Propoxur (ISO)

Pesticide -> EPA IRIS

Insecticides

Active substance -> EU Pesticides database: Not approved

Pesticides -> Carbamate Insecticides

Pesticide (Propoxur) -> USDA PDB

Pesticide

log Kow = 1.52

1.52

1.12 at 20 °C

Density (at 20 °C): 1.1 g/cm³

1.12 @ 20°C

Minute crystals

White, crystalline powder

White to tan, crystalline solid

0.2 % (NIOSH, 2024)

Soluble in methanol, acetone, and many organic solvents; slightly soluble in cold hydrocarbons

Soluble in most polar solvents

Readily soluble in 2-propanol, dichloromethane, toluene; hardly soluble in n-hexane

In water, 1860 mg/L at 30 °C

Solubility in water, g/100ml at 20 °C: 0.2 (poor)

greater than 300 °F (NIOSH, 2024)

>300 °F

>300 °F

Decomposes (NIOSH, 2024)

Decomposes on distillation

decomposes

Decomposes

When heated to decomposition it emits toxic fumes of /nitrogen oxide/.

Decomposition products: oxides of nitrogen & methyl isocyanate at high temperatures.

187 to 197 °F (NIOSH, 2024)

87 °C

MP: 91 °C. Unstable in highly alkaline conditions; stable under normal use conditions

91 °C

187-197 °F

87 °C

Danger

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

P264, P270, P273, P301+P316, P321, P330, P391, P405, and P501 (click each P-code to see the statement)

Danger

H300 (23.8%): Fatal if swallowed [Danger Acute toxicity, oral]

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

Hazard Traits - Carcinogenicity; Neurotoxicity

Regulation (EC) No 396/2005 (amended)

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

2002/2076

Propoxur: HSNO Approval: HSR003072 Approved with controls

The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)

Excerpt from ERG Guide 151 [Substances - Toxic (Non-Combustible)]:

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

Propoxur is an insecticide used to control cockroaches, flies, mosquitoes, and lawn and turf insects. Acute (short-term) exposure of humans to propoxur by ingestion leads to cholinesterase inhibition of red blood cells, with mild cholinergic symptoms including blurred vision, nausea, vomiting, sweating, and tachycardia; however, the effects are transient. Chronic (long-term) inhalation exposure has resulted in depressed cholinesterase levels, headaches, vomiting, and nausea in humans. Chronic ingestion studies in animals have reported depressed cholinesterase levels, depressed body weight, effects to the liver and bladder, and a slight increase in neuropathy. No information is available on the reproductive, developmental, or carcinogenic effects of propoxur in humans. Mixed results are available from cancer studies of propoxur in animals. EPA has not classified propoxur for carcinogenicity.

Classified as highly toxic with an LD50 of approximately 100 mg/kg in rats and mice, propoxur has a field half-life of 14 to 50 days. [EXTOXNET] The animal and human studies demonstrated consistent NOAELs in the range of 3 mg/m3 to 18.7 mg/m3, thus a TLV-TWA of 0.5 mg/m3 is recommended to be sufficiently protective. [ACGIH] See CARBAMATE INSECTICIDES.

USEPA/Office of Pesticide Programs; Reregistration Eligibility Decision Document - Propoxur, EPA 738-R-97-009 (August 1997). The RED summarizes the risk assessment conclusions and outlines any risk reduction measures necessary for the pesticide to continue to be registered in the U.S.[Available from, as of September 13, 2010: http://www.epa.gov/pesticides/reregistration/status.htm]

U411; As stipulated in 40 CFR 261.33, when propoxur, 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 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).

Based on the reviews of the generic data for the active ingredient propoxur, the Agency has sufficient information on the health effects of propoxur and on its potential for causing adverse effects in fish and wildlife and the environment. The Agency has determined that propoxur products, labeled and used as specified in this Reregistration Eligibility Decision, will not pose unreasonable risks of adverse effects to humans or the environment. Therefore, the Agency concludes that products containing propoxur for all uses are eligible for reregistration.

