Oxamyl

Slight sulfurous odor

Garlic-like odor

0.97 g/cu cm @ 25 °C

0.98 @25 °C

White crystalline solid

Colorless crystals

Soluble at 77.0 °F (280g/kg) (NTP, 1992)

Solubility (g/100 ml @ 25 °C): acetone, 67; ethanol, 33; 2-propanol, 11; methanol, 144; toluene, 1

In water, 280 g/l @ 25 °C

Decomposes on distillation

310 °C @760 [mm Hg]

Decomposes to innocuous materials in natural waters and soil.

When heated to decomposition it emits very toxic fumes of /sulfur and nitric oxides/.

Aeration, sunlight, alkalinity, and higher temperatures increase the rate of decomposition.

DT50 >31 day (pH 5), 8 day (pH 7), 3 hr (pH 9)... .

Decomposes on distillation.

212 to 216 °F Pure compound changes to different form upon melting, with a melting point of 226 to 230 °F. (EPA, 1998)

100-102 °C, changes to a different crystalline form, mp 108-110 °C

0.00023 mmHg at 77 °F (EPA, 1998)

0.00023 [mmHg]

0.00023 mm Hg @ 20-25 °C

0.00023 [mm Hg] @25 °C

Oxamyl is a white, crystalline solid, with slight sulfurous odor. Used as an insecticide, nematicide and acaricide on many field crops, vegetables, fruits, and ornamentals. (EPA, 1998)

Colorless or white solid with sulfurous or garlic-like odor; [HSDB]

Solid and formulations are stable... .

Decompostion is increased by aeration, sunlight, alkalinity and higher temperatures.

Danger

H300: Fatal if swallowed [Danger Acute toxicity, oral]；H312: Harmful in contact with skin [Warning Acute toxicity, dermal]；H330: Fatal if inhaled [Danger Acute toxicity, inhalation]；H411: Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

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

Danger

Hazard Traits - Neurotoxicity; Other Toxicological Hazard Traits；Authoritative List - CA MCLs; CWA 303(d)；Report - if used as a fragrance or flavor ingredient

Commission Regulation (EC) No 451/2000

Dir 06/16/EC, Reg. (EU) 2018/1796, Reg. (EU) 2019/2094, Reg. (EU) 2021/2068, Reg. (EU) 2021/52, Reg. (EU) 2023/741, Reg. (EU) 84/2018, Reg. (EU) No 1136/2013, Reg. (EU) No 2023/116, Reg. (EU) No 540/2011

Oxamyl: Does not have an individual approval but may be used as a component in a product covered by a group standard. It is not approved for use as a chemical in its own right.

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.)

IMAP assessments - Ethanimidothioic acid, 2-(dimethylamino)-N-[[(methylamino)carbonyl]oxy]-2-oxo-, methyl ester: Human health tier I assessment；IMAP assessments - Ethanimidothioic acid, 2-(dimethylamino)-N-[[(methylamino)carbonyl]oxy]-2-oxo-, methyl ester: Environment tier I assessment

USEPA/Office of Pesticide Programs; Interim Reregistration Eligibility Decision (IRED) for Oxamyl. 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 July 24, 2003: http://www.epa.gov/pesticides/reregistration/status.htm]

P194; As stipulated in 40 CFR 261.33, when oxamyl, as a commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate, becomes a waste, it must be managed according to federal and/or state hazardous waste regulations. Also defined as a hazardous waste is any container or inner liner used to hold this waste or any residue, contaminated soil, water, or other debris resulting from the cleanup of a spill, into water or on dry land, of this waste. Generators of small quantities of this waste may qualify for partial exclusion from hazardous waste regulations (40 CFR 261.5(e)).

