Azinphos-Methyl

Pesticides

Acaricides, Insecticides

Active substance -> EU Pesticides database: Not approved

Pesticides -> Organophosphate Insecticides

Pesticide (Azinphos methyl) -> USDA PDB

Pesticide

log Kow = 2.75

2.75

2.43

1.44 at 68 °F (EPA, 1998) - Denser than water; will sink

1.44 g/cu cm at 20 °C

1.4 g/cm³

1.44

1.44 @25 °C

1.44

Yellowish crystals

Crystals from methanol

Brown, waxy solid

Colorless crystals or a brown, waxy solid.

Colorless to white crystalline solid

less than 1 mg/mL at 66 °F (NTP, 1992)

Soluble in methanol, ethanol, and propylene glycol, xylene, other organic solvents.

In dichloroethane, acetone, acetonitrile, ethyl acetate, and dimethyl sulfoxide, the solubility is >250 g/L at 20 °C; n-heptane, 1.2 g/L at 20 °C; xylene, 170 g/L at 20 °C

In toluene, dichloromethane, >20 g/L

Readily soluble in most organic solvents (toluene, chloroform, acetonitrile, benzene, carbon tetrachloride, and chlorobenzene), slightly soluble in 1-propanol.

In water, 20.9 mg/L at 20 °C

Decomposes (NTP, 1992)

decomposes

Decomposes

... Decomposes at elevated temperatures.

When heated to decomposition it emits very toxic fumes of /phosphorous oxides, sulfur oxides, and nitrogen oxides/.

163 to 165 °F (EPA, 1998)

73-74 °C

Cream to yellow-brown granular solid, MP: 67-70 °C /Technical/

73-74 °C

163 °F

74 °C

Danger

H300: 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)

Danger

H300 (100%): 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 - Developmental Toxicity; Neurotoxicity

Council Directive (EEC) No 414/1991 (Repealed by Reg. EC No 1107/2009 (amended))

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

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.)

Some of the formulations may burn, but none of them ignite easily. Container may explode in the heat of the fire. Rapidly hydrolyzed by cold alkali or cold acid. Unstable at temperatures above 390F. (EPA, 1998)

Combustible. Liquid formulations containing organic solvents may be flammable. Gives off irritating or toxic fumes (or gases) in a fire.

Guthion, also called azinphos-methyl, is an organophosphorous pesticide that was used on many crops, especially apples, pears, cherries, peaches, almonds, and cotton. Many of its former uses have been cancelled by the EPA, and its few remaining uses are currently in the process of being phased out. Guthion is a synthetic substance, it does not occur naturally. Pure guthion is a colorless to white odorless crystalline solid that melts at about 72-74ºC (162-165ºF). Technical-grade guthion is a cream to yellow-brown granular solid. Guthion is poorly soluble in water.

It is classified as highly toxic; the EPA reentry interval is 24 hours; [EXTOXNET] A dermal sensitizer based on positive animal testing (maximization and patch testing); [ACGIH] 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]

DHEW/NCI; Bioassay of Azinophosmethyl for Possible Carcinogenicity Technical Report Series No. 69 (1978) NIH Publication No. 78-1319[Available from, as of April 4, 2003: http://ntp.niehs.nih.gov/ntp/htdocs/LT_rpts/tr069.pdf]

WHO/IPCS; Pesticide Residues in Food - 1991. Part II - Toxicology (1992)

USEPA/Office of Pesticide Programs; Interim Reregistration Eligibility Decision (IRED) for Azinphosmethyl. EPA issues an IRED for a pesticide that is undergoing reregistration, requires a reregistration eligibility decision, and also needs a cumulative assessment under FQPA. The IRED, issued after EPA completes the individual pesticide's aggregate risk assessment, may include taking risk reduction measures -- for example, reducing risks to workers or eliminating uses that the registrant no longer wishes to maintain -- to gain the benefits of these changes before the final RED can be issued following the Agency's consideration of cumulative risks.[Available from, as of December 1, 2003: http://www.epa.gov/pesticides/reregistration/status.htm]

WHO; Environmental Health Criteria No. 63: Organophosphorus Insecticides: A General Introduction (1986)[Available from, as of December 3, 2003: http://www.inchem.org/documents/ehc/ehc/ehc63.htm]

Tolerances for residues of the insecticide O,O-dimethyl S-[(4-oxo-1,2,3-benzotriazin-3(4H)-yl)methyl]phosphorodithioate in or on the following raw agricultural commodities:[Table#2946]

Classified for restricted use, limited to use by or under the direct supervision of a certified applicator. Formulation: All liquids with a concentration greater than 13.5%; Use Pattern: Agricultural crop uses; Classification: Under further evaluation; Criteria Influencing Restriction: Inhalation hazard to humans.

