아세시온

When heated to decomposition it emits very toxic fumes of /phosphorus and sulfur oxides/.

... A number of phosphate and thiophosphate esters are of limited thermal stability and undergo highly exothermic self-accelerating decomp reactions which may be further catalyzed by impurities ... /Phosphorus esters/

The average of two baseline respective cholinesterase activity determinations three days apart, with no exposures to enzyme inhibiting pesticides for at least 30 days, is recommended for each worker prior to exposure to cholinesterase inhibitors because of large inter-individual differences in published baseline values. To be established at least once a year. Removal from workplace exposures is recommended until the cholinesterase activity returns to within 20% of baseline. [TLVs and BEIs]

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]

...Must be stored in its sealed original containers, in well-aired, fresh & dry storehouses or in shaded & possibly well-aired places. It is recommended that the product's temp...not exceed 25-30 °C, & keep...away from sources of heat, free flames or spark-generating equipment. Containers must be stacked in such a way as to permit free circulation of air...at bottom & inside of piles. Storage areas must be located at suitable distance from inhabited buildings, animal shelters, & food stores; moreover, they must be inaccessible to unauthorized persons, children, & domestic animals. /Dimethoate/

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.

... A number of phosphate and thiophosphate esters are of limited thermal stability and undergo highly exothermic self-accelerating decomp reactions which may be further catalyzed by impurities. The hazards can be reduced by appropriate thermal control measures. An example is the substitution of hot water at 60 °C for pressurized steam to melt a solid phosphate ester, which on adiabatic calorimetric examination was found to have a time to maximum decomp rate of 6 hr at 110 °C but 11 hr at 100 °C. The combined used of vapor phase pyrolysis to decomp various phosphorus esters, and of GLC and mass spectrometry to analyze the pyrolysis products, allowed a thermal degradation scheme to be developed for phosphorus esters ... /Phosphorus esters/

A final diagnosis of mild to moderate acute organophosphate pesticide poisoning is rarely justified unless all of the following five conditions are present: 1. A definite history of exposure to an organophosphate pesticide. 2. A latent interval of not more than a few hours between that last exposure and the onset of illness. 3. A clinical picture in which most or all of the following signs or symptoms are present: headache, blurred vision, weakness, tightness in chest, and constricted pupils. 4. Reduction of plasma and RBC cholinesterase activity to a level substantially below 50% of baseline values. Because of the wide normal range of RBC cholinesterase in the population, symptoms may be present with reported "normal" levels. 5. An acute illness that is not substantially longer than 48 hours. The classic presentation for acute organophosphate toxicity includes history, evidence of exposure to organophosphate (garlic odor), signs/symptoms of cholinergic excess, improvement with atropine or pralidoxime, and inhibition of cholinesterase in blood. /Organophosphate pesticide poisoning/

/SIGNS AND SYMPTOMS/ Toxic effects may include anorexia, abdominal cramps, nausea, vomiting, diarrhea, incontinence, eye changes, weakness, dyspnea, bronchospasm, lacrimation, increased salivation and sweating, bradycardia, hypotension or hypertension due to asphyxia, cyanosis, and muscular twitching of the eyelids, tongue, face, and neck, possibly progressing to convulsions. Central nervous system symptoms include restlessness, anxiety, dizziness, drowsiness, tremor, ataxia, depression, confusion, and coma. Death may occur from depression of the respiratory or cardiovascular system. Neuropathy appears to be a rare problem with the organophosphorus insecticides now in use. /Organophosphorus insecticides/

/OTHER TOXICITY INFORMATION/ Muscarinic signs of /organophosphorus compounds/...consist of hypersalivation, lacrimation, sweating and nasal discharge. Miosis, dyspnea, vomiting, diarrhea and frequency of urination... Nicotinic effects consist of fasciculation of muscles, weakness and paralysis. Central effects /of organophosphorus compounds/...nervousness, apprehension, ataxia, convulsions and coma. Death...due to respiratory failure, or...cardiac arrest. There is little difference betweeen symptoms produced by different...compounds, but route of absorption may influence one system more than another. /Organophosphorus compounds/

