Some General info about various breathing devices

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peakbagger

Minister of Fire
Jul 11, 2008
6,470
Northern NH
I used to work in the pulp and paper industry and emergency breathing apparatus was part of the job. Some general observations from having to deal with it over the years, not necessarily complete but a primer.

The vast majority of passive negative pressure breathing devices will not work with facial hair. If you need to use your lungs to breath through a filter its a negative pressure device. The sealing edge has to be on clean shaven skin. I have seen many people claim they can pass a fit test with facial hair in the sealing areas but never seen anyone who has. We kept shaving cream and disposable razors for those who showed up at the gate and needed to visit the site. They usually could keep their mustache.

The infamous N95 masks in the news are rated to remove 95% of a specific particle size. To use them on the job everyone using them needs to have a documented fit test. Its pretty simple, don the mask and bend the nose bridge to fit then the qualified fit tester squirts some odorant like citrus around your face while they have you read something out loud from a page. if you smell the odorant, then you need to readjust and retest. Many folks just fake it the first time and say they don't smell it. Unless you crank the straps tight its real easy to have leaks when you move.

The next grade up is half mask respirator equipped with P100 filters (note there are also P99s but I never saw them). They remove 99.997% of the same particle size. The particle size is larger than the corona virus but since its spread on droplets the hope is that the droplets which are larger will get trapped in the process of going through the filter. P100 filters are used by Asbestos removal workers and painters. The big down side is in order to use a half mask filter you need to have pulmonary function test prior to a fit test. This requires a trained professional to have you blow into machine that measures your lung capacity. Its measure of how elastic the lungs are. Smokers, those with long term occupational exposure and other lung conditions can not pass the test. Many of the union welders that showed up at our site got paid to pick up trash if it was union job as they couldn't not pass the PFT. Once the PFT is done, then a similar fit test to the N95 mask is done. There are usually several sizes of masks to fit different people. The approval is specific to a particular size and device, once we were fit tested we were given one for our own use and expected to maintain it. There are different filters for different exposures that screw/attach to the mask . We used an activated carbon filter designed for the hazardous gases we may encounter usually topped off with P100 filter that usually is purple. The P100s were cheap compared to the activated carbon filters so it made sense to protect the expensive one. Autobody painters use a similar setup. Medical folks would not need the activated carbon. The P100s do impose some resistance to breathing and as they clog up the resistance increases. it takes awhile to get used to wearing one for several hours at a stretch. The half masks can be disassembled and sanitized in few minutes. Once used they are supposed to be sanitized before reuse. Pulmonary Function Testing, fit testing and buying and assigning masks costs money and potentially reduces the number of qualified workers plus possibly identifies disability cases, so many firms and governments elect not to use them and stick with the disposable N95s. If we didn't follow the rules and OSHA came a knocking it was inevitable that OSHA would check the records and cite us for deficiencies in our program. No doubt lawyers are salivating over the potential lawsuits although occupation injuries are generally covered by workman's comp so they need to weasel their way around to sue.

There are also full face masks with cartridge's that are similar to the half masks. They are more expensive, harder to fit test but better coverage.

The next step up is positively pressurized full or half masks. There is a battery or line powered blower that either attaches to users belt or may be a fixed device with hoses. The blower can be equipped with filters or just can draw air from a different location. I have a non certified one that plugs into the wall for sandblasting and painting and there are also welding helmets equipped for supplied air. The mask is always pressurized so the user cant breath in outdoor air. If used in industry a person with poor lung function may be approved to use them on a case by case basis as the blowers assist with the breathing but usually they are used by people who have had a clean PFT. Approved positive pressure gear is quite expensive but when working on dangerous gases they are superior to negative pressure units.

The ultimate for us was SCBA like firemen use. Its a full mask fed from compressed air tanks. They were mostly rescue only as the tanks have limited life. They are pressurized so in theory they can supply air to someone with facial hair but the tanks will drain quickly due to lack of seal. There was a full training course to use them and when I took an entry level course they made us run up and down several flights of stairs until the warning bell rang that we were almost out of air and then we had to make our way out on the reserve. That was years ago and expect a fireman could fill in a lot of details on the process. I don't see them practical for medical use. Supplied air is lot lighter.

