Effects of N-nitrosodiethanolamine and 1,1-diethanolhydrazine in Syrian golden hamsters.

N-Nitrosodiethanolamine (NDEA) and 1,1-diethanolhydrazine (DEH) were synthesized and injected subcutaneously weekly in male and female Syrian golden hamsters. The total NDEA dose per hamster was approx. 15 g/kg body wt. applied in either 7 or 27 subdoses. DEH was administered in 78 applications to two groups yielding total doses of 1.1 g and 273 mg/kg body wt. Under these conditions, DEH did not show a specific demonstrable carcinogenic effect. However, within 78 weeks after the first application, 39 out of 56 hamsters treated with NDEA developed tumors. Primarily, neoplasms of the nasal cavity and tracheal tumors were observed, as well as a few hepatocellular adenomas and sarcomas at the injection site. These findings and those of the earlier study on carcinogenicity of NDEA in rats raise concern as to the safety for human consumption or industrial use of products with the potential for forming NDEA.