Air-Supplied Respirators

There are several types of air supplied respirators: continuous flow, pressure demand, abrasive blast, self-contained breathing apparatus (SCBA), and self-contained-self-rescuer (SCSR).

Continuous Flow -  A respirator that maintains air flow at all times, rather than only on demand.  However, this type of respirator may not maintain positive pressure within the mask at all times.  Negative pressure conditions may occur during inhalation involving strenuous activity.

Pressure Demand -  A respirator that maintains a positive pressure within the facepiece, in relation to the immediate surrounding environment, during both exhalation and inhalation.

Abrasive Blasting -   An atmosphere-supplying respirator to be used when performing abrasive blasting (sandblasting) operations. These respirators are equipped with additional devices designed to protect the wearer's head and neck from abrasion and impact from rebounding materials as well as ensure that the user maintains visual acuity.

Self-Contained Breathing Apparatus -  An atmosphere-supplying respirator for which the breathing air source is designed to be carried by the user.