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their continued use. Under this pesticide reregistration program, EPA examines newer health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether the use of the pesticide does not pose unreasonable risk in accordance to newer saftey standards, such as those described in the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA '88 were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern than those on List C, and with List C containing pesticides of greater concern than those on List D. Propoxur is found on List B. Case No: 2555; Pesticide type: insecticide; Case Status: RED Approved 9/97; OPP has made a decision that some/all uses of the pesticide are eligible for reregistration, as reflected in a Reregistration Eligibility Decision (RED) document .; Active ingredient (AI): propoxur; Data Call-in (DCI) Date(s): 4/4/91, 12/26/91, 7/13/92; AI Status: OPP has completed a Reregistration Eligibility Decision (RED) for the case/AI.

Excerpt from ERG Guide 151 [Substances - Toxic (Non-Combustible)]:

Use water spray, foam, powder, carbon dioxide.

Fresh air, rest. Artificial respiration may be needed. Refer immediately 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.

Give a slurry of activated charcoal in water to drink. Refer immediately for medical attention.

Excerpt from NIOSH Pocket Guide for Propoxur:

(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]

2.0 [mg/m3], inhalable fraction[German Research Foundation (DFG)]

Use dry chemical, carbon dioxide, water spray, or alcohol foam extinguishers ... If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters. Notify local health and fire officials and pollution control agencies. From a secure, explosion-proof location, use water spray to cool exposed containers. If cooling streams are ineffective (venting sound increases in volume and pitch, tank discolors or shows any signs of deforming), withdraw immediately to a secure position ... The only respirators recommended for fire fighting are self-contained breathing apparatuses that have full facepieces and are operated in a pressure-demand or other positive-pressure mode.

Store in original container, preferably in locked area, away from children, food, feed.

Safe Storage of Pesticides. Always store pesticides in their original containers, complete with labels that list ingredients, directions for use, and first aid steps in case of accidental poisoning. Never store pesticides in cabinets with or near food, animal feed, or medical supplies. Do not store pesticides in places where flooding is possible or in places where they might spill or leak into wells, drains, ground water, or surface water. /Residential uses/

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

Evacuate persons not wearing protective equipment from area of spill or leak until cleanup is complete. Remove all ignition sources. Collect powdered material in the most convenient and safe manner and deposit in sealed containers. Ventilate area after cleanup is complete. It may be necessary to contain and dispose of this chemical as a hazardous waste. If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters. Contact your Department of Environmental Protection or your regional office of the federal EPA for specific recommendations.

Facultative and aerobic digesters for livestock wastes were used to degrade pesticide materials, ie ... Baygon, in the lab. Three different animal wastes were used as digester media for the process: swine, chicken, and dairy cattle manure. Process effects on disappearance of /Baygon/ was observed over periods of 0-8 wk (facultative) and 0-6 wk (aerobic). Disappearance ranged 10-72% under facultative conditions, and 29-100% under aerobic conditions. ...

The Carbolator 35B, a recirculatory C filtration system, successfully treated pesticide wastes in both pilot-scale and field tests. In pilot-scale tests, the system was challenged with 400 gal of water containing 20, 60, and 100 mg/l of Baygon. The pesticide waste was pumped through the Carbolator and returned to the waste holding tank. The tank contents were analyzed by gas chromatography and TLC. A TLC method was developed to perform pesticide anal in the field. A simple lab recirculating system using 4 liter of waste was also built to simulate the Carbolator system. A math model was developed to predict the disappearance of the pesticides from the waste holding tank.

If a spill occurs, clean it up promptly. Don't wash it away. Instead, sprinkle the spill with sawdust, vermiculite, or kitty litter. Sweep it into a plastic garbage bag, and dispose of it as directed on the pesticide product label./Residential uses/

For more Cleanup Methods (Complete) data for Propoxur (6 total), please visit the HSDB record page.

