Escape breathing apparatus, also called escape respirators, escape sets, self-rescuer masks, emergency life saving apparatus (ELSA), emergency escape breathing devices (EEBD), and Respiratory Protective Smoke Escape Devices (RPED), are portable breathing apparatus that provide the wearer with respiratory protection for a limited period, intended for escape from or through an environment where there is no breathable ambient atmosphere. This includes escape through water and in areas containing harmful gases or fumes or other atmospheres immediately dangerous to life or health (IDLH).

Escape breathing apparatus may be air-purifying escape respirators or self-contained atmosphere-supplying escape respirators. They may use a breathing hood, facepiece or mouthpiece and nose-clip as the user respiratory interface. Atmosphere-supplying apparatus may be rebreathers with a chemical or compressed gas oxygen supply, positive pressure demand apparatus, or constant flow apparatus using high pressure compressed air. Contamination of the breathing gas may be avoided by relying on a good seal around the user respiratory interface, or by a small positive pressure relative to the surroundings.

Escape breathing apparatus are not generally intended to be used for anything other than escaping a dangerous environment. An escape-only respirator is defined as "a respirator intended to be used only for emergency exit".

Escape breathing apparatus are a class of self contained atmosphere supplying or air purifying breathing apparatus for use in emergencies, intended to allow the user to pass through areas without a breathable atmosphere to a place of relative safety where the ambient air is safe to breathe. These are ambient pressure systems, and include:

Early escape sets were often rebreathers and were typically used to escape from submarines that were unable to surface. Escape sets are also used ashore, in the mining industry, and by the military for escape from tanks.

The small open-circuit scuba Helicopter Aircrew Breathing Device has the similar purpose of providing breathing gas to escape from a ditched helicopter.

Escape breathing apparatus have the function of allowing a person working in an environment that is normally safe, enough time to escape from respiratory hazards that may occur without sufficient warning to evacuate without respiratory protection. Therefore selection relies mainly on the time required to escape, and the probability of IDLH or oxygen deficiency, rather than assigned protection factors.

Calculation of the time likely to be needed for escape and the recommended escape route is the responsibility of the employer, and should take into account the reasonably foreseeable emergencies that might require escape.