- Email: [email protected]
1243. Dimethylpolysiloxanes exonerated
PROCESSING AND PACKAGING CONTAMINANTS
263
Ethylene dibromide I is used as a food fumigant. It is known to exercise detrimental effects on laying hens and on bulls (Cited in F.C.T. 1965, 3, 864). In common with many alkyl and aryl halogenated compounds, I was metabolized to the mercapturic acid following administration of a dose of I00 mg/kg to rats (route unspecified). S(fl-hydroxyethyl)-N-acetylcysteinewas excreted in the urine together with lesser amounts of S(fl-hydroxyethyl) cysteine and inorganic bromide, but no attempt was made to estimate the amount of I metabolized. The same metabolites were detected in the urine after administration of ethylene dichloride and bromohydrin.
1242. Hazards of industrial exposure to methylene dichloride v
.
Kuzelova, Marie & Vlasfik, R. (1966). Vliv metylenchloridu na zdravt pracujicich p~-i wjrob~ filmov6 frlie a sledov~ni kyseliny mraven~i jako metabolitu metylenchloridu. "The effect of methylene-dichloride on the health of workers in production of film-foils and investigation of formic acid as the methylene-dichloride metabolite." Pracovni Ldk. 4, 167. Methylene dichloride (I) finds considerable use as an industrial solvent in extraction processes, particularly where high volatility is required. Among a group of 33 Czechoslovakian workers exposed to I for an average of 2 yr at concentrations sometimes exceeding 500 ppm, respiratory and gastro-intestinal disorders similar to those already described (Am. ind. Hyg. Ass. J. 1965, 26, 633) were reported. The authors also claim to have identified formic acid as a metabolite of I in the urine of "most" of the exposed workers. [No allowance has been made for levels of endogenous formic acid which may be present in urine. Nor is there any explanation of why only 35 of the 59 urine samples studied gave a positive reaction in the test. As a last straw, the test employed is not specific for formic acid and could demonstrate with equal facility the presence of other urinary compounds containing the keto group, e.g. aldehydes, ketones etc. Hence, this study has far from proved that formic acid is a metabolite of methylene dichloride.]
1243. Dimethylpolysfloxanes exonerated Carson, S., Weinberg, M. S. & Oser, B. L. (1966). Safety evaluation of Dow Corning 360 Fluid and Antifoam A. Proc. scient. Sect. Toilet Goods Ass. No. 45, p. 8. Polysiloxanes find wide use as anti-foam agents in a variety of cosmetics and toilet formulations as well as in the manufacture of many foods and beverages. Three dimethylpolysiloxanes (I; Dow Coming Antifoam A and Dow Coming 360 Fluid of 50 and 350 cS viscosity) fed to rabbits and rats at dietary levels of 1 ~o for 8 and 12 months respectively had no adverse effect with regard to growth, haematology, liver and kidney function tests and organ weights and pathology. Since diets containing I and supplemented with cholesterol (II) have previously been reported to induce widespread liver and kidney changes in rabbits but not in rats, a comparison was made of the effects seen in rats and rabbits placed on a basic diet or on diets containing I, II or I + I I . Pathological changes characteristic of hypercholesterolaemia occurred with equal intensity and incidence in rabbits fed II or I +II, thus exonerating I from the effects now attributed to II alone. Since the rat is resistant to experimentallyinduced hypercholesterolaemia, only marginal changes occurred but again no difference was seen between groups on II or I +II. 1244. A plasticizer of low toxicity MacFarland, H. N. & Punte, C. L., Jr. (1966). Toxicological studies on tri-(2-ethylhexyl)phosphate. Archs envir. Hlth 13, 13.
263
Ethylene dibromide I is used as a food fumigant. It is known to exercise detrimental effects on laying hens and on bulls (Cited in F.C.T. 1965, 3, 864). In common with many alkyl and aryl halogenated compounds, I was metabolized to the mercapturic acid following administration of a dose of I00 mg/kg to rats (route unspecified). S(fl-hydroxyethyl)-N-acetylcysteinewas excreted in the urine together with lesser amounts of S(fl-hydroxyethyl) cysteine and inorganic bromide, but no attempt was made to estimate the amount of I metabolized. The same metabolites were detected in the urine after administration of ethylene dichloride and bromohydrin.
1242. Hazards of industrial exposure to methylene dichloride v
.
Kuzelova, Marie & Vlasfik, R. (1966). Vliv metylenchloridu na zdravt pracujicich p~-i wjrob~ filmov6 frlie a sledov~ni kyseliny mraven~i jako metabolitu metylenchloridu. "The effect of methylene-dichloride on the health of workers in production of film-foils and investigation of formic acid as the methylene-dichloride metabolite." Pracovni Ldk. 4, 167. Methylene dichloride (I) finds considerable use as an industrial solvent in extraction processes, particularly where high volatility is required. Among a group of 33 Czechoslovakian workers exposed to I for an average of 2 yr at concentrations sometimes exceeding 500 ppm, respiratory and gastro-intestinal disorders similar to those already described (Am. ind. Hyg. Ass. J. 1965, 26, 633) were reported. The authors also claim to have identified formic acid as a metabolite of I in the urine of "most" of the exposed workers. [No allowance has been made for levels of endogenous formic acid which may be present in urine. Nor is there any explanation of why only 35 of the 59 urine samples studied gave a positive reaction in the test. As a last straw, the test employed is not specific for formic acid and could demonstrate with equal facility the presence of other urinary compounds containing the keto group, e.g. aldehydes, ketones etc. Hence, this study has far from proved that formic acid is a metabolite of methylene dichloride.]
1243. Dimethylpolysfloxanes exonerated Carson, S., Weinberg, M. S. & Oser, B. L. (1966). Safety evaluation of Dow Corning 360 Fluid and Antifoam A. Proc. scient. Sect. Toilet Goods Ass. No. 45, p. 8. Polysiloxanes find wide use as anti-foam agents in a variety of cosmetics and toilet formulations as well as in the manufacture of many foods and beverages. Three dimethylpolysiloxanes (I; Dow Coming Antifoam A and Dow Coming 360 Fluid of 50 and 350 cS viscosity) fed to rabbits and rats at dietary levels of 1 ~o for 8 and 12 months respectively had no adverse effect with regard to growth, haematology, liver and kidney function tests and organ weights and pathology. Since diets containing I and supplemented with cholesterol (II) have previously been reported to induce widespread liver and kidney changes in rabbits but not in rats, a comparison was made of the effects seen in rats and rabbits placed on a basic diet or on diets containing I, II or I + I I . Pathological changes characteristic of hypercholesterolaemia occurred with equal intensity and incidence in rabbits fed II or I +II, thus exonerating I from the effects now attributed to II alone. Since the rat is resistant to experimentallyinduced hypercholesterolaemia, only marginal changes occurred but again no difference was seen between groups on II or I +II. 1244. A plasticizer of low toxicity MacFarland, H. N. & Punte, C. L., Jr. (1966). Toxicological studies on tri-(2-ethylhexyl)phosphate. Archs envir. Hlth 13, 13.