Classified for restricted use, limited to use by or under the direct supervision of a certified applicator. Formulation: All other formulations; Use Pattern: Agricultural crop uses; Classification: Under further evaluation.

... EPA has completed its assessment of the cumulative risks from the organophosphate (OP) class of pesticides as required by the Food Quality Protection Act of 1996. In addition, the individual OPs have also been subject to review through the individual-chemical review process. The Agency's review of individual OPs has resulted in the issuance of Interim Reregistration Eligibility Decisions (IREDs) for 22 OPs /including azinphos-methyl/, interim Tolerance Reassessment and Risk Management Decisions (TREDs) for 8 OPs, and a Reregistration Eligibility Decision (RED) for one OP, malathion. These 31 OPs are listed in Appendix A. EPA has concluded, after completing its assessment of the cumulative risks associated with exposures to all of the OPs, 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 AZINPHOSMETHYL (6 total), please visit the HSDB record page.

Move containers from fire area if you can do it without risk. Fight fire from maximum distance. Dike fire control water for later disposal; do not scatter the material.

Use water spray, powder, foam, carbon dioxide.

Fresh air, rest. Artificial respiration may be needed. 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!). Refer 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], inhalable fraction[German Research Foundation (DFG)]

Self contained breathing apparatus with a full facepiece operated in pressure demand or other positive pressure mode /when fighting fire/.

If material on fire or involved in fire: Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Solid streams of water may be ineffective. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Use "alcohol" foam, dry chemical or carbon dioxide. /Organophosphorus pesticides, liquid, flammable, toxic; Organophosphorus pesticides, liquid, toxic/

If material on fire or involved in fire: Use water in flooding quantities as fog. Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) Use foam, dry chemical, or carbon dioxide. /Organophosphorus pesticides, solid, toxic/

Store in a cool dry area, away from excessive heat or open flame. Store 2L formulation above 45 °F; others above 32 °F. Store in an area designated specifically for pesticides.

Do not contaminate water, food or feed by storage or disposal. /Azinphosmethyl 50W Soluble/

Environmental considerations: Air spill: Apply water spray or mist to knock down vapors. /Organophosphorus pesticides, liquid, flammable, toxic; Organophosphorus pesticides, liquid, toxic; Organophosphorus pesticides, solid, toxic/

Containers ... should be cleaned with a suspension of bleaching powder in water or with other alkaline soln after soaking for 24 hr and then be rinsed with hot water. /Organophosphorus pesticides/

Environmental considerations: Water spill: Use natural barriers or oil spill control booms to limit spill travel. Remove trapped material with suction hoses. /Organophosphorus pesticides, liquid, flammable, toxic; Organophosphorus pesticides, liquid, toxic; Organophosphorus pesticides, solid, toxic/

Environmental considerations: 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, cement powder, or commercial sorbents. /Organophosphorus pesticides, liquid, flammable, toxic; Organophosphorus pesticides, liquid, toxic; Organophosphorus pesticides, solid, toxic/

Do not contaminate /downstream/ water when disposing of equipment washwater or rinsate. /Azinphosmethyl 50W Soluble/

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. 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 soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.

This highly toxic material is rapidly hydrolyzed by cold alkali. Use 5 parts by volume 4% wt/vol sodium hydroxide soln to 1 volume of pesticide. Hydrolysis is improved by making the sodium hydroxide soln in 50% ethanol. ... Large amt - Incinerate in a unit with effluent gas scrubbing. (Peer-review conclusions of an IRPTC expert consultation (May 1985))

Hydrolysis: Alkaline hydrolysis leads to complete degradation: the alkaline salt of dimethyldithiophosphoric acid and the anthranilic acid formed are nontoxic. Oxidation: Complete degradation but the gutoxon formed is equally toxic. For the decontamination of glass and metal containers triple rinse and use of a rinse soln containing caustic soda and detergent are considered.

