Pirimiphos methyl

305.33

305.33

249-528-5

2VQZ4PK548

3082|2902

DTXSID0024266

Straw-colored liquid

2933599011

88.8

4.12

Liquid

1.17 g/cm³ @ Temp: 20 °C

15 °C

Decomposes

-18 °C

1.555

Miscible with most organic solvents

APPROX 4°C

1.5×10 -2 Pa (30°C)

Henry's Law constant = 6.01X10-7 atm-cu m/mol at 25 °C (est)

pKa = 4.30

167.15 Ų [M+H]+

Hydroxyl radical reaction rate constant = 1.60X10-10 cu cm/molecule-sec at 25 °C (est)

Hydrolyzed by strong acid or base.

Amines, Phosphines, and Pyridines

Organophosphates are susceptible to formation of highly toxic and flammable phosphine gas in the presence of strong reducing agents such as hydrides. Partial oxidation by oxidizing agents may result in the release of toxic phosphorus oxides.

UN30829/PG3

3

22-50/53-67-65-38-11

60-61-62

TF1410000

Xn,N,F

P273-P301 + P312 + P330-P391-P501

H302-H410

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.|Open dumping is prohibited. /Actellic 5E Insecticide Low Odor Formulation/|Pesticides are acutely toxic. Improper disposal of excess pesticide; spray mixture or rinsate is a violation of Federal law. If these wastes cannot be disposed of by use according to label instructions, contact your State Pesticide or Environmental Control Agency, or the Hazardous Waste representative at the nearest EPA Regional Office for guidance. /Actellic 5E Insecticide Low Odor Formulation/|Nonrefillable containers. Do not reuse or refill this container. Clean container promptly after emptying. /Actellic 5E Insecticide Low Odor Formulation/|For more Disposal Methods (Complete) data for PIRIMIPHOS-METHYL (8 total), please visit the HSDB record page.

Pirimiphos-methyl is hydrolyzed by strong acids & alkalies.

USEPA/Office of Prevention, Pesticides and Toxic Substances; Interim Reregistration Eligibility Decision (IRED) for Pirimiphos-methyl (June 2001). 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 October 11, 2012: http://iaspub.epa.gov/apex/pesticides/f?p=CHEMICALSEARCH:1]|USEPA/Office of Prevention, Pesticides and Toxic Substances; Reregistration Eligibility Decision Document - Pirimiphos-methyl (July 2006). 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 October 11, 2012: http://iaspub.epa.gov/apex/pesticides/f?p=CHEMICALSEARCH:1]

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Some may burn but none ignite readily. Containers may explode when heated. Some may be transported hot. For UN3508, be aware of possible short circuiting as this product is transported in a charged state. (ERG, 2016)

|Warning|H302: Harmful if swallowed [Warning Acute toxicity, oral]|P264, P270, P273, P301+P312, P330, P391, and P501|Danger|H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]|P260, P264, P270, P273, P280, P301+P312, P302+P352, P305+P351+P338, P307+P311, P312, P314, P321, P322, P330, P332+P313, P337+P313, P362, P363, P391, P405, and P501|Aggregated GHS information provided by 173 companies from 6 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|P201, P202, P260, P264, P270, P280, P281, P301+P312, P305+P351+P338, P308+P313, P314, P330, P337+P313, P405, and P501

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: SMALL FIRE: Dry chemical, CO2, water spray or regular foam. LARGE FIRE: Water spray, fog or regular foam. Do not scatter spilled material with high-pressure water streams. Move containers from fire area if you can do it without risk. Dike fire-control water for later disposal. FIRE INVOLVING TANKS: Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks engulfed in fire. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. 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)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Do not touch or walk through spilled material. Stop leak if you can do it without risk. Prevent dust cloud. Avoid inhalation of asbestos dust. SMALL DRY SPILL: With clean shovel, place material into clean, dry container and cover loosely; move containers from spill area. SMALL SPILL: Pick up with sand or other non-combustible absorbent material and place into containers for later disposal. LARGE SPILL: Dike far ahead of liquid spill for later disposal. Cover powder spill with plastic sheet or tarp to minimize spreading. Prevent entry into waterways, sewers, basements or confined areas. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection. (ERG, 2016)|Mixers, loaders, and other handlers supporting admixture seed and/or grain treatments must: long sleeve shirt and long pants, shoes plus socks, chemical-resistant gloves, protective eyewear. /Actellic 5E Insecticide Low Odor Formulation/|All other mixers, loaders, applicators and other handlers must wear: coveralls over long sleeve shirt and long pants; chemical-resistant footwear plus socks; chemical-resistant gloves; protective eyewear. In addition, mixers and loaders must wear: chemical-resistant apron. /Actellic 5E Insecticide Low Odor Formulation/|Skin decontamination ... In patients ... Attendants should wear rubber gloves as vinyl provides no protection against skin absorption. /Organophosphate pesticides/