Tolerances are established for the sum of the residues of the insecticide oxamyl (methyl N',N'-dimethyl-N-[methylcarbamoyl)-oxyl]-1-thiooxamimidate) and its oxime metabolite N,N-dimethyl-N-hydroxy-1-thiooxamimidate calculated as oxamyl in or on the following food commodities: apple; banana; cantaloupe; celery; cottonseed; cucumber; eggplant; fruit, citrus; melon, honeydew; peanut; peanut; peanut, hay; pear; peppermint, hay; pepper, bell; pepper, non-bell ; pineapple; potatoe; pumpkin; root crop vegetables; soybean; spearmint, hay; squash, summer; squash, winter; tomatoe, and watermelon.

A tolerance is established for residues of the insecticide oxamyl (methyl N',N'-dimethyl-N- [(methylcarbamoyl)oxy]-1-thiooxamimidate) in pineapple, bran as a result of application of the insecticide to growing pineapples.

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their future use. Under this pesticide reregistration program, EPA examines health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether they are eligible for reregistration. In addition, all pesticides must meet the new safety standard of the Food Quality Protection Act of 1996. Oxamyl is found on List A, which contains most food use pesticides and consists of the 194 chemical cases (or 350 individual active ingredients) for which EPA issued registration standards prior to FIFRA, as amended in 1988. Case No: 0253; Pesticide type: Insecticide (acaricide), fungicide (nematicide); Registration Standard Date: 06/30/87; Case Status: OPP is reviewing data from the pesticide's producers regarding its human health and/or environmental effects, or OPP is determining the pesticide's eligibility for reregistration and developing the Reregistration Eligibility Decision (RED) document.; Active ingredient (AI): Oxamyl; Data Call-in (DCI) Date(s): 10/13/95, 03/01/96; AI Status: The producers of the pesticide has made commitments to conduct the studies and pay the fees required for reregistration, and are meeting those commitments in a timely manner.

Based on its review, EPA has identified risk mitigation measures that the Agency believes are necessary to address the human health and environmental risks associated with the current use of oxamyl. EPA is now publishing its interim reregistration eligibility and risk management decision for the current uses of oxamyl and its associated human health and environmental risks. The tolerance reassessment decision for oxamyl will be finalized once a cumulative assessment with similar carbamates is complete. The Agencys decision on the individual chemical oxamyl can be found in the ...Interim Reregistration Eligibility Decision for Oxamyl, which was approved on September 30, 2000... .

OXAMYL is a carbamate ester. Carbamates are chemically similar to, but more reactive than amides. Like amides they form polymers such as polyurethane resins. Carbamates are incompatible with strong acids and bases, and especially incompatible with strong reducing agents such as hydrides. Flammable gaseous hydrogen is produced by the combination of active metals or nitrides with carbamates. Strongly oxidizing acids, peroxides, and hydroperoxides are incompatible with carbamates.

/GUIDE 131: FLAMMABLE LIQUIDS-TOXIC/ Health: TOXIC; may be fatal if inhaled, ingested or absorbed through skin. Inhalation or contact with some of these materials will irritate or burn skin and eyes. Fire will produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or suffocation. Runoff from fire control or dilution water may cause pollution. /Carbamate pesticide, liquid, flammable, poisonous; Carbamate pesticide, liquid, flammable, toxic; Carbamate pesticide, liquid, poisonous, flammable; Carbamate pesticide, liquid, toxic, flammable/

/GUIDE 131: FLAMMABLE LIQUIDS-TOXIC/ Fire or Explosion: HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion and poison hazard indoors, outdoors or in sewers. Those substances designated with a "P" may polymerize explosively when heated or involved in a fire. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water. /Carbamate pesticide, liquid, flammable, poisonous; Carbamate pesticide, liquid, flammable, toxic; Carbamate pesticide, liquid, poisonous, flammable; Carbamate pesticide, liquid, toxic, flammable/

/GUIDE 131: FLAMMABLE LIQUIDS-TOXIC/ Public Safety: CALL Emergency Response Telephone Number ... . As an immediate precautionary measure, isolate spill or leak area for at least 50 meters (150 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. Ventilate closed spaces before entering. /Carbamate pesticide, liquid, flammable, poisonous; Carbamate pesticide, liquid, flammable, toxic; Carbamate pesticide, liquid, poisonous, flammable; Carbamate pesticide, liquid, toxic, flammable/

/GUIDE 131: FLAMMABLE LIQUIDS-TOXIC/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible. /Carbamate pesticide, liquid, flammable, poisonous; Carbamate pesticide, liquid, flammable, toxic; Carbamate pesticide, liquid, poisonous, flammable; Carbamate pesticide, liquid, toxic, flammable/

For more DOT Emergency Guidelines (Complete) data for OXAMYL (16 total), please visit the HSDB record page.

