The Shanghai Consumer Rights Protection Commission (上海市消费者权益保护委员会) has hit another home run! Last year, they published a fantastic report of their independent testing of two dozen air purifiers, which I translated and blogged here. Now they have turned their focus on the second crucial anti-pollution gear: N95 masks. Specifically, they tested 17 disposable pollution masks you’d find all over China, in your corner convenience stores and most pharmacies. Our 7-11 now has a special display for masks (sad but true), and now we have some real data as to which are better and which to avoid. Their tests are very well done: filtration efficiency, leakage rates, and resistance to breathing in and out. It’s such a useful treasure of evidence-based data that I had to translate their Excel spreadsheet data and share with you below.
The Top Five Disposable Masks
I narrowed the list down to a handful of the top five you should look for, all of which had filtration efficiency over 95%, leakage rates under 7%, and low breathing resistance rates. They are the 3M 9041 and 9010; MASkin 6135; 3L N95; and Gangkai KN95 港凯KN95防尘口罩. My vote for the best is the usual gold standard: 3M, with two masks that did well here. I also think people should check out 3M’s new line of Vflex masks, the 9105, specifically designed for consumer markets in the developing world such as China (see their videos here). This new model wasn’t tested this time, but here’s the data on the good ones (click on the image to enlarge):
Here are pictures of the best ones:
Masks That Don’t Work
Quite a few masks did very poorly, with terrible filtration as well as unacceptable air leakage. Just take a look at the worst offenders below and you can see why: all those pleated ones just don’t seal well, even if the fabric is technically effective. Here are some masks to avoid:
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And here is the chart (click to enlarge):
My Bottom Line
I think this is extremely helpful data for anyone in China who is stressing out about air pollution, and who doesn’t currently use any mask. This is valuable consumer data showing that a properly fitting mask can reduce your PM2.5 exposure at least 95%. At the very least you should have a couple of these in your day bag just in case. I still think 3M should be your top choice, but others were just as effective. So wander over to your local convenience store and check them out!
UPDATE 2024: Please follow me at my new website, DrSaintCyr.com. Also my new YouTube channel youtube.com/@drsaintcyr
Hello,
I never saw a review of the Filtrete (3M) Air Purifiers on your site:
http://www.filtrete.com/wps/portal/3M/en_US/FiltreteNA/Filtrete/Products/?N=7569913+4315+3294529207&rt=r3
Why is that?
Because I’ve never tested them! I don’t have HVAC system…
I see, no problem. They also have stand-alone machines. Maybe one of your friends can give input.
Thanks Dr. for sharing this information
I guess Totobobo was not listed since it is a reusable mask. You ranked it among the best 3 in your previous posts, I have been wearing it since last year’s air apocalypse and I’m very satisfied. My only and major concern is the precedence of the filters. During the winter season I spend not more than 30 mins outdoors (no sports) and I need to change the filters at least every two days sometimes even everyday because they turn black quite fast. I think Totobobo’s biggest advantage over the others is that makes it visually evident when the filters need to be replaced.
I used to buy them at the Torana store but since they are now selling other brands I had to start purchasing them from taobao (it was linked to Totobobo’s official website) and now can be found at http://www.totobobo.tmall.com.
When you wear Totobobo’s mask do you buy the filters from the websites mentioned above or from overseas (Singapore, US)? It is clear that Totobobo’s has been duly tested and it’s super efficient but if the filters that can be bought in China are not so reliable then all this would not have much use.
Many thanks in advance for your suggestions.
I have no problem using Totobobo’s official Tmall store that you mentioned ago. It’s certainly the most trusted site I would use in China for them, and I use that instead of importing from Singapore…I don’t know if you need to change their filters so quickly, just because they turn a bit grey? By the way, I mentioned a new fundraising campaign to officially test all masks at a site in California, please check out my article here https://www.myhealthbeijing.com/children/please-help-test-pollution-masks-for-kids-and-adults/
In view of the poor test results on the Totobobo mask are you going to continue promoting it through your site?
Yes, in the recent testing by the China Consumers Group a Totobobo only got 3.5 out of 5. I wish I could read the Chinese and find out more details about the actual testing (ie was it a qualitative fit test? How many samples? Etc? What’s the exact % and not just a 5 star scale?) I will be covering those results more in detail soon. Otherwise, I don’t “promote” Totobobo or any other mask or any other consumer product, I offer the current evidence as we know it and everyone is welcome to make their own choices.
Hi,
The filters get dirty so quickly, because of the small surface area that the air has to pass through. This increases the inhalation resistance (when you breathe in) and as it has no valve, the water vapor in your breath makes the filter wet which increase the inhalation even more.
If you look at a 3M mask, you will see that the whole mask is filter material not just a portion of it. This means that the air that you are breathing in, is passing over a much greater amount of filter material. This lowers the inhalation resistance and allows a greater area of filter material to actually filter your air.
Imagine breathing through a ball point pen tube, its going to be tough to get the amount of air you require through the small orifice. So what do you do? A – make the pipe bigger and you get less inhalation resistance.
Valves are a must for good air flow and minimal pressure variations in the mask. When you exhale, the back pressure from the drenched filter (No valves 🙁 ) will cause the air that you breath out to pass around the masks edges breaking that all important seal
My message is – understanding how a mask works is crucial to making good decisions, try to get as much information from many different sites.
I agree that valves in general are a good thing, but let’s find out! That’s one reason why I am testing masks and will directly compare valves vs no valves…
Valves are a no brainer, Why would you not want valves on a mask?
I notice that the top five disposable masks listed above are all indusrtrial safety masks which require certification. So why not test all the masks to that same standard?. Then you have a level playing for which to give valid impartial advice. Singular tests like the face fit test could be open to personal misinterpretation and mislead the general public.
I agree that all “consumer level” masks should go through the same NIOSH-level standards as construction workers — but they aren’t required to do so. The quantitative fit test is impossible to be open to personal misinterpretation, it’s just a hard number and so is the best “consumer” level test if you have to choose only one. Regarding valves, I disagree that they are a no-brainer; 3M for example has plenty of masks without valves and they are all rigorously NIOSH tested and certified N95, both with hard data as well as test subject’s assessments of comfort.
Dear Dr. Saint Cyr,
First of all, let me thank you for constantly sharing first-order information with all of us. This really is a service to the online community. Second, I’d like to ask you if you’ve had any experience with “Nasal Filters”? I’m thinking whether I should give nasal filters a try. I found these two brands online:
(1) WoodyKnows Nasal Filters: http://www.hayfevermask.com/
(2) Health Naso Mask: http://www.healthnaso.com/
but information about their effectiveness seems to be scant (and the second webpage doesn’t really have an english version). Do you have any thoughts on these or other Nasal Filters?
Thanks in advance!
Thanks, Edgar. Yeah, these nasal filters — I really don’t like any of them in principle, certainly not as a viable anti-pollution device for anybody. There’s no way even to test them, and just practically speaking you’d have to have your mouth closed 100% all time otherwise mouth breathing would totally negate any theoretical benefit. So I say no way, not when there’s a pile of N95 masks and independent testing on masks. Show me some independent testing proving 95% effectiveness and maybe we can restart such a conversation…