Mask Category by NIOSH
NIOSH particulate filter approval Categories
| Minimum filter effisciency | N SeriesNot resistant to oil | R Series Somewhat resistant to oil | P Series Strongly resistant to oil |
| 95% | N95 | R95 | P95 |
| 99% | N99 | R99 | P99 |
| 100%(99.97%) | N100 | R100 | P100HEPA |
Quality Parameters of Masks
Important Quality Parameters of masks Explained
| Bacterial filtration efficiency 3STM F2101 | • Evaluation of filtration efficiencies related to both patient generated aerosols and wearer generated aerosols. • Higher BFE, better the protection level. BFE > 95% indicates the Type-I surgical face masks BFE > 98% indicates the Type-II surgical face masks. |
| Breathing resistance (∆P) BSEN 13274- 3 – 2001 & EN 143 | Used to determine the resistance of airflow through the facemask. • Lower the breathing resistance values per cm2 higher the comfort |
| Splash resistance (ASTM F1862-07): | Higher splash resistance, better protection |
| Flammability (16 CFR 1610): | The materials used in operation theatre will burn if high intensity heat energy is applied to them, especially in the presence of elevated oxygen levels.· Hence, the flammability test for surgical face masks is essential. The flame spread characteristics are classified in terms of class 1 to class 4 for the above tests.· For NFPA, class 1- slow burning |