Objectives-The aim was to examine the cause specific mortality of men exposed to hydrazine.

Methods-Hydrazine was produced at a factory in the east midlands between 1945 and 1971.

The cohort of all 427 men who were employed there for at least six months with varying degrees of occupational exposure to hydrazine were followed up until the end of January 1992.

Results

By the end of July 1982 49 deaths had occurred and the observed mortality was found to be close to that expected at each level of exposure.

By the end of January 1992 a further 37 deaths had occurred.

Again the observed mortality was close to that expected for all causes and also for lung cancer, cancers of the digestive system, other cancers, and all other causes, irrespective of the level of exposure.

Conclusion-The results weigh against there having been any material hazard of occupational exposure to hydrazine.

The small number of men studied means, however, that a relative risk as high as 3-5 for lung cancer cannot confidently be excluded.