Combined chronic toxicity and carcinogenicity studies of morpholine oleic acid salt in B6C3F1 mice

Morpholine oleic acid salt (MOAS) was administered to groups of 50 male and 50 female B6C3F1 mice in the drinking-water at levels of 0, 0.25 and 1.0%. Both sexes given 1.0% MOAS and females given 0.25% showed growth retardation. Significant increases in blood-urea nitrogen concentrations were only observed in the 1.0% male group. The incidence of squamous-cell hyperplasia of the forestomach epithelium was significantly higher in the males given 1.0% than in the controls. The male mice given 0.25% MOAS had a significantly reduced incidence of hepatocellular carcinoma in comparison with the control group and this trend was indicated also in the 1.0% group. This experiment did not demonstrate any carcinogenic effect of MOAS in mice at levels up to 1.0% in the drinking-water.