Young persons under 18 yr, expectant or nursing mothers, /alcoholics/, or persons for whom work with toxic chemicals is contraindicated on account of their state of health /are at elevated risk from the toxic effects of organophosphorus pesticides. Those individuals with/ organic diseases of the CNS, mental disorders & epilepsy, pronounced endocrine & vegetative disorders, pulmonary tuberculosis, bronchial asthma, chronic respiratory diseases, cardiovascular diseases and circulatory disorders, gastrointestinal diseases (peptic ulcer), gastroenterocolitis, diseases of the liver & kidneys, eye diseases (chronic conjunctivitis and keratitis) /are at elevated risk from exposure/. /Organophosphorus pesticides/

Those individuals who are exposed to organophosphorus pesticides with pre-existing/ organic diseases of the central nervous system, mental disorders & epilepsy, pronounced endocrine & vegetative disorders, pulmonary tuberculosis, bronchial asthma, chronic respiratory diseases, cardiovascular diseases & circulatory disorders, gastrointestinal diseases (peptic ulcer), gastroenterocolitis, diseases of liver & kidneys, eye diseases (chronic conjunctivitis & keratitis) /are at elevated risk from exposure/. The blood cholinesterase activity 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 to organophosphorus pesticides until this activity is completely restored. Persons with initial signs of indisposition should cease work with pesticides. /Organophosphorus pesticides/

/SRP:/ 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/

/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. 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/

LD50 Mouse ip 1280 mg/kg

LD50 Mouse oral 1200 mg/kg

Toxicants of this class phosphorylate almost irreversibly varying amt of acetylcholinesterase enzyme of tissues, allowing accum of acetylcholine at cholinergic neuro-effector junctions (muscarinic effects), & at skeletal muscle myoneural junctions & in autonomic ganglia (nicotinic effects). /Organophosphate pesticides/

The signs of poisoning due to organophosphorus cmpd are those due to accumulation of acetylcholine & hence overstimulation of parasympathetic nervous system. It is usual to divide them under 3 headings: muscarinic, nicotinic & central. Muscarinic signs ... consist of hypersalivation, lacrimation, sweating & nasal discharge. Miosis, dyspnea, vomiting, diarrhea & frequency of urination ... Nicotinic effects consist of fasciculation of muscles, weakness & paralysis. Central nervous system effects include nervousness, apprehension, ataxia, convulsions & coma. Death is due to resp failure, or sometimes cardiac arrest. There is little difference between signs produced by different organophosphorus compounds, but route of absorption may influence one system more than another. /Organophosphorus cmpd/

Organophosphorus derivatives act by combining with and inactivating the enzyme acetylcholinesterase (AChE). ... The inactivation of cholinesterase by cholinesterase inhibitor pesticides allows the accumulation of large amounts of acetylcholine, with resultant widespread effects that may be ... separated into 4 categories: (1) Potentiation of postganglionic parasympathetic activity. ... (2) Persistent depolarization of skeletal muscle ... (3) Initial stimulation following depression of cells of central nervous system ... (4) Variable ganglionic stimulation or blockade ... /Cholinesterase inhibitor pesticides/

Degradation of acethion was rapid & 77-88% of injected dose appeared as chloroform extractables within 0.5 hr after treatment. Chromatographic separation & anal showed principal metabolite to be acethion acid. Some mono- & diethyl phosphorodithionic acids were also found.

All undergo hydrolytic degradation in liver & other tissues, usually within hours of absorption. Degradation products are...excreted in urine & feces. /Organophosphate pesticides/

Many of /the organophosphorus insecticides/ are excreted in the milk ... /Organophosphorus insecticides/

Used as an insecticide; [HSDB]

Farming (Pesticides) [Category: Industry]

For acethion: 0 ACTIVE products with label matches. /SRP: Not 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 /Former use/