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number U411, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

Hydrolysis & landfill: Propoxur is hydrolyzed in highly alkaline media, with 50% loss at 20 °C in 40 min at pH 10. It should be treated with alkali before burial. Recommendable method: Incineration. Peer-review: Large amt should be incinerated in a unit with effluent gas scrubbing. (Peer-review conclusions of an IRPTC expert consultation (May 1985))

Safe Disposal of Pesticides. The best way to dispose of small amounts of excess pesticides is to use them - apply them - according to the directions on the label. If you cannot use them, ask your neighbors whether they have a similar pest control problem and can use them. If all of the remaining pesticide cannot be properly used, check with your local solid waste management authority, environmental agency, or health department to find out whether your community has a household hazardous waste collection program or a similar program for getting rid of unwanted, leftover pesticides. These authorities can also inform you of any local requirements for pesticide waste disposal. /Residential uses/

Safe Disposal of Pesticides. An empty pesticide container can be as hazardous as a full one because of residues left inside. Never reuse such a container. When empty, a pesticide container should be rinsed carefully three times and the rinsewater thoroughly drained back onto the sprayer or the container previously used to mix the pesticide. Use the rinsewater as a pesticide, following label directions. Replace the cap or closure securely. Dispose of the container according to label instructions. Do not puncture or burn a pressurized container like an aerosol - it could explode. Do cut or puncture other empty pesticide containers made of metal or plastic to prevent someone from reusing them. Wrap the empty container and put it in the trash after you have rinsed it. /Residential uses/

For more Disposal Methods (Complete) data for Propoxur (9 total), please visit the HSDB record page.

Personal protection: chemical protection suit including self-contained breathing apparatus. Do NOT let this chemical enter the environment. Sweep spilled substance into sealable containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations.

SRP: Contaminated protective clothing should be segregated in such a manner so that there is no direct personal contact by personnel who handle, dispose, or clean the clothing. Quality assurance to ascertain the completeness of the cleaning procedures should be implemented before the decontaminated protective clothing is returned for reuse by the workers. Contaminated clothing should not be taken home at end of shift, but should remain at employee's place of work for cleaning.

SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.

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 wash daily at the end of each work shift.

For more Preventive Measures (Complete) data for Propoxur (27 total), please visit the HSDB record page.

Propoxur concentrations in personal air samples of 6 of 9 residents, 0.13 to 0.60 ug/cu m, mean of 0.14 ug/cu m. Sampling took place in nine homes, ranging from a mobile home to 2-bedroom apartments to houses of up to 800 sq m built on concrete slabs over crawl spaces, in Jacksonville, FL were analyzed during August 1985(1). Propoxur was present at a median concentration of 18.7 ng/cu m (range 1.7-342.9 ng/cu m; 96 of 96 samples positive) in 48-hr personal air samples from of pregnant women over the final 2 months of pregnancy and who were African-American and Dominican women from New York City; sampling was conducted between February 2001 and May 2004(2). Propoxur was reported present in urine samples at a 95 th percentile concentration of <1 ug/g creatine, based upon U.S. resident sampling from 2001-2002(3).

If the compound has been ingested, rapid gastric lavage should be performed using 5% sodium bicarbonate. For skin contact, the skin should be washed with soap and water. If the compound has entered the eyes, they should be washed with large quantities of isotonic saline or water. In serious cases, atropine and/or pralidoxime should be administered. Anti-cholinergic drugs work to counteract the effects of excess acetylcholine and reactivate AChE. Atropine can be used as an antidote in conjunction with pralidoxime or other pyridinium oximes (such as trimedoxime or obidoxime), though the use of '-oximes' has been found to be of no benefit, or possibly harmful, in at least two meta-analyses. Atropine is a muscarinic antagonist, and thus blocks the action of acetylcholine peripherally.

... The effects of subchronic per os exposures to cadmium chloride (CdCl(2)) and ... propoxur (Pr), were investigated in male Wistar rats on general toxicological (body weight gain, relative organ weights) hematological (RBC, WBC, Ht, MCV, cell content of the femoral bone marrow) immune function (plaque forming cell (PFC) assay, delayed type hypersensitivity (DTH) reaction) and neurotoxicological (spontaneous and stimulus-evoked cortical activity, nerve conduction velocity) parameters. The animals were treated for 4, 8 and 12 weeks with 6.43 mg/kg CdCl(2), 8.51 mg/kg Pr, or with a combination of 6.43 mg/kg CdCl(2)+0.851 mg/kg Pr or 8.51 mg/kg Pr+1.61 mg/kg CdCl(2). Cadmium exposure affected the relative thymus, liver, and adrenal weight, RBC count, hematocrit and MCV, and there was an increase in nerve conduction velocity and a decrease in the cortical evoked potential latency. Pr induced a decrease in thymus weight, had some effect on the liver weight but none on the electrophysiological parameters. A significant interaction between Cd and Pr was detected by the following parameters: RBC, Ht, PFC, and nerve conduction velocity ...