This is a solid carbamate pesticide. Move container from fire area. Fight fire from maximum distance. Dike fire control water for later disposal; do not scatter the material. Wear positive pressure breathing apparatus and special protective clothing.；Extinguish fire using agent suitable for type of surrounding fire, as the material itself does not burn or burns with difficulty. Use water in flooding quantities as a fog. Use alcohol foam, carbon dioxide or dry chemical. (EPA, 1998)

Signs and Symptoms of Acute Oxamyl Exposure: Acute exposure to oxamyl usually leads to a cholinergic crisis. Signs and symptoms may include increased salivation, lacrimation (tearing), perspiration, spontaneous defecation, and spontaneous urination. Pinpoint pupils, blurred vision, tremor, muscle twitching, mental confusion, convulsions, and coma may occur. Gastrointestinal symptoms include abdominal pain, diarrhea, nausea, and vomiting. Bradycardia (slow heart rate) is common. Dyspnea (shortness of breath) and pulmonary edema may also occur.；Emergency Life-Support Procedures: Acute exposure to oxamyl may require decontamination and life support for the victims. Emergency personnel should wear protective clothing appropriate to the type and degree of contamination. Air-purifying or supplied-air respiratory equipment should also be worn, as necessary. Rescue vehicles should carry supplies such as plastic sheeting and disposable plastic bags to assist in preventing spread of contamination.；Inhalation Exposure:；1. Move victims to fresh air. Emergency personnel should avoid self-exposure to oxamyl.；2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.；3. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.；4. Transport to a health care facility.；Dermal/Eye Exposure:；1. Remove victims from exposure. Emergency personnel should avoid self- exposure to oxamyl.；2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.；3. Remove contaminated clothing as soon as possible.；4. If eye exposure has occurred, eyes must be flushed with lukewarm water for at least 15 minutes.；5. Wash exposed skin areas three times with soap and water.；6. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.；7. Transport to a health care facility.；Ingestion Exposure:；1. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.；2. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.；3. Vomiting may be induced with syrup of Ipecac. If elapsed time since ingestion of oxamyl is unknown or suspected to be greater than 30 minutes, do not induce vomiting and proceed to Step；4.Ipecac should not be administered to children under 6 months of age.Warning: Ingestion of oxamyl may result in sudden onset of seizures or loss of consciousness. Syrup of Ipecac should be administered only if victims are alert, have an active gag-reflex, and show no signs of impending seizure or coma. If ANY uncertainty exists, proceed to Step

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]

If you spill this chemical, you should dampen the solid spill material with water,then transfer the dampened material to a suitable container. Use absorbent paper dampened with water to pick up any remaining material. Seal your contaminated clothing and the absorbent paper in a vapor-tight plastic bag for eventual disposal. Wash all contaminated surfaces with a strong soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.

This is a solid carbamate pesticide. Keep unnecessary people away; isolate hazard areas and deny entry. Stay upwind, keep out of low areas. Do not touch spilled material, or breathe the vapors, dusts or fumes from burning materials. Do not handle broken packages without protective equipment. Wash away any material that may have contacted the body with soap and water. (EPA, 1998)

Generators of waste (equal to or greater than 100 kg/month) containing this contaminant, EPA hazardous waste number P194, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

Oxamyl should be treated with alkali. Recommendable methods: Alkaline hydrolysis, adsorption.

