Comparison of Mask Ratings, Standards, and Filtration Effectiveness (N95, KN95, FFP1, FFP2)

Mask ratings can be confusing: N95, KN95, FFP1, FFP2, P2, or surgical mask? This quick run-down of mask specifications covers mask types, mask ratings, and their effectiveness at filtering particles.

Let’s begin by discussing mask types or certification types. There are generally three commonly used, disposable masks: single-use face masks, surgical masks, and respirators.

Table of surgical and N95 respirator mask standards in Europe, USA and China

Mask Standards and Effectiveness Bottom Line

  1. Single use masks (normally one layer, very thin) are typically only effective at capturing larger dust particles, but can do so fairly well.
  2. Surgical mask standards have higher requirements for capturing virus-sized (0.1 micron) particles, however they vary by region.
  3. Pollution masks (respirators) typically capture >90% of virus-sized particles. You can use the rating system in the table above to see the exact proportion each certification requires. This includes ratings such as N95, KN95, FFP1, FFP2 and FFP3.

Mask Standards Vary by Country

Each country has their own certification standard for each mask type. For example, Europe uses the EN 14683 standard for surgical masks, whereas China uses the YY 0469 standard. Each standard varies a little by country, however they are broadly similar. For respirator masks, China uses the KN standard (e.g. KN95) and the US uses the N standard (e.g. N95).

Read more: what’s the difference between KN95 and N95 masks »

Requirements Are Lowest for Single Use Face Masks

The standard with the lowest requirements on filtration effectiveness are the single use face masks (not to be confused with surgical masks). Surgical masks have higher requirements, and respirators have the highest requirements. Respirators also usually fit tighter around the face (data shows they score higher on fit effectiveness) than surgical masks and single-use face masks.

N95 Mask Fit Test Filtration Effectiveness

Coronavirus & Mask Livestream

Wondering whether masks work to protect you against the coronavirus? Check out our livestream recap covering all the info here!

3M vs. FFP1 vs. FFP2 vs. N95 vs. KN95? What Do Mask Numbers and Letters Mean?

A visitor to the website asked this in the comment section on coronavirus and Pitta masks a few days back:

Could you please explain: if a mask is FFP2 or 3, but NOT 3M – what does it mean exactly concerning COVID-19? Thank you!

Here’s an explanation on the difference between N95, 3M and PM2.5, to help you out.

N95, N99, FFP1, FFP2 and FFP3 Mask Ratings

The ratings cover (most importantly for us) the filtration level, among other things. You can think of them like G, PG, PG-13, R ratings for movies. The movie ratings cover who can watch them.

Movie rating system like ffp1 ffp2 n90 n95 n100 respirator rating system

EN 149:2001+A1:2009 / ASTM F2100 / NIOSH

These are standards for masks. They specify the rules and testing methods companies should follow to rate their masks. These standards define the N95, FFP1, and FFP2 ratings above. Using the movie rating analogy, you can think of it like this: the people reviewing movies and choosing the appropriate movie rating must have a set of rules to decide if the movie is considered PG-13 or R. They’ll follow these rules to rate the movie. These standards are the set of rules for masks.

Why are there so many? Standards labelled “EN” are for the EU. ASTM F2100 (NIOSH) is for the US. Many other countries will have their own rating systems too.

3M Masks?

3M is a company that manufactures masks. They generally produce masks that meet KN95 or N95 standards. Buying masks from a trusted company may reduce the odds of the masks failing quality standards.

What Are KF94 Masks?

KF94 is a respirator mask standard of South Korea. KF94 masks are similar to N95 and KN95 masks, but instead of filtering out 95% of particles, they filter out 94%. In Korea, KF94 respirator performance standards are not considered to be equivalent to N95 or FFP2 respirators, while Korea’s 1st class respirators are.

PM2.5 vs. N95

As we now know, N95 is a mask rating. PM2.5 refers to “particulate matter” or a fancy way of saying “pollution particles” that are in the air. The 2.5 refers to the size of these particles as being 2.5 microns or smaller. This picture can give you a visual example of how big PM2.5 particles are.

Size of coronavirus particle pm2.5 and bacteria

FFP2 vs. N95

FFP2 and N95 masks are quite similar in regards to filtration effectiveness. The key difference is FFP2 follows the European EN 149 standard, while N95 follows the American NIOSH standard. FFP2 must filter at least 94% of airborne particles, while N95 must filter at least 95%.

Medical Grade Air Purifiers?

This article has covered medical grade masks, but they’re just one tool in protecting against airborne pollutants and viruses. When indoors, HEPA air purifiers are extremely effective at removing viruses and other pollutants from the air. So what is the deal with medical grade air purifiers? Do you really need a “medical grade” purifier?

Learn more: what are medical grade air purifiers »

Bottom Line: To Understand Mask Ratings

1. Three randomized studies have found surgical masks are just as effective as N95 masks at preventing virus transmission. They hypothesize the main reason for this is that any mask can reduce the hand-to-face contact, although we don’t know this for sure.
2. If you’re wearing a mask with a valve, you are protected. The valve does not bring in any outside air into the mask. Fit-test data has found that masks with valves are often among the highest scoring.
Mask Fit Effectiveness Valve vs No Valve
However, valves will not protect other people as well. If you are sick, and you breathe out, some of the moisture from your breath can expel through the valve, potentially putting others in danger.
3. Tests have found that DIY masks can filter a percentage of virus-sized particles. While they’re not as effective as surgical or N95 masks at filtering viruses, they can still provide some benefit. They can also reduce hand-to-face contact.

Smart Air


Along with wearing masks, air purifiers with HEPA filters are also one of the best ways to stay safe from a variety of pollutants in our air including viruses and dangerous PM2.5. A recent CDC study confirmed significantly lower COVID-19 infection rates in schools that used HEPA air purifiers. HEPA filters can significantly lower the risk of a variety of deadly diseases including diabetes, heart disease, cancer, and high blood pressure.

Read More: Four Steps to Choosing the Best Air Purifier

Smart Air is a certified B Corp committed to combating the myths big companies use to inflate the price of clean air.

Experience breathing truly clean air with gimmick-free, effective air purifiers that won’t break the bank. Join the clean air movement.

Sqair Air Purifier

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.

Notify of

Inline Feedbacks
View all comments
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