Direct comparison
N95 vs N100: Efficiency, Oil Limits, Use
N95 vs N100: 95 vs 99.97 percent minimum filter efficiency under 42 CFR Part 84, the shared oil restriction, and when a 100 percent filter is called for.
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How do N95, N100 compare side by side?
The table below compares N95, N100 across 9 procurement-relevant dimensions, from minimum filter efficiency through source.
Side-by-side comparison
| Dimension | N95 | N100 |
|---|---|---|
| Minimum filter efficiency | 95 percent (42 CFR 84.170(a)(3)(iii)) | 99.97 percent (42 CFR 84.170(a)(3)(i)) |
| Oil aerosols | Restricted to workplaces free of oil aerosols (N-series, 42 CFR 84.170(a)(2)) | Same restriction: N-series, workplaces free of oil aerosols (42 CFR 84.170(a)(2)) |
| Test aerosol | Solid sodium chloride particulate aerosol (42 CFR 84.174(a)(1)) | Same solid sodium chloride aerosol (42 CFR 84.174(a)(1)) |
| Oil-resistant counterpart | P95 or R95 (R- and P-series are intended for any particulate, including oil-based liquid particulates; 84.170(a)(2)) | P100 or R100, with the same 99.97 percent minimum (84.170(a)(3)(i)) |
| Where a specific standard calls for it | Moldex treats the 95 percent filter as the general-purpose level, usually adequate for a half mask | Manufacturer guidance (Moldex) says 100 percent filters are called for where a specific standard requires HEPA filtration: asbestos, lead, inorganic arsenic, cadmium, MDA |
| Assigned protection factor (half mask) | APF of 10, which Moldex says usually makes a 95 percent filter adequate | Same APF of 10 for any half mask; the higher filter efficiency does not change it (Moldex) |
| Other situations | General particulate work in a workplace free of oil aerosols | A qualified health professional may recommend a 100 percent filter in situations beyond the standards listed above (Moldex) |
| When to pick each | General particulate protection where no standard calls for a 100 percent filter and no oil aerosols are present | A governing standard calls for HEPA-level filtration, or a qualified health professional recommends it; still only where no oil aerosols are present |
| Source | 42 CFR Part 84, Subpart K (eCFR), read 2026-10-29: https://www.ecfr.gov/current/title-42/part-84 | Moldex technical brief, "When to Use a 95, 99 or 100 Filter" (manufacturer guidance), read 2026-10-29: https://www.moldex.com/resources/technical-briefs/when-to-use-a-95-99-or-100-filter/ |
Common questions
Common questions about N95 vs N100
Is N100 better than N95?
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An N100 filter must demonstrate a higher minimum efficiency than an N95: 99.97 percent versus 95 percent (42 CFR 84.170(a)(3)). Whether that makes it better for a given task depends on the task. Moldex notes that because half masks carry an APF of 10, a 95 percent filter will usually be adequate, and that 100 percent filters are called for where a specific standard requires HEPA filtration.
Is N100 the same as P100?
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They share the same 99.97 percent minimum efficiency, but not the oil limit. N-series filters are restricted to workplaces free of oil aerosols, while R- and P-series filters are intended for removal of any particulate, including oil-based liquid particulates (42 CFR 84.170(a)(2)). N-series filters are tested with a solid sodium chloride aerosol; R and P with a DOP or equivalent liquid aerosol (84.174(a)).
Can an N100 be used where oil aerosols are present?
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No. Under 42 CFR 84.170(a)(2), N-series filters, including N95 and N100, are restricted to use in workplaces free of oil aerosols. R- and P-series filters are the classes intended for oil-based liquid particulates.
When is a 100 percent filter called for?
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Moldex states that 100 percent filters (N100, R100, P100) are called for where a specific standard calls for HEPA filtration, such as asbestos, lead, inorganic arsenic, cadmium and MDA, and that a qualified health professional may recommend one in other situations.
