
Common Types of Masks
*Specifically referring to medical grade masks vs OTC Comfort and dust masks
Filter Performance
Reduction in concentrations of specific aerosols (typically 0.1 – 0.5 microns in size) in air that passes through the filter. For reference, red blood cells are about 7 microns wide.
Aerosol
Suspension of fine solid or liquid droplets in air or another gas.
Test Agent
Aerosol that is generated in the filter performance test.
Total Inward Leakage
Amount of specific aerosol that enters tested respirator via both filter penetration and seal leakage while wearer performs exercise in test chamber.
Inward Leakage
Amount of specific aerosol that enters tested respirator while wearer performs normal breathing for 3 minutes.
Pressure Drop
The resistance air is subjected to as it moves through the medium.
Personal Protective Equipment (PPE)
Any gear necessary to minimize exposure to hazards; includes masks, gloves, goggles, clothing, etc.