Comparison of FFP2, KN95, and N95 and Other FFR Classes
Filtering facepiece respirators (FFR), which are sometimes called disposable respirators, are subject to various regulatory standards around the world. These standards specify certain required physical properties and performance characteristics in order for respirators to claim compliance with the particular standard. During pandemic or emergency situations, health authorities often reference these standards when making respirator recommendations, stating, for example, that certain populations should use an “N95, FFP2, or equivalent” respirator.
This article is only intended to help clarify some key similarities between such references, specifically to the following FFR performance standards:
- N95 (United States NIOSH-42CFR84)
- FFP2 (Europe EN149-2001)
- KN95 (ChinaGB2626-2006)
- P2 (Australia/New Zealand AS/NZA1716:2012)
- Korea 1st class (Korea KMOEL -2017-64)
- DS (Japan JMHLW-Notification 214,2018)
As shown in the following summary table, respirators certified as meeting these standards can be expected to function very similarly to one another, based on the performance requirements stated in the standards and confirmed during conformity testing.
One notable comparison point is the flow rates specified by these standards for the inhalation and exhalation resistance tests. Inhalation resistance testing flow rates range from 40 to 160L/min. Exhalation resistance testing flow rates range from 30 to 95 L/min. Some countries require testing to be performed at multiple flow rates, others at only the high or low end of those ranges. Although this appears to suggest that the standards’ requirements for breathing resistance (also called“pressure drop”) differ from each other, it’s important to understand that pressure drop across any filter will naturally be higher at higher flow rates and lower at lower flow rates. Given typical pressure curves for respirator filters, the standards’ various pressure drop requirements are actually quite similar. This chart shows a representative filter pressure drop curve. If one filter is tested at a high flow rate, the pressure drop performance will be relatively high. If that same filter is tested at a low flow rate, the pressure drop performance will be relatively low.
Based on this comparison, it is reasonable to consider China KN95, AS/NZ P2, Korea 1st Class, and Japan DS FFRs as “equivalent” to US NIOSHN 95 and European FFP2 respirators, for filtering non-oil-based particles such as those resulting from wild fires, PM2.5 air pollution, volcanic eruptions or bio-aerosols (e.g.viruses). However, prior to selecting a respirator, users should consult their local respiratory protection regulations and requirements or check with their local public health authorities for selection guidance.
|Certification/ Class (Standard)||N95 (NIOSH-42CFR84)||FFP2 (EN 149-2001)||KN95 (GB2626-20 06)||P2 (AS/NZ 1716:2012)||Korea 1stClass (KMOEL – 2017-64)||DS (Japan JMHLW-Notification 214, 2018)|
|Filter performance – (must be ≥ X% efficient)||≥ 95%||≥ 94%||≥ 95%||≥ 94%||≥ 94%||≥ 95%|
|Test agent||NaCl||NaCl and paraffin oil||NaCl||NaCl||NaCl and paraffin oil||NaCl|
|Flow rate||85 L/min||95 L/min||85 L/min||95 L/min||95 L/min||85 L/min|
|Total inward leakage (TIL)* – tested on human subjects each performing exercises||N/A||≤ 8% leakage (arithmetic mean)||≤ 8% leakage (arithmetic mean)||≤ 8% leakage (individual and arithmetic mean)||≤ 8% leakage (arithmetic mean)||Inward Leakage measured and included in User Instructions|
|Inhalation resistance – max pressure drop||≤ 343 Pa||≤ 70 Pa (at 30 L/min)≤ 240 Pa (at 95 L/min)≤ 500 Pa (clogging)||≤ 350 Pa||≤ 70 Pa (at 30 L/min)≤ 240 Pa (at 95 L/min)||≤ 70 Pa (at 30 L/min)≤ 240 Pa (at 95 L/min)||≤ 70 Pa(w/valve)≤ 50 Pa (no valve)|
|Flow rate||85 L/min||Varied – see above||85 L/min||Varied – see above||Varied – see above||40 L/min|
|Exhalation resistance – max pressure drop||≤ 245 Pa||≤ 300 Pa||≤ 250 Pa||≤ 120 Pa||≤ 300 Pa||≤ 70 Pa(w/valve)≤ 50 Pa (no valve)|
|Flow rate||85 L/min||160 L/min||85 L/min||85 L/min||160 L/min||40 L/min|
|Exhalation valve leakage requirement||Leak rate ≤ 30 mL/min||N/A||Depressurization to 0 Pa ≥ 20 sec||Leak rate ≤ 30 mL/min||visual inspection after 300 L /min for 30 sec||Depressurizatio n to 0 Pa ≥ 15 sec|
|Force applied||-245 Pa||N/A||-1180 Pa||-250 Pa||N/A||-1,470 Pa|
|CO2 clearance requirement||N/A||≤ 1%||≤ 1%||≤ 1%||≤ 1%||≤ 1%|
- Filter performance – the filter is evaluated to measure the reduction in concentrations of specific aerosols in air that passes through the filter.
- Test agent – the aerosol that is generated during the filter performance test.
- Total inward leakage (TIL) – the amount of a specific aerosol that enters the tested respirator facepiece via both filter penetration and faceseal leakage, while a wearer performs a series of exercises in a test chamber.
- Inward leakage (IL)– the amount of a specific aerosol that enters the tested respirator facepiece, while a wearer performs a normal breathing for 3 minutes in a test chamber. The test aerosol size (count median diameter) is about 0.5 micro meter.
- Pressure drop – the resistance air is subjected to as it moves through a medium, such as a respirator filter. IMPORTANT: Always read and follow respirator user instructions