A whisker's more protection for clean-shaven mask wearers
Clean-shaven frontline and professional workers may reap slightly better protection from some styles of face masks according to a new study. But bearded or not, the key to pandemic safety is getting a proper fit.
The study, commissioned by Corrections Canada, was carried out by Sherri Ferguson, Director of Simon Fraser University’s Environmental Medicine and Physiology Unit. Ferguson and her team were tasked with analyzing the efficacy of nine different facial masks and respirators—from full face respirator masks with self-contained breathing apparatus (SCBA) to the simple N95 mask used in care facilities—on men who were non-bearded, fully bearded and semi-bearded.
Under current regulation in Canada, based on the Canadian Standards Association (CSA) standard, one must be clean-shaven when fit-testing and wearing a respirator (OHS Regulation 8.39). However, the study demonstrated that such standards may not always be necessary.
“Our study showed that the ‘pass rate’ for many masks was not affected by facial hair, and so from a human rights standpoint, some people who do not shave for cultural reasons may still pass a fit test and be able to have protection," says Ferguson.
In each case, the mask pass rate was determined by comparing the particle count in the ambient air (surrounding the outside of the mask) with the particles inside the mask. The higher the pass rate, the more particles are filtered.
Fit testing in progress during the study.
Not surprisingly, the full-face respirator-style masks with self-contained breathing apparatus offered the best protection with a 98 per cent pass rate among all participants. While pass rates for other styles varied, those for the simple N95 half-mask used by professionals were low regardless of having facial hair or not.
“If you can’t get a proper seal on a mask, there’s not much point to using one,” says Ferguson, who carried out earlier tests on pilots with beards and mask use for Air Canada. “The N95 mask is designed to filter 95 per cent of particulate when worn properly but we found that less than half the participants achieved a proper seal in order to attain that percentage of filtration.”
Ferguson says that a fit testing program is key to ensuring good use and application of all face masks, and strongly recommends that frontline users conduct a seal test each time they don a mask, especially when using an N95.
She says studies that could simulate a variety of workplace conditions over a prolonged period of time would be beneficial to further understanding how facial hair impacts protection.
The study will shortly undergo peer-review for publishing.