The protective clothing should be kept in separate places where it cannot be contaminated with toxic chemicals. It should be forbidden to keep this clothing in living quarters. Protective clothing must be washed at least once a week and each time it is contaminated with pesticides. Before washing the clothing should be soaked for several hours in a calcium carbonate solution. /Pesticides/

Smoking, eating, and drinking before washing should be absolutely prohibited when any pesticide ... is being handled or used. /Pesticides/

Excerpt from ERG Guide 131 [Flammable Liquids - Toxic]:；IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 50 meters (150 feet) in all directions.；SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary.；FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)

Tolerances are established for the sum of the residues of the insecticide oxamyl (methyl N',N'-dimethyl-N-[methylcarbamoyl)-oxyl]-1-thiooxamimidate) and its oxime metabolite N,N-dimethyl-N-hydroxy-1-thiooxamimidate calculated as oxamyl in or on the following food commodities: apple, 2.0 ppm; banana, 0.3 ppm; cantaloupe, 2.0 ppm; celery, 3.0 ppm; cottonseed, 0.2 ppm; cucumber, 2.0 ppm; eggplant, 2.0 ppm; fruit, citrus, 3.0 ppm; melon, honeydew, 2.0 ppm; peanut, 0.2 ppm; peanut, 0.2 ppm; peanut, hay, 2.0 ppm; pear, 2.0 ppm; peppermint, hay, 10.0 ppm; pepper, bell, 3.0 ppm; pepper, non-bell, 5.0 ppm; pineapple, 1.0 ppm; potatoe, 0.1 ppm; pumpkin, 2.0 ppm; root crop vegetables, 0.1 ppm; soybean, 0.2 ppm; spearmint, hay, 10.0 ppm; squash, summer, 2.0 ppm; squash, winter, 2.0 ppm; tomatoe, 2.0 ppm, and watermelon, 2.0 ppm.

A tolerance of 6 ppm is established for residues of the insecticide oamyl (methyl N',N'-dimethyl-N- [(methylcarbamoyl)oxy]-1-thiooxamimidate) in pineapple, bran as a result of application of the insecticide to growing pineapples.

0.15 [mg/m3]

1.7 [mg/m3]

2.5 [mg/m3]

For emergency situations, wear a positive pressure, pressure-demand, full facepiece self-contained breathing apparatus (SCBA) or pressure- demand supplied air respirator with escape SCBA and a fully-encapsulating, chemical resistant suit. (EPA, 1998)

The current personal protective equipment required for all uses of oxamyl is short-sleeve shirt and short pants with coveralls, chemical resistant gloves, head gear for air blast, and an organic vapor respirator.

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.

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. Chronically high (>10 years) exposure leads to neuropsychological consequences including disturbances in perception and visuo-motor processing (A15321).

LC50 Bobwhite oral 54 ppm/8 day

LC50 Mallard oral 369 ppm/8 day

LD50 Japanese quail (Coturnix coturnix japonica) oral 4.3 mg/kg body wt

LD50 Mallard (Anas platyrhynchos) oral 2.6 mg/kg body wt

For more Ecotoxicity Values (Complete) data for OXAMYL (11 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values ranging from 6 to 10(2), indicate that oxamyl is expected to have very high mobility in soil(SRC). Volatilization of oxamyl from moist soil surfaces is not expected to be an important fate process(SRC) given a Henry's Law constant of 2.37X10-10 atm-cu m/mole(SRC), derived from its vapor pressure, 0.00023 mm Hg(3) and water solubility, 2.8X10+5 mg/l(4). Oxamyl is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(3). Half-lives of oxamyl in soil ranged from 11 days in loamy sand(5) to 415 days in fine sand (6) under aerobic conditions, and 6 days in silt loam under anaerobic conditions(5). Photolysis on soil does not appear to be significant(7).