Do not contaminate /downstream/ water by cleaning of equipment or disposal of waste. /Actellic 5E Insecticide Low Odor Formulation/

Users should: Wash hands before eating, drinking, chewing gum, using tobacco, or using the toilet; Remove clothing/PPE immediately if pesticides get inside. Then wash thoroughly and put on clean clothing; Remove PPE immediately after handling this product. Wash the outside of gloves before removing. As soon as possible, wash thoroughly and change into clean clothing. /Actellic 5E Insecticide Low Odor Formulation/|Avoid contact with skin or clothing. Wash thoroughly with soap and water after handling. Remove contaminated clothing and wash clothing before reuse. /Actellic 5E Insecticide Low Odor Formulation/|Follow manufacturer's instructions for cleaning/maintaining PPE. If no such instructions for washables exist, use detergent and hot water. Keep and wash PPE separately from other laundry. Discard clothing and other absorbent material that have been drenched or heavily contaminated with this product's concentrate. Do not reuse them. /Actellic 5E Insecticide Low Odor Formulation/|Do not apply directly to water. /Actellic 5E Insecticide Low Odor Formulation/|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. The completeness of the cleaning procedures should be considered before the decontaminated protective clothing is returned for reuse by the workers. Contaminated clothing should not be taken home at the end of shift, but should remain at employee's place of work for cleaning.

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.

SEDIMENT: Pirimiphos-methyl was not detected in sediment samples (locations and dates of samples not reported) from locations in Egypt(1).|SOIL: In the Bangkok area of Thailand, pirimiphos-methyl was not detected in the soil of soybean, onion, Chinese kale fields or citrus plantations(1).

Pirimiphos-methyl was not detected in 292 samples of 30 types of herbal drug materials from China and Korea(1).

The effect of L-ascorbic acid supplementation on Pirimiphos-methyl induced toxicity was studied in albino rats. Biochemical estimations were made in rats administered orally the insecticide at 100 and 200 mg/kg body weight with or without oral supplementation of L-ascorbic acid at 200 mg/kg b.w. The biochemical assessments included estimations of brain and plasma cholinesterases, levels of ascorbic acid in liver, kidney and adrenals, urinary levels of ascorbic acid and glucuronic acid. A lower degree of inhibition of the cholinesterases was evident in ascorbic acid supplemented rats. Marked elevation in urinary levels of ascorbic acid and glucuronic acid was observed in the insecticide treated rats. Results of this study suggests that L-ascorbic acid supplementation partially offsets Pirimiphos-methyl induced toxicity|Technical hexachlorocyclohexane (100 mg/kg/d) and pirimiphosmethyl EC 50 (250 mg/kg/d) given individually and in combination to female rats for 7, 15 or 30 d by skin application caused poisoning, pathomorphological changes in vital organs, and significant enzymatic changes in liver and serum. The changes produced by the 2 compounds in combination did not suggest potentiation at the tested dose levels.|The pesticides benomyl, a benzimidazole fungicide, and pirimiphos-methyl, an organophosphorus insecticide, were tested separately and in combination at a ratio of 6:1, a mixture frequently found in foodstuffs by residual analysis, to determine their possible genotoxic action. The effect was measured by the micronucleus test carried out on cultured rat hepatocytes stimulated to proliferate by epidermal growth factor (EGF). Adult rat hepatocytes were exposed in vitro for 48 hr to the substances at increasing non-cytotoxic doses, chosen on the basis of cytotoxicity tests such as LDH and Neutral red assays. Benomyl induced a significant dose-related increase in micronucleus frequency; in contrast, pirimiphos-methyl was not genotoxic at any dose tested. When the hepatocytes were exposed to the two pesticides together at increasing doses, an enhancement in micronucleus frequency similar to that of benomyl alone was found, indicating that at this ratio and non-cytotoxic doses (up to 25 micrograms/mL benomyl + 4.2 micrograms/mL pirimiphos-methyl) no interaction occurs.

