FFP2, KN95, N95 & P2!! What are the differences?
Hey, if you are reading this, you must know that the interest in N95 masks is surging. With more transmissible Covid-19 variants circulating in between the countries, people are feeling the need for extra protection. Most people don’t realize different countries have different standards for their respirators. We are here to help clarify some key similarities between these respirators in various countries:
- N95 (United States NIOSH-42CFR84)
- FFP2 (Europe EN 149-2001)
- KN95 (China GB2626-2006)
- P2 (Australia/New Zealand AS/NZA 1716:2012)
- Korea 1st class (Korea KMOEL – 2017-64)
- DS2 (Japan JMHLW-Notification 214, 2018)
- KMOEL – 2017-64PFF2 (ABNT/NBR 13.698-2011 – Brazil)
|Korea 1st Class
(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|
|Total inward leakage (TIL)*
– tested on human subjects each performing exercises
|N/A||≤ 8% leakage (arithmetic mean)||≤ 8% leakage (arithmetic mean)||≤ 8% leakage (individual & 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 Pa ≥ 20 sec||Leak rate ≤ 30 mL/min||visual inspection after 300 L /min for 30 sec||Depressurization to 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%|
|*Japan JMHLW-Notification 214 requires an Inward Leakage test rather than a TIL test.|
EU: FFP2 & FFP3 masks
EU uses two different standards. The “filtering facepiece” score (FFP) comes from EN standard 149:2001. EN 143 standard covers P1, P2 & P3 ratings for the product strength. Both standards are maintained by CEN (European Committee for Standardization) :
- P1 (80% filtering)
- P2 (94% filtering)
- P3 (99% filtering)
Both the European standard EN 143 and EN 149 test the penetration of filters with dry aerosols containing sodium chloride (NaCl) and paraffin oil after storing the filters at 70 ° C and -30 ° C for 24 hours each. Standards include mechanical strength, breathing resistance, and obstruction tests.
EN 149 tests leakage between mask and face, where 10 human subjects perform 5 exercises each, and for 8 individuals the measured average leakage should not exceed 22%, 8%, and 2% respectively.
According to EU standards (EN 149:2001), FFP2 masks (filtering 94% of particles) are similar to N95 masks in non-oily particle filtration, and higher standard FFP3 (high-efficiency filter masks) can filter 99% of particles. The EU and NIOSH standards are different, and both oily (paraffin oil mist) and non-oily (sodium chloride) particles need to be filtered at the same time. The EU standards cover a wider range.
In addition, suffixes are often added to the label of FFP2/3 masks, such as “R” for reusable, “NR” for non-reusable, and “D” for passing the dolomite obstruction test. 
US& EU standards comparison:
|Respirator Standard||Filter Capacity (removes x% of all particles that are 0.3 microns in diameter or larger)|
|FFP1 & P1||At least 80%|
|FFP2 & P2||At least 94%|
|N95||At least 95%|
|N99 & FFP3||At least 99%|
|P3||At least 99.95%|
|N100||At least 99.97%|
Australia: P2 masks
In Australia, masks similar to N95 are called P2 masks. P2 Masks have slightly different testing methods comparing with the N95 masks.
The aerosol flow
There are some minor differences in the aerosol flow rates and particle sizes that both these masks protect against.
P2 filter has efficiency of 94% and N95 filter has efficiency of 95%
Besides the 1% difference infiltration, there are some other small differences in other factors.
The exhalation resistance
The exhalation resistance of P2 masks is lower than the N95 masks. 
Australia requires manufacturers to test their masks for “CO2 clearance,” which prevents CO2 from building up inside the mask. In contrast, N95 masks don’t have this requirement.
Although CO2 can build up can be a scary issue for the public, studies have found no reason to worry about blood oxygen levels. One study has indicated that even during moderate exercise, women wearing N95 masks had no change in blood oxygen levels. Even pregnant women asked to exercise while wearing N95 masks had no reduction in blood oxygen. 
N95 and P2 masks are nearly identical on filtration–the factor most people care about. However, there are small differences in other factors, such as breathing resistance and requirements for fit-testing.
Japan: DS2 masks and RS2 masks
There are two types of masks in Japanese standard that works similar to the N95 mask:
- DS2: disposable masks
- RS2:reusable masks
The filtration standards are the same as N95 masks 
Mainland China: KN95 mask
Both masks, KN95 & N95 are made from several synthetic material layers and are intended to be worn over the mouth and nose. Both filter out 95 percent of aerosol particles that could potentially be carrying the novel coronavirus. Authentic KN95 respirators can provide equivalent protection to an N95 mask.
So, what is the difference between an N95 and a KN95 mask?
N95 is the only standard that has been approved by the National Institute for Occupational Safety and Health (NIOSH), the U.S. organization responsible for regulating face masks and respirators.
In September 2020, ECRI had conducted a review test for KN95 masks, and ECRI had discovered that nearly 70 percent of those produced in China did not meet the NIOSH filtering requirements. 
South Korea: KF94 mask
The “KF” stands for “Korean Filter,” and “The ’94’ represents the filtration efficiency, which means how good the mask is at filtering out particles.
- KF94: Korean standard, which means that the filtration rate of masks for particles with an average diameter of 0.4μm is greater than 94%.
- N95: American standard, which means that the mask can filter more than 95% of non-oily particles with a diameter of 0.3μm.
The two standards are different. The US data comes from the National Institute of Occupational Safety and Health (NIOSH), and the Korean data refers to its Food and Drug Administration (MFDS).
Other than the quality filtering properties of the mask itself, it is important to note that all masks are not effective unless it’s worn properly. It is critical for healthcare workers and others who may have contact with confirmed COVID-19 patients or those who are at risk.
- M. (2020, March 30). Comparison of FFP2, KN95, and N95 and Other Filtering Facepiece Respirator Classes by 3M. Work Safegear Pty Ltd. https://worksafegear.com.au/blog/comparison-of-ffp2-kn95-and-n95-and-other-filtering-facepiece-respirator-classes-by-3m
- What face mask for what use in the context of the COVID-19 pandemic? The French guidelines. (2020, July 1). PubMed Central (PMC). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7194956/
- Clogging Test Dolomite Dust Is 9473:2002. (n.d.). Indiamart.Com. https://www.indiamart.com/proddetail/clogging-test-dolomite-dust-is-9473-2002-22551381162.html
- PRESSURE DROP OF FILTERING FACEPIECE RESPIRATORS: HOW LOW SHOULD WE GO? (n.d.). PubMed Central (PMC). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4499853/
- Respiratory consequences of N95-type Mask usage in pregnant healthcare workers—a controlled clinical study. (2015). PubMed Central (PMC). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4647822/
- JICOSH Home | Standard for Dust Mask. (n.d.). JICOSH. https://www.jniosh.johas.go.jp/icpro/jicosh-old/english/law/DustMask/index.html
- Healthline: The request could not be satisfied. (2021, February 3). Healthline. https://www.healthline.com/health-news/which-facial-covering-is-better-experts-talk-kn95-cloth-and-surgical-masks#N95-vs.-KN95
- Up to 70% of Chinese KN95 Masks Tested by ECRI Don’t Meet Minimum Standards. (2020, September 22). ECRI. https://www.ecri.org/press/up-to-70-of-chinese-kn95-masks-tested-by-ecri-dont-meet-minimum-standards