Mask recommendations
If you're still using a cloth or surgical mask, upgrade to an N95 or P100 for much better protection
This is part of a collection of articles on Covid-19
Permanent link that will always go to the latest version of this article: https://firstsigma.github.io/masks
Summary
When to wear a mask:
For Covid protection, masks are most important for crowded indoors situations when Covid prevalence is high. Masks are unnecessary outdoors. Masks are less important if it’s less crowded, Covid prevalence is low, everyone is vaccinated, and the room has high-quality air filtration/ventilation.
Masks are not just for Covid: high-quality masks (KN95 and up) provide great protection from particulate pollution, e.g. wildfire smoke, air pollution, if you just created a lot of cooking smoke, if you're doing woodworking, etc.
What mask to wear and how to wear it:
Wear a N95 (great protection) or P100 (best protection and comfort).
If you're still using a cloth or surgical mask, you should upgrade to an N95 or P100 for much better protection. Unlike earlier in 2020, there is now a plentiful supply of high-quality masks, which are cheap and readily available. (Some of my top picks may be temporarily out of stock due to Omicron, but other high-quality masks remain available.)
Masks need to fit well, forming a good seal, to provide great protection. You should not feel air leaking around the edges when you inhale or exhale.
You should use the best mask that you will actually wear. I review comfort and convenience, in addition to protection. The good news is that the best masks are both highly protective and comfortable.
N95s are great protection and serve well as an all-purpose choice for most indoors situations - but again, good protection requires a good seal, which depends a lot on the mask and the shape of your face, so try different masks until you find one that fits you well.
Top recommendations: 3M Aura and WellBefore N95.
KF94 and FFP2 masks are just as good as N95s if you get a good face seal (but masks with ear loops tend not to seal as well as headbands). How well it fits to your face is the most important thing!
Only rely on KN95s that are vetted and independently tested - otherwise they can easily be half as effective as they’re supposed to be.
You can reuse an N95 until it gets wet, hard to breathe through, visibly dirty, or the elastic straps lose strength. You can typically expect to get about 40 cumulative hours of use in a clean environment (e.g. office), less in a polluted environment (e.g. smoke).
Leave them in the air or a breathable container between uses, do not clean with water, alcohol, heat, or anything else.
P100s are the best protection, are much easier to get a good fit, are generally a lot more breathable and comfortable, and are durable instead of disposable. But they are bulkier and harder to talk clearly through.
See links to recommended models below (favorites: mask and filters).
Personally, I prefer to use P100s if I don’t need the mask to fit in my pocket, and talking isn’t the main thing I’m doing. E.g. grocery shopping, public transit, movie theater, etc. They are my choice for these situations regardless of risk level, because of their better comfort. Of course, they are also the best protection, so they are also the best choice for any high-risk situation.
Face shields and goggles are almost useless by themselves without a mask, but do provide a little extra protection in conjunction with a good mask. Personally, I don’t bother with them.
This article is heavily based on Microcovid's mask guide, @masknerd (Aaron Collins), and Wirecutter.
Contents
Which masks to use, with buying recommendations
Cloth, Surgical, N95/KN95/FFP2/KF94, P100
How to check mask fit and seal
How long you can reuse a mask
This is a long article with a lot of detail, feel free to skip around to the parts that are relevant to you.
Comparison of mask types
Quick comparison of mask types:
Cloth: Minimal protection: baseline risk to 2/3 the risk. Varying breathability and comfort
Surgical: Moderate protection: 1/2 the risk. Good breathability and comfort.
Poorly sealed N95 or KN95: Good protection: 1/3 the risk. Decent breathability and comfort.
N95 (well-sealed): Great protection: 1/8 the risk when worn with a good seal. Decent breathability and comfort.
P100: Excellent protection: 1/20 the risk. Excellent breathability, good comfort, but large and hard to speak through.
Aspects to consider in a mask are:
Protection quality, which includes both filtration efficiency (how many particles that pass through the mask are caught by it) and fit quality (how much air goes through the mask vs leaking around the mask when you breathe). I list estimated effectiveness as overall filtration, which includes both - this is how much the mask reduces the particles you breathe in overall. I also translate this into risk reduction: how many times lower your risk of catching Covid is compared to without the mask. These estimates are from microcovid.
Masks help protect both you and others. The effectiveness estimates I listed are for protection to yourself, and the estimated risk to others is about 1/2 of that risk, i.e. you can roughly estimate masks as 2x more protective of others than of yourself (except where otherwise noted).
Comfort - this depends on many factors like shape, fit, weight, and material.
Breathability - how easy is it to breathe while wearing the mask?
This can be measured as pressure drop, which is basically the amount of effort needed to inhale (lower is better). And quality factor measures the bang-for-buck of protection vs pressure drop (higher is better). You can find data at @masknerd (Aaron Collins)’s testing data set.
Breathability on exhalation depends on pressure drop as well as the mask’s shape/design - where does the warm air you breathe out go? This affects how humid and stuffy a mask gets, and how much it fogs your glasses.
Convenience - how easy is it to carry the mask around while you aren't wearing it, and how easy is it to put on and take off?
Speech - how easily can you talk to someone while wearing the mask?
Durability - see section below on reusing a mask. There shouldn't be much difference in the lifetime of the filter material between different N95s, the main difference in durability comes from the elastic straps. My recommended models are sturdy and durable.
