A
self-contained breathing apparatus (
SCBA) is a device worn to provide an autonomous supply of breathable gas in an atmosphere that is immediately dangerous to life or health. They are typically used in firefighting and industry. The term
self-contained means that the SCBA is not dependent on a remote supply of breathing gas. If designed for use under water, it is also known as a scuba set. When not used underwater, they are sometimes called
industrial breathing sets. Some types are also referred to as a
compressed air breathing apparatus (
CABA) or simply
breathing apparatus (
BA). Unofficial names include
air pack,
air tank,
oxygen cylinder or simply
pack, which are mostly used in firefighting.