Pesticide Disposal: Pesticide wastes are acutely hazardous. Improper disposal of excess pesticide, spray mixture, or rinsate is a violation of Federal law. If these cannot be disposed of by use according to label instruction, contact your State Pesticide or Environmental Control Agency, or the Hazardous Waste representative at the nearest EPA Regional Office for guidance. /Azinphosmethyl 50W Soluble/

Container Disposal: Completely empty bad into application equipment. Then dispose of empty bag into a sanitary landfill or by incineration, or, if allowed by state and local authorities, by burning. If burned, stay out of smoke. /Azinphosmethyl 50W Soluble/

Personal protection: complete protective clothing including self-contained breathing apparatus. Do NOT wash away into sewer. Sweep spilled substance into covered sealable containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations.

Use this product only in accordance with its labeling and with the Worker Protection Standard, 40 CFR part 170. /Azinphosmethyl 50W Soluble/

SRP: The scientific literature for the use of contact lenses by industrial workers is inconsistent. The benefits or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

The worker should immediately wash the skin when it becomes contaminated.

Work clothing that becomes wet or significantly contaminated should be removed and replaced.

For more Preventive Measures (Complete) data for AZINPHOSMETHYL (20 total), please visit the HSDB record page.

Azinphosmethyl metabolites dimethylthiophosphate (DMTP) and dimethyldithiophosphate (DMDTP) were analyzed in urine samples from residence of agricultural pesticide applicators, farm workers and reference homes (no resident working in agriculture and at least a quarter mile from treated orchards) from the Wentachee area of Washington state(1). DMTP and DMDTP are also metabolites of phosmet that was also used in this study(1).[Table#2940]

Dimethylthiophosphate (DMTP) and dimethyldithiophosphate (DMDTP) are metabolites of azinphosmethyl, phosmet and malathion which are often used in conjunction and it can not be distinguished as to the parent compound in this study(1). DMTP and DMDTP were detected at mean concentrations of 0.65 and 0.44 umol/L in urine samples from 170 farm worker samples from commercial apple orchards in Quebec, Canada(1).

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.

Mixtures of azinphos methyl with synthetic pyrethroids are synergistic insecticides.

The in vitro effect of azinphosmethyl on the fungicidal activity of captan and mancozeb was investigated by a cellophane transfer technique. The fungistatic and fungicidal activity of mancozeb was reduced by the addition of azinphosmethyl, as was that of captan.

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.

Atropine and enzyme-reactivating compounds have been shown to counteract the effects of azinphos-methyl.

For more Interactions (Complete) data for AZINPHOSMETHYL (9 total), please visit the HSDB record page.

Neurological (Nervous System)

respiratory system, central nervous system, cardiovascular 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.

LD50; Species: Colinus virginianus (Northern bobwhite) oral 32 mg/kg (88.8% active ingredient)

LC50; Species: Colinus virginianus (Northern Bobwhite Quail) game farm obtained, age 14 days; oral via capsule 488 ppm for 8 days (95% confidence interval: 394-601 ppm)

LC50; Species: Coturnix japonica (Japanese Quail) captive breeding colony, age 9 days; oral via capsule 639 ppm for 8 days (95% confidence interval: 572-796 ppm)

LC50; Species: Phasianus colchicus (Ring-Necked Pheasant) game farm obtained, age 22 days; oral via capsule 1821 ppm for 8 days (95% confidence interval: 1355-2468 ppm)

For more Ecotoxicity Values (Complete) data for AZINPHOSMETHYL (86 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of 298 to 4644(2-3), indicate that azinphosmethyl is expected to have moderate to slight mobility in soil(SRC). Volatilization of azinphosmethyl from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.9X10-9 atm-cu m/mole(SRC), based upon its vapor pressure, 2.0X10-7 mm Hg(4), and water solubility, 29 mg/L(4). Azinphosmethyl is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(4). Half-lives of 5.3 to 40 days have been reported under soil field conditions(2,5).

TERRESTRIAL FATE: Field tests with azinphosmethyl indicated that on treated apple trees the half-life of this pesticide was about 2.6 to 6.3 days.

