When respiratory protective equipment is used, it must be capable of providing adequate protection to the user. The Association of Individual Protection Equipment Companies (ASEPAL) has warned, during the crisis caused by COVID-19, of the risks posed by a poor adjustment of respiratory protection equipment (RPE).
A mask that does not fit properly to the face and does not achieve a perfect facial seal, does not guarantee adequate protection no matter how effective the filter is. A good face seal allows the air we breathe to enter only through the filter, where it filters and protects us. If there are gaps around the edges of the mask, “polluted” air will pass through the gaps and easily reach our lungs leaving the way for all kinds of particles, including viruses, above the levels allowed by EN149: 2001 + A1: 2009.
It is common to see workers wearing masks and safety spectacles with fogged lenses. This situation is due to the fact that the hot air that we expel when we breathe escapes upwards due to a poor fit of the mask in the nose-bridge area. This gives us a conclusion: if the air leaves through a leak zone when we exhale, when we inhale, the air will also enter through the same place without going through the filter, leaving us partially or totally unprotected.
In general, the narrower the face, the more difficult it is to achieve a perfect facial fit. An article in El País from last April 2020, during the first wave of Covid-19 infections, assures that “three out of every four infected health professionals are women.” This can be explained by the fact that the majority of masks on the market are excessively large for smaller faces and, therefore, expose the users who use them to contagion exponentially.
On the other hand, in the male sector, wearing a beard makes it impossible to properly seal the face. The user will not be able to get the mask to fit close enough to their face to keep total inward leakage below maximum safe levels. The larger the beard, the less or no efficacy of a mask.
The COSHH (Control of Substances Harmful to Health) in some countries of the European Union, such as the United Kingdom, oblige each operator to undergo a facial adjustment test that certifies adequate respiratory protection. Not only does the mask have to have a CE certificate, but the mask must be suitable for the user.
These tests are derived from the American OSHA directive 29 CFR 1910.134.
A facial fit test is mandatory for people who are going to use respiratory protective equipment for the first time. Fit testing should be repeated when there is a change in both the EPRs and the people (a major change in weight, for example) who will use them, as a variation in the user’s circumstances could reduce protection and endanger your safety.