AQUATIC FATE: Based on a classification scheme(1), Koc values ranging from 6 to 10(2), indicate that oxamyl is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon a Henry's Law constant of 2.37X10-10 atm-cu m/mole(SRC), derived from its vapor pressure, 0.00023 mm Hg(4) and water solubility, 2.8X10+5 mg/l (5). According to a classification scheme(6), an estimated BCF of 3.1(SRC), from a log Kow of -0.48(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). The half-lives for the hydrolysis of oxamyl in sterile water-ethanol (99:1) phosphate buffers at 25 °C were 300 weeks, 17 weeks, 1.6 weeks, and 1.4 days at pHs of 4.5, 6.0, 7.0 and 8.0 respectively(8). Oxamyl was found to be stable at pH 4.7 for at least 11 days and hydrolyzed slowly in neutral solution (pH 6.9) with 3 and 9% hydrolysis occurring after 24 and 28 hours, respectively(9). At pH 9, hydrolysis was rapid with 30% conversion after 6 hours(9). Exposure to ultraviolet light was found to accelerate hydrolysis(9). An experimental value of the rate constant for the reaction of oxamyl with photochemically produced hydroxyl radicals in water has been determined to be 2.0X10+9 l/mol-s at 22 °C(10), which corresponds to a half-life of about 134 days(SRC), assuming a hydroxyl radical concentration of 3X10-17 molar(11). Photolysis appears to be significant in acidic surface water(12).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), oxamyl, which has a vapor pressure of 0.00023 mm Hg at 20-25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase oxamyl 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 1.4 days(SRC), calculated from its rate constant of 2.3X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Oxamyl is not expected to absorb light at wavelengths >290 nm, and would not be expected to be susceptible to direct photolysis by sunlight in air(SRC).

In a study conducted from 1982-1984 sampling dietary intake of 25-30 yr old males, oxamyl was found in 2 of 201 adult foods sampled at a total of 0.012 ug; 83% of total the oxamyl intake was from cucumbers(1). Oxamyl was found in two ready-to-eat foods at an average concentration of 0.021 ug/g: once in cucumbers at 0.031 ug/g and once in raw sweet green pepper at 0.011 ug/g(2). Oxamyl was found in 4 out of 1219 samples of domestic (US) tomatoes at a maximum concentration of 0.12 ppm and twice in imported tomatoes at trace concentrations(3). Oxamyl has been detected as residues during the 1978-82, 1983-86, and 1994 US regulatory monitoring studies, however, concentrations were not reported(4,5,6). In a 1985-1991 US study of domestic foods which may be eaten by infants/children, oxamyl was found in one of 2464 samples of apples at a concentration of 0.06 ppm, and in 3 of 571 samples of pears at a maximum concentration of 0.38 ppm(7). Oxamyl was detected 8 times in imported agricultural commodities (cucumbers, grapes, sweet peppers, and strawberries) in Canada between Jan 1992-March 1994(8). Oxamyl residue was found 7 times at a maximum concentration of 0.26 in domestic (US) and imported apples in 1993-1994(9). Oxamyl residues were detected in various vegetables in Thailand during 1987-1989, at concentrations of 0.03 mg/kg(10).

Oxamyl is a cholinesterase or acetylcholinesterase (AChE) inhibitor. Carbamates form unstable complexes with chlolinesterases by carbamoylation of the active sites of the enzymes. This inhibition is reversible. A cholinesterase inhibitor suppresses the action of acetylcholine esterase. Because of its essential function, chemicals that interfere with the action of acetylcholine esterase are potent neurotoxins, causing excessive salivation and eye-watering in low doses. Headache, salivation, nausea, vomiting, abdominal pain and diarrhea are often prominent at higher levels of exposure. 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.

/BIRDS and MAMMALS/ For avian species, reproductive effects include reduction in egg production and egg fertility based on the results of a mallard duck study. Chronic /levels of concern/ (LOC's) were exceeded for all use patterns for all-food items (except for seeds) using maximum and average /estimated environmental concentrations/ (EECs).

