EN 137 sets the requirements for self-contained breathing apparatus. The wearer carries a compressed-air cylinder on their back, from which a reducer and demand valve feed clean air to a full face mask. It is the highest level of respiratory protection available.
Types
- Type 1
- Industrial use — limited thermal requirements
- Type 2
- Firefighting use — includes a 60-second exposure to flame at 950 °C
Main components
- Cylinder — typically 6 or 6.8 litres at 300 bar; duration depends on workload and is usually 25–45 minutes.
- High-pressure reducer and a demand valve maintaining positive pressure inside the mask.
- Pressure gauge and a warning whistle that sounds before the supply runs out.
- Full face mask to EN 136 Class 3.
The apparatus requires regular servicing, periodic hydrostatic testing of the cylinder and mandatory user training. It must never be used without that training.