Abstract
Pollution of the atmosphere with halothane has been measured during general anaesthesia for outpatients undergoing dental extractions. The level of contamination was far in excess of that recorded in surgical operating theatres, and halothane was inhaled at similar concentrations by both the anaesthetist and the dental surgeon. The room air-changing system and a local fan had little effect on contamination. Scavenging devices on the exhalation valve of the anaesthetic circuit were only moderately effective in reducing the concentration of halothane in the atmosphere.