A non-sterile, refillable container (e.g., a canister) intended to be placed in an anaesthesia unit/workstation breathing circuit for the removal of carbon dioxide (CO2) exhaled by the patient. It is filled with an appropriate carbon dioxide absorbent (e.g., granules of treated soda lime), directly or via a single-use absorbent cartridge, to chemically remove CO2. A drain may be included to channel water accumulated from expired-gas moisture or other source. This is a reusable device.