ASTM F3502-21: Standard Specification for Barrier Face Coverings
One Label, Two Levels: Filtration and Breathability
Introduced in 2021,
ASTM F3502 is the only fabric mask standard recognized by the US Centers for Disease Control and Prevention.
Why? Because F3502 is the only industry-approved standard that shows you how well your mask actually works.
An ASTM F3502 facemask has to pass rigorous laboratory testing before it can be labelled as compliant. In addition to filtering a critical mass of fine aerosols, an F3502 mask must be significantly more breathable than a medical respirator. The filtration and breathability scores go right on the ASTM-approved label so you can see exactly how the mask strikes the balance between comfort and protection.
Puraka is proud to offer its Essential line of F3502-compliant masks. Even without a filter, these premium-quality facemasks exceed the level one requirements for breathability and filtration. With the filter, the bacterial filtration efficiency increases to 98%, without significantly impacting the breathability. In fact, here's our F3502-21 label, so you can see for yourself.
What does the label of an F3502 barrier face covering tell you about how well the mask performs?
[Infographic Text: ASTM F3502 Mask Labels, Explained. Specification for Barrier Face Covering. Two levels of performance: Filtration Efficiency (Higher = Better): <20% Fail, >20% Level 1, >50% Level 2. Breathability (Lower = Better): <5mm level 2, <15mm Level, >15mm Fail. N( respirators have an exhalation limit of 35mm.
Wait, isn't 20% kind of low? 20% sounds low, but the filtration efficiency score is for sub-micron particles, even smaller than a virus! Larger airborne particles are filtered at exponentially greater rates. In other words, The bigger the particle, the easier it is to capture! Graph showing filtration efficiency as a function of particle size, with the "most penetrating particle"
size having the lowest filtration efficiency. Breathing resistance is measured in millimeters. 1 - 5mm is level 2, 6 - 15mm is level 1, and more than 15mm is a fail. N95 masks test at 35mm. This is a failing grade range.
Bacterial Filtration Efficiency (BFE). Reporting is optional. The BFE score helps by showing effectiveness against slightly larger virus-carrying particles.
Electrostatic filter inserts can increase the BFE score to 90% or more. ASTM surgical masks need a BFE score of at least 95%. Woven fabric provides 'mechanical' protection from larger particles. Nonwoven filters provide 'electrostatic' protection from smaller particles.
ONE MORE THING... he manufacturer must conduct a "Fit Analysis" to make sure leakage is minimal and the mask sufficiently covers the wearer's nose & mouth. The F3502 standard offers best-in-class protection and breathability. That's why it's the only non-medical face covering standard recognized by the CDC. ASTM F3502. Raise your standards. Learn more and browse ASTM F3502-compliant masks at store.purakamasks.com.]