This contract provides inhalation exposure capability for the research program of the National Toxicology Program and the intramural research program of the National Institute of Environmental Health Sciences (NIEHS). The contract provides a site for the NIEHS inhalation exposure facility and for the complete operation of the facility. The contract requires both operating the exposure facility and conducting animal research on the inhalation toxicology of environmental chemicals. Specific studies aredesigned by government researchers and presented as research protocols to be executed by the contractor. The contract provides for the measurement of a variety of experimental end points and for the delivery of treated animals and biological samples to government researchers.