ABSTRACT
Laboratory work and chemical testing involves procedures that could contaminate the air inside occupied spaces. The nature of the contaminants varies widely: high humidity from steam baths, odors from hydrogen sulfi de analyses, corrosion capabilities of alkalies and acids, solubility of acetone, explosive properties of perchloric acid, health hazards of bacteriological aerosols, and poisonous properties of nickel carbonyl. Ideally, best procedure is not to emit; but the next best is to remove or exhaust directly and as close to the point of origin for safety of laboratory personnel and protection of property.
