A self-contained breathing apparatus or SCBA is a device worn by workers to provide portable, breathable air in an IDHL-environment.

An airline respirator provides a continuous supply of air to the user via a hose connected to stationary source of breathable air. Some airline respirators also integrate a small cylinder of compressed air into the system for emergency escape from a dangerous environment in case the airline hose is blocked or severed.

Escape respirators are designed for use only to egress from hazardous atmospheres within 5, 10 or 15 minutes. Some escape respirators are used in conjunction with an airline to provide a small source of air in emergencies where an airline air source is severed.