Equipment used for the administration and monitoring of anesthesia of patients must be maintained in optimal working order to ensure patient safety as well as convenience and economy of operation. After use, disinfection, sterilization, and cleaning of breathing circuits of anesthesia machines and mechanical ventilators is essential to avoid cross-contamination. Common methods of sterilization involve the use of glutaraldehyde, heat, or ethylene oxide. The last agent is strongly recommended in those situations where heat might damage the materials or equipment being treated. Mechanical checking of anesthesia machines is necessary to make sure that they can be relied upon to deliver known amounts of oxygen, nitrous oxide, and inhalation anesthetic agents. Ideally, electronic monitoring devices should be kept in proper working order by a daily preventive program by trained, biomedical technicians.