Coronavirus: More Thoughts on N95 Masks, by Survivormann99

First, I should mention that I have no medical training beyond the first aid level. The purpose of this article is to address questions that have been of concern to me, and to toss out ideas on which others with more training and experience can comment on .

As the news about the coronavirus was gaining more attention nationally, a relative pooh-poohed the coronavirus threat by citing the annual number of flu fatalities as being a basis for comparison. In a subsequent response, he said, “Well, I’m going to keep doing what I always do. After all, what can I do about it here?” I responded, “You mean like buying a bunch of N95 masks, hand sanitizer, and avoiding crowds.” I heard only crickets after that point.

I have another relative who said, “I don’t think that we’re very threatened here in little old _________ville.” Pointing out that viruses have absolutely no respect for political boundaries and that the 1918 Spanish Flu reached remote Aleutian Islands had no effect on him. As far as I know, three weeks later he still has the same attitude, so I don’t even bring up the issue now. As someone said a long time ago, “You can only do what you can do.”

While many “panicked early” (I, myself, believe that it is more accurate to say “took precautions early”) and drove up N95 mask prices, even more people are searching for N95 masks now and are turning pale at the price tags. These efforts couldn’t be a better example of the effects of the Normalcy Bias having come home to roost for so much of the population.

Many in Europe suddenly woke up last weekend because, when the outbreak occurred in Italy, the issue was unavoidable. People around the world are accustomed to hear that bad things happen in China and Africa, but in Italy? That was too close to home for the rest of Europe and, suddenly, the head in the sand approach was no longer tenable.

They’re Living in Denial

I think that all of us have friends and family who were living in a state of denial until the stock market tanked on Monday. News from half a world away was deemed a curiosity, i.e., “What’s that got to do with me?” Bloggers and “talking heads” on television had only a limited effect on so many. Suddenly, the financial losses made it no longer possible to avoid the seriousness of the matter. “If Wall Street is tanking, what should I be doing?”

N95 Mask Supplies Depleted

So now the search for N95 masks has intensified even more so than it was a week ago. With the head of the CDC saying that the coronavirus will be with us into 2021, one wonders just how many readers here are prepared to ride out that period if they do not live on a remote homestead on a mountaintop. (While it may be excellent advice to make this lifestyle choice, such advice really isn’t helpful for the mass of readers of this blog at this particular time and concerning this particular issue.) Regarding the face mask issue, it is likely to be a “desperate times, desperate measures” situation.

In January, I was able to add to my face mask supply and purchase 25 N95 masks for $8.95 at I sent an email to friends and acquaintances about my great find. I am absolutely certain that most of them ignored me. The next day, the price of the box of masks went to $12.95/box. Five days later, the vendor’s supply was completely depleted.

Last night, I found a box of 30 N95 masks for $99.00, plus shipping, at Sportsman’s Guide (not the first place I would think to look). In 2012, I purchased the same box of masks on Amazon for $34.00, delivered. This morning, as write this, the masks at Sportsman’s Guide are out of stock.

Potential For Mask Re-Use?

N95 masks are described as being single-use masks by manufacturers (who profit accordingly), vendors (who profit accordingly), and a great many healthcare professionals (who routinely have daily deliveries that fill the shelves of stockrooms and from which they are supplied for free by their employers). But what should the rest of the population do when faced with a crisis like the one presented with the coronavirus?

I have posed questions on numerous sites concerning re-using N95 masks. I have received some helpful replies, but I also notice that specific parts of questions I have asked are not addressed. I expect that responders simply didn’t want to admit that they didn’t know the answer and hoped that I wouldn’t notice (an approach commonly used by politicians in handling tough questions during interviews and political debates.)

I recall finding this NIOSH link in a Survivalblog reader’s comment.

Once I read it, I posed a series of 14 questions to the CDC (see my questions on February 18 at 5:39 p.m.) my intention by breaking down the questions this way was to force answers to each specifc one. See the CDC’s response below it. Even the CDC is ducking answering certain questions with useful responses, e.g., “Many of the activities you have described are not recommended disinfection techniques for respirators. Please consult the manufacturer’s instructions on how to clean a reusable respirator.”