Cloth mask
Effectiveness: baseline to 2/3 risk = 0% to 33% overall filtration: masks range from almost useless (bandanas) to lightly protective (well-fitting cloth masks with a PM2.5 filter insert).
I don't see much point to cloth masks for Covid now that higher-quality masks are readily available. They’re typically worse in multiple ways - little protection as well as poor breathability.
Some of their potential advantages include being washable and looking stylish, but I think there are better options on both points:
On washability, Wirecutter found that filtration efficiency for their recommended cloth masks dropped by half after many washes. If washability and reusability are important to you, check out P100s (see below).
If looking stylish is important to you, I recommend highly-protective masks with a stylish printed pattern like the MaskLab KF series or the Posh KF94 masks.
I occasionally wear a cloth or similar mask not for Covid protection but purely as cold-weather wear.
If you are going to wear a cloth mask, look for one with good independent test results, since many provide almost no protection. Check out Wirecutter’s reviews which measure effectiveness and breathability (pressure drop). However, note that their testing may be on the optimistic side because they’re testing the filtration effectiveness of the material only, not testing face fit. Aaron Collins's test results find much lower effectiveness - still really good for a cloth mask, and better than your typical surgical mask, but not as good as a KN95+. If you find a good cloth mask that you think is more comfortable than other masks, it could be a viable option for lower-risk situations.
Surgical mask
Effectiveness: 1/2 risk = 50% overall filtration.
I sometimes use these in low-risk situations where I care more about convenience, e.g. walking inside an uncrowded store for just a few minutes, although a KN95 also serves me well for that purpose.
They fit loosely so don't provide a good seal. You can potentially improve effectiveness a lot by improving your seal:
Double-masking with a well-fitting cloth mask over a surgical mask can greatly improve fit and effectiveness, roughly to the level of a poor-fitting N95. But it makes it much harder to breathe through, and just wearing an N95 is better in almost all respects: better protection, breathability, comfort, and convenience.
Another option is a mask fitter or brace, but again, I’d rather wear a N95.
You can Knot and Tuck Your Mask to improve fit somewhat.
DemeMask Surgical Mask is the Wirecutter's top recommendation, which I also like.
They're very lightweight and convenient, but a downside in terms of comfort is that the mask is right up against your mouth, compared to most N95s which have a good amount of clearance between the mask and your mouth.
Fakes: many masks that look like surgical masks (disposable pleated blue masks) may not actually be real surgical masks. The packaging on these may simply say "face mask". Avoid this by buying well-reputed masks. One way to detect a fake is to hold it top side up under a dripping faucet: If the droplets soak in instead of completely beading up, it’s not a real surgical mask, which by default has some level of water resistance.
N95 / KN95
Effectiveness:
Poorly sealed N95 or KN95: 1/3 risk = 66% overall filtration
Well-sealed N95: 1/8 risk = 88% overall filtration.
Compared to surgical masks, N95s provide both much better filtration for the air that goes through the mask, and a much better seal (less air leaking around the mask).
The N95 rating means at least 95% filtration in a lab test with a perfect seal. In practice a good seal provides around 90-99% effectiveness and a bad seal more like 60-80%. It's often hard for untrained users to get a perfect seal on an N95, but it's still a far better seal than a surgical mask. See the section on how to check for mask fit.
N95 recommendations
There are a lot of options, but if it's N95 rated, NIOSH-approved, and from a reputable manufacturer: they all have highly effective filter material, and it mainly comes down to fit / seal quality and comfort. Fit depends on the shape of your face, so you will probably want to try a couple different models to choose the one you like best. I recommend buying small quantities of different types of mask until you find one you like.
Other factors include breathability, durability, and convenience - all of my top recommendations are highly breathable and durable, and convenience varies depending on how you use the masks.
Top recommendation: the 3M Aura (a boat-shaped mask, horizontal trifold). This mask fits most faces but might not fit larger faces. It’s very well-fitting, comfortable, and sturdy, although a downside I found was it doesn’t provide much clearance over my mouth. This is available in two almost-identical models:
3M Aura 9210+ (mostly out of stock right now) (WellBefore, Amazon) if you plan to take the mask on and off multiple times (slightly more durable elastics, also slightly tighter fitting)
3M Aura 9205+ (Home Depot, WellBefore, Amazon) if you plan to take the mask off only once before throwing away (slightly cheaper but less durable elastics)
European equivalent (FFP2): 3M Aura 9320+
Also great:
3M VFlex 9105 (or small size) - duckbill-shaped, horizontal bifold.
WellBefore N95 - cone-shaped, vertical bifold. Compared to the 3M Aura, I find it a bit more convenient but less well-fitting. I found them more sturdy and comfortable than most cone-shaped masks.
3M 9502+ - cone-shaped, vertical bifold
Again, it’s important to find a mask that fits you, everyone has a different face shape.
Some popular models that I don’t recommend, but may be worth trying if the masks above don't work well for you:
Inflexible, cup-shaped models like 3M 8210 - I find these less comfortable (puts a lot of pressure on the small area where it touches your face) and less convenient. And it may be harder to get a good seal as these non-flexible masks only work well on certain face shapes.
