The 3M 6200 Half-Mask Reusable Respirator

The premise

To protect myself from Delhi's 1 Outside of the winter months, Delhi's pollution is just as bad as any major Indian city. So you should really be wearing a mask no matter what city you're in. air pollution, I had been wearing disposable N95 respirators for some time - namely, the 3M Aura 1870+, which I bought from Amazon for ₹40-50 per unit (usually in packs of 10 or 20).

Wearing a respirator in public - especially if you use public transport as I do - is also very helpful in protecting against coughs, colds, fevers, and COVID-19. Even when my whole family got a really bad respiratory infection last year, I was singularly free of it.

I also hate Delhi's pervasive surveillance, and wearing a mask is also my little way of trying to frustrate it.

However, disposable masks aren't really meant to be worn for more than one day. To save money, I would try to make each one last for a week or two, but their elastic bands would loosen after a single wear and the fit would suffer. Quite often, the bands would break.

I also don't like the waste created by disposable items, and prefer reusable items wherever possible.

Reusable elastomeric respirators

I was aware of reusable elastomeric respirators since the pandemic started. But I had never seen anyone else wearing one. It would look quite weird in India, I was told - and this social stigma forced me to stick with disposables.

This year, I joined Mastodon. I saw people wearing reusable elastomeric respirators in their Mastodon profile pictures. While none of these people were from India, it nevertheless inspired me to get a reusable respirator too, social stigma be damned. It would not be the first time I was doing something that made me look different from others.

Inspired by my friend and fellow software freedom activist Ravi Dwivedi, I was also determined to stop buying things online. After failing to find a reusable respirator at my local pharmacy, I found (via sites like IndiaMart) a shop in Chawri Bazar called Delhi Safety House that supposedly kept them.

Visiting Chawri Bazar, I discovered that it was a whole market of industrial supplies, including a number of shops dedicated to PPE. I made sure to add them to OpenStreetMap.

I got myself a 3M 6200 half-face reusable respirator, which cost me ₹1000. This is the medium size among 3M's entry-level 6000 series of respirators - there's also the 6100 (small) and 6300 (large).

Reusable masks also need a filter or cartridge, and once again I chose one of the cheaper options - a pair of 3M P100 2091 filters 2 "N95" and "P100" are NIOSH air filtration ratings. The "N" in "N95" means "not resistant to oil mists", and the "95" means that at least 95% of particles are filtered out. The "P" in "P100" means "highly resistant to oil mists", and the "100" means that at least 99.97% of particles are filtered out. See en.wikipedia.org/wiki/NIOSH​_air​_filtration​_rating. for ₹500.

(For better or worse, I opted to get these without a bill, so these prices are exclusive of 18% GST.)

The positives

First off - even though it is an entry-level model, it is seriously comfortable. A disposable respirator starts to become uncomfortable after a while. Not this one - you can wear it for hours on end without much discomfort.

Secondly, I was surprised to discover that the breathing resistance on this respirator is better than any disposable respirator or cloth mask 3 Given that they don't form a perfect seal to begin with, this goes to show just how high the breathing resistance of cotton is. I've ever worn.

With cloth masks and disposable N95 respirators, I would struggle to breathe if I were to even walk somewhat briskly. But wearing the 6200 with the P100 filters, I can walk as fast as I want. And resistance during normal breathing is so low, you can hardly tell you're wearing a respirator. It's probably due in part to the larger surface area of the filters, and the exhalation valve.

(I guess it is to be expected. You've probably seen soldiers wear full-face elastomeric respirators to protect against chemical warfare. They do need to be able to run about in that.)

Wearing the 3M 6200 with 3M 2091 filters and carrying a 15kg rucksack and a 1-2kg waist pack, I was able to briskly walk from home to the bus stop. Then, carrying the same load, I was able to run along a railway platform - weaving between crowds, climbing over and under rope barriers - from roughly one end to the other. All with no breathlessness outside the ordinary.

It's also really effective. You're typically supposed to shave your beard for tight-fitting respirators like these, but even with my 5-10mm beard, I get a pretty good seal.

The filters have lasted me over a month of daily wear. They're starting to get dirty, and I'm starting to notice some breathing resistance that wasn't there before, so I guess I should be replacing them about once a month. Note that Delhi's AQI was around 100~150 during this time - results may vary with a different AQI.

The negatives

Frequent donning and doffing

Update - I realized later that there is a way to drop this mask down. Loosen the top straps, then pull the head harness back behind your neck. Preferably follow up by unbuckling the bottom straps, so the mask can rest flat against your sternum. All this still takes two hands and is not as fast as the Quick Latch, but it's definitely a handy trick to know if you have a 6000 series mask.

It takes a few seconds - and two hands - to don (wear) and doff (take off) the respirator. If you're like me, you'll also do a seal check each time you don it, adjust the mask if the seal check fails, and try again until the seal check succeeds. All of this can be troublesome if you have to take the respirator off frequently.

The thin plastic head harness is also somewhat vulnerable to getting bashed in if the respirator is just hanging around your neck, so you have to pack the whole thing away to be safe…but that's not always easy to do.

For these reasons, I'm aiming to upgrade to a 3M 6500 QL series mask - the "QL" stands for "Quick Latch", and it's a feature which makes the mask really easy to don and doff, all without taking off the head harness.

