Mask Testing Fallacies

Vincent J. Curtis

13 Nov 20

The CBC News show Marketplace reported on some testing it had done on twenty-four  different masks. The testing was to evaluate of the filtration ability of the various designs and materials, and was done in accordance with NIOSH (National Institute for Occupational Safety and Health) protocols.

It is admirable that finally someone is evaluating for effectiveness the masks mandated by various governments.  It is my contention that the masks mandated are generally ineffective, and have the drawback of imparting a false sense of security.  Finally, the media is looking into the mask matter seriously.

The CBC report, however, contains two fallacies.  The first is that the test was of the effectiveness of the filtration material, not of the mask-as-worn.  While some materials performed quite well, if the mask is not well-fitting and allows air to follow the path of least resistance and pass around the filtration material, the mask is to that degree rendered ineffective.  Masks have to be close-fitting to work.

The second fallacy was the discounting of masks that have by-pass valves.  These valves allow exhausted air to by-pass the filtration portion of the mask and enter the atmosphere  unfiltered.  These masks are allegedly bad because they don’t protect the people around the wearer.  The fallacy is that the best masks, the canister-type respirators, and the N95 industrial dust masks – recognized as the best protection for the wearer – utilize these by-pass valves.  By the CBC standard, the NIOSH approved masks are bad because they don’t protect people around you from you.

It is good that finally the media are examining masks in light of the second wave, which continues to rise.  The best industrial masks provide the best protection for you, combining good filtration with a close fit to the face.  Now that it is recognized that the virus is transmitted as a dry dust, industrial dust masks should be turned to as the best means of protecting yourself.

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