Sodium pentachlorophenol, effects

PCP presents a different picture from that of the lower chlorophenols and their derivatives. The corresponding dioxin shows much more stability to light than does TCDD, enough to permit its prolonged existence at low concentrations in a photoreactor. As a phenol it can directly yield dioxins, a process favored by its normal mode of application as the sodium salt. Although octachlorodibenzo-p-dioxin has much lower mammalian toxicity than TCDD (6), its formation, properties, and effects demand additional investigation. Technical preparations of PCP are frequently mixtures of tetra- and pentachlorophenols consequently, hepta-and possibly hexachlorodibenzo-p-dioxins might be expected as photolysis products in addition to the octachloro derivative. 

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. 

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. 

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. 

Deichmann, W.B., Machle, W., Kitzmiller, K.V. Thomas, G. (1942) Acute and chronic effects of pentachlorophenol and sodium pentachlorophenate upon experimental animals. J. Pharmacol. exp. Ther., 16, 104-117... 

Kehoe, R.A., Deichmaim-Gruebler, W. Kitzmiller, K.V. (1939) Toxic effects upon rabbits of pentachlorophenol and sodium pentachlorophenate. J. ind. Hyg. Toxicol., 21, 160-172... 

Other compounds enhance PCB photodegradation including sodium borohydride (44)/ alkaline alcoholic solutions (45) and aqueous suspensions of titanium dioxide (46), a system also effective in treating pentachlorophenol (47). 

Zielke and Pinnavaia [106] compared the adsorption of several chlorinated phenols by pillared montmorillonite and Laponite (Laponites are synthetic hectorite-like materials). Pentachlorophenol, which is the strongest Brensted acid, is best adsorbed by the polyoxoaluminum derivative and less by the polyhydroxo form. The adsorption capacity decreases strongly with increasing solution pH (from pH = 4.7 to 7.4), showing that this pollutant is adsorbed in undissociated form. The effectivity of the smectites (at pH = 4.7) is polyoxoaluminum laponite > polyhydroxoaluminum laponite > polyoxoduminum montmorillonite > polyoxochromium montmorillonite. Sodium laponite and montmorillonite show no tendency to adsorb the pollutant from aqueous solution. 

---