This contract provides appropriately trained personnel which, together with government employees, run the on-site inhalation toxicology facility at NIEHS. Study design and priorities are established through the Project Officer. Studies are conducted to assess the toxicity of chemicals during and following exposure by the inhalation route, based on a wide range of physiological and toxicological parameters. Work is also done to improve the methods for conducting inhalation toxicology studies and for interpreting results. The capabilities of the inhalation facility are available, on a priority basis, to all NIEHS scientists.