Inward Leakage in Tight-Fitting PAPRs

الملخص EN

A combination of local flow measurement techniques and fog flow visualization was used to determine the inward leakage for two tight-fitting powered air-purifying respirators (PAPRs), the 3M Breathe-Easy PAPR and the SE 400 breathing demand PAPR.

The PAPRs were mounted on a breathing machine head form, and flows were measured from the blower and into the breathing machine.

Both respirators leaked a little at the beginning of inhalation, probably through their exhalation valves.

In both cases, the leakage was not enough for fog to appear at the mouth of the head form.