Kimberly-Clark 53358 pouch respirator (alternate Amazon link) - duckbill-shaped, horizontal bifold. A lot of people like these (including Wirecutter), but unfortunately the elastic headbands have poor durability and strength - they often start to noticeably lose strength after even a couple of hours of continuous wear. This means it may be hard to get a good seal that lasts the whole day, and it may not be very reusable. Also a lot of people think this mask's duckbill shape looks particularly silly.
See also Wirecutter for more N95 reviews.
Fakes: Counterfeiting of masks is rampant, and Amazon is notoriously bad at dealing with counterfeiting since they mix stock from different sellers together, so it’s safer to buy masks from a reputable retailer. See seller link suggestions for well-reputed suppliers in general as well as links for specific masks here. Here are some suggestions:
Zoro (subsidiary of Grainger)
See this @masknerd video for more info. Many fakes look pretty much identical to the real thing, so the best way to avoid them is to buy from reliable suppliers (avoid Amazon and Ebay). For KN95s, you can identify some low-effort fakes by checking whether the mask has specific mandatory labels printed on it: “KN95”, the manfacturer’s name, and “GB2626-2019” or “GB2626-2006” (these are specific versions of the KN95 standard). If it only says “KN95” it’s probably not a real high-quality mask, but this is far from a surefire test because some real KN95s are missing some of the mandatory labels, and many fakes look just like legitimate masks.
Exhalation valve: Get N95s without an exhalation valve - most models today including all of the above recommendations do not have an exhalation valve. If you do have an N95 with an exhalation valve, it’s best to cover the valve by taping over it, wearing a surgical mask over it, or cutting out a piece of surgical mask and taping that over the valve. That said, CDC studies found that a N95 with an exhalation valve still provides similar or better protection to others than a surgical mask.
KN95 / KF94 / FFP2 masks
N95s are the US standard (approved by NIOSH). They are well-regulated and are typically considered the gold standard here.
KF94s (the Korean standard) and FFP2s (the European standard) are also well-regulated and I would generally consider them as good as N95s assuming you get a good face seal (that’s a big assumption - more on that below).
KN95s (the Chinese standard) are poorly regulated and vary widely in quality - according to CDC, 60% of them failed to actually meet the KN95 standard. Some are as good as N95s, but most aren't, and some don't even come close. Only rely on KN95s that are vetted and independently tested - otherwise they can easily be half as effective as they’re supposed to be.
In my view, the main reasons to consider a KN95/KF94/FFP2 mask instead of a NIOSH-approved N95 are:
Availability (depends a lot on which country you live in - I live in the US, but if you live in Europe or South Korea, you probably have easier access to FFP2 or KF94 masks)
Kids-sized masks (NIOSH does not approve masks for kids)
Ear loops (NIOSH requires all approved N95s to have headbands for better fit and seal)
Now that NIOSH-approved N95s are widely available in the US at least, I personally use these non-NIOSH masks only for the ear loops, mostly for their convenience in short, low-risk situations. But if you find a good non-NIOSH-standard mask that works well for you and seals well to your face, and is from a reputable manufacturer, that can be just as good as a N95.
Also check out @masknerd (Aaron Collins)'s short explainer on mask standards.
Ear loops vs headbands
Ear loops are more convenient than headbands, since they make the mask easier/faster to put on and take off. And different people find headbands or earloops more comfortable. But earloops generally do not provide as good a seal and therefore do not protect you as well, which is why NIOSH-approved N95s must have headbands instead. Ear loop masks typically have a design target of 8-11% max leakage, while N95s have a design target of 1% max leakage. (Those are intended as the max leakage, so the actual leakage in practice should be lower - if you get a good fit.) Additionally, many find ear loops uncomfortable for long-duration wear. But many people have trouble getting headbands to sit right on their heads, or much prefer ear loops - it’s all about personal fit.
Aaron Collins’s testing showed many high-quality ear loop masks with a good seal getting 99% filtration, just as good as N95s with headbands. But other masks that didn’t fit well showed e.g. 80% filtration efficiency as worn on his face, vs 99% when held to the face to fix the seal. Some studies find that typical leakage is much higher with ear loops than headbands, so based on those you should expect your typical leakage with an ear loop mask to be much higher than with a headband mask. But again, it’s all about fit, and fit varies a ton depending on the mask and your face. You can’t easily measure fit quantitatively at home1, but you should do a user seal check to get a rough sense of how good your seal is.
KN95 / KF94 / FFP2 mask suggestions
For KN95s in particular, it’s important to make sure that the mask is well reputed and/or has good certified test results, because the market for them is very poorly regulated. KF94s are much better regulated - as long as the mask is actually coming out of South Korea it’s most likely the real deal.
Some suggestions - there are a ton of different shapes and sizes so the best one for you really depends on the shape of your face:
3M 9501 - cone-shaped, vertical bifold (There’s also the 9502 headband version, which is a NIOSH-approved N95; the 9505 has a neck loop with S clip; and 9132 is the surgical version with headbands.)
Powecom KN95 - cone-shaped, vertical bifold. (There’s also a headband version, but if you want headbands I recommend the N95s above instead.)
MaskLab KF series (FFP22) - boat-shaped, horizontal trifold. Has stylish printed patterns.
Posh KF94 masks - boat-shaped, horizontal trifold. Has stylish printed patterns.
