Some of the issues surrounding the indoor air quality (IAQ) problems presented by science labs are discussed. Described are possible contaminants in labs, such as chemicals and biological organisms, and ways to lessen accidents arising from these sources are suggested. Some of the factors contributing to comfort, such as temperature levels, are explored, and an overview of exposure standards for air contaminant levels are discussed. Recommended control methods to avoid IAQ problems include eliminating or reducing the use of potentially harmful chemicals such as ether and mercury; ensuring that room ventilation meets government standards; and using hoods in labs to vent harmful vapors. Various laboratory hood exhaust systems are described and recommendations for hood placement are provided. It is emphasized that maintenance and sound operation policies are needed to ensure proper ventilation and that labs should use negative pressure whenever production of contaminants may occur. An overview of laboratory hood performance is provided. Others control methods include the proper storage of chemicals, careful disposal of laboratory waste, and implementation of a chemical hygiene plan. (Contains 1 table, 3 figures, and 14 references.) (RJM)