The N95 is the most popular series of particulate respirator masks that meet US government standards. Face masks are tested to reduce exposure to airborne contaminants by NIOSH, the National Institute for Occupational Safety and Health. NIOSH has nine approval classes in total, N95, N99, N100, R95, R99, R100, P95, P99, P100 organized by oil compatibility and filter efficiency.

The letter stands for how the filter tests in environments exposed to oil aerosols:

N95, N99 and N100. These filters are not to be used with oil sprays. These should be used in environments exposed to particles that do not contain oil. In many cases, respirators cannot be reused multiple times.

R95, R99 and R100. These filters are oil dressing. Respirators r can be used in atmospheres containing particulates and any solid or liquid hazard, including oil-based hazards. These are single use masks.

P95, P99 and P100. These filters are oil Test. These respirators can be used in any environment exposed to hazardous particles. P respirators are subject to wear time limitations.

The filter efficiency number refers to the percentage of airborne particles that were removed in the test: 95%, 99%, and 100%. If a facepiece is NIOSH approved, it will have an approval class stamp printed on the respirator.

NIOSH-approved masks also come in different sizes, and a well-fitting mask is vitally important. When fit testing an N95 or other particulate respirator mask, follow these simple steps:

1. Press the mask (respirator) firmly against the face with the outer nosepiece on the bridge of the nose.

2. Stretch and place the top headband on the back of your head above your ears. Stretch the bottom headband over your head and tuck it under your ears.

3. With both hands, mold the metal nose piece to the shape of your nose.

4. To test the fit, place both hands over the respirator and exhale vigorously. If air flows around the nose, adjust the nosepiece: If air flows around the edges of the respirator, reposition the headbands for a better fit and retest until there are no air leaks.

Before choosing the proper respirator, it is also suggested that you speak with experienced industrial safety personnel about an assessment of your particular environment.

For more information on the N95 and other NIOSH-approved particulate respirator masks, visit our website: http://www.newtonsafety.com.