Chlorethoxyfos

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 immediately for medical attention. Wear protective gloves when administering first aid.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

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

Biological Exposure Indices (BEI) [ACGIH] - Acetylcholinesterase activity in red blood cells = 70% of individual's baseline; Butylcholinesterase activity in serum or plasma = 60% of individual's baseline; Sample at end of shift; [TLVs and BEIs]

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

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

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

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

Environmental considerations: Land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Absorb bulk liquid with fly ash, cement powder, or commercial sorbents. /Organophosphorus pesticides, liquid, flammable, toxic; Organophosphorus pesticides, liquid, toxic; Organophosphorus pesticides, solid, toxic/

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure 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, aquatic, and plant life; and conformance with environmental and public health regulations.

Personal protection: complete protective clothing including self-contained breathing apparatus. Do NOT let this chemical enter the environment. Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations.

If material not on fire and not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. /Organophosphorus pesticides, solid, toxic

If material not on fire and not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Build dikes to contain flow as necessary. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors. /Organophosphorus pesticides, liquid, toxic/

If material not on fire and not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Build dikes to contain flow as necessary. Use water spray to knock-down vapors. /Organophosphorus pesticides, liquid, flammable, toxic/

Personnel protection: Avoid breathing dusts, and fumes from burning material. Keep upwind. Avoid bodily contact with the material. Do not handle broken packages unless wearing appropriate personal protective equipment. Wash away any material which may have contacted the body with copious amounts of water or soap and water. /Organophosphorus pesticides, solid, toxic/

For more Preventive Measures (Complete) data for CHLORETHOXYFOS (8 total), please visit the HSDB record page.

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

Acute exposure to cholinesterase inhibitors can cause a cholinergic crisis characterized by severe nausea/vomiting, salivation, sweating, bradycardia, hypotension, collapse, and convulsions. Increasing muscle weakness is a possibility and may result in death if respiratory muscles are involved. Accumulation of ACh at motor nerves causes overstimulation of nicotinic expression at the neuromuscular junction. When this occurs symptoms such as muscle weakness, fatigue, muscle cramps, fasciculation, and paralysis can be seen. When there is an accumulation of ACh at autonomic ganglia this causes overstimulation of nicotinic expression in the sympathetic system. Symptoms associated with this are hypertension, and hypoglycemia. Overstimulation of nicotinic acetylcholine receptors in the central nervous system, due to accumulation of ACh, results in anxiety, headache, convulsions, ataxia, depression of respiration and circulation, tremor, general weakness, and potentially coma. When there is expression of muscarinic overstimulation due to excess acetylcholine at muscarinic acetylcholine receptors symptoms of visual disturbances, tightness in chest, wheezing due to bronchoconstriction, increased bronchial secretions, increased salivation, lacrimation, sweating, peristalsis, and urination can occur. Certain reproductive effects in fertility, growth, and development for males and females have been linked specifically to organophosphate pesticide exposure. Most of the research on reproductive effects has been conducted on farmers working with pesticides and insecticdes in rural areas. In females menstrual cycle disturbances, longer pregnancies, spontaneous abortions, stillbirths, and some developmental effects in offspring have been linked to organophosphate pesticide exposure. Prenatal exposure has been linked to impaired fetal growth and development. Neurotoxic effects have also been linked to poisoning with OP pesticides causing four neurotoxic effects in humans: cholinergic syndrome, intermediate syndrome, organophosphate-induced delayed polyneuropathy (OPIDP), and chronic organophosphate-induced neuropsychiatric disorder (COPIND). These syndromes result after acute and chronic exposure to OP pesticides.

LC50 Rainbow trout 0.10 mg/L/96 hr /Conditions of bioassay not specified/

LC50 Bluegill sunfish 0.0023 mg/L/96 hr /Conditions of bioassay not specified/

LC50 Sheepshead minnow 0.00047 mg/L/96 hr /Conditions of bioassay not specified/

LC50 Daphnia magna 0.00041 mg/L/48 hr

LD50 Bobwhite quail (gavage) 28 mg/kg

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 890(SRC), determined from a structure estimation method(2), indicates that chlorethoxyfos is expected to have low mobility in soil(SRC). Volatilization of chlorethoxyfos from moist soil surfaces is expected(SRC) given an estimated Henry's Law constant of 4.2X10-6 atm-cu m/mole(SRC), using a fragment constant estimation method(3); however, volatilization may be attenuated by adsorption to soil(SRC). Chlorethoxyfos is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 7.95X10-4 mm Hg(4). Half-lives in soil at 25 °C of chlorethoxyfos in laboratory studies were 7 days in Handord sandy loam and 20 days in Flanagan loam(4). Field soil dissipation half-lives were reported in the range of 2-3 days(4).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 890(SRC), determined from a structure estimation method(2), indicates that chlorethoxyfos is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 4.2X10-6 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 10 hours and 9 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 680(SRC), from a log Kow of 4.59(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is high(SRC). Half-lives for the hydrolysis of chlorethoxyfos are 4.3, 59, and 72 days at pH 5, 7, and 9, respectively6).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), chlorethoxyfos, which has a vapor pressure of 7.95X10-4 mm Hg at 20 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase chlorethoxyfos 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 4.2 hours(SRC), calculated from its rate constant of 9.2X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Chlorethoxyfos is not expected to absorb light with wavelengths >290 nm and is not expected to be susceptible to direct photolysis by sunlight(SRC).

