N95 Mask Quality Inspection

Like surgical masks, N95 Masks go through several tests to ensure their effectiveness. At the C.D.C., N95 Masks are conditioned for 24 hours before testing by being kept in a 38 degree C environment with 85% relative humidity. During tests, the respirator’s filtration ability must stay above its certification class level at all times.
 

N95 Masks are tested with:

● Charge neutralized sodium chloride aerosol spray, which features particles with a median of .3 microns in diameter. This tests for particle penetration.

● An airflow of 85 L per minute, which tests for a moderately high work rate.

● A breathing resistance test at 35 mm or below water column height pressure, and exhalation resistance at 25 mm or below water column height pressure (A millimeter of water column height pressure is the pressure from one millimeter of water at 39 degrees F).

● At least 200 mg of aerosol loading, which simulates a high level of exposure by clogging up the mask with aerosol particles.

● These respirators are also tested for flammability, biocompatibility, fluid resistance, and particulate and bacteria filtration by the FDA.

N95 is the United States standard, it is also called KN95 masks in China, able to filter out 95% of particles as small as 0.3 microns from the air.