Here's an advert from 3M demonstrating the Quick Latch. I've seen some video reviews too - it's really as easy as shown.

It's also compatible with the filters I already have, so it's easy to upgrade to.

Intelligibility of speech

With the 6200, I discovered that the intelligibility of speech suffers a lot. You get used to speaking louder and clearer - which I'd say is not at all a bad thing. But in noisy environments, the issue is even more pronounced.

Here are some videos by Gerard Hughes demonstrating the difference in intelligibility between some respirators, including the 3M 6200 at the end.

There are respirators with speech diaphragms/speaking diaphragms which help with this issue. I may get one in the future, but they're pricey, and none of them are compatible with the filters I currently have.

Here are some respirators I found which feature speaking diaphragms -

  1. 3M Secure Click HF-800 SD series. These are 3M's latest and greatest line of respirators, with a host of features not found anywhere else on the market. Here's a demo video of the HF-803SD by Sydney Tools.

    A 3M representative told me that it would cost around ₹3600 for the mask and around ₹1200 for a pair of particulate filters - almost ₹5000 in all. I like them…but I can't afford that right now 🥲

  2. Honeywell North RU8500
  3. MSA Advantage 900

Form factor of 3M P100 2091 filters

The filters I have are rather large and take up a fair bit of my field of view. You're also supposed to replace them if they get wet, so I live in constant fear of random drops of water.

I want to try the 3M P100 7093 cartridges - they provide the same level of protection (P100) in an enclosed cartridge form factor, which provides a greater field of view and also protects the filters from splashes. I also expect them to last longer. They're more expensive, though - about ₹1200-₹1300 for a pair.

An alternative route could be to get 3M N95 5N11 filter pads (I think you can get a pack of 10 for ₹1680 - around ₹340 a pair), in combination with 3M Filter Adapter 603 and 3M 501 Filter Retainers. These three combine to make an N95 cartridge in which you can replace the filter pads. This video shows what it looks like - 3M™ 6000 Series Half Facepiece Respirator with 5N11 Combination in Healthcare.

Now, sure, the N95 filter pads are less protective than the P100 filters. And sure, 3M says that each filter retainer is only meant to be used once, otherwise you risk air leakage. But if you are fine with those caveats, this can be a cheaper alternative to P100 filters in lower-risk situations. And the resulting cartridges have a swept-back design, which remedies the field of view issue.

Source control

All 3M reusable respirators have exhalation valves, which means the air you exhale does not pass through the filters. This makes them a lot more comfortable for the wearer, but it also means that you can transmit infectious respiratory diseases like the common cold and COVID-19 to those around you.

You can get 3M 604 exhalation valve filters for 3M 6000 series respirators, 4 Mysteriously, only this series! but I haven't been able to find them at any brick-and-mortar stores in Chawri Bazar. There are also designs for 3D-printable exhalation valve filters online, which I might try sometime.

Heat and sweat

While this mask was perfectly comfortable to wear in Delhi's winter, it became a different matter with the onset of summer. As I wandered the streets of Chandni Chowk on an April afternoon, the edges of the mask got quite sweaty.

The 3M 6500 QL series I mentioned above also has a silicone facepiece (which is supposed to be more comfortable) and something 3M calls a "Cool Flow valve", which is supposed to prevent heat buildup inside the mask. I'm curious to know how much of an improvement these provide when wearing the mask in hot environments.

Other things to note

Most elastomeric respirators come in small, medium, and large sizes, so if one doesn't fit you too well, you can try another (and you'll be able to use the same filters and cartridges). Ideally, we would be able to get fit-tested, but unfortunately, I couldn't find any place in India that can perform respirator fit-testing.

3M provides replacement parts for all their respirators, in case anything degrades or breaks. I haven't had to buy any yet, but it's good to have a repairable product.

As with any reusable item, these need to be cleaned. It's fairly easy - remove the filters/cartridges, mix some dishwash (Vim etc) in some water, and gently rinse the facepiece in the soapwater. Then rinse a few times in fresh water, and leave it to air dry.

People call it a "gas mask" and think it will protect me from anything up to nuclear fallout, but the particulate filters only protect against, well, particulates - dust, particulate pollution, viruses, and so on. There are other cartridges for gases and vapors. And 3M warns that these half-masks are not for use in IDLH (Immediately Dangerous to Life and Health) situations. You're better off with full-face respirators for that, which also protect your eyes and face.

(And no, it does not supply oxygen to you - at least not until you hook it up to a supplied-air system…)

The first time I wore this outside, I was nervous as hell…until I saw that most people didn't even notice me.

It's been over a month since I got it, and I've been wearing it outside on a daily basis. A lot of people do double-takes, which I don't really mind. Some stare too much, so I gently look back at them to help them get back to their senses. But most of time I have my own business to attend to, so who cares about who's looking?

All said and done, I'm definitely not going back to disposable masks, and I recommend everyone get themselves a reusable respirator…and also do your part in making the air cleaner.

  • Quit driving. Start walking, cycling, and using public transport. Demand better infrastructure for all three. Electric cars are not made to save the planet, they're made to save the car industry.
  • Stop using gas stoves and wood fires. Switch to induction cooktops and electric heaters.
  • Stop burning waste.
  • Speak up and educate others.