LD50 Rat oral 1250 mg/kg|LD50 Mouse oral 1180 mg/kg|LD50 Rabbit oral 1150 mg/kg|LD50 Guinea pig oral 1000 mg/kg|For more Non-Human Toxicity Values (Complete) data for PIRIMIPHOS-METHYL (15 total), please visit the HSDB record page.

/AQUATIC SPECIES/ The acute toxicity of Pirimiphos-methyl (Actellic) was investigated using Guppy (Poecilia reticulata) in a 96 hr static renewal laboratory bioassay. Based on probit analysis the LC50 was 0.026, 0.024, 0.022 and 0.019 ml/L at 24, 48, 72 and 96 hr, respectively. Analysis of Variance (ANOVA) showed that there was significant difference (p < 0.05) in the quantal response (mortality) of P. reticulata to different concentrations of Actellic at 24, 48, 72 and 96 hr of exposure. Actellic insecticide is toxic to fish.|/AQUATIC SPECIES/ ... Evaluations were conducted in southeastern Queensland, Australia, to determine the toxicities of two organophosphate compounds (temephos and pirimiphos-methyl), an insect growth regulator (s-methoprene), and an entomopathogenic bacterium (Bacillus thuringiensis variety israelensis de Barjac ...) to Culex annulirostris ..., an Australian freshwater mosquito vector of arboviruses, and to Caradina indistincta, ... a co-habiting nontarget shrimp species. S-methoprene and B.thuringiensis were safest for C. annulirostris control with lethal dose ratios (LC95 nontarget/LC95 target) of 3,300 and 846,000, respectively. In contrast, lethal dose ratios for temephos and pirimiphos-methyl were 0.05 and 0.00005, respectively, suggesting that they are environmentally unsuitable. Based on their high lethal dose ratios, s-methoprene and B. thuringiensis are recommended for control of larval C.annulirostris in Australian freshwater habitats.

Pirimiphos-methyl's production may result in its release to the environment through various waste streams; its use as an insecticide(1) will result in its direct release to the environment(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), reported Koc values of 950 to 8500(2) indicate that pirimiphos-methyl is expected to have low to no mobility in soil(SRC). Volatilization of pirimiphos-methyl from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 6.0X10-7 atm-cu m/mole(SRC), based upon its vapor pressure, 1.5X10-5 mm Hg(2), and water solubility, 10 mg/L(2). Pirimiphos-methyl is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(2). Pirimiphos-methyl had a dissipation half-life of 5.2 to 5.9 days in soil(3). Calculated hydrolysis half-lives of 7.3 days at pH 5, 79.0 days at pH 7, and 54.0-62.0 days at pH 9(4) suggest that hydrolysis in moist soil may be an important environmental fate process(SRC).|AQUATIC FATE: Based on a classification scheme(1), reported Koc values of 950 to 8500(2) indicate that pirimiphos-methyl is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 6.0X10-7 atm-cu m/mole(SRC), derived from its vapor pressure, 1.5X10-5 mm Hg(2), and water solubility, 10 mg/L(2). According to a classification scheme(4), an estimated BCF of 270(SRC), from its log Kow of 4.12(2) and a regression-derived equation(5), suggests the potential for bioconcentration in aquatic organisms is high(SRC). Calculated hydrolysis half-lives for pirimiphos-methyl are 7.3 days at pH 5, 79.0 days at pH 7, and 54.0-62.0 days at pH 9(6).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), pirimiphos-methyl, which has a vapor pressure of 1.5X10-5 mm Hg at 20 °C(2), is expected to exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase pirimiphos-methyl is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 2.4 hours(SRC), calculated from its rate constant of 1.6X10-10 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase pirimiphos-methyl may be removed from the air by wet or dry deposition(SRC). Pirimiphos-methyl contains chromophores that absorb at wavelengths >290 nm(4) and, therefore, may be susceptible to direct photolysis by sunlight(SRC).