TERRESTRIAL FATE: A half-life in soil of 194.15 days in the dark horizon was determined from a groundwater monitoring study conducted from October 1995 to March 1997 in the fruit production fields of the Neuquen River, Northern Patagonic, Argentina(1). Azinphosmethyl has reported field half-lives of 10 to 40 days(2). Using data from the 1993 UK database, half-lives for azinphosmethyl were 5.30 to 15 days in soil(3).

AQUATIC FATE: Based on a classification scheme(1), Koc values of 298 to 4644(2-3), indicate that azinphosmethyl is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(4) based upon an estimated Henry's Law constant of 2.9X10-9 atm-cu m/mole(SRC), derived from its vapor pressure, 2.0X10-7 mm Hg(5), and water solubility, 29 mg/L(5). According to a classification scheme(6), an estimated BCF of 30(SRC), from its log Kow of 2.75(7) and a regression-derived equation(8), suggests the potential for bioconcentration in aquatic organisms is moderate(SRC). Hydrolysis half-lives for azinphosmethyl in water at pH 8.6 were 36.4, 27.9, and 7.2 days at 6, 25, and 40 °C, respectively(9). The half-life of azinphosmethyl in seawater was 11 days when exposed to natural sunlight, while the half-life in river water was 8 days when exposed to natural sunlight(10). A decrease from 99 mg/L to 49 mg/L after 4 days incubation in a stirred flask containing azinphosmethyl as the sole carbon source and a mixed culture indicates that biodegradation in water may be an important environmental fate process(11).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), azinphosmethyl, which has a vapor pressure of 2.0X10-7 mm Hg at 25 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase azinphosmethyl is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 2.5 hours(SRC), calculated from its rate constant of 1.5X10-10 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase azinphosmethyl may be removed from the air by wet or dry deposition(SRC). Azinphosmethyl contains chromophores that absorb at wavelengths >290 nm(4) and, therefore, may be susceptible to direct photolysis by sunlight(SRC).

Azinphosmethyl has been detected in unspecified fruits and vegetables and in beans(1); however, concentrations were not reported. Azinphosmethyl was detected in 68 of 851 foods and animal feeds analyzed from Oct 1981 to Sept 1986, collected from the Los Angeles District of California: 12 samples <0.05 ppm; 14 samples 0.05-0.10 ppm; 33 samples 0.10-0.50 ppm; 6 samples 0.5-1.0 ppm; and 3 samples 1.0-2.0 ppm(2). Azinphosmethyl was identified, not quantified, in adult foods during an FDA survey from 1978-1982(3) and in adult foods from 1982-1986(4). During an FDA survey of domestic foods from 1985-1991 azinphosmethyl was detected in 233 of 2464 apples at a maximum concentration of 1.4 ppm, in 64 of 816 pears at a maximum concentration of 1.2 ppm and in 119 of 571 pears at a maximum concentration of 0.8 ppm(5). In an FDA survey of imported foods from 1985-1991, azinphosmethyl was detected in an apple juice sample at 0.16 ppm, in 30 of 735 apples at a maximum concentration of 1.3 ppm and in 64 of 816 pears at a maximum concentration of 1.2 ppm(5). Azinphosmethyl was detected in 2 of 1219 domestic tomatoes at a maximum concentration of 0.07 ppm during a 1992-1993 FDA survey(6).

Azinphosmethyl was detected in 7 peach samples collected in 1980-82 in Ontario, Canada: 5 below and 2 above 2 mg/kg(1) but was not detected in any of 354 vegetables samples during 1980-85(2). Azinphosmethyl was detected in 15 of 843 apples at 0.5-1.0 ppm, in 1 of 42 peaches at 0.05 ppm, in 2 of 431 strawberries at 1 ppm and in 1 of 978 tomatoes at 0.05 ppm, all grown in Canada(3). Azinphosmethyl was detected in 22 of 21,982 agricultural commodities from Canada at concentrations of 0.05-1.0 ppm between 1992 and 1994(4). Residual azinphosmethyl on apples from commercial apple orchards in Quebec, Canada, were measured immediately prior to harvesting for the 2003 season(5). Azinphosmethyl concentrations were 0.009-4.36 ng/g in 142 individual apples and 0.122-1.23 ng/g in 18 composite samples (each composite included 8 apples)(5). Azinphosmethyl was detected in 3 of 69 samples of honey from Spain at concentrations of 2 to 13 ug/kg(6). Azinphosmethyl was detected, not quantified as part of the Danish National Pesticide Monitoring Program of 4182 commodities conducted from 1995-1996 in the following commodities: 1996, 2 of 32 mandarin/clementine samples; 1996, 1 of 20 nectarine samples; 1996, 1 of 21 black currant samples(7). Azinphosmethyl was not detected in canned peaches from the 1999 season or fresh peaches from Aug 2000 in 210 samples from Imathia and Pella, Greece(8).