“Many of the activities” are not “recommended disinfection techniques?” How about telling me which ones? I can’t believe that the CDC doesn’t have a clue and can’t be a little more specific. Since some of my questions involved using military surplus gas masks as an alternative to N95 masks and involved how long I could use these masks before the filters became too contaminated, the advice to contact the manufacturer wasn’t much help. I have to think that a call from the CDC to the Fort Leonard Wood CBRN School would get a great deal more attention than I would. (I expect tp have better luck when I call the paint respirator manufacturers.)

I suppose that the bottom line is that, with face masks and contamination levels, we are not dealing with, say, anything remotely similar to pregnancy tests where any coloration indicates that a woman is pregnant. After a certain point in re-using N95 face masks, I suppose that we will just have to guess and hope for the best

I cannot imagine, however, that a military gas mask with NATO filters will not stop the coronavirus. If they can stop anthrax spores (admittedly larger than viruses) and Soviet VX gas, I have to think that stopping coronaviruses would be a “walk in the park.” I also cannot imagine how the filters could ever become so clogged by microscopic viruses (rather than by particulate matter) that they would stop working, but what do I know?

Of course, even military gas mask filters have expiration dates. Yet, does this expiration date have anything to do with the effectiveness of the filters in blocking coronaviruses, or is this something that is only of concern, for example, with Russian nerve agents?

For what it is worth–and it may not be worth much–I have seen recent comments on web sites saying that heat at low temperatures in ovens will damage the coatings on N95 masks, and that repeatedly placing an N95 mask in the sun in order to kill viruses that have collected on it will result in UV damage. I have no idea whether these opinions were solidly based on facts. Again, perhaps those with the proper credentials can comment on this issue.

Will UV Light Suffice?

I have seen comments about how UV light kills viruses. I am very interested to hear from a knowledgeable reader about whether or not using a UV light on an N95 mask will kill coronaviruses, and whether repeated use of a UV light will damage the mask.

One of the links in the CDC article, states, “Ideally [the N95 mask] should be discarded after each patient encounter and after aerosol-generating procedures. It should also be discarded when it becomes damaged or deformed; no longer forms an effective seal to the face; becomes wet or visibly dirty; breathing becomes difficult; or if it becomes contaminated with blood, respiratory or nasal secretions, or other bodily fluids.” So, “ideally” an N95 mask should be discarded after a single use. A pandemic is hardly an ideal situation.

Regarding elastomeric half-face mask respirators, the CDC states:

“[It is] Reusable and must be cleaned/ disinfected and stored between each patient interaction.” Note that it does not say what “cleaned/disinfected” means. Cleaning the hard surface of an elastomeric mask is an easy concept. What is it saying about the filter itself and whether it should (or even can) be cleaned and disinfected? If a person does not touch the filter, can it be safely used numerous times since the virus will be, presumably, trapped inside or on the filter? Of course, that still begs the question of just how many times it can be used. A week? A few weeks? Months? I expect the response to that question will be, “It all depends” and that any answer is merely an educated guess, if that.

Here are a couple of additional CDC articles I found concerning the re-use of N95 masks. (I may have found one of these links in a reader’s comment here. Perhaps it was Tunnel Rabbit, a reader who has been very helpful on this subject). Read these:

If all that is needed is N95 mask fabric in order to prevent the airborne inhalation of droplets of saliva and phlegm, wouldn’t it make sense that a person could cut into several pieces the limited number of N95 masks he has on hand and then secure them with suitable tape over the intake ports of elastomeric half-face masks and military gas masks? Cutting into pieces one N95 face mask might result in having 4 or 5 useable, if smaller filters, for use with an elastomeric face masks or military gas masks. (Note that, from my limited experience, when I tried taping N95 material over a military gas mask’s intake ports, it was too hard to draw breath. That is why I pose the possibility of entirely removing the original gas mask filters. I seem to recall that one of the CDC links said not to place standard surgical masks over N95 masks as a covering. I expect that doing so changes the flow of air and, therefore, the mask’s performance, negatively.)

Another idea I have is to use the replaceable N95 filter inserts used in the more expensive N95 masks and to place them externally over elastomeric paint respirator intake ports with the respirator’s factory filters removed in order to improve air flow. These replacement filters still appear to be plentiful and are commonly available on Amazon, The price of these filters is currently much more modest than the price of complete N95 face masks.  Note that the description says that they are N95 filters, so I am hoping that this representation is accurate.

