Equipment that enables a person to get a supply of oxygen in an environment where little or no air exists, e.g. a smoke-filled compartment.
Two types are in use; the smoke helmet and the self-contained unit using air cylinders. The smoke helmet covers the head and is connected to an air hose. A hand-operated pump supplies the air. The self-contained unit consists of one or two cylinders of compressed air kept in a harness, which is carried on the back. The high-pressure air is fed through a reducing valve and then to a demand valve fitted into a facemask.