1,3-butadiene, which is used extensively in the synthetic rubber industry, is a highly reactive, potentially explosive compound, presenting particular problems for the design and execution of inhalation toxicity studies. Before undertaking inhalation studies with butadiene, it was necessary to develop safe systems for the generation and control of stable exposure chamber atmospheres. Infrared and gas chromatographic analytical methods were adapted for monitoring the concentration and distribution of butadiene in exposure chambers, and for analysis of known impurities, particularly, t-butyl catechol and 4-vinyl-1-cyclohexene, in atmospheres generated for inhalation tests.