Cross-infection by contaminated equipment is a potential hazard associated with conscious sedation with nitrous oxide and oxygen . Nosocomial infections have occasionally been linked wih the use of unsterile inhalation devices; microbial contamination of sterile nasal hoods routinely occurs during administration of nitrous oxide; and in vitro experiments indicate that subsequent use of contaminated nasal masks may lead to aspiration of microorganisms. Although the incidence of respiratory disease after such contamination is unknown, it is clear that disinfection of the nitrous oxide apparatus between patients is desirable. A simple cleaning method involving alkaline glutaraldehyde is described that provides adequate disinfection of the rubber goods used in the administration of gas. Superiority of this technique over previously recommended cleaning methods is shown.