It is essential in the midst of the COVID-19 pandemic to take adequate measures to protect oneself and others. The simplest method to do so is through the use of a face mask, the most important barrier to prevent infection from coronavirus.
The reason face masks are so important is due to their ability to prevent the wearer’s mucous membranes in the mouth and nose from exposure to harmful fluids such as airborne droplets from coughing or sneezing. The level of protection provided by a mask depends upon how much penetration through the material there is. Obviously the mask should cover the mouth and nose for proper protection, but it is equally important to ensure that the mask fits snugly and is changed at regular intervals. For true protection from COVID-19 it is recommended to use an FFP2 or equivalent particulate respirator. Face masks, including Civil Protective masks, Type IIRs and everything in between do not adequately protect against airborne particles.
Unfortunately, even with the growing demand and appreciation for face masks and respirators, very few people properly understand what it is they’re wearing or how it works. This lack of knowledge is critical, as both your health and that of the people around you may depend upon it.
Applying a face mask:
Below are some of the basic terms you should familiarise yourself with regarding masks and respirators.
Bacterial Filtration Efficiency (BFE)
A measure of the filtration efficiency of a mask using viable particles that vary in size from 1 to 5 micrometres (typically live bacteria). For comparison, human hair is on average between 60-80 micrometres thick.
Particle Filtration Efficiency (PFE)
A measure of the filtration efficiency of a mask using non-viable particles that range in size from 0.1 to 1 micrometres. HIV and the Tuberculosis bacteria are approximately 0.1 and 1.0 micrometres, respectively.
Which is better
A higher BFE or PFE rating? PFE is always the better measure of a masks usefulness. If there are two masks, one with BFE of 95% and one with PFE of 95%, always pick the PFE mask. A filter that will block 0.1 micrometre particles will also block 1 micrometre particles, but not vice-versa. Do not be misled by a high BFE/PFE rating without knowing the particle size upon which it is based.
What is the importance of fluid resistance?
In a clinical environment, it is very important that the mask you wear is fluid-resistant unless you are only performing an examination. The same applies for carers for vulnerable demographics such as the elderly or immunocompromised. A fluid-resistant mask does not permit blood or other potentially infectious materials like mucous to pass through to reach the skin, nose, mouth, or other mucous membranes under normal conditions of use.
What is Delta P?
Delta P is a combination of the Greek letter Δ (meaning change of, pronounced Delta) and Pressure (P). It measures the breathability of the mask by the difference in air pressure on both sides of the mask during breathing. The lower the number, the better the breathability; the higher the number, the higher the level of filtration efficiency. For masks that are intended to be used repeatedly better breathability is useful, but for higher levels of protection you should prioritise filtration efficiency.
How often should I change my mask? At the very least, once per day. The more often you can change your mask the more protected you will be, but supplies/costs may not permit. Remember, even a mask at half effectiveness due to wear is better than no mask at all.
The importance of a face mask cannot be overstated, nor can knowing how to wear one properly. Always use sanitiser after removing and disposing of a mask, the same as you would with any protective equipment. Know what you are wearing, and know the level of protection it provides. Wearing a mask does not make you immune to catching COVID-19, so you should act as if you aren’t wearing one and continue to observe social distancing and frequently wash hands and face.