Parathion products

Releases to the atmosphere from production facilities and disposal sites have also been reported. Studies have shown that releases of methyl parathion to the atmosphere occur in the vicinity of pesticide-producing factories. At two predominately downwind sites located 1 mile from a plant producing methyl parathion, average monthly concentrations were <0.57 and <0.64 ng/m (Foster 1974). Air emissions from methyl parathion production facilities have been reported to contain 1.0 kg/1,000 kg pesticide produced. In addition, evaporation from holding ponds for pesticide waste potentially contributes 7.4 mg/1,000 kg pesticide produced to the atmosphere (EPA 1978d). 

A chlorinator exploded killing eight employees. The accident occurred in the chlorination step during methyl parathion production. The temperature was controlled automatically on this occasion, however, the thermocouple output was very low. A leak in the thermowell was discovered and an instrument mechanic was called to carry out repairs. Chlorine was added faster than normal due to the fault. The agitator and brine cooling were stopped while the faulty thermowell was being replaced. 

The use of alkali or alkaline-earth sulfides cataly2es the reaction so that it is complete in a few hours at 150—160°C use of aluminum chloride as the catalyst gives a comparable reaction rate at 115°C. When an excess of sulfur is used, the product can be distilled out of the reactor, and the residue of sulfur forms part of the charge in the following batch reaction. The reaction is carried out in a stainless steel autoclave, and the yield is better than 98% based on either reactant. Phosphoms sulfochloride is used primarily in the manufacture of insecticides (53—55), such as Parathion. 

S-oxidation of sulfur-containing pesticides such as aldicarb, parathion, and malathion can be of importance in the absence of microbial activity (29). The products of chemical vs biological oxidation are generally identical (eq. 8). 

FMC Agricultural Products Group, 228 FMC Corporation, 228 FMC Lithium Division, 228 FOLIDOL , parathion, 70 Fonofos, 70... 

The zinc. salts of these acids are extensively used as additives to lubricating oils to improve their extreme-pressure properties. The compounds also act as antioxidants, corrosion inhibitors and detergents. Short-chain dialkyl dithiophosphates and their sodium and ammonium salts are used as flotation agents for zinc and lead sulfide ores. The methyl and ethyl derivatives (RO)2P(S)SH and (RO)2P(S)CI are of particular interest in the large-scale manufacture of pesticides such as parathion, malathion, dimethylparathion, etc. For example parathion. which first went into production as an insecticide in Germany in 1947. is made by the following reaction sequence ... 

Several medical tests can determine whether you have been exposed to methyl parathion. The first medical test measures methyl parathion in your blood or measures 4-nitrophenol, which is a breakdown product of methyl parathion, in your urine. These tests are only reliable for about 24 hours after you are exposed because methyl parathion breaks down quickly and leaves your body. These tests cannot tell whether you will have harmful health effects or what those effects may be. The next medical test measures the levels of a substance called cholinesterase in your blood. If cholinesterase levels are less than half of what they should be and you have been exposed to methyl parathion, then you may get symptoms of poisoning. However, lower cholinesterase levels may also only indicate exposure and not necessarily harmful effects. The action of methyl parathion may cause lower cholinesterase levels in your red blood cells or your blood plasma. Such lowering, however, can also be caused by factors other than methyl parathion. For example, cholinesterase values may already be low in some people, because of heredity or disease. However, a lowering of cholinesterase levels can often show whether methyl parathion or similar compounds have acted on your nerves. Cholinesterase levels in red blood cells can stay low for more than a month after you have been exposed to methyl parathion or similar chemicals. For more information, see Chapters 3 and 7. 

Table 5-2. Methyl Parathion Use in Crop Production in 1992 (continued)...

Very little information exists in the literature on the transformation and degradation of methyl parathion in air. An early study indicated that direct photolysis of methyl parathion may occur however, the products of this photolysis were not determined (Baker and Applegate 1974). A later study found a transformation product of methyl parathion, methyl paraoxon, in air samples taken from areas where methyl parathion had been applied. Formation of methyl paraoxon was attributed to the vapor phase oxidation of methyl parathion (Seiber et al. 1989). Recent monitoring studies in California have also found both methyl parathion and methyl paraoxon (Baker et al. 1996). 

Results from other studies support the rapid degradation of methyl parathion in soils with a high water (i.e., low oxygen) content (Adhya et al. 1981, 1987 Brahmaprakash et al. 1987). Experiments in flooded and nonflooded soils showed that the redox potential affected both the rate of degradation and the transformation products of methyl parathion (Adhya et al. 1981, 1987). Transformation to volatile products was suggested by Brahmaprakash et al. (1987) as the reason that significant amounts of " C from labeled methyl parathion could not be accounted for, especially in flooded soils. 

An extensive study was undertaken to determine if pesticide residues are present in any infant formula products (Gelardi and Mountford 1993). Milk- and soy-based formulas were analyzed, as was the water used to make the formula. No pesticide residues, including methyl parathion, were detected in any infant formula manufactured in the United States. Thus, it does not appear that infants will be exposed to... 

Production, Import/Export, Use, Release, and Disposal. Methyl parathion is commercially produced in the United States and abroad. Since 1977, production volume statistics for methyl parathion have been combined with those of ethyl parathion, also known as parathion. In 1983, the combined production capacity was estimated at 29 million kg for the United States and 10-15 million kg for western Europe (lARC 1983). Data on recent production in the United States were not located. In 1980,... 

In a study of the metabolism of methyl parathion in intact and subcellular fractions of isolated rat hepatocytes, a high performance liquid chromatography (HPLC) method has been developed that separates and quantitates methyl parathion and six of its hepatic biotransformation products (Anderson et al. 1992). The six biotransformation products identified are methyl paraoxon, desmethyl parathion, desmethyl paraoxon, 4-nitrophenol, />nitrophenyl glucuronide, and /wiitrophenyl sulfate. This method is not an EPA or other standardized method, and thus it has not been included in Table 7-1. 

Kirchner K, Berge H. 1975b. [TAS method for the detection of parathion-methyl and various transformation products in organic substances]. Arch Exp Veterinarmed 29 649-653. (German)... 

Ortiz D, Yanez L, Gomez H, et al. 1995. Acute toxicological effects in rats treated with a mixture of commercially formulated products containing methyl parathion and permethrin. Ecotoxicol Environ Safety 32 154-158. 

Suba, LA. 1981. Information in support of the registration of methyl parathion One-year chronic feeding study in dogs. Monsanto Agricultural Products Company, St. Louis, MO. 

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