Oxamyl

219.26

219.26

245-445-3

SWV4D62X9E

2991|2757

DTXSID6021086

White crystalline solid|Colorless crystals

2930909052

96.3

-0.47

0.97 g/cm³ @ Temp: 25 °C

101 °C

Decomposes on distillation

1.532

H2O: 28 g/100 mL

0-6°C

5.1×10 -5 Pa (25 °C)

Oral-rat LD50: 2.5 mg/kg; Oral-Mouse LD50: 2.3 mg/kg

Thermal decomposition of toxic nitrogen oxide and sulfur oxide gases

Slight sulfurous odor|Garlic-like odor

Solid and formulations are stable; aqueous solution decomposes slowly; half-lives: >31 days (pH 5); 8 days (pH 7); 3 hours (pH 9); accelerated by aeration and sunlight

Decomposes to innocuous materials in natural waters and in soil. Aeration, sunlight, alkalinity, and higher temperatures increase the rate of decomposition. (NTP, 1992)

Amides and Imides

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.

Non-corrosive

I

6.1(a)

UN 2811

3

21-26/28-51/53

36/37-45-61

RP2300000

T+;N,N,T+

The warehouse is ventilated, low temperature and dry; stored and transported separately from food materials

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

P260-P264-P273-P280-P284-P301 + P310

H300-H312-H330-H411

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.

Incompatible with alkaline materials.

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]

When heated to decomposition, it emits toxic fumes of nitrogen oxides and sulfur oxides. This is a solid carbamate pesticide. Container may explode in heat of fire. (EPA, 1998)

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)

Excerpt from ERG Guide 131 [Flammable Liquids - Toxic]: As an immediate precautionary measure, isolate spill or leak area for at least 50 meters (150 feet) in all directions. SPILL: Increase, in the downwind direction, as necessary, the isolation distance shown above. FIRE: If tank, rail car or tank truck 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, 2016)

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)

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 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.

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/

/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.

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./|The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.|The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.|Marine pollutant

Carbamates produce slight to moderate skin and eye irritation, depending on the vehicle used, duration of contact, and on whether the substance is applied to the abraided or intact skin. From the available data, it cannot be excluded that some of the carbamates will have a slight to moderate sensitization potential. /Carbamate Pesticides/

P194; An acute hazardous waste when a discarded commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate.

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 ... .

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)).

most toxic

LD50 Rat oral 5.4 mg/kg|LD50 Rabbit dermal 2,960 mg/kg|LC50 Rat inhalation 170 mg/cu m/ 1hr|LD50 Mouse oral 2300 ug/kg|For more Non-Human Toxicity Values (Complete) data for OXAMYL (13 total), please visit the HSDB record page.

/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.

Oxamyl's production may result in its release to the environment through various waste streams; its use as an insecticide, acaricide, and nematicide(1) and will result in its direct release to the environment(SRC).

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).

The rate constant for the vapor-phase reaction of oxamyl with photochemically-produced hydroxyl radicals has been estimated as 2.3X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 1.4 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). 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(2). The rate constant for the hydrolysis of oxamyl has been determined to be 169 L/min-mol(3). 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(4). At pH 9, hydrolysis was rapid with 30% conversion after 6 hours(4). Exposure to ultraviolet light was found to accelerate hydrolysis(4). The half-life for the photodegradation of a thin film of oxamyl, thickness of 0.67 ug/sq-cm, was 55.38 hours(5). 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(6), which corresponds to a half-life of about 134 days(SRC), assuming a hydroxyl radical concentration of 3X10-17 molar(7). Oxamyl underwent rapid and extensive degradation in solvents (methanol and hexane) and in the solid state as a thin film under a 300 nm light; half-lives were approximately 7 h and 2h, respectively(8). Photolysis appears to be significant in acidic surface water, but not on soil(9).

An estimated BCF of 3.1 was calculated for oxamyl(SRC), using a log Kow of -0.48(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

An experimental study using Arrendondo, Cecil, and Webster soils found Koc values of 8, 6, and 10, respectively(1). According to a classification scheme(2), these Koc values suggest that oxamyl is expected to have very high mobility in soil. Laboratory experiments show that oxamyl is fairly mobile in muck, loamy sand, and 2 silt loam soils (with movement faster in the loamy sand and slowest in the muck)(3). However, field leachate studies in silt loam, loamy sand, and fine sand show that movement is not that extensive even after 3 to 5 months with very little oxamyl below 15 inches(3). This difference may be attributed to oxamyl degradation losses being greater than movement through soil despite large rainfall levels(3).

