Sodium Pentachlorophenate

SODIUM PENTACHLOROPHENATE SODIUM PERCARBONATE SODIUM PERCARBONATE... 

A drastically diflEerent reaction is indicated on the thermogram of sodium pentachlorophenate (Figure 3) as a strongly exothermic reaction at 360°C. Upon cooling, essentially pure octachloro-p-dibenzodioxin crystallized. 

For 2,3,4,6-tetrachlorophenol hardly any discoloration was detected above 200°C instead the sample vaporized rapidly. Its sodium salt reacted similarly to sodium pentachlorophenate except that its exothermic decomposition (Figure 4) is less clearly defined no crystallization occurred on cooling, and the yield of hexachlorodioxins was much lower, the remaining products being higher molecular weight materials. The hexachlorodioxins were identified by gas-liquid chromatography as two isomers in a ratio of 35 65. 

This paper discusses the effects of the pyrolysis of wood and paper treated with pentachlorophenol or sodium pentachlorophenate along with the exposure of sodium pentachlorophenate to ultraviolet light. The effect of heat, light, and air with respect to some of the chlorinated dibenzo-p-dioxins will be considered. 

Table I. Octachlorodibenzo- >-dioxin Concentration before and after Burning Paper and Wood Treated with Pentachlorophenol and Sodium Pentachlorophenate...

Effects of Combustion and Heat. The results of combusting wood and paper treated with pentachlorophenol or sodium pentachlorophenate are shown in Table I. These results indicate that octachlorodibenzo-p-dioxin concentration did not increase as the result of combusting either wood or paper treated with pentachlorophenol. It seems that the concentration of octachlorodibenzo-p-dioxin concentration was actually decreased during combustion. However, paper treated with sodium pentachlorophenate did increase in octachlorodibenzo-p-dioxin concentration as the result of combustion. 

Effect of UV Radiation on Sodium Pentachlorophenate. Sodium pentachlorophenate is quickly degraded in the presence of ultraviolet light as well as daylight, as shown in Table III. The degradation is almost complete after 16 hours exposure to the General Electric R.S. sunlamp. Three and one-half days of rainy and overcast skies account for the somewhat lower degradation observed in the sample exposed to daylight. 

Table III. Stability of Sodium Pentachlorophenate to Sunlight and Artificial Sunlight in pH 8 Phosphate Buffer...

Combustion of wood or paper treated with pentachlorophenol resulted in no increase and more probably a decrease in octachlorodi-benzo-p-dioxin concentrations while octachlorodibenzo-p-dioxin increased slightly in paper treated with sodium pentachlorophenate. The pho-tolytic degradation of sodium pentachlorophenate at pH 8 is very rapid. Under these controlled conditions formation of no more than 0.03% octachlorodibenzo-p-dioxin was observed. The 2,3,7,8 isomer, one of the most active chloracnegens is seemingly stable towards air oxidation but... 

Natural rubber latices in which the customary 0.7% ammonia content has been reduced to 0.2% in conjunction with the addition of a secondary preservative, either sodium pentachlorophenate, zinc diethyl dithiocarbamate or boric acid such latices have the advantage that the deammoniation process before manufacture is unnecessary. 

Sodium pentachlorophenol, latex auxiliary. Sodium Pentachlorophenate... 

Pentachlorophenol is readily soluble in most organic solvents, oils, and highly aromatic and olefinic petroleum hydrocarbons — a property that makes it compatible for inclusion in many pesticide formulations (Table 23.1 Figure 23.1). Purified PCP, however, is practically insoluble in water therefore, the readily water-soluble sodium pentachlorophen-ate salt is substituted in many industrial applications (Table 23.1) (Bevenue and Beckman 1967 USPHS 1994). 

Pentachlorophenol in terrestrial ecosystems clears rapidly (Haque et al. 1988). In one case, a terrestrial ecosystem was given a single surface application of radiolabeled PCP equivalent to 5 kg sodium pentachlorophenate/ha. PCP residues on foliage decreased rapidly, with 50% metabolized within 15 days. After 131 days (autumn), most of the remaining PCP was in the topsoil and plant litter. After 222 days (winter), 39% of the radiocarbon remained. There was little bioconcentration in the resident fauna, due to rapid metabolism and excretion (Haque et al. 1988). 

Chapman, G.A. and D.L. Shumway. 1978. Effects of sodium pentachlorophenate on survival and energy metabolism of embryonic and larval steelhead trout. Pages 285-299 in K.R. Rao (ed.). Pentachlorophenol Chemistry, Pharmacology, and Environmental Toxicology. Plenum Press, New York. 

Gupta, P.K. and V.S. Durve. 1984. Evaluation of the toxicity of sodium pentachlorophenate, pentachlorophenol and phenol to the snail Viviparus bengalensis (L.). Arch. Hydrobiol. 101 469 475. 

Gupta, P.K. and P.S. Rao. 1982. Toxicity of phenol, pentachlorophenol and sodium pentachlorophenate to a freshwater pulmonate snail Lymnaea acuminata (Lamarck). Arch. Hydrobiol. 94 210-217. 

Haque, A. and W. Ebing. 1988. Uptake and accumulation of pentachlorophenol and sodium pentachlorophenate by earthworms from water and soil. Sci. Total Environ. 68 113-125. 

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