/OTHER TERRESTRIAL SPECIES/ Oxamyl is moderate to highly toxic to bees on an acute contact basis. Results of a residue on foliage study indicate that residues of oxamyl applied at 1.0 lb al/acre, may remain toxic to bees for as long as 6 days after treatment. Because oxamyl is moderate to highly toxic to honeybees, precautions with respect to spray drift to flowering plants should be followed.

/PLANTS/ Non-phytotoxic when used as directed. Some strawberry varieties may be injured.

/FIELD STUDIES/ New Zealand white rabbits maintained in outdoor pens were exposed to three simulated field-spray applications of oxamyl at 3.36 kg/ha. No clinical signs of toxicity, behavioral alterations, or gross pathologies were observed in any rabbits 5 days after the last treatment.

As with organophosphates, the signs and symptoms are based on excessive cholinergic stimulation. Unlike organophosphate poisoning, carbamate poisonings tend to be of shorter duration because the inhibition of nervous tissue acetylcholinesterase is reversible, and carbamates are more rapidly metabolized. Muscle weakness, dizziness, sweating and slight body discomfort are commonly reported early symptoms. Headache, salivation, nausea, vomiting, abdominal pain and diarrhea are often prominent at higher levels of exposure. Contraction of the pupils with blurred vision, incoordination, muscle twitching and slurred speech have been reported. (L795)

Hazard Traits - Neurotoxicity; Other Toxicological Hazard Traits；Authoritative List - CA MCLs; CWA 303(d)；Report - if used as a fragrance or flavor ingredient

Commission Regulation (EC) No 451/2000

Dir 06/16/EC, Reg. (EU) 2018/1796, Reg. (EU) 2019/2094, Reg. (EU) 2021/2068, Reg. (EU) 2021/52, Reg. (EU) 2023/741, Reg. (EU) 84/2018, Reg. (EU) No 1136/2013, Reg. (EU) No 2023/116, Reg. (EU) No 540/2011

Oxamyl: Does not have an individual approval but may be used as a component in a product covered by a group standard. It is not approved for use as a chemical in its own right.

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.)

P194; As stipulated in 40 CFR 261.33, when oxamyl, as a commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate, becomes a waste, it must be managed according to federal and/or state hazardous waste regulations. Also defined as a hazardous waste is any container or inner liner used to hold this waste or any residue, contaminated soil, water, or other debris resulting from the cleanup of a spill, into water or on dry land, of this waste. Generators of small quantities of this waste may qualify for partial exclusion from hazardous waste regulations (40 CFR 261.5(e)).

Tolerances are established for the sum of the residues of the insecticide oxamyl (methyl N',N'-dimethyl-N-[methylcarbamoyl)-oxyl]-1-thiooxamimidate) and its oxime metabolite N,N-dimethyl-N-hydroxy-1-thiooxamimidate calculated as oxamyl in or on the following food commodities: apple; banana; cantaloupe; celery; cottonseed; cucumber; eggplant; fruit, citrus; melon, honeydew; peanut; peanut; peanut, hay; pear; peppermint, hay; pepper, bell; pepper, non-bell ; pineapple; potatoe; pumpkin; root crop vegetables; soybean; spearmint, hay; squash, summer; squash, winter; tomatoe, and watermelon.

A tolerance is established for residues of the insecticide oxamyl (methyl N',N'-dimethyl-N- [(methylcarbamoyl)oxy]-1-thiooxamimidate) in pineapple, bran as a result of application of the insecticide to growing pineapples.

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their future use. Under this pesticide reregistration program, EPA examines health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether they are eligible for reregistration. In addition, all pesticides must meet the new safety standard of the Food Quality Protection Act of 1996. Oxamyl is found on List A, which contains most food use pesticides and consists of the 194 chemical cases (or 350 individual active ingredients) for which EPA issued registration standards prior to FIFRA, as amended in 1988. Case No: 0253; Pesticide type: Insecticide (acaricide), fungicide (nematicide); Registration Standard Date: 06/30/87; Case Status: OPP is reviewing data from the pesticide's producers regarding its human health and/or environmental effects, or OPP is determining the pesticide's eligibility for reregistration and developing the Reregistration Eligibility Decision (RED) document.; Active ingredient (AI): Oxamyl; Data Call-in (DCI) Date(s): 10/13/95, 03/01/96; AI Status: The producers of the pesticide has made commitments to conduct the studies and pay the fees required for reregistration, and are meeting those commitments in a timely manner.