The rate constant for the vapor-phase reaction of pirimiphos-methyl with photochemically-produced hydroxyl radicals has been estimated as 1.6X10-10 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 2.4 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Pirimiphos-methyl hydrolyzes rapidly at acidic pHs and is relatively stable at neutral and alkaline pH(2). Calculated hydrolysis half-lives or pirimiphos-methyl are 7.3 days at pH 5, 79.0 days at pH 7, and 54.0-62.0 days at pH 9(2). The main hydrolysis degradate recovered from all three pH's was 2-(diethylamino)-4-hydroxy-6-methyl pyrimidine, a second degradate, O-2-diethylamino-6-methylpyrimidin-4-yl o-methyl-phosphorothioate, was recovered in the pH 7 and 9 solutions(2).

An estimated BCF of 270 was calculated in fish for pirimiphos-methyl(SRC), using a log Kow of 4.12(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is high(SRC), provided the compound is not metabolized by the organism(SRC).

1.00e+03 L/kg|Koc values of 950 to 8500 were reported for pirimiphos-methyl(1). According to a classification scheme(2), this estimated Koc value range suggests that pirimiphos-methyl is expected to have low to no mobility in soil(SRC).

The Henry's Law constant for pirimiphos-methyl is estimated as 6.0X10-7 atm-cu m/mole(SRC) derived from its vapor pressure, 1.5X10-5 mm Hg(1), and water solubility, 10 mg/L(1). This Henry's Law constant indicates that pirimiphos-methyl is expected to be essentially nonvolatile from moist soil and water surfaces(2). Pirimiphos-methyl is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).

GROUNDWATER: The concentration of pirimiphos-methyl in one groundwater well from New Zealand was 0.06 mg/cu m in 1990(1).|SURFACE WATER: Pirimiphos-methyl was detected in water samples (types, locations and dates of samples not reported) from locations in Egypt at 24.8 ppb(1).|RAIN/SNOW: The mean concentration of pirimiphos-methyl in rain from the Axios River Basin, Greece was 0.007 ug/L(1); the percentage of rain events with positive detections was 0.5%(1). Pirimiphos-methyl was detected in three of eight rainwater samples taken May to July 1997 in South Holland, Netherlands, reported concentrations were 0.02, 0.07 and 0.09 ug/L, however the quantification limit is 0.03 ug/L(2). The average annual concentration of pirimiphos-methyl in rainwater was 0.2 and 0.04 ng/L for 1998 and 2000 at five locations in Flanders, Belgium(3). Pirimiphos-methyl was not detected at the same locations in 1997, 1999 and 2001(3). Pirimiphos-methyl was detected in snow collected near a paper mill in Siberia, Russia at 0.26 ug/kg, but was not detected at 9 other locations in Russia and Finland(4).

In a 1995 monitoring program in Egypt pirimiphos-methyl was not detected in cabbage, cauliflower, carrot, courgette, cucumber, eggplant, green beans, green peas, lettuce, onion, pepper, apple, cantaloupe, grape, guava, mango, peach or strawberry samples(1). Pirimiphos-methyl was detected in 1 of 62 tomato samples at 0.06 mg/kg in the same 1995 monitoring program(1). In a 1996 monitoring program in Egypt pirimiphos-methyl was not detected in cabbage, lettuce, melokhia, spinach, watercress, artichoke, broad bean, cauliflower, cantaloupe, eggplant, green peas, okra, onion, squash, tomato, sweet potato, taro, apple, aqricot, banana, dates, fig, grape, quava, lemon lime, mango, peach, pear, plum or strawberry(2). Pirimiphos-methyl was detected in 1 of 24 grape leaf, 2 of 94 cucumber, 1 of 161 green beans, 7 of 91 pepper, and 1 of 42 carrot samples at 0.02, 0.07, 0.03, 0.39, and 0.08 mg/kg, respectively, in the same 1996 monitoring program(2). Pirimiphos-methyl was not detected (detection limit 0.015 mg/kg) in 130 commercial egg samples taken from Sao Paulo City, Brazil from Oct 2003 to July 2005(3). Pirimiphos-methyl was detected in 7 of 2223 fruit and vegetable samples at 0.05 to 0.10 mg/kg (positive detections were in green bean, guava, strawberry, spice, sweet pepper), samples were collected from Brazilian Sao Paulo General Storage and Wholesale over the period of Jan 1994 to Dec 2001(4). A market basket survey of produce conducted in Trinidad, West Indies from Oct 1996 to May 1997 reported that pirimiphos-methyl was not detected in sweet pepper, cabbage, lettuce, cauliflower, celery, Pak-choi, cucumber, spinach, chive tomato, hot pepper, cilantro, okra, watercress, eggplant, sorrel fruit or green beans(5). Pirimiphos-methyl was not detected (detection limit 25 ug/kg) in 298 raw milk samples obtained directly from tank trucks during delivery at nine Italian dairy plants, sampling took place Oct 2004, Jan and May 2005(6).

