regulated at the message level. Although we observed some evidence of neuromuscular impairment in exposed fish that may have resulted in reduced feeding, the alterations in gene expression in exposed fish cannot readily be explained by nutrient deprivation.

The main target of neurotoxins is neurons because they comprise the main part of neural function, but glial cells may be indirect targets because they support the function of neurons. Among the glial cells, astrocytes in particular act as "nurse cells", regulating neuronal survival and functions. In the present study, to reveal whether a known neurotoxic substance, organophosphate dichlorvos (DDVP), affects the differentiation of astrocytes, we used an astrocyte differentiation model in rat glioma C6 cells. Morphological change and induction of GFAP expression in the differentiating C6 cells were suppressed by DDVP treatment. The known potential targets of DDVP are acetylcholine esterase (AChE), fatty acid amide hydrolase and methyl guanine methyl transferase. Among the specific inhibitors against these enzymes, the AChE inhibitor paraoxon successfully suppressed the cellular morphological changes and the induction of GFAP expression in differentiating C6 cells. These results indicate that DDVP inhibits differentiation in the C6 astrocyte-differentiation model, in which at least AChE inhibition is involved and that AChE is a potent regulator of the differentiation. Furthermore, considering that the main substrate of AChE is ACh, thus, ACh may act as regulators of astrocyte differentiation.

For more Mechanism of Action (Complete) data for Dichlorvos (7 total), please visit the HSDB record page.

Half-lives for degradation of dichlorvos in whole blood after inhalation were 8.1 min for men and 11.2 min for women.

An elimination half-life of 13.5 min was estimated based on dichlorvos concentration in rat kidney after 2 or 4 hr exposure to 5 mg/cu m.

Dichlorvos binds to acetylcholinesterase forming dimethoxy-phosphorylated acetycholinesterase and dichloroacetaldehyde. Alternatively, it is metabolized (primarily in the liver but also in the blood, adrenal, kidney, lung, and spleen) via 2 pathways. The major pathway is catalyzed by A-esterases and produces dimethyl phosphate and dichloroacetaldehyde. Dichloroacetaldehyde is converted to dichloroethanol which is then excreted as the glucuronide. Alternatively, dichloroacetaldehyde is dehalogenated and the carbon atoms are incorporated into normal tissue constituents via intermediary metabolism. The second minor pathway is catalyzed by glutahione-S-transferase and produced desmethyl dichlorvos and S-methyl glutathione. Subsequent degradation of desmethyl dichlorvos to dichloroacetaldehyde and monomethyl phosphate is catalyzed by A-esterases. S-methyl glutathione is broken down to methylmercapturic acid and excreted in urine. CO2 is also the major metabolite following inhalation exposures. The major urinary metabolite following either oral or inhalation exposures is dichloroethanol glucuronide.

Dichlorvos is rapidly metabolized in human blood by A-esterases ... Dichlorvos A-esterase appears to be normally distributed. Half-lives for degradation of dichlorvos in whole blood after inhalation were 8.1 min for men and 11.2 min for women.

Dichlorvos (DDVP) is a methylating agent. DNA from mice given 1.9 x 10-6 mol/kg of DDVP, degree of alkylation of guanine-n-7 accounting to 8 x 10-13 mol methyl per gram of DNA was found. Rate of clearance was (estimated) to be 29 hr .

Dichlorvos, one of the active metabolites of trichlorofon ... is hydrolyzed to give dimethyl phosphate and dichloroacetaldehyde. The latter is subsequently reduced to beta,beta-dichloroethyl alcohol, characteristically converted by rats when administered intraperitoneally. After hydrolysis to a two-carbon fragment, dichloroacetaldhyde is able to enter a pathway of intermediary metabolism, and carbon dioxide is the major radioactive metabolic.

For more Metabolism/Metabolites (Complete) data for Dichlorvos (6 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.

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.

At least 85% of an oral dose of dichlorvos is absorbed. Dichlorvos is well absorbed following inhalation exposure based on the occurrence of toxic symptoms associated with inhalation exposures and the detection of specific dichlorvos metabolites (dichloroethanol and dimethyl phosphate) in urine of individuals exposed to dichlorvos.