The Henry's Law constant for oxamyl is 2.37X10-10 atm-cu m/mole(SRC), derived from its vapor pressure, 0.00023 mm Hg(1), and water solubility, 2.8X10+5 mg/l(2). This Henry's Law constant indicates that oxamyl is expected to be essentially nonvolatile from water surfaces(3). Oxamyl's Henry's Law constant indicates that volatilization from moist soil surfaces is not expected to occur(SRC). Oxamyl is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).

GROUNDWATER: Oxamyl has been found in Long Island, NY and Rhode Island ground water at concentrations typically between 5 and 65 ppb(1). Oxamyl has also been detected in approximately 3 groundwater wells at a maximum concentration of 1.0 ug/L in Massachusetts(2). Oxamyl was not detected in 1003 wells (Jul 1994-Jun 1995) in 26 counties in California(3). According to the US Environmental Protection Agency Office of Pesticide Programs Pesticides in Groundwater Database, which complied monitoring studies for 1971-1991, oxamyl was detected in 904 of 23,305 total wells at concns ranging from 0.01 to 395.00 ug/l(4). Five of these were in Rhode Island (1984-1986), and 897 were in New York (1980-1991), one was in Massachusettes, with concns ranging from 1.0-2.0 ug/l and 0.01-395.00 ug/l respectively(4). One well in Massachusetts (1985)and one well in New Jersey (1987-1988) contained oxamyl at a concn of 0.1 and 1.4 ug/l, respectively(4). Three of the 904 wells exceeded the maximum contamination level of 200 ug/l(4).|SURFACE WATER: Oxamyl was found in 2% of samples with concentration >0.1 ug/l in estuaries and coastal waters in England and Wales in 1994(1).

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).

Radioactive thiocyanate was the major metabolite identified in the milk... /of lactating goats orally administered five consecutive daily doses of 31 ppm oxamyl/.

Occupational exposure to oxamyl may occur through inhalation and dermal contact with this compound at workplaces where oxamyl is produced or used. Monitoring data indicate that the general population may be exposed to oxamyl via ingestion of food. (SRC)

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.

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.

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/

Classified by the World Health Organization as highly hazardous. Has also been rated as extremely to super-toxic. Acute oral exposure (ingestion) to oxamyl has caused death. Oxamyl is a potent cholinesterase inhibitor. (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 4.The following dosages of Ipecac are recommended: children up to 1 year old, 10 mL (1/3 oz); children 1 to 12 years old, 15 mL (1/2 oz); adults, 30 mL (1 oz). Ambulate (walk) the victims and give large quantities of water. If vomiting has not occurred after 15 minutes, Ipecac may be readministered. Continue to ambulate and give water to the victims. If vomiting has not occurred within 15 minutes after second administration of Ipecac, administer activated charcoal. 4. Activated charcoal may be administered if victims are conscious and alert. Use 15 to 30 g (1/2 to 1 oz) for children, 50 to 100 g (1-3/4 to 3-1/2 oz) for adults, with 125 to 250 mL (1/2 to 1 cup) of water. 5. Promote excretion by administering a saline cathartic or sorbitol to conscious and alert victims. Children require 15 to 30 g (1/2 to 1 oz) of cathartic; 50 to 100 g (1-3/4 to 3-1/2 oz) is recommended for adults. 6. Transport to a health care facility. (EPA, 1998)

The clinical approach to carbamate toxicity is similar to that for organophosphate poisoning; the major exception is that pralidoxime usually is not recommended. /Carbamates/|Stabilization: Assess the adequacy of the airway and ventilation and use oxygen, suction, intubation, artificial ventilation, intravenous lines, and cardiac monitors as needed. /Carbamates/|Elimination Enhancement: No methods are recommended, because of the short clinical effect of carbamates and the presence of an effective antidote (atropine). /Carbamates/|Emergency and supportive measures. Caution: rescuers and health care providers must take measures to prevent direct contact with the skin or clothing of contaminated victims, because secondary contamination and serious illness may result, especially with potent pesticides and nerve agents. 1. Maintain an open airway and assist ventilation if necessary. Pay careful attention to respiratory muscle weakness; sudden respiratory arrest may occur. If intubation is required, note potential interactions between neuromuscular blockers and cholinesterase inhibitors. Administer supplemental oxygen. 2. Treat hydrocarbon pneumonitis, seizures, and coma if they occur. 3. Observe patients for at least 6-8 hours to rule out delayed-onset symptoms resulting from skin absorption. /Organophosphates and carbamates/|For more Antidote and Emergency Treatment (Complete) data for OXAMYL (11 total), please visit the HSDB record page.