Based on its review, EPA has identified risk mitigation measures that the Agency believes are necessary to address the human health and environmental risks associated with the current use of oxamyl. EPA is now publishing its interim reregistration eligibility and risk management decision for the current uses of oxamyl and its associated human health and environmental risks. The tolerance reassessment decision for oxamyl will be finalized once a cumulative assessment with similar carbamates is complete. The Agencys decision on the individual chemical oxamyl can be found in the ...Interim Reregistration Eligibility Decision for Oxamyl, which was approved on September 30, 2000... .

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 (statutory level). The toll free number of the NRC is (800) 424-8802; In the Washington D.C. metropolitan area (202) 426-2675. 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. oxamyl is an extremely hazardous substance (EHS) subject to reporting requirements when stored in amounts in excess of its threshold planning quantity (TPQ) of 100 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 ... .

(AZ) ARIZONA 180 ug/l

(ME) MAINE 175 ug/l

Carbamates are effective insecticides by virtue of their ability to inhibit acetylcholinesterase (AChE) in the nervous system. They also inhibit other esterases. The carbamylation of the enzyme is unstable, and the regeneration of AChE is relatively rapid compared with that from a phosphorylated enzyme. Thus, carbamate pesticides are less dangerous with regard to human exposure than organophosphorus pesticides. The ratio between the dose required to produce death and the dose required to produce minimum symptoms of poisoning is substantially larger for carbamate compounds than for organophosphorus compounds. /Carbamate Pesticides/

The carbamates alone weakly activated estrogen- or progesterone-responsive reporter genes in breast and endometrial cancer cells. All of the carbamates decreased estradiol- or progesterone-induced reporter gene activity in the breast and endometrial cancer cells. In whole cell competition binding assays, the carbamates demonstrated a limited capacity to displace radiolabeled estrogen or progesterone from /estrogen receptor/ or /progesterone receptor/. /Carbamates/

The metabolism of oxamyl ... has not been much studied in humans. Oxime production would be expected to occur again ... with subsequent ketone formation as for methomyl. The dimethylacetyl group may hydrolyze to form N,N-dimethylformamide, excreted as N-methylformamide and formamide in urine ... or N,N-dimethyl carbamic acid.

All three of the oxime carbamates, aldicarb, methomyl, and oxamyl, will produce the N-methylformamide ... and N-methylamino formic acid ... as a result of R1 cleavage. The former is a urinary biological monitoring marker for N,N-dimethylformamide ... .

(14)C-oxamyl was degraded by two major pathways in rats that received 1 mg each (2.5 to 4.6 mg/kg) after having received nonradioactive oxamyl for 18 days or more at a dietary level of 50 to 150 ppm (about 2.5 to 7.4 mg/kg/day). Oxamyl was hydrolyzed to an oximino metabolite (methyl N-hydroxy-N',N'-dimethyl-1-thioxamimidate) or converted enzymatically via N,N-dimethyl-1-cyanoformide (DMCF) to N,N-dimethyloxamic acid. Conjugates of the oximino cmpd, the acid, and their monomethyl derivatives constituted over 70% of the metabolites excreted in the urine and feces. Less than 0.3% of the oxamyl was exhaled as carbon dioxide, but incorporation of (14)C-CO2 accounted for more than 50% of the radioactivity remaining in the tissues ... .

The major component present in the urine was glucuronide of oxime (31 - 37% of the dose), metabolite oxime (13 - 18% of the dose) and the parent oxamyl (7 - 11% of the dose).

For more Metabolism/Metabolites (Complete) data for OXAMYL (9 total), please visit the HSDB record page.

