This testimony considered the work conducted by NIOSH in the area of indoor air quality. The quality of indoor air often worsened soon after energy conservations measures were enacted at many business places following the Arab oil embargo in the 1970s. Concurrently, new office technologies in some cases presented chemical and physical hazards to the office staff as well. Of the 1200 NIOSH Health Hazard Evaluations performed between 1971 and 1978, six were to study indoor air quality problems, or 0.5 percent of the total number of studies. Between 1978 to 1980 this percentage increased dramatically to 7.4 percent of the total and since 1980 indoor air quality studies have accounted for 12 percent of the total Health Hazard Evaluation studies. Such pollution arises from human metabolic activity, smoking, structural components of the building and contents, biological contamination, office and mechanical equipment, and outside air pollutants that enter the building. In more than half the investigations, lack of adequate ventilation was the cause of the complaints. In 20 to 25 percent of the cases, sources inside the building were identified as the major generators of indoor air contaminants. These sources included duplicators, signature machines, blueprint copiers, boiler additives, pesticides, cleaning compounds, tobacco smoke and combustion gases, building materials, lined ventilation ducts, silicone caulking and curing agents. Some major examples of governmental and nongovernmental research along this same line of study were highlighted.