Azinphosmethyl was detected, not quantified as part of the Danish National Pesticide Monitoring Program of 4,182 commodities conducted from 1995-1996 in the following commodities: 1996, 2 of 32 manderin/clementine samples; 1996, 1 of 20 nectarine samples; 1996, 1 of 21 black currant samples(1). From 1991 to 1995, 802 fruit and 1,536 vegetable samples produced in Ontario, Canada underwent analysis for pesticide residues; azinphosmethyl detections numbered 295 with 7 violations(2). Fruit results were as follows: 125 apple samples, 21.6% positive, 0.12 ug/g mean, 0.009 ug/g minimum, 1 ug/g max; 21 apricot samples, 61.9% positive, 0.2 ug/g mean, 0.016 ug/g minumum, 0.8 ug/g max; 120 cherry samples, 29.2% positive, 0.15 ug/g mean, minimum 0.004 ug/g, max 1.6 ug/g, 1 sample exceeding maximum residue level (MRL) of 1 ug/g; 114 grape samples, 38.6% positive, 0.35 ug/g mean, 0.011 ug/g minumum, 7.7 ug/g max, 1 sample exceeding MRL of 5 ug/g; 168 peach/nectarine samples, 50.6% positive, 0.13 ug/g mean, 0.003 ug/g minimum, 1 ug/g max; 69 pear samples, 37.7% positive, 0.24 ug/g mean, 0.006 ug/g minimum, 3.7 ug/g max; 1 sample exceeding MRL of 2 ug/g; 79 plum samples, 40.5% positive, 0.09 ug/g mean, 0.004 ug/g minimum, 1.3 ug/g max, 1 sample exceeding MRL of 1 ug/g; 53 raspberry and blueberry samples, 11.3% positive, 0.079 ug/g mean, 0.011 ug/g minimum, 0.3 ug/g max; 51 strawberry samples, 15.7% positive, 0.028 ug/g mean, 0.005 ug/g minimum, 0.061 ug/g max(2).

From 1991 to 1995, 802 fruit and 1,536 vegetable samples produced in Ontario, Canada underwent analysis for pesticide residues; azinphosmethyl detections numbered 295 with 7 violations. Azinphosmethyl was not detected in 2 rhubarb, 57 asparagus, 19 beet, 62 broccoli, 59 cabbage, 58 carrot, 54 cauliflower, 45 mushroom, 21 parsnip, 126 potato, 23 radish or 11 spinach samples taken in the same survey(1).[Table#2947]

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

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

Oral (L580) ; dermal (L580) ; inhalation (L580)

Guthion 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.

Tolerances for residues of the insecticide O,O-dimethyl S-[(4-oxo-1,2,3-benzotriazin-3(4H)-yl)methyl]phosphorodithioate in or on the following raw agricultural commodities:[Table#2946]

Classified for restricted use, limited to use by or under the direct supervision of a certified applicator. Formulation: All liquids with a concentration greater than 13.5%; Use Pattern: Agricultural crop uses; Classification: Under further evaluation; Criteria Influencing Restriction: Inhalation hazard to humans.

Classified for restricted use, limited to use by or under the direct supervision of a certified applicator. Formulation: All other formulations; Use Pattern: Agricultural crop uses; Classification: Under further evaluation.