Larger face sizes:
LG Airwasher Adult KF94 (KollecteUSA)
BOTN Large KF94 (BeHealthyUSA)
Smaller face sizes:
BOTN Medium KF94 (BeHealthyUSA)
Dr. Puri Medium (Kmact.com)
Kids masks:
Check out Aaron Collins’s kids masks recommendations video and spreadsheet.
A lot of these are based on @masknerd (Aaron Collins)'s testing and reviews of best N95-like masks - check that out for more reviews and comparisons.
How to check mask fit and seal
Video guides:
Getting a good seal is very important for the mask to provide a high degree of protection. The N95 rating means >95% filtration in a lab test with a perfect seal. In practice a good seal provides around 85-90% effectiveness and a bad seal more like 60-70%. In other words, a N95 with a poor seal is around 3x risk reduction and a good seal around 8x - that’s a very big difference! From microcovid:
Even small holes around the side will drop the mask’s filtration efficiency from 95% to something like 70% (link to study). Thus it’s vital that your mask forms a tight seal around your mouth. You may need to try a few brands until you find one that fits you and your beautiful, unique nose.
A general method to check your mask seal is: while wearing the mask, breathe out forcefully, moving your hands around all edges of the mask to feel for air leaking between your face and the mask - you shouldn’t feel any leaks.
Adjust the fit (the straps, nose band, positioning, etc) until you get a good seal. If you can’t get a good seal, you should try a different model of mask - each mask fits each face differently.
Check around all edges - the top around your nose, the sides, and the bottom. It is also a good idea to check the seal while moving your head around, since the way the mask sits on your face changes as you look up/down or left/right.
This is a general method that works for most masks. NIOSH-approved masks (N95s and P100s, but not KN95s) will come with instructions for the specific mask model on how to wear the mask and check the seal - this is called a "user seal check" or “fit check.” (Not to be confused with the "fit test" - you don’t need that, that’s done by professionals when selecting a mask to ensure it fits. The manuals are aimed at professionals working in potentially highly polluted environments, not at laypeople, so don't worry about following everything in the manual.)
One common question is: if my glasses are fogging, does that mean I have a bad seal? Check out this short video. If your glasses fog right away, that may be a leak - feel with your hands to check for air leaking. If your glasses fog slowly towards the end of your exhalation, that’s probably not a leak, it’s because warm air you exhale slowly rises out of the mask and fogs your glasses. To avoid this, you can try masks that are shaped differently, try taping over the upper parts of the mask to help direct warm air in other directions, or try P100s which usually direct your exhalations away from your glasses to avoid fogging.
This section is for KN95 and higher masks - most surgical and cloth masks cannot provide a good seal, so a lot of air leaks around them. There are strategies to reduce leakage a bit but it’s generally hard to get anything close to a proper seal like you can on a N95 or similar mask.
See also CDC guidance on mask fit.
How long you can reuse a mask
In general, they're still effective until they get difficult to breathe through, wet, or if the elastics lose durability, at which point you should replace them. Also replace masks if they’re physically damaged, soiled, or visibly dirty. This is because:
Wet: This applies to surgical and up, not to cloth masks. Water destroys the electrostatic charge that attracts particles, so getting the mask wet will make it stop working as well. From microcovid: If a N95 gets wet, “its filtration efficiency will drop to around 70%, making it much less effective than an intact N95, but still better than a cloth or surgical mask."
Elastic straps lose durability: Over time the elastic straps get looser as they stretch and lose strength, which can affect the quality of face fit. You may be able to adjust the elastics to re-tighten them.
Physically damaged: Creases or the mask losing its shape can mean it doesn’t fit and seal well. The straps or nose bridge can break or deform. Tears or holes can create leaks.
Soiled or visibly dirty: This is not necessarily about Covid protection, but just like you’d replace anything else you wear that’s too dirty.
Difficult to breathe through: As the filter material absorbs particles it starts to clog up, which makes it harder to breathe through. So this correlates with when it’s starting to lose effectiveness. However, N95 masks are designed to handle 200mg of particles (as much as wearing a mask 24/7 in Shanghai for ~200 days), so except in highly polluted environments the straps will wear out first.
In between uses, just leave your masks in a clean place where they can air out - in the air, in a breathable container such as a paper bag, or in an open bag. Do not clean disposable masks (surgical, N95/KN95/etc) with water, alcohol, heat, or anything else - these damage the mask. (Hospitals use fancy equipment to clean masks, which you do not have or need for personal use.)
As a rule of thumb, you can expect an N95 to last about 40 cumulative hours of use in a relatively clean environment (e.g. office). For use in highly polluted atmospheres, e.g. smoke, I’d replace more frequently - 8 cumulative hours of use is a reasonable rule of thumb. Usually the first thing that forces you to replace the mask is the elastic straps losing strength or the mask getting too dirty from sweat or dropping it on the ground - not the filter material. But you can use this as a rule of thumb for expected lifetime.
So if I’m wearing a N95 for 8 hours a day I might replace after a few days of use, and if I’m wearing intermittently for 1 hour a day I might replace after several weeks of use. However, if supplies are low, you can likely reuse N95s for much longer than this, and even a very worn N95 will be much more protective than a cloth/surgical mask.
