There is substantial confusion over the effectiveness of face masks and respirators against Covid-19. While cloth masks offer varying and often poor protection, surgical masks that meet ASTM standards (EN 14683 in Europe) are quite good and their performance can be improved with mask braces that reduce air leakage. Respirators are far superior but it is important to purchase them from reputable suppliers.

Another misconception is that, as the virus is much smaller than the 0.3-micron challenge particles against which respirators are tested, respirators (and surgical masks) are not effective. 0.3 microns is however close to a worst-case scenario because filtration efficiency increases as particle sizes decrease. This is counterintuitive but the reason involves Brownian motion that throws the particles into the filter medium.

Learning Objectives:-

Know that, contrary to misinformation that is circulating on the Internet and elsewhere, surgical face masks that conform to ASTM standards and respirators that meet NIOSH standards offer substantial protection against contagion. They must however be used properly, and buyers must be very wary of counterfeit respirators.

Areas Covered:-

• Even cloth face masks offer substantial, albeit far from ideal, protection. The monetary return in terms of avoided health care costs is enormous.
• Experiments performed in 1918 (in response to the Spanish Flu pandemic) offer substantial information about contagion. While the ordinary conversation will not propel infectious material much further than 4 or 5 feet, a cough can propel it to 10 feet or more and also propel it through ordinary masks.
• Placement of an ordinary mask over a respirator with an exhalation valve will protect others while the respirator offers excellent protection to the wearer.
• Bacterial filtration efficiency is assessed per ASTM F2100 - 19e1 "Standard Specification for Performance of Materials Used in Medical Face Masks." This relates to surgical masks and not respirators.
• Respirators must meet the requirements of 42 CFR Part 84 (FFP, Filtering Face Piece, in Europe). If a workplace requires respirators, then it must have a respiratory protection program (including, among other things, worker assessment and training) as opposed to just issuing the respirators. The 0.3-micron challenge particles used to test respirators meanwhile represent close to a worst-case scenario because filtration efficiency actually goes up for smaller particles.
• Improvised masks are more problematic due to varying materials of construction and also not being tested like surgical masks and respirators.
• Beware of counterfeit respirators; this is a major problem.
• Eye protection may also offer protection against contagion if the virus can enter through the eyes (mucous membranes).

Why Should You Attend:-

The highly contagious omicron variant of Covid-19 means it is still a problem despite the availability of vaccination. There is considerable conflicting information about personal protective equipment (PPE) for Covid-19, e.g. to the effect that face masks do not protect the wearer and/or others and that the virus is so small that it will go through respirators. This webinar will clarify what does and does not work, noting that cloth masks of unknown quality offer limited protection while surgical face masks that meet ASTM standards offer excellent protection, and respirators (such as N95) even better.

Who Should Attend:-

All people with OH&S responsibilities, and also individuals