Chlorethoxyfos is a cholinesterase or acetylcholinesterase (AChE) inhibitor. A cholinesterase inhibitor (or 'anticholinesterase') suppresses the action of acetylcholinesterase. Because of its essential function, chemicals that interfere with the action of acetylcholinesterase are potent neurotoxins, causing excessive salivation and eye-watering in low doses, followed by muscle spasms and ultimately death. Nerve gases and many substances used in insecticides have been shown to act by binding a serine in the active site of acetylcholine esterase, inhibiting the enzyme completely. Acetylcholine esterase breaks down the neurotransmitter acetylcholine, which is released at nerve and muscle junctions, in order to allow the muscle or organ to relax. The result of acetylcholine esterase inhibition is that acetylcholine builds up and continues to act so that any nerve impulses are continually transmitted and muscle contractions do not stop. Among the most common acetylcholinesterase inhibitors are phosphorus-based compounds, which are designed to bind to the active site of the enzyme. The structural requirements are a phosphorus atom bearing two lipophilic groups, a leaving group (such as a halide or thiocyanate), and a terminal oxygen.

Dizziness. Nausea. Sweating. Muscle twitching. Pupillary constriction, muscle cramp, excessive salivation. Laboured breathing. Convulsions. Unconsciousness.

MAY BE ABSORBED! See Inhalation.

Blurred vision.

Abdominal cramps. Diarrhoea. Vomiting. Further see Inhalation.

Symptoms of low dose exposure include excessive salivation and eye-watering. Acute dose symptoms include 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. Hypertension, hypoglycemia, anxiety, headache, tremor and ataxia may also result.

Measurement of whole blood-AChE is the most widely adopted method for monitoring the effects of occupational exposure to organophosphorus insecticides. Physiological variations in blood ChE levels occur in a healthy person and are seen among a population. It has been estimated that the coefficient of variation for AChE activity in samples from an individual is 8-11%, and that a decrease of 23% below pre-exposure level may, therefore, be considered significant. If the average of several pre-exposure values were available, then a decrease of 17% would be significant. It has been recommended that, if measured activity is reduced by 30% or more of the pre-exposure value, AChE measurements should be repeated at appropriate intervals to confirm the results. Depressions of AChE or ChE in excess of 20-25% are considered diagnostic of exposure but not, necessarily, indicative of hazard. Depressions of 30-50% or more are considered indicators for removal of an exposed individual from further contact with pesticides until levels return to normal. /Organophosphorus Pesticides/

...Organophosphorus pesticides may undergo hydrolysis in vivo to yield substituted phosphoric acids that are subsequently excreted in urine. Advances in gas chromatography and combined gas chromatography/mass spectrometry (GC/MS) have made it possible to analyse the urine of exposed persons for the presence of appropriate metabolites. It is usually necessary to preserve the sample by the addition of chloroform, to concentrate or extract the metabolite(s), and to convert them to suitably-volatile derivatives that can be detected by GC. Obviously, access to a well-equipped analytical laboratory, capable of the quick processing of samples, is a necessary factor if monitoring by urine analysis is proposed. However, in some cases, simpler and sensitive colorimetric tests are available for screening the urine of exposed persons. Thus, 4-nitrophenol can be measured directly in the urine of workers exposed to parathion. Consideration of the concentration of metabolite(s) in the urine can be helpful in determining patterns of exposure, and these concentrations can be calibrated against the effects on AChE for a particular pesticide. However, the time-course and peak of excretion of metabolites appears to vary according to dose, so that serial sampling and analyses of urine are desirable. Levels of metabolite alone cannot be considered a guide to hazard. This is obvious when it is realized that pesticides that have very different toxicities may yield identical acidic metabolites. Thus, the level of metabolites in urine, after exposure to sufficient amounts of the very toxic parathion-methyl to depress blood-AChE to 50%, will be much lower than that of the identical metabolites, following exposure to the related fenitrothion, which is about 40 times less toxic. /Organophosphorus Pesticides/

SRP: Workers should undergo an annual medical exam. Contraindications for work with organophosporous pesticides are organic diseases of the CNS, mental disorders and epilepsy, and pronounced endocrine disorders. Blood cholinesterase, both plasma and RBC, must be determined before work starts. In the event of prolonged work periods, this activity should be determined at intervals of 3-4 days. Persons exhibiting a fall in cholinesterase activity of 25% or more must be transferred to other work where they are not exposed until cholinesterase activity is restored. /Organophosphorous pesticides/

Using a structure estimation method based on molecular connectivity indices(1), the Koc for chlorethoxyfos can be estimated to be 890(SRC). According to a classification scheme(2), this estimated Koc value suggests that chlorethoxyfos is expected to have low mobility in soil.

New Active Ingredients ... includes pesticide active ingredients initially registered after November 1, 1984, that currently have active product registrations. By law, these newer pesticides are not subject to the reregistration program. They must, however, meet the new safety standard of the FQPA, and will be reviewed on a 15-year cycle under the registration review program. ... Active Ingredient Number: 129006; Type of Pesticide: insecticide; Use Site: food use; Year: 1995.

Tolerances are established permitting the residue of the insecticide phosphorothioic acid, O,O-diethyl O-(1,2,2,2-tetrachloroethyl) ester in or on the following raw agricultural commodities: corn, field, forage; corn field, grain; corn, field, stover; corn, pop, grain; corn, pop, stover; corn, sweet, kernel plus cob with husks removed; corn, sweet, forage; and corn, sweet, stover (fodder).

The Environmental Protection Agency has completed its review of the available data and public comments related to the revised human health risk assessment for the organophosphate pesticide chlorethoxyfos. The ...document entitled, Report on FQPA Tolerance Reassessment and Interim Risk Management Decision for Chlorethoxyfos summarizes the Agency's assessment of the dietary and occupational risk from chlorethoxyfos. Based on its review, EPA has identified risk mitigation measures believed necessary to address the human health risks associated with the current use of chlorethoxyfos.