The toxicity of ... propoxur decreased in rats given Aroclor 1242.

... The effect of Withania somnifera (Ashwagandha), a widely used herbal drug possessing anti-stress and immunomodulatory properties, was studied on propoxur-induced acetylcholine esterase inhibition and impairment of cognitive function in rats. Male Wistar rats were divided into four groups. Group I was treated with olive oil and served as control. Group II was administered orally with propoxur (10 mg/kg bw) in olive oil, group III received a combination of propoxur (10 mg/kg bw) and W. somnifera (100 mg/kg bw) suspension, and group IV W. somnifera (100 mg/kg bw) only. All animals were treated for 30 days. Cognitive behavior was assessed by transfer latency using elevated plus maze. Blood and brain acetylcholine esterase (AChE) activity was also assessed. Oral administration of propoxur (10 mg/kg bw) resulted in a significant reduction of brain and blood AChE activity. A significant prolongation of the acquisition as well as retention transfer latency was observed in propoxur-treated rats. Oral treatment of W. somnifera exerts protective effect and attenuates AChE inhibition and cognitive impairment caused by sub-chronic exposure to propoxur.

The effect of melatonin, a major secretory product of the pineal gland, in attenuation of propoxur -induced modulation of cell-mediated immune (CMI) response was studied in rats. Male Wistar albino rats were exposed to propoxur ... orally (10 mg/kg) and/or melatonin (10 mg/kg) orally for 4 weeks. CMI was measured by delayed-type hypersensitivity (DTH), leukocyte and macrophage migration inhibition (LMI and MMI) responses and estimation of cytokines TNF-alpha and IFN-gamma levels. Rats exposed to propoxur for 4 weeks showed significant decrease in DTH, LMI and MMI responses. Propoxur also suppressed TNF-alpha and IFN-gamma production significantly. Administration of melatonin alone caused a significant increase in DTH response. Although there were no changes in the LMI and MMI response, the cytokine levels were significantly increased, as compared to control. Co-administration of melatonin along with propoxur significantly nullified the effect of the pesticide on the CMI response, except DTH and reversed levels of cytokines to near control/normal values ...

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

Nervous

central nervous system, liver, kidneys, gastrointestinal tract, 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. Chronically high (>10 years) exposure leads to neuropsychological consequences including disturbances in perception and visuo-motor processing (A15321).

LD50; Species: Bullfrog (male) oral 595 mg/kg (95% confidence limit 500-707 mg/kg)

LD50; Species: Canada goose (male, female) oral 5.95 mg/kg (95% confidence limit 4.89-7.24 mg/kg)

LD50; Species: Anas platyrhychos (Mallard female 4-6 months of age) oral 11.9 mg/kg (95% confidence limit 10.0-14.1 mg/kg)

LD50; Species: Anas platyrhychos (Mallard female 4-6 months of age) oral 9.44 mg/kg (95% confidence limit 7.49-11.9 mg/kg)

