What’s the Difference Between N95 and KF94 Masks?

Many people wonder about the difference between N95 and KF94 masks. But actually, for the things most people care about, the difference is not small. KF94 is the “Korean filter” standard similar to the US N95 mask rating. Let’s dive into the differences: KF95 vs N95.

Note, there is no “N94” or “K94” mask standard (even though many seem to think so!). We wrote an article going over all of the different mask standards to make everything clear.

Difference Between N95 and KF94 Masks: Charted Out

They look similar, and they filter a nearly identical percentage of particles—95% versus 94%. This chart from 3M explains the differences between the N95 and “first-class” Korean masks. The columns highlight these two types of masks.

Difference Between N95 and KF94 Masks

On the metric that most people care about (filtration effectiveness), they’re nearly identical. In most circumstances, mask users will not care about a 1% difference in filtration.

KF94 Standards Borrow More From Europe Than US

However, of the differences between the standards, the Korean standards are more similar to the EU standards than the US standards. For example, US certification agencies test filtering performance using salt particles, whereas European and Korean standards test against salt and paraffin oil.

Paraffin Oil Mask Testing Standards Ratings

Similarly, the US tests filtration at a flow rate of 85 liters per minute, whereas the EU and Korea test against a flow rate of 95 liters per minute. However, these differences are minor.

Other Differences Between Mask Ratings

Besides the 1% difference in filtration, there are some small differences in other factors.

  • For example, the standards require N95 masks to be somewhat easier to breathe out of (“exhalation resistance”). But this doesn’t always mean they are more breathable than KF94.
  • Korean masks are required to test for “CO2 clearance,” which prevents CO2 from building up inside the mask. In contrast, N95 masks don’t have this requirement.
  • In Korea, KF94 respirator performance standards are not considered to be equivalent to N95 or FFP2 respirators, while Korea 1st class respirators are.

However, concerns about CO2 buildup may be overblown. For example, one study found that, even during moderate exercise, women wearing N95 masks had no difference in blood oxygen levels.

  • To get the mask label certified, Korea requires human fit-tests, like the one I’m doing below. The US N95 certification does not require a fit test.
N95 Mask Fit Test

However, that doesn’t mean people shouldn’t do fit tests with N95 masks. The US agency that regulates workplace safety (OSHA) requires workers in certain industries to get fit-tested once a year. It’s just that fit tests aren’t required for the manufacturer to get the N95 label.

Which Mask Is Better: N95 vs KF94?

Mona Lisa prefers KN94?

Since the filtration effectiveness of both masks is quite similar, comfort and fit are important factors that may make one more suitable for you than the other. Each grade and model of a mask will fit differently depending on the face type.

We recommend testing a few different models of masks to find which one you feel comfortable wearing for long periods of time. Because at the end of the day, a mask is not effective whatsoever if not worn over your face. Shocker!

Read More: How to test your N95 or KF94 mask’s fit at home

Bottom Line: N95 vs. KF94 Masks

On the factor that most people care about (filtration) N95 and KF94 masks are nearly identical. However, there are small differences in other factors, such as breathing resistance and fit-testing.

Smart Air
KF94 Mask

Free Guide to Breathing Safe

Want to learn more about breathing clean air? Join thousands more and stay up to date on protecting your health.

18 thoughts on “What’s the Difference Between N95 and KF94 Masks?”

  1. N95 masks are primarily used in the United States and are regulated by the National Institute for Occupational Safety and Health (NIOSH), which is part of the Centers for Disease Control and Prevention (CDC). On the other hand, KF94 masks are commonly used in South Korea and are regulated by the Korea Food and Drug Administration (KFDA).

  2. Hi, I think you should correct the article accuracy. KF94 is not equivalent to N95.

    KF94 respirator is categorized as a quasi-drug and is considered as public use (consumer) product. It is managed by MFDS (Ministry of Food and Drug Safety).

    Korea 1st Class is categorized as industrial respirator. It is managed by KOSHA (Korea Occupational Safety and Health Agency).

    KF94 performance standards is considered not an equivalent to N95 while Korea 1st class is.

    You may refer to this 3M technical document which i have quoted and extracted below: https://multimedia.3m.com/mws/media/1793278O/3m-anz-2020-respiratory-protection-faq-healthcare.pdf

    Note that in some countries, there are different respirator performance standards for occupational-use respirators and public-use respirators. For example, in Korea there are occupational-use (1st class) and public-use respirators (KF94).

    KF94 respirator performance standards are not considered to be equivalent to N95 or FFP2 respirators, while Korea 1st class respirators are. Always consult with your local authorities to see what respirators are approved in your country and what is recommended to help reduce your exposure to the airborne hazard of concern.

    • We have updated the article this information regarding the first-class masks and KF94 in Korea. Thanks for the info!

  3. Thanks for sharing this article. It’s easy to confuse the two masks, given that their names are fairly similar. But, while the masks have some things in common, there are plenty of differences between them.

  4. Thanks for the great article! I’ve read the more common KF94s are the “health masks” vs the “1st class”, and its filtration is for 0.4um, rather than 0.3um. Knowing now that COVID can be transmitted via aerosol, the 1% is likely not very significant, but could the 0.1um difference be?

  5. Good to know that the referenced study showed no difference in blood oxygen levels, but in regards to CO2, wouldn’t we be concerned about blood CO2 levels?

  6. Korean government has released some of their kf94 mask inventory. US government agencies can “purchase” these goods as a relief supplies almost at a cost of goods purchased by the Korean government. Any thoughts on how to present this deals to US government agencies?

    • Hey Daniel, those masks are sorely needed here in the US, where I am! Given the similarities in mask standards between the N95 and KF94, I’d be comfortable wearing either.

  7. I can’t find out the comparison chart between N95 vs K94 you posted in 3M site, can you send the source of the chart ? Also the test agent, NaCI , what does NaCI stand for ? Is it National Advisory Committee on Immunization (NACI) or something else ? Thank you !

    • Hi David, NaCl is sodium chloride. Aerosolized NaCl is used in mask sample testing and the concentration of NaCl is measured before and after impact with the sample. You can find more details on searching NIOSH testing on Google.

  8. Thanks for this information. I am able to purchase KF94 mask during this COVID outbreak but I’m trying to determine if they are fake or real. Any advice or insight?

    • It’s difficult to know for sure without testing them. We suggest you check the manufacturer’s certification to see that it is in date and appears accurate. You can also look at the quality of the masks being made as an indication of their ability to capture viruses.

    • If it is made in Korea. Then it is kf94.. there are some Chinese ones. Some of them are also from Chinese fake ones too..


Leave a Comment

Smart Air low cost purifiers

Smart Air is a social enterprise and certified B-Corp that offers simple, no-nonsense air purifiers and provides free education to protect people from the harms of air pollution. We are proud to be the only certified B-Corp dedicated to fighting air pollution.

Certified B-Corp air purifier company