/CASE REPORTS/ A 53 year old woman employed in transplanting tobacco plants apparently mistook a jug containing oxamyl for a water jar ... She drank a "swallow" of the clear liquid and within 10 min was semiconscious. Despite reasonably prompt attention in a university medical center, she died 12 hr later. ...The woman immediately realized her mistake and took some salt water, but apparently without benefit. When she reached the hospital, she was unconscious, incontinent of feces, apneic, and without detectable blood pressure, and her pupils were constricted. Autopsy revealed thrombotic and hemolytic crisis in sickle-cell disease, undoubtedly triggered by the oxamyl; this crisis may have been the cause of her death. The same hospital had a record of a 73 yr old man who ingested oxamyl by mistake but survived.|/EPIDEMIOLOGY STUDIES/ Cholinesterase activity measurements for 542 California agricultural pesticide applicators under medical supervision during the first 9 mo of 1985 were analyzed. Medical records of applicators were used if the subject had been exposed for over 3 hr in a 30 day period to category I and II organophosphate and carbamate pesticides. Employers of all workers with cholinesterase activity depressions that fell to 70% or less of the workers' plasma or RBC baselines were contacted to obtain a list of pesticides handled in the 2 wk interval preceding the greatest reported cholinesterase activity depression. In evaluating pesticide exposure data, it was not possible to distinguish listed pesticides primarily or cumulatively responsible for the noted cholinesterase activity depressions from those not responsible for the cholinesterase activity depression, but coincidentally used during the same period. The pesticides associated with plasma or RBC cholinesterase activity depression to 70% of baseline or lower are listed. Oxamyl (vydate) usage in California for 1985 was 25,200 lb. Twenty six workers, 4.8% of the sample, had cholinesterase values at or below the California action level value for removal from continued exposure to cholinesterase inhibiting pesticides. Eight of these 26 workers (31.5%) had pesticide related illnesses.|/SIGNS AND SYMPTOMS/ Principal effects /of anticholinesterases as toxic components of insecticides/ on eye, whether from local contact or systemic poisoning, are miosis and spasm of accommodation for near vision. /Anticholinesterases/|/SIGNS AND SYMPTOMS/ The clinical picture of carbamates intoxication results from accumulation of ACh at nerve endings. ...The signs and symptoms can be categorized into the following 3 groups: (a) Muscarinic manifestations - increased bronchial secretion, excessive sweating, salivation, and lachrymation; pinpoint pupils, bronchoconstriction, abdominal cramps (vomiting and diarrhea); and bradycardia. (b) Nicotinic manifestations - fasciculation of fine muscles (in severe cases, diaphragm and respiratory muscles also involved); and tachycardia. (c) Central nervous system manifestations- headache, dizziness, anxiety, mental confusion, convulsions, and coma; and depression of respiratory center. All these signs and symptoms can occur in different combinations and can vary in onset and sequence, depending on the chemical, dose, and route of exposure. The duration of symptoms is usually shorter than that observed in organophosphorus poisoning. Mild poisoning might include muscarinic and nicotinic signs only. Severe cases always show central nervous system involvement; the clinical picture is dominated by the respiratory failure sometimes leading to pulmonary edema due to the combination of the above mentioned symptoms. /Carbamate pesticides/

DPX 1410

National Use = 725839 lbs ai/year. (From survey during 1989-1991 crop years)

Vydate L, a water soluble liquid containing 24% oxamyl|Water soluble liquid concentrate|Vydate|Vydate G

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

/Analyzed/ by spectrophotometry.|EMSLC Method 632 Methods for the Determination of Organic Compounds in Wastewater. Using a HPLC with an Ultra-violet detector with a method detection limit of 9.2 ug/L.|Method: AOAC 985.23, N-Methylcarbamate Insecticide and Metabolite Residues by Liquid Chromatographic Method; Analyte: Oxamyl; Matrix: Grapes and potatoes.[|Method: OSW Method 8321A, Determination of Solvent Extractable Non-Volatile Components by High Performance Liquid Chromatography/Thermospray/Mass Spectrometry (HPLC/TSP/MS) or Ultraviolet (UV) Detection; Analyte: Oxamyl; Matrix: Wastewater, Ground Water, and Soil/Sediment; Method Detection Limit (Water), 0.3 ug/l; Method Quantitation Limit (Soil), 0.015 ug/g.[|For more Analytic Laboratory Methods (Complete) data for OXAMYL (8 total), please visit the HSDB record page.

Agrochemicals -> Insecticides, Nematicides|INSECTICIDES