Definitions
Medical masks are defined as surgical or procedure masks that are flat or pleated; they are affixed to the head with straps that go around the ears or head or both. Their performance characteristics are tested according to a set of standardized test methods (ASTM F2100, EN 14683, or equivalent) that aim to balance high filtration, adequate breathability and optionally, fluid penetration resistance.(34, 35)
Filtering facepiece respirators (FFR), or respirators, similarly offer a balance of filtration and breathability; however, whereas medical masks filter 3 micrometre droplets, respirators must filter more challenging 0.075 micrometre solid particles. European FFRs, according to standard EN 149, at FFP2 performance filter at least 94% solid NaCl particles and oil droplets, and US N95 FFRs, according to NIOSH 42 CFR Part 84, filter at least 95% NaCl particles. Certified FFRs must also ensure unhindered breathing with maximum resistances during inhalation and exhalation. Another important difference is the way filtration is tested; medical mask filtration tests are performed on a cross- section of the masks whereas FFRs are tested for filtration across the entire surface. Therefore, the layers of the filtration material and the FFR shape, ensuring outer edges of the FFR seal around wearer’s face, result in a guaranteed claimed filtration when worn compared to the open shape, or leaking structure, of medical masks. Other FFR performance requirements include being within specified parameters for maximum CO2 build up, total inward leakage and tensile strength of straps.(36, 37)
