All below information is direct or paraphrased from the official 3M website.
For a complete guide direct from 3M, visit their website or click here to download.
To see the a guide on the individual differences between masks, check out this descriptive guide.
What is the difference between a certified respirator and a surgical mask?
Respirators are designed to help reduce the wearer’s exposure to airborne particles. The primary purpose of a surgical mask is to help prevent biological particles (e.g. bacteria and viruses) from being expelled by the wearer into the environment. Surgical masks are not necessarily designed to seal tightly to the face, so air might leak around the edges.
Some approved respirators are designed to have the characteristics of both a respirator and a surgical mask. In the U.S., surgical N95 respirators are both approved by NIOSH and cleared by the U.S. Food and Drug Administration (FDA) for use in surgery. In other countries, these products are often approved by two equivalent or similar agencies.
Do I need a surgical respirator?
In general, members of the public would not expect to be exposed to high-pressure streams of infectious liquid. Liquid-droplet aerosols, such as those generated by coughs and sneezes, are capturable by the particulate filter in certified filtering facepiece respirators (FFRs).
Therefore, in nearly all scenarios in which a member of the general public might desire to wear a respirator, a non-medical FFR should be acceptable, and a surgical respirator not necessary.
Can a respirator help protect against very small particles like PM2.5, smoke, soot, bacteria and viruses?
A certified FFR is one way to help reduce exposure to fine particles like PM2.5, smoke, soot, bacteria and viruses. However, local recommendations (such as from a local health agency) should be consulted and followed. Often, such guidance indicates exposure should be avoided by staying away from the source of the hazard - such as staying indoors, away from outdoor air
pollution, and avoiding sick people - before relying on respiratory protection.
Does 95% efficient mean that 5% of the particles get through the filter?
All respirators are designed to help reduce, not eliminate, exposures to airborne hazards. For example, N95-rated FFRs have a filtration efficiency of at least 95% against non-oily particles when tested using the NIOSH criteria. The particles used to test the filtration are in a size range that are considered the most penetrating.
It’s important to remember that the filter efficiency alone does not determine the overall reduction in airborne hazards provided by a respirator. There are two other key determinants in reducing exposure: fit and wear time, both of which are addressed in the How to Use Respirators section of this document.