化合物详情

Pesticide Ecotoxicity Data from EPA: 37

LC50; Species: Daphnia magna (Water flea, age 8-24 hr juvenile); Conditions: freshwater, renewal, 22 °C; Concentration: 660 ug/L for 48 hr />98% purity; fosthiazate, racemic mixture/

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), fosthiazate, which has a vapor pressure of 4.2X10-6 mm Hg at 25 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase fosthiazate is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 1.5 hours(SRC), calculated from its rate constant of 8.76X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase fosthiazate may be removed from the air by wet or dry deposition(SRC). Fosthiazate contains chromophores that absorb at wavelengths >290 nm(4), and therefore may be suscepti...

The Koc of fosthiazate is estimated as 71(SRC), using a log Kow of 1.68(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that fosthiazate is expected to have high mobility in soil. The compound is mobile in soil and can leach in acidic soils with low organic matter content as indicated in soil column studies. Using a soil column test employing three orchard soils from Veris, Greece collected in April 2006, fosthiazate was detected in leachates at 0.04, 0.09, and 0.004% of applied on clay (1.77% organic matter, pH 8.10, 37.0% sand, 21.0% silt, 41.0% clay), sandy clay loam (0.49% organic matter, pH 4.80, 57.0% sand, 21.0% silt, 22.0% clay), and clay loam (1.58% organic matter, pH 8.59, 43.0% sand, 19.0% silt, 38.0% clay, r...

ANAEROBIC: The half-life using a water/sediment inoculum was reported as 37 days(1).

An estimated BCF of 6 was calculated in fish for fosthiazate(SRC), using a log Kow of 1.68(1) and a regression-derived equation(2). Using a modeling approach based on the quantitative structure-activity relationship (QSAR), a log BCF of 0.50515, corresponding to a BCF of 3 was calculated(3). According to a classification scheme(3), these BCF values suggest the potential for bioconcentration in aquatic organisms is low(SRC).

The Henry's Law constant for fosthiazate is 1.32X10-7 atm-cu m/mole(1). This Henry's Law constant indicates that fosthiazate is expected to be essentially nonvolatile from water and moist surfaces(2). Fosthiazate is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 4.2X10-6 mm Hg(1).

Stability in water, half-life = 3 days at pH 9, 50 °C

Fosthiazate was detected at a range of 4.0 to 12.2 ng/g in 4 of 173 samples of Japanese agricultural products (carrots, bananas, grapefruit); limit of detection 1.6 ng/g(1).

/AQUATIC SPECIES/ ... In the present study, the stereoisomeric separation and toxicity of fosthiazate, a chiral OP with two asymmetric centers on phosphorus and carbon atoms, was investigated. ... The inhibition potencies of the stereoisomers against acetylcholinesterase of Electrophorus electricus were slightly stereoselective, with a maximum difference of 1.4-fold among the isomers. A 3.1-fold difference, however, was observed in the acute toxicity of isomers to Daphnia magna. The 48-hr toxicity of isomers to D. magna followed the order pk1 > pk2 > pk4 > racemate approximately pk3. The stereoselective toxicity to D. magna found in fosthiazate suggests that the environmental safety of fosthiazate should be evaluated on the basis of its individual isomers.

Fosthiazate's production may result in its release to the environment through various waste streams; its use as a nematicide/insecticide(1) will result in its direct release to the environment(SRC).

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

Fosthiazate's production may result in its release to the environment through various waste streams; its use as a nematicide/insecticide will result in its direct release to the environment. If released to air, a vapor pressure of 4.20X10-6 mm Hg at 25 °C indicates fosthiazate will exist in both the vapor and particulate phases. Vapor-phase fosthiazate will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 1.5 hours. Particulate-phase fosthiazate will be removed from the atmosphere by wet or dry deposition. Fosthiazate contains chromophores that absorb at wavelengths >290 nm, and therefore may be susceptible to direct photolysis by sunlight. If released to soil, fosthiazate is expected to...

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.

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.

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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...

Fosthiazate 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...

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Oral Chronic Reference Dose Reference: OPP

No indication of carcinogenicity to humans (not listed by IARC).

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/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ Fosthiazate (IKI-1145) /was delivered in the /diet /at/ 0, 1.07, 10.7, 53.6, 429 ppm (M: 0, 0.08, 0.77, 4.12, 36.37 mg/kg/day, respectively; F: 0, 0.09, 0.89, 4.74, 41.03 mg/kg/day, respectively); 10 rats/sex/group for 13 weeks, additional 10 rats/sex/group (0, 429) observed for a 10 week recovery period (not dosed); Mortalities: 1 male (0), 1 female (0) during dosing period, 1 male (0) during recovery period; adverse effects indicated: tachypnea, emaciation, tremors and nervousness in the 429 ppm group, clearing by week 3-4 of dosing; dose-related inhibition of plasma and erythrocyte cholinesterase activity (10.7, 53.6, 429) (p<0.05; 80-7% of control) week 13, largely recovered by week 4 post-dosing; significant brain cholinestera...

/SRP:/ 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. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use...