Assessment of the mutagenic effect of 1,1-dimethyl hydrazine

The mutagenic effect of the rocket fuel 1,1-dimethyl hydrazine has been studied experimentally and compared to the well-recognized mutagene N-nitroso dimethylamine. The manifestation of the effect for both compounds was disclosed through a significant increase in the chromosome aberration frequency in the bone marrow cells of intoxicated rats. The levels of chromosome aberrations induced by 1,1-dimetyl hydrazine were studied following both single (1 h) and repeated doses (daily for 10 consecutive days) by inhalation (205–1028 mg/m3) and gavage (5.4–26.8 mg/kg) administration, respectively. For comparison N-nitroso dimethylamine were administered by inhalation (2 h/daily for 10 consecutive days) and by gavage in concentrations of 2.4–48 mg/m3 and 1–30 mg/kg, respectively. A clear dependence of concentration as well of time was disclosed. The BenchMark Dose approach was employed to derive guideline doses for the two compounds, the implications towards human health being discussed.