The carbamates are hydrolyzed enzymatically by the liver; degradation products are excreted by the kidneys and the liver. (L793)

When (14)C-oxamyl was administered to lactating goats, most of the dose was rapidly eliminated via urine and feces. Some (14)CO2 also formed. No intact oxamyl or related metabolites were detected in milk, blood, urine or tissues; however, (14)C was incorporated into lactose, casein, triglyceride fats, and amino acids of protein in blood and tissues.

Following ip injection of (14)C oxamyl, mice excreted 75.5% of the activity within 6 hours. By 96 hours, 88.7% had been excreted in the urine and 7.7% in the feces. At 6 and 72 hours after injection, organosoluble radioactive material constituted 24.7 and 6.5%, respectively, of the total radioactivity in the urine. The organosoluble cmpds identified included oxamyl and methyl N'-methyl-N-(methyl(carbomyl)oxy)-1-thiooxamimidate ...

Little information is available on the distribution of carbamates in the various organs and tissues in mammals following exposure by inhalation or the oral route. The organs in which residues have been reported are the liver, kidneys, brain, fat, and muscle. The half-life in the rat is of the order of 3-8 hr. It seems that the excretion of carbamates via urine is also rapid in man, and that the metabolic pathways in man are the same as those in the rat. /Carbamate pesticides/

In a rat metabolism study, SD rats (5 animals/sex/group) received a single oral dose of 14C-oxamyl (1 mg/kg) by gavage. Approximately 80% of the administered radioactivity was eliminated in the urine after 24 hours of dosing, and approximately 91% of the dose was eliminated in the urine by 168 hours. Less than 3% of the dose was found in the feces, and approximately 1% of the dose was found in the carcass. Except for muscle and skin, less than 1% of the dose was found in any tissue examined. The data indicated that oxamyl was readily absorbed with oral administration and rapidly metabolized and eliminated in the urine. There was no sex difference m the pattern of elimination, and there was essentially no sequestration of oxamyl or its metabolites in any tissue examined.

The metabolic fate of (1-14C)oxamyl in a lactating goat was investigated. The test animal was administered five consecutive daily doses orally at 31 ppm oxamyl dietary burden. Most of the radioactivity was eliminated via urine (45.3%) and feces (7.2%). (14C)Oxamyl equivalents in edible tissues (liver, kidney, muscle, and fat) and in milk accounted for 6.7 and 10.2% of the dose, respectively. A small percentage (1.9%) of the dose was exhaled as volatile metabolites (primarily 14CO2). No oxamyl nor any closely related metabolites were detected in tissues, milk, or urine. Extensive degradation/metabolism of (1-14C)oxamyl was observed. Radioactive thiocyanate was the major metabolite identified in the milk as well as in the methanol/water extracts for all tissue samples.

Used as contact and systemic insecticide, acaricide, and nematicide to protect ornamentals, fruit trees, vegetables, cucurbits, beet, bananas, pineapples, peanuts, cotton, soya beans, tobacco, potatoes, and other crops; [HSDB] Used on several vegetables, fruits, and non-food items, oxamyl residues in food and drinking water do not pose risk concerns for the general population. [Reference #1]

Farming (Pesticides) [Category: Industry]

For oxamyl (USEPA/OPP Pesticide Code: 103801) 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./

Insecticide, nematicide, acaricide

Contact and systemic insecticide, acaricide, and nematicide. Absorbed by the foliage and roots, with translocation... . /For/ control of chewing and sucking insects (including soil insects, but not wireworms), spider mites, and nematodes in ornamentals, fruit trees, vegetables, cucurbits, beet, bananas, pineapples, peanuts, cotton, soya beans, tobacco, potatoes and other crops.

Oxamyl is widely used as an insecticide or pesticide in homes, gardens and agricultural applications. It is a synthetic compound.

Vydate L, a water soluble liquid containing 24% oxamyl

Water soluble liquid concentrate

Vydate

Vydate G