Pirimiphos-methyl was not detected (detection limit 25 ug/kg) in 298 raw milk samples obtained directly from tank trucks during delivery at nine Italian dairy plants, sampling took place Oct 2004, Jan and May 2005(1).|/EXPERIMENTAL/ In cows ... during the first 3 days 0.35% of the label was excreted in milk. The milk contained 0.04 ppm of pirimiphos-methyl equivalents, of which <2% was unchanged compound & phosphorus metabolites.

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

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. (See all compounds classified as Insecticides.)

Pirimiphos-methyl is known to be absorbed through intact skin, from the GI tract, & by inhalation.|Oral administration of 2-(14)C-ring-labelled pirimiphos-methyl at a dose of 0.6 mg/kg bw to five male rats resulted in a mean urinary excretion of 80.7% and mean fecal excretion of 7.3% in 24 hr, indicating rapid absorption. At 96 h, 86.0% and 15.2% of the administered dose had been excreted in urine and feces, respectively. Nine (unidentified) metabolites were present in the urine.|Female rats given 2-(14)C-pirimiphos-methyl at a dose of 7.5 mg/kg bw orally were bled (cardiac puncture, three rats per time interval) at 0.5, 1, 3, 5, 7 or 24 hr after dosing. Maximum blood concentrations (at 0.5 hr) were 2-3 ug/mL, declining by 50% 1 hr after dosing. By 24 hr, concentrations of (14)C in blood were 0.2-0.3 ug/mL, and of pirimiphos-methyl, 0.01-0.02 ug/mL. Rats treated for 4 days with 2-(14)C-pirimiphos-methyl at a dose of 7.5 mg/kg bw per day and sacrificed at intervals of 24 hr did not show any increase in blood concentrations with time. Tissue concentrations of total radioactivity in the liver, kidney and fat over the 4 days were generally less than 2 mg pirimiphos-methyl equivalents/kg tissue (concentrations of unchanged pirimiphos-methyl being less than 0.15 mg/kg tissue). There was no evidence of tissue accumulation.|Adult male Wistar rats were intubated with (14)C-labelled pirimiphos-methyl at a dose of 1 mg/kg bw per day. Four groups of three animals were dosed for 3, 7, 14 or 21 days and sacrificed 24 hr after the final dose. A further five groups of three rats were given similar doses for 28 days and sacrificed 1, 3, 7, 14, or 28 days after dosing. For each of the nine groups, one rat that did not receive pirimiphos-methyl was used as a control. After sacrifice, samples of liver, kidney, muscle, fat, erythrocytes and plasma were taken for analyses. Urine and feces were collected from two rats during the 24 hr after the seventh dose. Recovery of (14)C from (14)C-labelled pirimiphos-methyl added to control tissues was 96.9 +/- 5.2%. In all tissue samples taken at all time intervals, the concentration of radioactivity was very low, close to or below detection limits. Concentrations did not increase with repeated dosing. Liver concentrations were fairly constant (0.03 ppm) and similar concentrations were detected in some kidney samples. In other tissues, the concentration of radioactivity was generally below the limits of detection (0.04-0.06 ppm). Three days after cessation of dosing, one animal had detectable concentrations of radioactivity in the kidney. At 7 days and on subsequent days, no residues were found. Excretion was between 70% and 80% of a single dose, after administration of seven consecutive doses, providing evidence for rapid metabolism and elimination rather than poor absorption.|For more Absorption, Distribution and Excretion (Complete) data for PIRIMIPHOS-METHYL (6 total), please visit the HSDB record page.

