Document kYjpq31nRBrGOe05rv0gBGOJ

LEAD CHROMATE AND ZING CHROMATE PRODUCT RISK (TOXICITY) At present, "there exists moderate hut inconclusive evidence that zinc chromate is a human and experimental carcino gen; there is less evidence linking lead chromate to human cancer and slight evidence experimentally" (1), There is no evidence that either chemical will pose a carcinogenic hazard from isolated acute exposures by the oral, inhalant, or percutan eous routes. Both chromates have been classified as suspect carcinogens by Du Pont. Specific environmental data on these two chemicals are lacking. The most suitable general guide available (2) states".... it appears that the following concentrations of chromium, triva- lent or hexavalent, will not interfere with the specified beneficial uses: a. Domestic water supply......................... 0.05 mg/1 b. Stock and wildlife watering _____...... 5.0 mg/1 c. Fish life ......................................................................... 1.0 mg/1 Other aquatic life ............................ 0.5 mg/1 REFERENCES s* 1. <T, :F. Morgan, "Background of consideration of carcinogenicity of lead chromate and zinc chromate pigments," memorandum dated April 14, 1975" (HL File C-01522). 2. J. E. McKee and H. W. Wolf, eds., Water Quality Criteria, 2nd ed., The Resources Agency of California, State Water Quality Control Board, Sacramento, California 1963, pp. 163-166 (A later edition. Water Quality Criteria 1972 (EPA) supports the recommended drinking water level Of 0,05 mg/1 with additional literature references - see p. 62). DUP050292193 DUP050292194 N 3X8X1.01 4 DUP050292195 N 31811.02 DUP050292285 N 31811.03