While the World Health Organisation is the authority on what should and shouldn’t be worn by the general public and medical professionals, we thought we’d explain the technical differences between respirators currently being worn, rightly or wrongly, for protection against airborne particulates.
Medical or surgical mask
A medical mask will not be sufficient to protect you from airborne particulate transmission. Medical masks are used by medical professionals who maintain distance and take droplet and contact precautions. They are not designed to seal on the face, so small particles can relatively easily go around the edges and into the lungs.
Fabric Home Made Masks
Fabric masks will also not provide an effective seal, or the filtration required, to protect you from airborne transmission of particulates.
Disposable & Reusable Half Face Respirators
P2 and P3 respirators provide a level of protection against mechanically and thermally generated particles and if correctly worn and fitted, can help protect against airborne biological aerosols
It is important to note that if the replaceable filter or disposable mask is exposed to an infective particulate, the filter component or mask itself becomes a potential source of infection. While the infected filter will continue to work and capture particulates and offer the wearer protection, it should not be touched or handled without gloves and at some point, must be carefully discarded.
There is no specific service-life timeframe for these filters. In a medical type application, it will depend on the infection control decision. For a respirator used “on the street”, that may simply mean every day.
A limitation of these respirators is that they cannot be used with facial hair. Even stubble will break the negative pressure seal and will not give you the expected level of protection. To ensure these masks will offer you the desired level of protection, you will also require fit testing.
Powered Air Purifying Respirators
As per the respirators above, a powered air purifying respirator fitted with a P2 or P3 particle filter, offers protection against airborne particulate transmission.
Likewise, in a medical situation, the infection control expert needs to decide what is needed in respect of replacement, handling, and disposal of the potentially infected filter. For use on the street where there should be no significant particle load, this may mean replacing the filter every 3-6 months.
It is important to remember that contaminants are not only concentrated on the filter/cartridge itself, they can potentially also reside on other surfaces of the PAPR system and head top. As a result, consideration needs to be given to the policies and practices used for cleaning the complete PAPR.
No fit testing is required for a powered air purifying respirator and they are suitable for use with certain amounts of facial hair.
While initially more expensive than disposable or reusable respirators, powered air respirators can often be the more economical option over the long-term (example: changing filters every 3-6 months Vs every day).