... EPA has completed its assessment of the cumulative risks from the organophosphate (OP) class of pesticides as required by the Food Quality Protection Act of 1996. In addition, the individual OPs have also been subject to review through the individual-chemical review process. The Agency's review of individual OPs has resulted in the issuance of Interim Reregistration Eligibility Decisions (IREDs) for 22 OPs /including azinphos-methyl/, interim Tolerance Reassessment and Risk Management Decisions (TREDs) for 8 OPs, and a Reregistration Eligibility Decision (RED) for one OP, malathion. These 31 OPs are listed in Appendix A. EPA has concluded, after completing its assessment of the cumulative risks associated with exposures to all of the OPs, 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 AZINPHOSMETHYL (6 total), please visit the HSDB record page.

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 1 lb or 0.454 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. Azinphos-methyl is an extremely hazardous substance (EHS) subject to reporting requirements when stored in amounts in excess of its threshold planning quantity (TPQ) of 10 or 10,000 lbs. Extremely hazardous substances that are solids are subject to either of two threshold planning quantities ... The lower quantity applies only if the solid exists in powdered form and has a particle size less than 100 microns; or is handled in solution or in molten form; or meets the criteria for a National Fire Protection Association (NFPA) rating of 2, 3 or 4 for reactivity. If the solid does not meet any of these criteria, it is subject to the upper ... threshold planning quantity ... .

Azinphos-methyl 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.

The objective of this work was to describe the effect of organophosphorous and organochlorine pesticides on phosphoinositides metabolism in human placenta. Pesticides concentration (10 uM) was used for in vitro incubations of cell-free homogenates labelled with (32)P orthophosphate. Heptachlor (HC) and dichloro-diphenyl-trichloroethane (o-p' DDT) increased phosphatidyl-inositol, phosphatidylinositolphosphate, and phosphatidyl-inositolbiphosphate phosphorylation while azinphosmethyl (AM) increased phosphatidylinositolbiphosphate labeling. Decreased (32)P incorporation in phosphatidylinositol was found with phosmet (PM), AM, and chlorpyriphos (CHL). The effects of these xenobiotics on PI4-kinase activity using different subcellular fractions were also examined. Both type of pesticides affected the postmembrane supernatant enzyme activity. A biphasic effect on membrane and nuclear PI4-kinase activity was seen with HC. The strongest effect found was seen with o-p' DDT in nuclear kinase activity while substantial changes were also observed in membrane. These data demonstrate the sensitivity of human placental PI4-kinase to pesticides currently found in human tissues and suggest deleterious consequences in different processes regulated by 4-phosphoinositides.

Organophosphates and their potent sulfoxidation ('-oxon') derivatives inhibit the enzyme acetylcholinesterase, allowing the accumulation of excessive acetylcholine at muscarinic receptors (cholinergic effector cells), at nicotinic receptors (skeletal neuromuscular junctions and autonomic ganglia), and in the central nervous system. Permanent damage to the acetylcholinesterase enzyme ('aging') may occur after a variable delay unless antidotal treatment with enzyme reactivator is given.

Azinphos-methyl requires metabolic activation to azinphos-methyl oxon by microsomal mixed-function oxidases to inhibit cholinesterase.

Organophosphorus derivatives act by combining with and inactivating the enzyme acetylcholinesterase (AChE). ... The inactivation of cholinesterase by cholinesterase inhibitor pesticides allows the accumulation of large amounts of acetylcholine, with resultant widespread effects that may be ... separated into 4 categories: (1) Potentiation of postganglionic parasympathetic activity. ... (2) Persistent depolarization of skeletal muscle ... (3) Initial stimulation following depression of cells of central nervous system ... (4) Variable ganglionic stimulation or blockade ... /Cholinesterase inhibitor pesticides/

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

The rate of disappearance of azinphos-methyl effected by a hepatic oxidative desulfurating system and a demethylating system was investigated in liver homogenates from four different species (rat, guinea pig, chicken and monkey). Azinphos-methyl was metabolized by both systems and homogenates from all species were uniformly active.

