RE: Respirators with beards

["Frame, Paul" <FRAMEP@ORAU.GOV>]

Paul:

I have one or two old, but possibly helpful references: "Facial Hair and
Respirator Fit: A Review of the Literature" Am. Ind. Hygiene Society Journal
Apr 1998 49 (4):199-204 by Stobbe, daRoza and Watkins. Quoting from it
(selectively of course) "All but two of the fourteen studies found that in
the presence of facial hair, face seal leakage increases from 20 times to
1000 times" .."In the other two studies, one completed with positive
pressure SCBAs and the other completed in the workplace, no statistically
significant leakage differences were found." "For modern, full-face piece
positive pressure respirators, the answer remains ambiguous."

The thing of interest is that the only large study involving positive
pressure tight fitting respirators apparently found that protection was just
as great with a full beard as with a clean shaven individual. 

The study in question is da Rosa et al "The effect of beard growth on
respiratory protection: SCBA and Air-purifying respirators under simulated
work conditions" The study was presented at the 1987 American Industrial
Hygiene Conference. This was probably published somewhere, but I have no
information about that.

Much of the material from this study might have appeared in "Powered
Air-Purifying Respirator Study Final Report" UCRL-53757, July 1986, daRoza,
R.A., Cadena-Fix, C.A., Kramer, J.E. Lawrence Livermore National Laboratory.

The latter report evaluated an MSA half mask PAPR. At all flows (60-210 lpm)
the fractional penetration (leakage) for the clean shaven individual was
approximately 0.0007 - 0.0003.  For the individuals with a full beard, the
fractional penetration varied from 0.01 - 0.0002 - the higher the flow rate,
the lower the penetration.  At the highest flow rate, the penetration was
lower with a full beard.

Regards

Paul Frame
Professional Training Programs
ORAU
framep@orau.gov
http://www.orau.gov/ptp/ptp.htm
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