What's in a N95 Mask?
Unmasking the N95
Below is a breakdown of what an N95 mask is:
N:
This is a Respirator Rating Letter Class. It stands for “Non-Oil” meaning that if no oil-based particulates are present, then you can use the mask in the work environment. Other masks ratings are R (resistant to oil for 8 hours) and P (oil proof).
95:
Masks ending in a 95, have a 95 percent efficiency. Masks ending in a 99 have a 99 percent efficiency. Masks ending in 100 are 99.97 percent efficient and that is the same as a HEPA quality filter.
.3 microns:
The masks filter out contaminants like dusts, mists and fumes. The minimum size of .3 microns of particulates and large droplets won’t pass through the barrier, according to the Centers for Disease Control and Prevention (CDC.)
Material:
The filtration material on the mask is an electrostatic non-woven polypropylene fiber.
Valve:
Some disposable N95 masks come with an optional exhalation valve. “The presence of an exhalation valve reduces exhalation resistance, which makes it easier to breathe (exhale,)” according to the CDC.
For information on how to protect yourself during the COVID-19 outbreak, contact your local health care professionals, visit the CDC and World Health Organization (WHO.)
Required Labeling of a NIOSH-Approved N95 Filtering Face-piece Respirator
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Surgical N95 NIOSH under 42 CFR Part 84 and FDA/NIOSH MOU 225-18-006 |
Commercial N95 NIOSH under 42 CFR Part 84 |
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Labelling Information on respirator |
(1) Manufacturer’s Name; (2) TC-84A-####; (3) NIOSH; (4) Lot Number; (5) Filter designation (i.e. N95) Additional information 1 |
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Nasal splints |
Must be adjustable and provide an airtight seal. |
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Mask Harness |
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Fit |
Half-mask face-pieces and full face-pieces shall be designed and constructed to fit persons with various facial shapes and sizes, either: (1) By providing more than one face-piece size; or (2) By providing one face-piece size which will fit varying facial shapes and sizes. |
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Filter performance – (must be ≥ X% efficient) |
≥ 95% |
≥ 95% |
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Test agent |
Sodium Chloride (NaCl) Particles |
Sodium Chloride (NaCl) Particles |
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Flow rate |
85 L/min |
85 L/min |
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Inhalation Resistance |
≤ 343 Pa |
≤ 343 Pa |
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Flow rate |
85 L/min |
85 L/min |
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Exhalation Resistance |
≤ 245 Pa |
≤ 245 Pa |
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Flow rate |
85 L/min |
85 L/min |
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Synthetic Blood Penetration |
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N/A |
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Surface Wetting Resistance |
N/A |
N/A |
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Microorganism Index (Bioburden) |
N/A |
N/A |
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Biological Filtration Efficency |
≥ 95% |
N/A |
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TIL (total inward leakage) |
N/A |
N/A |
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Exhalation valve leakage requirement |
- |
Leak rate 30 mL/min |
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Force applied |
- |
-245 Pa |
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CO2 clearance |
N/A |
N/A |