Twelve metabolites of pirimiphos-methyl were separated by thin-layer chromatography from the urine of rats & a dog. No unchanged compound was detected & no metabolite had anticholinesterase activity. Briefly, the P-O bond is cleaved extensively & N-dealkylation &/or conjugation is a further step in the metabolism of the pyrimidine leaving group.|The mechanism by which large repeated doses of pirimiphos-methyl reduces the hemoglobin of rats is unknown. It may be caused by 2-diethylamino-4-hydroxy-6-methylpyrimidine, a metabolite formed by both mammals and plants. Although this metabolite has an acute toxicity of the same order of magnitude as the parent compound, it was (unlike the parent compound) tolerated by rats at a dosage of 400 mg/kg for 2 wk; even so, its action on the blood was indicated by an incr in reticulocytes & a decr in lymphocytes.

Female rats given 2-(14)C-pirimiphos-methyl at a dose of 7.5 mg/kg bw orally were bled (cardiac puncture, three rats per time interval) at 0.5, 1, 3, 5, 7 or 24 hr after dosing. Maximum blood concentrations (at 0.5 hr) were 2-3 ug/mL, declining by 50% 1 hr after dosing.

Systemically, pirimiphos-methyl inhibits cholinesterase, & this is the only known mechanism of its toxic action. In spite of its rapid absorption, rats, given a dosage of 1,450 mg/kg, did not show clear signs of poisoning until 24 hr later, when their brain cholinesterase was inhibited by 46%. Recovery of cholinesterase activity began to be apparent in 72 hr; it was complete for plasma enzyme by 96 hr but was slower for the red cell enzyme.

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Inhalation of material may be harmful. Contact may cause burns to skin and eyes. Inhalation of Asbestos dust may have a damaging effect on the lungs. Fire may produce irritating, corrosive and/or toxic gases. Some liquids produce vapors that may cause dizziness or suffocation. Runoff from fire control may cause pollution. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves. Move victim to fresh air. Call 911 or emergency medical service. Give artificial respiration if victim is not breathing. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. (ERG, 2016)

Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR as necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Organophosphates and related compounds/|Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Aggressive airway control may be needed. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . /Organophosphates and related compounds/|Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously and consider vasopressors if patient is hypotensive with a normal fluid volume. Watch for signs of fluid overload ... . Administer atropine. Correct hypoxia before giving atropine ... . Administer pralidoxime chloride (2 PAM). USE UNDER DIRECT PHYSICIAN ORDERS ONLY ... . Treat seizures with adequate atropinization and correction of hypoxia. In rare cases diazepam or lorazepam may be necessary ... . Watch for signs of fluid overload ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Organophosphates and related compounds/|Airway protection. Insure that a clear airway exists. Intubate the patients and aspirate the secretions with a large-bore suction device if necessary. Administer oxygen by mechanically assisted pulmonary ventilation if respiration is depressed. Improve tissue oxygenation as much as possible before administering atropine, so as to minimize the risk of ventricular fibrillation. In severe poisonings, it may be necessary to support pulmonary ventilation mechanically for several days. /Organophosphate pesticides/|For more Antidote and Emergency Treatment (Complete) data for PIRIMIPHOS-METHYL (19 total), please visit the HSDB record page.