For more Ecotoxicity Values (Complete) data for Propoxur (56 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), the range of Koc values from <1 to 103(2,3) indicate that propoxur is expected to have very high to high mobility in soil(SRC). Volatilization of propoxur from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 3.35X10-9 atm-cu m/mole(SRC), derived from its vapor pressure, 9.68X10-6 mm Hg(2), and water solubility, 1.86X10+3 mg/L(4). Propoxur is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(2). Propoxur photodegradated on a pH 8.2 sandy loam soil with a half-life of 77 days(2). The biodegradation of propoxur under aerobic conditions in silt loam and sandy loam soils followed first order kinetics for the first 112 and 180 days, resulting in half-life values of 80 days for the silt loam and 210 days for the sandy loam, respectively(3); this suggests that biodegradation is a moderate environmental fate process in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), the range of Koc values from <1 to 103(2,3) indicate that propoxur is not 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 3.35X10-9 atm-cu m/mole(SRC), derived from its vapor pressure, 9.68X10-6 mm Hg(2), and water solubility, 1.86X10+3 mg/L(5). According to a classification scheme(6), an estimated BCF of 5(SRC), from its log Kow(7) and a regression-derived equation(8), suggests the potential for bioconcentration in aquatic organisms is low(SRC). The hydrolysis half-life for propoxur (at 22 °C) is 1 yr at pH 4, 93 days at pH 7, and 30 hrs at pH 9(9). The half-life of propoxur in water was determined to be 87.9 hrs when irradiated with light >290 nm(10). The major photolysis degradates were isopropoxy phenol, unidentified polar compounds, and carbon dioxide(3). Propoxur is reported to biodegrade quite rapidly in water, particularly when the bacterial activity and temperature are high(11); a half-life of 44 days was reported when incubated in a combination of activated sludge, silt loam soil, and sediment under aerobic conditions(12).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), propoxur, which has a vapor pressure of 9.68X10-6 mm Hg at 20 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere(SRC). Vapor-phase propoxur 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 12 hours(SRC), calculated from its rate constant of 3.17X10-11 cu cm/molecule-sec at 25 °C(SRC) determined using a structure estimation method(3). Particulate-phase propoxur may be removed from the air by wet and dry deposition(SRC). The photodegradation half-life in water was determined to be 88 hr when irradiated with light >290 nm in water(4), suggesting that propoxur may be susceptible to direct photolysis by sunlight(SRC).

A non-random sampling of 39 different fresh crops, dehydrated apples, crackers, and wines analyzed for carbamate residues (319 samples), found 1 sample of rice and 1 sample of crackers containing propoxur residue of 8.1 and 0.08 ppm, respectively(1). Propoxur was detected in spinach from Belgium at a concentration of 0.034 ppm(2).

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

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

Inhalation (L793) ; oral (L793); dermal (L793)

Propoxur 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/ Signs of intoxication /after acute oral admin to birds/: nutation, lacrimation, ataxia, miosis, lethargy, asynergy, imbalance, salivation, hypoactivity, goose-stepping ataxia, falling, tachypnea, dyspnea, fasciculation, ptosis, diarrhea, immobility, tremors, convulsions, wings spread in tetany, and opisthotonos. Depending on the species, signs appeared as soon as 5 min, mortalities occurred between 5 and 45 min or overnight, and remission occurred from 90 min to several days after treatment.

/AQUATIC SPECIES/ ... Five carbamate insecticides were subjected to 96 hr acute toxicity tests to examine their effects on three cyanobacteria, Anabaena flos-aquae, Microcystis flos-aquae, and Mirocystis aeruginosa, and five green algae, Selenastrum capricornutun, Scenedesmus quadricauda, Scenedesmus obliquus, Chlorella vulgaris, and Chlorella pyrenoidosa. The average acute toxicity of the carbamate insecticides to the cyanobacteria and the green algae was in descending order carbaryl>carbofuran, propoxur, metolcarb > carbosulfan. Wide variations in response to the tested carbamate insecticides occurred among the eight individual species of cyanobacteria and green algae ... With regard to the differential sensitivity of cyanobacteria and green algae, the cyanobacteria were less sensitive than green algae to carbosulfan and propoxur. The pollutants may initiate a shift of algal group structure; especially, a shift from dominance by green algae to dominance by cyanobacteria, and may sustain cyanobacterial blooms at particular times. Therefore, the descending order of the ecosystem risk was carbosulfan > propoxur > carbofuran > carbaryl, metolcarb. There was a strong variance between toxicity and ecosystem risk; i.e., "low toxicity" does not imply "low ecosystem risk."

/AQUATIC SPECIES/ Acetylcholinesterase (AChE) activity was measured in Daphnia magna that had been exposed to ... propoxur for 48 hr. These results were related to acute toxicity (median effective concentration [EC50] for immobility) ... The EC50 for propoxur was 449.90 picomolar. Reduction in AChE activity was directly related to an increase in immobility ... A 50% reduction in AChE activity generally was associated with detrimental effects on mobility ...