The vast majority of particles are caught in the middle layers of the mask, not the surface of the mask, so I also wouldn’t worry too much about catching Covid from handling the mask, but to be safer you can try to handle it mostly by the straps and edges.
To be on the safer side, after wearing a mask, leave it for 3-7 days in the air or a breathable paper bag before wearing it again. This time allows for any viruses to decay before you reuse it. E.g. you can have 7 masks that you rotate between, one for each day of the week. I don’t think this is necessary or that important for safety, though.
For long-term storage (e.g. months), I’d put any opened masks in an airtight bag to avoid collecting dust. (Prefer an airtight bag for long-term storage, breathable bag for short-term storage between uses).
Masks usually have a expiration date listed by the manufacturer - 5 years is typical for many 3M products. CDC tested expired stockpiled N95s (summary results and detailed report) and found that after 10-15 years, masks typically lost a slight amount of filtration. The biggest problems were physical damage to the respirators which could be seen by visual inspection. So, try to stick to the expiration dates if you can easily get new masks, but if you can’t, old expired masks should work fine (and the CDC results show that even damaged respirators can perform well if you can’t get anything else).
Further reading at Wirecutter, NYT, Washington Post.
P100 masks are completely reusable and the replaceable filters last much longer than an N95, see details in the P100 section.
P100 reusable respirators
Effectiveness: 1/20 risk = 95% overall filtration.
Reusable elastomeric respirators with P100 filters3 are the best personal protection from airborne disease and particulate pollution. They fit well, have excellent breathability, and in my experience are even more comfortable than the best N95s. They’re durable, reusable masks with long-lasting, replaceable filters.
The P100 standard means the filter is 99.97% effective, which is a big upgrade from an N95. Just as important is that it is much easier for an untrained user (like me) to get a good seal on these reusable masks compared to most disposable masks.
I personally prefer to use a P100 in many everyday situations (e.g. grocery shopping, public transit, movie theater), not only because they provide the best protection, but also because I find them more comfortable and breathable than N95s.
Advantages (compared to N95s):
Best protection - both due to better face seal and higher filter effectiveness
Excellent breathability
Generally much more comfortable. Comfort depends on a lot of factors so your mileage may vary, but this is the common consensus. Reasons they are more comfortable include being well-shaped to fit a face, superior materials, spreading pressure across a wider area, and better straps.
Generally easier to put on/take off, and to get a good fit and face seal. They are shaped to fit faces without having to unfold or adjust nosewires, and have easy-to-use and more secure headbands.
Reusable instead of disposable
Relatively inexpensive compared to disposable masks. They cost $30-$40 (which is comparable to a pack of N95s) and you only have to replace the filters every ~half year (~$10-$15).
Less fogging of glasses.
Downsides:
They're bulky and less portable (can't just put it in your pocket like a flat-fold N95)
They are harder to speak through - they muffle and distort your voice. It's fine in a quiet environment but hard for others to hear you in a crowded/loud environment. As discussed below, some respirators have designs that help your voice carry better, although still not as well as a N95.
Most (but not all) P100s have an exhalation valve, which you typically want to cover with a piece of surgical mask (takes a few minutes).
People may look at you funny. (On the other hand, you can be the "badass with a fancy mask")
Top recommendations - more detailed compare and contrast below:
3M 7500 or 6500 series half-facepiece reusable respirators
Top recommendation for comfort and breathability
The 3M masks are the most breathable and comfortable P100s I know of. But like most P100s, they have an unfiltered exhalation valve, which you have to cover with e.g. a surgical mask (see instructions below), and poor intelligibility of speech.
There are a couple very similar options, which are all great:
The 3M 7500 series (Amazon, Zoro - also has small/large sizes) would be my default recommendation
The main difference vs the 6500 series is an advanced silicone material that I think is even more comfortable (slightly).
Currently both the 7500s and 6500s cost ~$20 on Amazon, if one costs much more then you can buy another as they’re all pretty similar.
The 3M 6500 Rugged Comfort series is a very close second in my opinion. I think it’s more comfortable than any other respirator I’ve tried other than the 7500. There are two choices:
3M 6502 Rugged Comfort (also has small and large sizes) is a great choice if the 7500 is out of stock or costs much more. It’s also slightly lighter (100 grams vs 135 grams), although personally I didn’t find the weight difference noticeable, the face seal material was a more noticeable difference.
3M 6502QL Rugged Comfort Quick Latch (also has small/large sizes) has a quick latch mechanism that allows you to remove the mask and lower it to around your neck without removing the head straps.
Many people find this convenient, but I personally found that with the non-quick-latch model it is very easy and quick to temporarily take off the mask by simply taking off the head harness while leaving the neck straps on.
If you think this could be convenient for you, I’d recommend this model. If you don't think it’s useful, then prefer the non-quick-latch version because it's a few grams lighter (100 grams vs 110 grams); or the 7500 series.
Sizing: There isn’t good size guidance but medium fits about 80% of the population, large 15%, small 5% - see EnviroSafety's size guide.
Filters: must purchase separately, not included with the mask. Two recommended options - I’d pick the first unless it’s a lot more expensive or out of stock:
3M 2291 P100 disk filters (Zoro, Amazon) - slightly more breathable
3M 2091 P100 disk filters (Zoro, Amazon) - slightly cheaper
To avoid the risk of counterfeit filters, it is safer to buy filters from reputable suppliers (not Amazon). See how to spot counterfeit 3M P100 filters for some tips, but it can be very hard to tell reals and fakes apart.
