Toxicity of diethanolamine. 2. Drinking water and topical application exposures in B6C3F1 mice

Toxicology studies of diethanolamine were conducted in male and female B6C3F1 mice to characterize and compare effects of exposure in the drinking water with those caused by topical application and to compare responses in mice to those observed in rats. Each study consisted of five dose groups plus controls and the size of each group was 10 animals per sex. Doses of diethanolamine ranged from 630 to 10,000 ppm in the drinking water study (approximately equivalent to daily doses of 100-1700 mg kg-1 in males and 140-1100 mg kg-1 in females) and from 80 to 1250 mg kg-1 in the topical application study. Exposure to diethanolamine caused dose-dependent toxic effects in the liver (hepatocellular cytological alterations and necrosis), kidney (nephropathy and tubular epithelial necrosis in males), heart (cardiac myocyte degeneration) and skin (site of application: ulceration, inflammation, hyperkeratosis, and acanthosis). Cytological alterations in the liver consisted of multiple hepatocyte changes, including enlarged cells that were frequently multinucleated, increased nuclear pleomorphism, increased eosinophilia and disruption of hepatic cords. A no-observed-adverse-effect level (NOAEL) was not achieved for hepatocellular cytological alterations or for acanthosis in the skin.