The metabolism of azinphos-methyl was investigated by administration of ring-UL-(14)C-azinphos-methyl to male and female Sprague-Dawley rats. The metabolic pathway of azinphos-methyl in rats is proposed. Upon absorption, azinphos-methyl is rapidly metabolized by mixed function oxidases and GSH-transferases in the liver and other tissues, which results in the formation of azinphos-methyl oxygen analog, mercaptomethylbenzazimide, glutathionyl methylbenzazimide and desmethyl isoazinphos-methyl. Further hydrolysis, methylation and oxidation of mercaptomethyl-benzazimide forms benzazimide, methylthiomethylbenzazimide and its corresponding oxidized metabolites. Hydrolysis of glutathionyl methyl-benzazimide may result in the formation of cysteinylmethyl-benzazimide. Subsequent oxidation of cysteinyl-methylbenzazimide forms its corresponding sulfoxide and sulfone.

Azinphos-methyl is readily absorbed and metabolized in mammals. Dimethylphosphorothioic and Dimethylphosphoric acids, desmethyl azinphosmethyl and azinphos-methyloxon are principal metabolites as demonstrated in in-vitro mouse tissue studies. The benzotrianzine moiety is rapidly excreted without degradation, less than 0.1% of the radioactivity of peroral or intraperitoneal doses (0.1-0.2 mg/kg bw) of (14)C-labelled azinphos-methyl is eliminated as CO2. Approximately 65% of the radioactivity of these doses was eliminated in urine, about 25% in feces. In studies with dairy cows no residues of azinphos-methyl or gutoxon appeared in milk, four unidentified non-phosphorus containing metabolites were present in low concentration.

The bioactivation of azinphos-methyl (AZIN), chlorpyrifos (CPF), diazinon (DIA), and parathion (PAR), four widely used organophosphorothioate (OPT) pesticides has been investigated in human liver microsomes (HLM). In addition, the role of human cytochrome P450 (CYPs) in OPT desulfuration at pesticide levels representative of human exposure have been defined by means of correlation and immunoinhibition studies. CYP-mediated oxon formation from the four OPTs is efficiently catalyzed by HLM, although showing a high variability (>40-fold) among samples. Two distinct phases were involved in the desulfuration of AZIN, DIA, and PAR, characterized by different affinity constants (K(mapp1) = 0.13-9 uM and K(mapp2) = 5- 269 uM). Within the range of CPF concentrations tested, only the high-affinity component was evidenced (K(mapp1) = 0.27-0.94 uM). Oxon formation in phenotyped individual HLM showed a significant correlation with CYP1A2-, 3A4-, and 2B6-related activities, at different levels depending on the OPT concentration. Anti-human CYP1A2, 2B6, and 3A4 antibodies significantly inhibited oxon formation, showing the same OPT concentration dependence. Our data indicated that CYP1A2 is mainly involved in OPT desulfuration at low pesticide concentrations, while the role of CYP3A4 is more significant to the low-affinity component of OPT bioactivation. The contribution of CYP2B6 to total hepatic oxon formation was relevant in a wide range of pesticide concentrations, being a very efficient catalyst of both the high- and low-affinity phase.

For more Metabolism/Metabolites (Complete) data for AZINPHOSMETHYL (11 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.

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.

A pesticide or chemical agent that kills mites and ticks. This is a large class that includes carbamates, formamides, organochlorines, organophosphates, etc, that act as antibiotics or growth regulators.

The pharmacokinetic behavior of benzazimide was investigated in rats using the ring-labeled (14)C-compound. After oral administration the (14)C-activity was almost completely absorbed from the gastrointestinal tract. Elimination of the activity took place quickly, 24 hours after administration only 1.3% of the amount administered was present in the animal not including the gastrointestinal tract. More than 99% of the amount administered was eliminated within 48 hours (54 to 66% in the urine and 33 to 45% via the feces). /benzazimide metabolite/

The pharmacokinetic behavior of carbonyl-(14C)-labelled azinphos-methyl was investigated in rats. The material was almost completely absorbed from the digestive tract, and irrespective of dose and route of administration, 60 to 70% was eliminated in the urine and 25 to 35% in the feces within 48 hours. Less than 0.1% of the administered activity was eliminated with the respiratory air within 24 hours of dosing, and in rats with biliary fistulas around 30% of the intravenously administered activity was eliminated in the bile within 24 hours of dosing. Two days after dosing the total activity content in the animal (excluding digestive tract) was less than 5% of the administered dose; by 4 days this had declined to 2% and by 16 days to 1%. Six hours after dosing, the highest concentrations of radioactivity were found in the organs of elimination (liver and kidney) with relatively high concentrations found in blood. The activity concentrations decayed rapidly in all organs up to 2 days post dosing, but thereafter the activity was more slowly eliminated. At 16 days after dosing the highest concentration was found in the erythrocytes. In vitro studies, in which whole blood was incubated with labeled parent compound, did not show any accumulation of radioactivity in the blood constituents.