An elimination half-life of 13.5 min was estimated based on dichlorvos concentration in rat kidney after 2 or 4 hr exposure to 5 mg/cu m. In mice and rats given single oral doses of dichlorvos, 59-65% was eliminated in urine, 3-7% was eliminated in feces, 14-18% was eliminated as CO2 by 4 days after dosing, and the vast majority was eliminated by 24 hr. Retained dichlorvos following either oral or inhalation exposure is high because it is incorporated into intermediary metabolism.

The vinyl moiety of the dichlorvos molecule undergoes two routes of biotransformation: conversion to dichloroethanol and subsequent formation of dichloroethanol glucuronide; or dehalogenation and incorporation of the carbon atoms into various metabolic pathways in the body. These pathways result in the production of hippuric acid, urea, carbon dioxide, and other endogenous compounds that result in a prolonged half-life of radioactivity in the tissues following the administration of [vinyl-C14] dichlorvos. Both radiolabelled dichloroethanol glucuronide and urea have been identified in the urine of men treated with [vinyl-C14] dichlorvos indicating that both pathways occur in humans.

Dichlorvos was undetectable (<0.1 mg/liter) in the blood of two men immediately after exposure, one to air concentrations of 0.25 mg dichlorvos/cu m for 10 hours and one to 0.7 mg dichlorvos/cu m for 20 hours.

For more Absorption, Distribution and Excretion (Complete) data for Dichlorvos (8 total), please visit the HSDB record page.

Dichlorvos is used as an agricultural insecticide on crops, stored products, and animals. It is also used as an insecticide for slow release on pest-strips for pest control in homes. Dichlorvos is used as an anthelmintic (worming agent) for dogs, swine, and horses, as a botacide (agent that kills fly larvae) for horses, and in flea collars for dogs. In 1995, EPA proposed cancellation of dichlorvos for all home uses, and for many commercial and industrial uses.

Used for insect control in food storage areas, greenhouses, and barns; it is not commonly used on field crops; [ATSDR ToxFAQs] Used to kill internal and external parasites of fish, other animals, and humans; [ACGIH]

Classified as highly toxic, dichlorvos may be used only by certified applicators. [EXTOXNET]

Farming (Pesticides) [Category: Industry]

Anthelmintics; Cholinesterase Inhibitors; Insecticides

For dichlorvos (USEPA/OPP Pesticide Code: 084001) 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./

This chemical is listed as a High Production Volume (HPV) (65FR81686). Chemicals listed as HPV were produced in or imported into the U.S. in >1 million pounds in 1990 and/or 1994. The HPV list is based on the 1990 Inventory Update Rule. (IUR) (40 CFR part 710 subpart B; 51FR21438).

(1986) >1 million-10 million pounds

(1990) 500 thousand-1 million pounds

(1994) 1 million-10 million pounds

(1998) 10 thousand-500 thousand pounds

Dichlorvos is produced by reacting trimethyl phosphate with chloral or by dehydrochlorination of trichlorfon in aqueous alkali.

Whetstone, Harman, United States of America patent S 2956073 (1960 to Shell).

The National Pesticide Information Retrieval System (NPIRS) identifies 8 companies with active labels for products containing the chemical dichlorvos. To view the complete list of companies, product names and percent dichlorvos in formulated products click the following url and enter the CAS Registry number in the Active Ingredient field.

Max Kill Vapo-cide (Douglas Products and Packaging Company): Active ingredient: DDVP 5%.

Max Kill Vapo-cide 2 (Douglas Products and Packaging Company): Active ingredient: DDVP 5%.

Alco Fly Fighter Insect Spray Pressurized (Amvac Chemical Corporation): Active ingredient: DDVP 0.5%.

For more Formulations/Preparations (Complete) data for Dichlorvos (30 total), please visit the HSDB record page.

Chemical Classes -> Organophosphates and carbamates

Animal Drugs -> FDA Approved Animal Drug Products (Green Book) -> Active Ingredients

Environmental transformation -> Pesticides (parent, predecessor)

Transformation products, Acaricides, Insecticides

INSECTICIDES

Phosphoric acid, 2,2-dichloroethenyl dimethyl ester: ACTIVE

The WHO Recommended Classification of Pesticides by Hazard identifies Dichlorvos (technical grade) as Class IB: highly hazardous; Main Use: insecticide.