/HUMAN EXPOSURE STUDIES/ Three men (body weight, 62-73 kg; age 22-27 years) and four women (body weight, 44-60 kg; age 21-49 years) were given capsules containing pirimiphos-methyl (purity, 97.8%) at a dose of 0.25 mg/kg bw per day for 56 days. Blood samples, for measurement of plasma and erythrocyte cholinesterase activity, liver enzymes and hematology, were taken twice before initiation of dosing, and on days 7, 14, 21, 28, 35, 42, 49 and 56 of the study, and also during the recovery period 7, 14, 21 and 29 days after treatment. Controls comprised two women (body weight, 44 and 46 kg; age 29 and 30 years). No compound-related effects were observed on liver function (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase or glutanyl transpeptidase activities in plasma), hematology (hemoglobin, erythrocyte volume fraction, MCHC, total and differential leukocyte counts, platelets, erythrocyte sedimentation rate) or erythrocyte cholinesterase activity. Plasma cholinesterase was depressed about 20% in two of four women on days 14, 21 and 28 and in one woman on days 28 and 35. The effect did not increase with time. All values were normal during the withdrawal period.|/HUMAN EXPOSURE STUDIES/ Five healthy men (body weight, 59.5-73 kg bw; age 25 45 years) were given pirimiphos-methyl (purity, 97.8%) at a dose of 0.25 mg/kg bw per day orally for 28 days. Blood samples for measurement of plasma and erythrocyte cholinesterase activity were taken on days -14, -7, 1, 3, 7, 14, 21 and 28. One subject showed inhibition of plasma cholinesterase activity (21.5%) on day 28. Otherwise changes in cholinesterase activity, both above and below values measured before dosing, were within 12%. Four of five subjects had erythrocyte cholinesterase activity values that were slightly below the pre-exposure values during the last 2 weeks of the study. However, the group means for each time interval did not differ significantly and the variations noted were within the range of variations found by others for normal untreated subjects.|/SIGNS AND SYMPTOMS/ Pirimiphos-methyl can cause cholinesterase inhibition in humans; that is, it can overstimulate the nervous system causing nausea, dizziness, confusion, & at very high exposures (e.g., accidents or major spills), respiratory paralysis & death.|/SIGNS AND SYMPTOMS/ The symptoms of chronic poisoning due to organophosphorus pesticides include headache, weakness, feeling of heaviness in head, decline of memory, quick onset of fatigue, disturbed sleep, loss of appetite, & loss of orientation. Psychic disorders, nystagmus, trembling of the hands & other nervous system disorders can be observed in certain cases. Sometimes neuritis, paresis & paralysis develop. /Organophosphorus pesticides/|For more Human Toxicity Excerpts (Complete) data for PIRIMIPHOS-METHYL (6 total), please visit the HSDB record page.

Actellic

USEPA/OPP Pesticide Code 108102; Trade Names: R-33986, PP 511, Actellic, Actellifog, Blex, Silosan, Pirimifosmethyl, ENT 27699GC.|Emulsifiable liquid concentrates at 57% a.i. Treated Articles (Ear Tags) at 14% and 20% a.i.|Dispersible powder, emulsifiable concentrate, ultralow-volume liquid, water-soluble powder, aerosol dispersion.|Smoke generate, hot fogging concentrate, cold fogging concentrate, solution for seed treatment, water soluble granules.|For more Formulations/Preparations (Complete) data for PIRIMIPHOS-METHYL (9 total), please visit the HSDB record page.

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

Method: OSHA PV2071; Procedure: gas chromatography using an electron capture detector; Analyte: primiphos-methyl; Matrix: air; Detection Limit: 13 ug/cu m.|AOAC Method 991.34. Pirimiphos-Methyl in Technical Products and Pesticide Formulations by Gas Chromatographic Method. Detection limit unspecified.|Method: EPA-OW/OST 1699; Procedure: high resolution gas chromatography combined with high resolution mass spectrometry; Analyte: primiphos-methyl; Matrix: water, soil, sediment, biosolids, and tissue; Detection Limit: 14 pg/L.|Product analysis by gas liquid chromatography with flame ionization detector ... Identity also by gas liquid chromatography, thin layer chromatography, infrared or nuclear magnetic resonance. Residues determined by gas liquid chromatography with flame photometric detector, flame thermionic detector or mass spectrometry.

Agrochemicals -> Insecticides|Acaricides, Insecticides|Environmental transformation -> Pesticides (parent, predecessor)

Pirimiphos-methyl has known environmental transformation products that include 2-diethylamino-6-methyl pyrimidin-4-ol and N,N-diethylguanidine.