Azinphos-methyl may be absorbed from the gastrointestinal tract, through the intact skin; and by inhalation of fine spray mist or dusts.

When radioactive azinphos-methyl was administered IV to volunteers, radioactivity equivalent to about 1.5% of the administered dose per hr was recovered in the urine during the first 12 hr. Recovery decreased gradually but was still slightly over 0.1% 96-120 hr after injection. The total recovery during 120 hr was 69.5% of the dose following IV administration and 15.9% following dermal application.

For more Absorption, Distribution and Excretion (Complete) data for AZINPHOSMETHYL (12 total), please visit the HSDB record page.

Used primarily to kill leaf feeding insects; [EXTOXNET] Used to control insects on fruits, melons, nuts, vegetables, field crops, ornamentals, and shade trees; [ACGIH]

Farming (Pesticides) [Category: Industry]

For azinphos-methyl (USEPA/OPP Pesticide Code: 058001) 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./

Control of chewing and sucking insects of the orders Coleoptera, Diptera, Homoptera, Hemiptera, and Lepidoptera, on fruit trees (including citrus), vines, strawberries, nuts, vegetables, potatoes, cereals, maize, cotton, ornamentals, beet, soya beans, tobacco, rice, coffee, sugar cane, forestry, and other crops.

Insecticide

Guthion is used as a pesticide, thus exposure usually occurs from eating contaminated food. (L580)

(1978) 7.18X10+7 G (PRINCPL CUSTMS DISTS)

(1982) 4.85X10+7 G (PRINCPL CUSTMS DISTS)

INSECTICIDE FOR DECIDUOUS FRUITS & NUTS, 53%; COTTON, 17%; SOYBEANS, 10%; VEGETABLES, 10%; CITRUS, 3%; OTHER FIELD CROPS, 7% (1982)

(1978) 1.09X10+9 G (CONSUMPTION-INCL IMPORTS)

(1982) 1.36X10+9 G (CONSUMPTION-INCL IMPORTS)

Azinphos-methyl is obtained by reaction of N-chloromethylbenzazimide with ammonium dimethyldithiophosphonic acid or directly from benzazimide by reaction with formaldehyde and Azinphos-methyl (dimethyldithiophosphonic acid in the presence of hydrochloric acid). N-Chloromethylbenzazimide is produced by reaction of anthranilic acid with phosgene, followed by treatment of the thus-obtained product with nitrous acid, and then with formaldehyde and sulfonyl chloride.

Azinophosmethyl is produced by the reaction of N-bromoethylazimidobenzoyl with sodium dimethyldithiophosphoric acid.

Wettable powder

Formulation types: dustable powder; emulsifiable concentrate; suspension concentrate (flowable concentrate)

SPRAY CONCN (1.5 AND 2.0 LB/US GAL); 20, 40% WETTABLE POWDER (BAYER); 25%, 50% WETTABLE POWDER (MOBAY); EMULSIFIABLE CONCN 20%.

Gustion MS, wettable powder (250 g azinphos-methyl + 75 g demeton-S-methyl sulfone)

For more Formulations/Preparations (Complete) data for AZINPHOSMETHYL (12 total), please visit the HSDB record page.

Chemical Classes -> Organophosphates and carbamates

INSECTICIDES

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

Air emissions of 0.16 kg of sulfur dioxide, 0.13 kg of nitrous oxide, 0.75 kg of hydrocarbons and 0.5 kg of guthion per metric ton of pesticide produced have been reported.

Azinphos methyl is a restricted use pesticide. ...All azinphos methyl liquids with a concentration >13.5% are classified as restricted use pesticides by the U.S. EPA because of their high toxicity.

Application rates: 0.047 to 10.35 lb active ingredient/acre

Types and methods of application: Foliar (by ground or aerial equipment), ultra low volume foliar application, soil application, and transplant water application.