All of the above mask models are compatible with the same filters.
An option if you need to protect the filters from getting wet (e.g. in the rain) or prefer a sturdier filter that can be wiped down - but I don’t prefer it because it’s much heavier: 3M 7093 P100 cartridge filters (Zoro, Amazon)
If you live in Europe, you can look for P3 R rated filters, e.g. the 2135 or 6035 filters.
These are all readily available in the US (more available than many N95s), but if you live in another country it’s possible your available selection may differ. All of the masks 3M makes are generally good. Additional options include the 6000 series and the HF-800 Secure Click series. Try searching for “3M reusable respirator” at your local supplier. For a overview of some (but not all) of the different models, check out the product catalog.
GVS SPR643 Elipse with Source Control
A great P100 without an exhalation valve
Best P100 in terms of protection to others and intelligibility of your speech, because of the lack of an exhalation valve, but that also makes it a lot less breathable and comfortable.
Sizes: small/medium, medium/large.
Not to be confused with the more standard model with an exhalation valve GVS SPR451 Elipse (note they use the same filters)
The thing that looks like it might be an exhalation valve is not (that's where the exhalation valve is on other GVS Elipse models).
Replacement filters (the mask comes with your first set of filters)
Optional: carrying case
How to choose
Quick flowchart on how to choose that highlights the key differences:
How much are you interacting and talking to others? If a lot, then intelligibility of speech and protection to others are likely important.
How long do you expect to wear the mask at a time? If you will regularly wear for hours, then breathability and comfort are likely especially important.
The GVS SPR643 Elipse with Source Control has much higher intelligibility of speech and protection to others but lower breathability and comfort, and especially much lower comfort when wearing it for hours (probably less comfortable for all-day wear than a good N95).
If the benefits for interacting with others outweigh the lower comfort, pick the GVS SPR643 Elipse with Source Control. Otherwise, pick one of the 3M respirators.
Comparison
There are many factors that affect how well the mask works for you - their importance varies depending on the circumstance and personal preferences. (I even use multiple different P100s to optimize the tradeoffs for different scenarios - but this is mainly just because I have a bunch of different respirators I tried over time. This is likely overkill for most people; switching between N95s and P100s already can give you good options for different scenarios.)
The comparison below is on a scale of 1 (Terrible) to 5 (Excellent). Convenience depends too much on your specific situation, so I give my review without a rating.
3M 6500 or 7500
Protection to self: 5 Excellent
Protection to others: 3.5 Fair
Breathability: 5 Excellent
Comfort: 4 Good
Speech: 2 Poor
Convenience: In my personal experience, this is the easiest N95+ mask to put on and get a good seal. It’s slightly bulkier than the GVS though.
GVS SPR643 Elipse with Source Control
Protection to self: 5 Excellent
Protection to others: 5 Excellent
Breathability: 3 Fair
Comfort: 3 Fair
Speech: 3 Fair
Convenience: Slightly harder (for me) to put on and get a good seal than the 3M P100, slightly more compact in size.
N95 - 3M Aura for comparison
Protection to self: 4 Good
Protection to others: 4 Good
Breathability: 4 Good
Comfort: 3.5 Good
Speech: 4 Good
Convenience: Can fold mostly flat so much better portability than the P100s. Harder to put on and take off because the straps are harder to use than the P100s.
More detailed reviews below.
How to wear and do a user seal check for 3M reusable respirators
Poster guide on how to wear and perform a user seal check: 7500 series and 6500 series (they’re basically identical).
Attaching the filters:
Wearing, user seal check, and cleaning:
The 6500 and 7500 series respirators work almost the same, but you can also find the video guide for the 7500 series here.
The GVS Elipse works similarly, see the included instructions or online guides.
Covering the exhalation valve
Most P100s have an exhalation valve which does not filter your exhalations. It’s best to cover it with a mask/filter to better protect others4, and comply with requirements in airplanes etc which do not allow uncovered exhalation valves.
For the 3M Rugged Comfort:
Cut a a piece of surgical (or KN95+) mask to cover the exhalation valve and tape around it. Do not tape over the valve itself because you want to allow air out through the piece of mask.
Or, after connecting the disk filters, place a surgical mask over the exhalation valve and loop the ear loops around the filter connectors
See another set of instructions here, or some links to DIY 3D printed exhalation valve filter attachments
For the GVS Elipse (standard version with exhalation valve):
The easiest solution I found was to put a surgical mask over the GVS (basically double-masking) by looping the surgical mask’s ear loops around the GVS’s strap attachment points on each side.
You can also cut a piece of surgical mask to cover the exhalation valve similar to above. I found it hard to stick tape to the elastomeric surface of the mask, so the best location I could find was to cut a rectangular piece of surgical mask and attach tape by the sides of the filters.
See some more guides and discussion from fragile credences (the Miller LPR-100 is the same as the GVS Elipse under a different name).
For the GVS Elipse with Source Control, there is no exhalation valve, so you don’t need to do anything. However, from the outside the mask looks the same as the version with an exhalation valve. So if you’re flying, I’d suggest being prepared to cover the mask with a surgical mask in case airline staff question the exhalation valve.
