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.
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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