An Oxygen Breathing Apparatus or OBA is a rebreather. It is used primarily in firefighting. Its oxygen is generated by chemicals contained in the green canister, which is inserted at the base of the breathing device. [1] The canister uses potassium superoxide as both a CO2 scrubber and an O2 generator. A sodium chlorate candle in the base generates additional oxygen when first beginning use. [2]
As of early 2001, the US Navy has been replacing the OBA for firefighting with the SCBA. The SCBA is more cost-effective than the OBA, and also does not produce hazardous waste, a problem with the chemical oxygen generation system. [3]