I’ve personally never had trouble with flying with a P100, but I’ve heard anecdotally that on rare occasions airline staff may question or reject them.
Maintenance and filter replacement
The mask itself is completely reusable. See the included instructions for cleaning it - generally, wipe with a damp cloth for a quick cleaning, and every once in a while do a deeper cleaning by removing the filters and washing with mild soap and water. Remember never to wash the filters, only the mask.
The P100 filters will typically last about 6 months of regular use before you need to replace them (much longer than an N95).5 Similar to N95s, the general rule of thumb is that you only need to replace the filters when they get difficult to breathe through, wet, physically damaged, or excessively dirty. See the mask reuse section.
If you're using them in highly polluted environments, e.g. smoke, then the filters may need to be replaced sooner. You can gauge this based on it becoming harder to breathe through or visibly dirty.
Between uses, prefer to leave the mask in the air or in a breathable bag, just like with a N95.
And if you are going to store a mask away for months, I would store the filters or the entire mask in an airtight bag, to avoid it collecting dust. Even when not in use the filters will still absorb particles from the open air, so a typical manufacturer recommendation is to replace filters after 6 months open, although I don’t think it’s important to follow this strictly.
See also 3M's filter replacement guidelines.
More detailed reviews
The biggest difference between my top recommendations is whether the mask has an exhalation valve. Most P100s do, because they were designed more for industrial settings rather than healthcare settings. The GVS Elipse with Source Control is one of the few P100s that does not.
Therefore it does filter your exhalations and provides excellent protection to others.
The moderate protection provided by a P100 with surgical mask over exhalation valve is not bad though. I would still use that over an N95 in high-risk situations, because protecting yourself is also the best way to protect those around you - you can't transmit the virus if you don't get it yourself.
This also means you don’t have to cover the exhalation valve with a surgical mask, which means less fiddling and a less DIY appearance.
It also has unusually high intelligibility of speech for a P100 respirator, albeit still inferior to most other masks. (This is because removing the exhalation valve also means removing the one-way valve system inside of the filters, which allows your voice to carry outwards much better.)
On the other hand, the lack of an exhalation valve makes it significantly less comfortable and breathable. Most pre-pandemic masks had an exhalation valve because it’s more comfortable, by keeping the air inside the mask cooler and less humid. Without an exhalation valve, the mask has a tendency to fill with condensation after a while, making it much less comfortable for long durations.
The filters most likely won't last as long because they are filtering both inhalations and exhalations.
The other main difference is the shape, material, and design differences between the GVS and 3M models.
The 3M and GVS masks have different shape, design, and face seal material. Most people find the 3M mask substantially more comfortable in fit, face seal, and breathability, but opinions vary (from people who hated the feel of the GVS to people who somewhat preferred it).
The GVS is a little more compact and portable.
The 3M was easier to put on and get a good seal, for me personally (your mileage may vary).
The GVS sits a bit less securely on the head because of its headband strap vs the 3M’s head harness. I also had trouble with the GVS headband straps coming loose from the strap adjusters.
The GVS is slightly lighter (4.5 oz) than the 3M (5.3 oz) - not enough to make a substantial difference in how it feels to wear.
Most people find the 3M more comfortable than the GVS. However, if you like the GVS mask’s shape, material, and design, and you do want an exhalation valve, you can consider the GVS SPR451 Elipse (standard version with exhalation valve). They are pretty much identical from the outside and in how they seal to your face, the difference is the one-way valves on the inside. I got one before the Source Control version was available, but don’t use it anymore because I prefer either the 3M or the GVS Elipse with Source Control.
I also tried the 3M HF-800 with Speaking Diaphragm. This mask has a speaking diaphragm for higher intelligibility of speech, but in my experience the speaking diaphgragm was underwhelming, and the GVS SPR643 Elipse with Source Control gets similar intelligibility of speech (by eliminating the one-way-valve design), and is superior in protection to others, weight, and size; but the 3M does have a more comfortable material and breathability (in my opinion). Compared to the 3M 7500 and 6500 series, the HF-800 series is a newer and more advanced but I didn’t find the advantages especially valuable to me, and it’s noticeably larger and heavier which makes it somewhat less comfortable (the HF-802SD with P100 square-pancake filters is 225g, vs the 7500 with P100 pancake filters is 150g). I think it’s a great mask, like most 3M respirators, but I preferred the 7500 or 6500 as long as I don’t need to talk much - I think it’s a viable option for speaking situations depending on personal preference. See some review comments here. Note it uses Secure Click filters which are different and non-interchangeable with the bayonet connector filters for the other 3M models.
3M P100 filter reviews
There is a wide range of options for filters for the 3M reusable respirators, for different applications. Filters with bayonet-type connectors should work with the 3M 6500 and 7500 respirators.
For the purposes of this guide, we are focused on particulate protection, which includes Covid aerosols - we don’t need to filter gases and vapors (and adding unnecessary filtering for those adds weight, pressure drop, and cost). I choose the P100 filters for the best particulate protection with great breathability, and they are also the most widely available. But any of P, N, or R rated filters would work6, and 99 or even 95 rated filters should still give strong protection.
My favorite: 3M 2291 P100 disk filters (Zoro, Amazon). This is an advanced version with better breathability (3M says 25% more breathable and
the pressure drop, which measures effort to inhale, is about ~40% lower than the more common 2091 filters)
Also great: 3M 2091 P100 disk filters (Zoro, Amazon). More common, slightly cheaper, slightly less breathable.
