Which air purifying respirator has a PF of 10?

The correct answer is the half mask respirator, which is known to have a protection factor (PF) of 10. This PF indicates that the respirator can provide a tenfold increase in protection against airborne contaminants compared to not wearing any respiratory protection.

Half mask respirators cover only the nose and mouth, relying on a snug fit to create a seal with the wearer's face. This effective fit allows the respirator to filter out particulates and some gases, effectively lowering the concentration of harmful substances inhaled by the wearer.

In contrast, full face piece respirators generally offer a higher protection factor as they cover the entire face, providing additional protection for the eyes and allowing for a superior seal. Powered Air-Purifying Respirators (PAPRs) that have half mask configurations can achieve a higher PF than basic half masks because they use a battery-powered blower to push filtered air into the breathing zone, enhancing the protective capability beyond what a non-powered half mask can offer.

Supplied air half masks are intended to be used in non-recirculating systems where clean air is supplied from a source outside the work area. These systems typically do not have a designated PF since they do not rely on the filtration principle but rather on providing