In the case of the negative pressure devices, the disposable cartridges have a shelf life. I haven't worked in the industry for 12 plus years but I do have a collection of half mask respirators and even have a N95 in stock most out of date but good enough for my hobbies. The N95 is definitely well used from boat building, nothing I could donate and there really is no legal demand for the half masks as they are not something that someone can use officially unless the proper paperwork and testing is in place. Digging around I have one relatively mint half mask with recent P-100 filters in a ziplock bag in the car if I really needed to get up close and personal to someone. In that case I would most likely be covered with the virus droplets so unless I washed down right away correctly its highly likely I would probably get it in my lungs from secondary contact.

Unlike the CV-19 virus, the stuff we needed the gear for was hazardous gases that could kill folks at low concentrations. It was real obvious if there was leak in the masks as the gases all were very noticeable. The big three were Hydrogen Sulfide (rotten eggs) Methyl Mercaptan (skunk smell) and chlorine or chlorine dioxide. In some cases it could be absorbed by the skin. Someone had to get their game right the first time using the gear.
 
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Ashful

Minister of Fire
Mar 7, 2012
15,715
Philadelphia
Very informative post, peakbagger. If anyone here hasn't moved to positive-pressure full-face masks for spraying paint, you don't know what you're missing! Had to buy a rig for spraying linear polyurethanes (isocyanate) fifteen years ago, and have never gone back.

No need to shave with positive pressure, but you'll look awful goofy wearing it outside the spray booth. >>
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
25,475
central pa
Very informative post, peakbagger. If anyone here hasn't moved to positive-pressure full-face masks for spraying paint, you don't know what you're missing! Had to buy a rig for spraying linear polyurethanes (isocyanate) fifteen years ago, and have never gone back.

No need to shave with positive pressure, but you'll look awful goofy wearing it outside the spray booth. >>
There are lots of positive pressure options out there. We have been using these for a few years. https://pekesafety.com/products/powercap-active-particulate-papr
 

Ashful

Minister of Fire
Mar 7, 2012
15,715
Philadelphia
Nice! I don't think I was even aware of options so compact, back when I invested in my rig.

Mine's old-school, a filtered lunch box blower you set outside the shop, with an umbilical hose fed thru a bulkhead in the wall or under a curtain. Full bunny suit and that rig for spraying linear polyurethane, makes me look like I'm working on the latest biohazard, but it gets the job done.

The thing I've grown to appreciate about the positive pressure mask, and the reason I always regret trying to do a quick job with a standard activated carbon negative-pressure mask, is the clear fog-free view. Any time I try to paint with full un-vented goggles and a negative-pressure mask, they fog up due to my sweat and activity, and vented goggles allow the paint solvent vapors to burn my eyes. The full face positive-pressure mask keeps cool fresh air flowing across the glass in the full-face mask, so it never fogs, and always stays clear. Heck, it even helps keep me cooler, when I'm fully suited up.
 

AlbergSteve

Minister of Fire
Dec 11, 2017
840
n
Why the PFT? Our construction company had a couple of people trained to do fit testing, required by WCB. We did a lot of nasty demo and asbestos work and a PFT was never required for mask fitting. If good lung function was needed to wear a half mask, it would eliminate about 90% of our staff.
 

peakbagger

Minister of Fire
Jul 11, 2008
6,470
Northern NH
Why the PFT? Our construction company had a couple of people trained to do fit testing, required by WCB. We did a lot of nasty demo and asbestos work and a PFT was never required for mask fitting. If good lung function was needed to wear a half mask, it would eliminate about 90% of our staff.
Maybe the rules are different in Canada then the US? or possibly OSHA changed the rules (its been 12 years since I had to deal with it.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
25,475
central pa
Nice! I don't think I was even aware of options so compact, back when I invested in my rig.

Mine's old-school, a filtered lunch box blower you set outside the shop, with an umbilical hose fed thru a bulkhead in the wall or under a curtain. Full bunny suit and that rig for spraying linear polyurethane, makes me look like I'm working on the latest biohazard, but it gets the job done.

The thing I've grown to appreciate about the positive pressure mask, and the reason I always regret trying to do a quick job with a standard activated carbon negative-pressure mask, is the clear fog-free view. Any time I try to paint with full un-vented goggles and a negative-pressure mask, they fog up due to my sweat and activity, and vented goggles allow the paint solvent vapors to burn my eyes. The full face positive-pressure mask keeps cool fresh air flowing across the glass in the full-face mask, so it never fogs, and always stays clear. Heck, it even helps keep me cooler, when I'm fully suited up.
Before that one we used a 3m system which was probably similar to what you use only with a belt mounted filter and blower pack powered by battery. They have been available for over 20 years.
 

peakbagger

Minister of Fire
Jul 11, 2008
6,470
Northern NH
I have the Breathe Cool system which is "lunchbox" sized blower with a variable speed knob and a long hose that hooks to my Sandblast/painting hood. It does keep me cool on hot day. The hood has removable clear shields that attach the faceplate so the faceplate doesn't get scratched or dirty. There is a go/no go flowmeter for setting the flow. I just set the blower around a corner well away from where I am working. Its pretty low bucks compared to NIOSH rated unit. Definitely funky looking when running but it does its job for the amount of work I do.
 