Option for wet environments or if you need a sturdier filter: 3M 7093 P100 cartridge filters (Zoro, Amazon). I prefer the disk filters over the cartridge filters because of their lighter weight, which makes the mask overall much more comfortable in my opinion. Cartridge filters protect the filters from getting wet, which can be useful if you’re e.g. in the rain often; and you can easily wipe down the outside in case you need to clean it. But they are a lot heavier - the 3M 7502 with 2291 filters is 150g = 5.2oz, and I think the 7093 filters add about 100g, so 65% heavier.
So, what masks do I personally use in what situations?
As you have probably guessed, I have tried a lot of different masks over time to find the ones that work best for me, and I use several different masks in different situations, because I can afford it and I’m picky about these things. It’s certainly not necessary for most people, you can do great with just one or two all-purpose masks - my general recommendation for that is a N95 (great for intermittent wear or if you need to speak a lot) or a P100 (best protection and comfort).
This is what I personally do, and your choices will vary depending on your situation, risk profile, personal preferences, and what masks fit your face personally.
A P100 (3M 7502 is my favorite) is my choice if I’m going to be wearing the mask for more than a few minutes, I don’t need the mask to fit in my pocket, and talking isn’t the main thing I’m doing. E.g. grocery shopping, public transit, movie theater, etc. They are my choice for these situations regardless of risk level, because of their better comfort. Of course, they are also the best protection, so they are also the best choice for any high-risk situation.
A N95 (3M Aura is my favorite) is my default mask for most other situations. Most common for me is if I’m wearing the mask intermittently or need to speak a lot.
A KN95 with ear loops or a surgical mask for conveniently and quickly putting on a mask for a couple minutes in low-risk situations, or in between bites if I need to eat in a high-risk situation.
A cloth or similar mask as cold-weather wear to keep my face warm - I don’t use them for Covid protection. (Non-cloth masks are an option for warmth too, but are generally less warm and cover less of your face.)
No mask at all for Covid protection in outdoors situations. I wear a N95 or P100 mask outdoors for bad air quality (smoke etc). My exceptions to this general rule would be if someone is known Covid-positive and for some reason I need to interact with them, or if social pressure demands it.
No mask for low-risk indoors situations (vaccinations required, high-quality air filtration, not too crowded, or Covid case rates are very low) where I view the mask as not worth it in terms of cost/benefit (e.g. eating/drinking, socializing, or just comfort). This is of course a judgement call, but see my covid risk analysis article for how I think about the tradeoffs.
Want more links?
Mask testing project: FAQ, spreadsheet
Mask picks video (from Mar 2021 so more focused on KF94/KN95 than N95)
Wirecutter reviews: cloth, N95/KN95/surgical, P100
Mask reuse guides from Wirecutter, NYT, Washington Post.
Acknowledgements
Thanks for recommendations and input from:
Eric on N95 and P100 picks
Amy on mask seal check
Florin on P100 picks
Changelog of major updates
Feb 2022:
Added several more picks for different situations or in case top picks are out of stock.
Jan 2022:
Updated reviews for P100s and N95s based on further testing.
P100: Added 3M 7500 respirator and 3M 2291 filters as top recommendations.
N95: Added more links to currently in-stock suppliers.
Added more KF94 and FFP2 suggestions.
Added “So, what masks do I personally use in what situations?” section.
Updated mask lifespan estimates based on further research.
Added more video guides on mask wearing and fitting.
Dec 2021 (updated since my original Google Doc version of this guide): New N95 and P100 picks, expanded seal check guide
Have input on which masks have worked or not worked for you? Let me know!
This article is an evergreen, living document that I will continue updating over time.
Like with all my posts, feedback/questions/comments are very welcome - feel free to send me an email or message, or comment on this post.
They are independently tested to meet the FFP2 standard but are not officially certified as of the time of this writing. I consider this good enough for me, and much more reputable than a typical KN95.
To be more precise, P100s aren’t all reusable elastomeric respirators (e.g. Moldex has disposable N100s and P100s) and reusable elastomeric respirators don’t necessarily use P100 filters (e.g. there’s a N95 filter option for the 3M elastomeric respirators). But they commonly go together, and I recommend a reusable elastomeric respirator with a P100 filter. So I’ll just call these P100s for short.
There are limited studies on the effect of elastomeric respirator exhalation valves on source control for aerosols. CDC studies found that disposable N95 respirators provided source control at least as effective as surgical masks, but elastomerics usually direct all air out through the unfiltered exhalation valve wheras for an FFR at least some of your exhalations would likely go through the mask material. This study found elastomeric respirators provide source control for droplets at least as good as surgical masks, but I interpret this study as providing no usable data on aerosols (despite what the abstract says).
It’s less clear how long the filters last on the GVS SPR643 Elipse with Source Control. The filters may have a shorter lifetime since they have to filter moist exhalations as well as inhalations, but based on discussion here I believe they are still designed to last for months of all-day hospital use.
3M doesn’t sell N100 or R100 disk filters, but if they did those would also be equivalent for our purposes. (I presume that there wasn’t enough advantage to manufacturing a separate line of N100 filters.)