/AQUATIC SPECIES/ Alterations in the biochemical parameters of the catfish treated with low sublethal concentration (2.15 mg/L; 1/3 of 96 hr LC50) of ... propoxur under static laboratory conditions for 10, 20 and 30 days were assayed. The fish elicited consistent hyperglycemia, concomitant with liver and muscle glycogenolysis, and hypoproteinemia in muscle and liver except 10 day post exposure to the pesticide, where hyperproteinemia was noticed in the liver. Throughout the exposure period the fish exhibited hyperphosphatemia. Hypocalcemia were recorded after 20 and 30 days, and serum magnesium level increased significantly only at 30 day exposure to the pesticide.

For more Ecotoxicity Excerpts (Complete) data for Propoxur (7 total), please visit the HSDB record page.

U411; As stipulated in 40 CFR 261.33, when propoxur, 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 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).

Based on the reviews of the generic data for the active ingredient propoxur, the Agency has sufficient information on the health effects of propoxur and on its potential for causing adverse effects in fish and wildlife and the environment. The Agency has determined that propoxur products, labeled and used as specified in this Reregistration Eligibility Decision, will not pose unreasonable risks of adverse effects to humans or the environment. Therefore, the Agency concludes that products containing propoxur for all uses are eligible for reregistration.

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their continued use. Under this pesticide reregistration program, EPA examines newer health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether the use of the pesticide does not pose unreasonable risk in accordance to newer saftey standards, such as those described in the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA '88 were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern than those on List C, and with List C containing pesticides of greater concern than those on List D. Propoxur is found on List B. Case No: 2555; Pesticide type: insecticide; Case Status: RED Approved 9/97; OPP has made a decision that some/all uses of the pesticide are eligible for reregistration, as reflected in a Reregistration Eligibility Decision (RED) document .; Active ingredient (AI): propoxur; Data Call-in (DCI) Date(s): 4/4/91, 12/26/91, 7/13/92; AI Status: OPP has completed a Reregistration Eligibility Decision (RED) for the case/AI.

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

Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 100 lb or 45.4 kg. The toll free number of the NRC is (800) 424-8802. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b).

(AZ) ARIZONA 3 ug/L

(CA) CALIFORNIA 30 ug/L

(FL) FLORIDA 2.8 ug/L

(ME) MAINE 28 ug/L

/A/ review of studies /was undertaken/ to evaluate mechanisms of rat urinary bladder tumors ... Propoxur or a metabolite was postulated to operate on or with growth factors to elicit hyperplasia and eventual tumor development. Since some propoxur metabolites are phenols, and since some phenols share with propoxur the property of being urinary bladder oncogens only at extremely high dose levels, threshold effects may be present. Low urinary pH was noted to inhibit binding of epidermal growth factor, which is abundant in rat urine. This is consistent with rat studies, in which pH reduction markedly reduced the extent of hyperplasia. Perspectives offered in this discussion suggest that propoxur-induced tumors in rats may not be relevant to man, but the "possible adverse effect" designation remains until more definitive evidence can be obtained.

Carbamylation of acetylcholinesterase produces accumulation of acetylcholine and the picture of muscarinic and nicotinic poisoning. Spontaneous hydrolysis of the carbamate-cholinesterase complex occurs in vivo, leading to the disappearance of clinical effects within 24 hours. Penetration of the blood-brain barrier by the carbamates is insignificant; for this reason, few CNS symptoms occur.

Propoxur inhibits cholinesterase & this effect is apparently the basis of its toxic action.

In a metabolism study, the following metabolites were identified in the urine of rats which had been fed 8000 ppm propoxur for 13 weeks: M1 = 1,2-dihydoxybenzene (= catechol); M2 = 2-isopropoxyphenol; M3 = 2-hydroxyphenyl methylcarbamate; M4 = 2- isopropoxyphenylcarbamic acid; M5 = isopropoxyphenyl-hydroxy(-) methylcarbamate; M6 = 2-isopropoxy-5-hydroxyphenyl-methylcarbamate; M7 = 2-isopropoxy-5-hydroxyphenyl carbamic acid; M8 = 2-isopropoxy-5-hydroxyphenylhydroxymethyl carbamate; M9 = 1,5-dihydroxy-2-isopropoxybenzene. In additional studies, M6 (= 2-isopropoxy-5-hydroxyphenylmethylcarbamate) was identified as a principle metabolite in hamsters, mice, and humans. The nitrosated compound M9A ( = 1-hydroxy-2- isopropoxy-4-nitrobenzene) has been identified as a metabolite in rats and mice, the rhesus monkey, and humans. Evidence from the human study suggests that M9A is synthesized in the stomach.