Ashful

Minister of Fire
Mar 7, 2012
15,715
Philadelphia
Before that one we used a 3m system which was probably similar to what you use only with a belt mounted filter and blower pack powered by battery. They have been available for over 20 years.
I think spraying atomized isocyanate usually dictates having a fresh outside air intake, unless it’s a very high-dollar filter unit. Mine is marketed toward extreme hobbyists, or small independent shops, definitely not industrial grade.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
25,475
central pa
I think spraying atomized isocyanate usually dictates having a fresh outside air intake, unless it’s a very high-dollar filter unit. Mine is marketed toward extreme hobbyists, or small independent shops, definitely not industrial grade.
Yes for your use outside air certainly is easier and more economical.
 

CaptSpiff

Minister of Fire
Jan 13, 2014
550
Long Island, NY

bholler

Chimney sweep
Staff member
Jan 14, 2014
25,475
central pa
Just a friendly heads-up: when I started surfing this site my Norton twice alerted me of "malicious activity".
Also, I did not bother running a "who is" on them, but their "About Us" page hides their geographic location which always puts me off.
Really? That is surprising I have never gotten anything like that. Peke is a very well respected English company supplying many govt agencies around the world as well as lots of industries. They are also one of the few catering directly to the chimney industry.
 
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CaptSpiff

Minister of Fire
Jan 13, 2014
550
Long Island, NY
Really? That is surprising I have never gotten anything like that. Peke is a very well respected English company supplying many govt agencies around the world as well as lots of industries. They are also one of the few catering directly to the chimney industry.
Yup, I noticed the "chimney industry" connection and that's what started me surfing the site.
They must be using some data-mining routines which my Norton doesn't like.
 

SpaceBus

Minister of Fire
Nov 18, 2018
6,117
Downeast Maine
We got some eclipse half mask p100 respirators (I think with activated charcoal as well as the purple filters) for demo work on drywall and other dirty stuff. These have a nice soft seal that actually did work with my beard, but I've been keeping a clean face in light of the virus. I also have a real US Army full face pro mask with cartridge that my supply buddy gave me when they got phased out. I think I've worn it twice just to make sure it works. January 2019 my doctor told me I had to "live like a Chinese person" so I did buy a pair of n95 masks with replaceable filters. I think these are better suited to dirty air more than virus particles, but they are still nice to have right now. My wife and I use them when we have to leave for food.
 

Highbeam

Minister of Fire
Dec 28, 2006
19,146
Mt. Rainier Foothills, WA
Just since we like pictures. I have two of the halfmasks with fresh p100 filters. They are so much better than n95 masks because they have the exhale valve that makes it easier to breathe and cuts down moisture to the filters.

I bought the masks for blowing cellulose insulation but have used them many times since. Very comfortable and easy to fit. Earthquakes with collapsed buildings, forest fires, volcanic ash event, or even dusty house projects.

Buy at Home Depot for pretty cheap money. Only slightly more than n95 masks.
 

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ben94122

Burning Hunk
Sep 4, 2017
135
California
I agree: the exhale valve is so nice. The thing I don't like about surgical masks and disposable N95s is that you smell your own breath all day. And fog your eye protection. That's two things. The problem with halfmasks for patient care is that you look like a space alien. Some people are taping photos of themselves on the front of their gowns so patients have a smiling face to look at...
 

SpaceBus

Minister of Fire
Nov 18, 2018
6,117
Downeast Maine
I agree: the exhale valve is so nice. The thing I don't like about surgical masks and disposable N95s is that you smell your own breath all day. And fog your eye protection. That's two things. The problem with halfmasks for patient care is that you look like a space alien. Some people are taping photos of themselves on the front of their gowns so patients have a smiling face to look at...
I have the n95 masks with a filter pocket and a valve, but it still fogs up my eye pro whenever I wear it. Same for any face covering really, except for a true half or full mask.
 
