A device intended to collect excess anaesthetic, analgesic, or trace gases or vapours from a patient's breathing system, ventilator, or extracorporeal oxygenator, and to expel them by means of an exhaust system. Some types may be connected to a special mixing box for the removal of orthopaedic bone cement gases. This device is an independent unit and may be used in association with various kinds of devices and systems. This device is also known as an anaesthetic gas scavenging system (AGSS).