Groups of 5 female rats received 50, 250, or 500 ppm unlabeled propoxur in their diets for 5 months, then received (by oral gavage) a single dose of 1 mg/kg radiolabelled material. Urine samples taken in the period from 0 to 24 hr after dosage had 87.9 to 99.8% of the total radiolabel; by thin layer chromatography it was found that 97-98% of the activity remained at the origin, and was contained in conjugated metabolites and/or extremely polar metabolites of unknown structure. By enzymatic cleavage 80-86% of the activity was identified as specific metabolites including M1, M2, M3, M4, M5, M6, M7, M8, as well as M6CII (= 2-isopropoxy-5-hydroxyphenyl carbamic acid), MS3 (= 2-isopropoxy-5-hydroxyphenyl-hydroxymethyl carbamate, and M7A (= 2- isopropoxy-3-hydroxyphenyl-methyl carbamate).

In ... studies with ... Musca domestica l ... /metabolites were/ (in order of decr amt): 5-hydroxy-2-isopropoxyphenyl methylcarbamate, 2-hydroxyphenyl methylcarbamate & acetone, 2-isopropoxyphenyl n-hydroxymethylcarbamate, & 2-isopropoxyphenyl carbamate. There were 6 or more addnl unidentified cmpd.

When the tert-carbon of 2-isopropoxy group of propoxur is oxidized to form a hemiketal, mono-N-methylcarbamoylcatechol is produced as a hydrolyzed metabolite that can normally be detected as 2-isopropoxyphenol by hydrolysis of the carbamoyl ester linkage, although this phenol has still not been detected. The 5-position of the phenyl ring is selectively metabolized in insects and their microsomes.

For more Metabolism/Metabolites (Complete) data for Propoxur (7 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)

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.

... Seven male rats were used /in a metabolic study/; one received only non-labeled propoxur; the others received 1 mg/kg (14)C-labeled (ring) with sacrifice at 1, 4, 8, 24, 48, and 72 hr. The rats were sagittally sectioned and exposed (29-124 days) in direct contact with X-ray film. At 1 hour, radioactivity was detectable in all organs (particularly intestines) except the bone. After 24 hr, there were high concentrations of radioactivity in the gastrointestinal tract and bladder, as well as the mucous membranes of the pharyngeal region. At 48 and 72 hr, some radioactivity was still detectable in the liver, kidneys and mucous membranes of the pharyngeal system. Propoxur (and/or its metabolites) was shown to be distributed via the lymph system.

Two studies ... provide information on the dermal adsorption of propoxur in humans and rats. In the human study, six individuals received a single intravenous dose of (14)C-propoxur, 1 Ci/mL. Total urine was collected for five days post-dose and the percent of radiolabeled-dose excreted in the urine was determined. Subsequently the same six individuals received a single dermal dose of (14)C-propoxur at 4 ug/sq cm for an exposure period of 24 hr. Total urine was collected for five days post-dose and the percent of radiolabeled-dose excreted in the urine was determined. The radiolabel excreted was corrected for the 81.8% of label excreted following the iv dose. Corrected total excretion was 19.6 percent of the dermally administered dose. In the rat study, four doses (0.648, 6.91, 69.5, and 692 ug/sq cm) were administered /to rats (strain and sex not given)/ for durations of 0.5, 1, 2, 4, 8, and 24 hr. Test material was administered in ethanol, a solvent which can increase the absorption of a dissolved chemical. Since percent absorption decreases in a nonlinear manner with dose, the absorption from the dose of 6.91 ug/sq cm (the nearest dose to that administered in the human study) was selected for comparison with the human study. The results indicate (for durations 0.5, 1, 2, 4, 8, and 32 hr) a total of 7.88, 10.2, 17.9, 23.2, and 32.5% absorption, respectively. The percent absorbed in the rat study exceeds the percent absorbed in the human study for exposure durations of 8 and 24 hr. This is expected, even without the addition of ethanol, as rat skin is more permeable than human skin. Alternatively, the use of acetone in the human study would show an expected increase of propoxur penetration.

