Powered Air-Purifying Respirators

PARPs abbreviations of Powered Air-Purifying Respirators, class of respiratory protective devices used by industrial and medical workers to protect themselves against noxious fumes or biological hazards. PAPRs are versatile and utilized in a diverse range of settings. From industrial sites, welding, painting, and smelting, to healthcare settings with dentists, surgeons, and vets.
They do not protect anyone but the wearers, unlike many masks that can provide a degree of protection to bystanders from wearers who happen to be infected themselves.

A typical PAPR consists of a helmet or hood, an airline, and usually, a belt-mounted power pack/blower/filtering unit, set up for welding and grinding includes a welding helmet with an inlet for connecting to a supply hose from the power pack. The helmet might include some additional draping to maintain a degree of closure of the helmet space.

The use of a PAPR requires an ambient air atmosphere and is unsuited for use in oxygen-deficient areas or in environments considered immediately dangerous to life or health (IDLH).
The differences between PAPRs and other industrial respirators consist in the positive vs. negative pressure element, and its filtration capacity and efficiency. Standard respirators such as N95 masks, and a half or full-face respirators are negative air pressure which means they rely on the user’s lungs to function drawing oxygen through filter media as they breathe. Because they are negative pressure, they rely on a tight seal on the user’s face, which prevents contaminants and particulates in the ambient air from entering. Respirators that are negative pressure have a lower APF rating as the lungs cannot draw through the same capacity of ambient air compared to battery-powered respirators. Having a higher rated APF enables operators to work in hazardous environments without putting their health at risk by exposing their lungs to contaminants and particulates.
Have become popular as they provide a level of comfort and protection that have sometimes been difficult to achieve with other respirators. They deliver a positive outflow of air at all times to the wearer, as opposed to many respirators which require the wearer to draw air in, creating a negative pressure within the confines of the mask. If the respirator is not sealed properly to the wearer’s face, this negative pressure can provide a route into the mask by which harmful agents can enter.
The positive pressure produced by a PAPR somewhat solves the problem of ineffective face sealing. Headgear can range from a welding helmet to a full-face mask, or, for biohazard work, a full hood manufactured from disposable materials. Facial hair, which renders a face-sealing mask unfunctional, can still be worn using PAPR.
Careful attention to donning and doffing, sanitizing, etc. is necessary. Infectious agents can remain on components of a PAPR for some period following exposure so protocols for usage and sterilizing must be established by individual healthcare facilities. Generally, industrial hazards created while working (such as welding fumes) dissipate when the work halts. Sanitizing the equipment between runs is less of an issue there.

Because these devices promote workplace health and safety, PAPRs are heavily regulated by NIOSH in the U.S. and through ISO standards in much of the rest of the world. As recently as 2019, the National Personal Protective Technology Laboratory has been working to modify the testing and approval of PAPRs for the healthcare industry as the use of these devices becomes more prevalent there.