A self-contained breathing apparatus is a type of respiratory protective equipment. It provides the user with a supply of breathable air from an independent source, typically a cylinder of compressed air or oxygen. These devices fully enclose the face, offering a secure seal against the environment and protecting the eyes and respiratory system from contaminants. For example, firefighters routinely employ this equipment to enter burning buildings and breathe safely in environments filled with smoke and toxic gases.
The importance of such apparatus lies in its ability to enable safe operation in immediately dangerous to life or health (IDLH) atmospheres. This includes environments with oxygen deficiency, high concentrations of toxic substances, or airborne particulate hazards. Historically, these systems have been crucial in mining operations, industrial settings involving hazardous materials, and emergency response scenarios, preventing countless injuries and fatalities.