In a dermal absorption study with rats, a mixture of 50% ethanol and 50% water was used as a solvent, with doses of 0.648, 6.91, 69.5, or 692 ug/sq cm (corresponding nominal doses: 0.009875, 0.105, 1.0625, and 10.5 mg, respectively) radiolabeled propoxur. The highest values for absorption (50 to 64.9%) were observed with the two lowest dose levels, with the highest percentages of radioactivity (0.1-0.18%) in the blood occurring at these dose levels at 0.5 to 1.0 hr after dosage. Because propoxur was applied in a mixture of ethanol and water, the values obtained for dermal absorption were probably somewhat higher than if water alone had been the solvent.

Like houseflies, rat ... degrades arpocarb... with 30% of applied dose expired as CO2 within 48-hr...

For more Absorption, Distribution and Excretion (Complete) data for Propoxur (15 total), please visit the HSDB record page.

Propoxur is a nonfood carbamate insecticide, marketed under the registered trademark name Baygon. It is used to control cockroaches, flies, mosquitoes, and lawn and turf insects. Propoxur has been used in malaria control activities and in flea collars for pets.

Used to control ants, cockroaches, crickets, flies, mosquitoes, and crop insects; [EXTOXNET]

Farming (Pesticides) [Category: Industry]

For propoxur (USEPA/OPP Pesticide Code: 047802) 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 registered for indoor (residential, institutional, industrial, commercial ... food handling establishments, food processing plants as crack and crevice treatments only) applications and very limited outdoor applications (structural perimeters, spot treatments to wasp nests and ant hills ... insecticidal tape for boat mooring lines)

Insecticide; molluscicide

(1972) PROBABLY GREATER THAN 4.54X10+5 GRAMS

(1974) 1.4X10+8 GRAMS (CONSUMPTION)

OVER 50% AS AN INSECTICIDE FOR MOSQUITOES IN OUTDOOR AREAS; UNDER 50% IN ALL OTHER APPLICATIONS AS AN INSECTICIDE (FOR FLIES ON AGRICULTURAL PREMISES, FOR FLEAS & TICKS ON PETS, ON LAWNS & TURF, FOR ANTS ON FLOWERING PLANTS, & IN DWELLINGS & PUBLIC FACILITIES) (1974)

Estimates of annual use: 170,000 to 400,000 lbs/ai (total); 20,000 to 50,000 lbs/ai (professional markets); 150,000 to 350,000 lbs/ai (consumer markets).

Propoxur can be prepared by condensation of o-isopropoxyphenol with methyl isocyanate

REACTION OF O-ISOPROPOXYPHENOL AND METHYL ISOCYANATE

USEPA/OPP Pesticide Code 047802; Trade Names: Baygon, Sendran, Bay 9010, Bay 39007, Tendx, Unden, ENT-25671, DMS 33, Blattanex, Suncide, Blattosep, Bolfo, Bay 5122, Chemagro 9010, Dalf dust, Invisi-gard, Isocarb, OMS 33, Propotox, Pillargon, Compound 39007, Propyon, Tugon fliegenkugel.

Formulations: Soluble concentrate; oilspray

Formulations: Aerosol; bait; emulsifiable concentrate; dustable powder; fumigant; granules; ULV liquid; wettable powder; Hercon Toxstrip BW in controlled release strip formulation; Premixes (propoxur +): disulfoton

Formulations: Aerosol; bait; emulsifiable concentrate; dustable powder; fumigant; granules; ULV liquid; wettable powder; Hercon Toxstrip BW in controlled release strip formulation; Premixes (propoxur +): disulfoton

For more Formulations/Preparations (Complete) data for Propoxur (29 total), please visit the HSDB record page.

The WHO Recommended Classification of Pesticides by Hazard identifies propoxur (technical grade) as Class II: moderately hazardous; Main Use: insecticide.

... No longer used in pet shampoos and dips.

Use Sites: ... Within homes, apartments, dwellings, on pets (flea collars and aerosol pet sprays); commercial, industrial, and institutional buildings ... Outdoors: foundations, sidewalks, patios and driveways ... in gypsy moth and medfly traps