Table 1 Classification and characteristics of masks
Types | Face covering masks
| Surgical masks
| N95 mask
| Surgical respirators
|
|---|---|---|---|---|
Purpose | Prevents large particles (> 10 um) expelled by the wearer from reaching the environment | Prevents large particles (> 10 um) expelled by the wearer from reaching the environment To be used as a physical barrier to protect people from large droplets of blood or body fluids | Reduces exposure to very small airborne particles or contaminants May not protect against sprays and direct liquid splashes | Provides the protection of both a surgical mask and N95 respirator To be used as a physical barrier for large droplets of blood or body fluids as well as very small particles (e.g., fine aerosolized droplets), such as those produced by coughing |
Fit | Does not fit tightly | Does not fit tightly | Tight fit | Tight fit |
Filtration efficiency | Windproof, keep warm, isolate large particles such as dust | Bacterial filtration efficiency above 95% | Minimum 95% against particulate aerosols (of 0.3 micron in size) free of oil | Minimum 95% against particulate aerosols (of 0.3 micron in size) free of oil |
Fluid resistance (i.e., resistance to penetration of bodily fluids) | Not fluid resistant | Yes | Not tested for fluid resistance | Tested to be fluid resistant |