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peakbagger

Minister of Fire
Jul 11, 2008
6,470
Northern NH
During the rare times I use N95 filters, they inevitable leak under my cheek. I much prefer a half mask with exhale valve. The P-100s I have in stock are a small diameter then the 3Ms shown in the photo.
 

SpaceBus

Minister of Fire
Nov 18, 2018
6,117
Downeast Maine
I was going to post a link to the half masks we bought for renovating the house, but the listing has vanished from amazon. Here's a photo, it's an elipse spr473 half mask p100. It works great when running the chipper/shredder as well.
 

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coaly

Fisher Moderator
Staff member
Dec 22, 2007
4,267
NE PA
I cut up an old N95 mask and put it over the exhale valve to protect others. I don’t see how many liquid particles could get out of the check valve and cover, but if anyone knows what they’re looking at they know a respirator only protects the wearer. Maybe they’ll realize I’m protecting them too. Ordered 20 of the particle only P100 filters when this started instead of the harder to breath through Multigas cartridges I had. Much better for long duration wearing. My glasses fog, so I don’t like surgical type masks. MSA Comfo half face.

EFC22BCD-D636-4855-A979-14098CCB1515.jpeg
 
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Ashful

Minister of Fire
Mar 7, 2012
15,715
Philadelphia
As far as I know, the official word is still that this virus is only transmitted by liquid droplet or contact, it cannot be aerosolized. You cannot catch it by breathing the air near an infected person, unless they sneeze or cough, putting liquid droplets onto you.

Masks are great when put on the infected person, for protecting others from any droplets they may be spraying when they cough or sneeze. When worn by healthy patients, they mostly just serve the purpose of keeping you from touching your face, or that rare scenario where someone sneezes or coughs right on your nose and mouth but somehow miraculously misses your eyes.

The no-valve masks are likely better than valve masks, in this application, as we all know the valves on most cheap masks leak liquid. If worn by a sick person, they may still pass water vapor and even drip on occasion.
 

Highbeam

Minister of Fire
Dec 28, 2006
19,146
Mt. Rainier Foothills, WA
I agree that the exhale valve makes these types of masks a personal protection device and not a device to protect other people from you. This is because you exhale unfiltered air. Maybe it depends on why you’re wearing a mask.
 

SpaceBus

Minister of Fire
Nov 18, 2018
6,117
Downeast Maine
As far as I know, the official word is still that this virus is only transmitted by liquid droplet or contact, it cannot be aerosolized. You cannot catch it by breathing the air near an infected person, unless they sneeze or cough, putting liquid droplets onto you.

Masks are great when put on the infected person, for protecting others from any droplets they may be spraying when they cough or sneeze. When worn by healthy patients, they mostly just serve the purpose of keeping you from touching your face, or that rare scenario where someone sneezes or coughs right on your nose and mouth but somehow miraculously misses your eyes.

The no-valve masks are likely better than valve masks, in this application, as we all know the valves on most cheap masks leak liquid. If worn by a sick person, they may still pass water vapor and even drip on occasion.
I've read plenty and heard virologist say that it can absolutely aerosolize. Most doctors not associated with the CDC are saying all persons should have a mask on if they go out. The virus can only enter your body through mucosal membranes.
 

CaptSpiff

Minister of Fire
Jan 13, 2014
550
Long Island, NY
I've read plenty and heard virologist say that it can absolutely aerosolize. Most doctors not associated with the CDC are saying all persons should have a mask on if they go out. The virus can only enter your body through mucosal membranes.
Yup, every person who wears glasses learns at an early age that breathing on the lenses transfers warm moist vapor onto the lenses and makes them easier to clean. There's lots of moisture in one's regular exhalations. You don't need to sneeze or cough.

That knowledge made me made me quite pissed when the "medical experts" went on the spin mission to convince folks that "masks don't work and could be harmful". Like the parent of a 2 year old "talking down" or lying to him for his own good. Just another nail in the coffin of trust.
 

SpaceBus

Minister of Fire
Nov 18, 2018
6,117
Downeast Maine
Yup, every person who wears glasses learns at an early age that breathing on the lenses transfers warm moist vapor onto the lenses and makes them easier to clean. There's lots of moisture in one's regular exhalations. You don't need to sneeze or cough.

That knowledge made me made me quite pissed when the "medical experts" went on the spin mission to convince folks that "masks don't work and could be harmful". Like the parent of a 2 year old "talking down" or lying to him for his own good. Just another nail in the coffin of trust.
I think they wanted to keep people from panic buying masks.