Other Ideas, Folks?

Again, I hope to see that a knowledgeable reader will confirm that this idea will work. If it does, instead of buying N95 masks at grossly inflated prices, buying a standard paint respirator and using these N95 replacement filters over the intake ports would be the most economical way to go, and it would stretch readers’ dollars by prolonging the use of limited supplies of masks.

About properly fitting and re-using an N95 mask, see this video.  Note that the video mentions re-using the mask and shows it being stored in a new bag each time. Think about it. Any viruses would be on the outside of the filter, and one side of the bag would always be contaminated. Once the mask was removed, the bag would close and the contaminated side would be in contact with the uncontaminated side. Re-using the bag would contaminate the clean side of the mask.

Besides Zip-Lock bags, I have to think that most types of plastic bags, or even paper bags, would be suitable for storing a face mask.

Having “spoken my piece” I now welcome any comments from people in “higher paygrades” that might shed light on what I may have gotten wrong, or to confirm what I got right. I also suggest that any reader check the Comments Section to find these helpful comments from others.

I also suggest that each reader who is concerned about this issue re-visit SurvivalBlog in a day, and even in a couple of days in order to read the comments that were posted later.


  1. with regards to military style masks – different masks (both year of build and manufacturer) have different chemical compositions which is why u won’t get a answer from the CDC (liability)(poison gas and delivery systems have changed chemically over the years). They recommend u contact the manufacturer for cleaning/disinfecting instructions since some cleaning compounds/methods can damage the mask/lens or other components (including UV resistance). Most manufacturers I dealt with (was OSHA officer for my facility and dealt with both military style gas and safety/fire masks) will readily provide u with specific information if asked. I was able to quickly Google some info online on for at least 4 masks/manufacturers and UTube also had some instructional videos.

    You will also need to pay attention to which filters u purchase since they will be rated as CS/CN (certain particulate size) or NBC/radiological/CBR. U need to make sure u get a filter they will block the virus and it will need to be a specific particulate size or rating. MOST (if not all) NBC/CBR rated filters should do the job but are significantly costlier.

    1. The masks have a higher temperature range than the virus.. most will tolerate temps of 130. The virus dies quickly at temps over 105.

      Throw the mask in the oven at 130 for 10 minutes.

      1. Is there some reason you couldn’t just keep your used mask in the back seat of your closed car on a sunny day?

        Per the CDC, “When temperatures outside range from 80 degrees to 100 degrees, the temperature inside a car parked in direct sunlight can quickly climb to between 130 to 172.” – Centers for Disease Control and Prevention “In terms of heat-rise over time, it makes very little difference whether a car’s windows are closed or partially open.

        Obviously this doesn’t work on an overcast day.

  2. Survivorman 99 said:

    “If it does, instead of buying N95 masks at grossly inflated prices, buying a standard paint respirator and using these N95 replacement filters over the intake ports would be the most economical way to go, and it would stretch readers’ dollars by prolonging the use of limited supplies of masks.”

    Good idea if the rating of the respirator is unknown. Better yet, get a respirator from Home Depot or such place that have the common P100 rated masks that filters 99.97%. These have a better seal to the face as well. I’ve use one when painting cars. It works good. I will wear ski googles as well as these are a better solution than standard safety goggles, yet these can fog up. Shop around. After removing the mask cover the inlet with duct tape, and then wet the entire mask inside and out with 70% to 91% alcohol, or 25% solution of bleach that after a contact time of at least 30 seconds, will kill the virus. A 10% solution of bleach requires 10 minutes. The duct tape seals and protects the filter from the alcohol, or bleach, and keeps the virus inside. When the mask is required again, put the mask on, and then remove the duct tape. Fold one edge of the duct tape over on to itself. This makes removal quick and easy.

    The P100 rated as approved by the CDC:

    Another option:

    Use the N95 mask, and after use, store it in a Ziploc or any other plastic bag that can be closed tightly. Then drench the outside of the bag with the appropriate quick acting disinfectant, and store it for at least 9 days. Carefully date the outside of the bag with a marker, or a tag. If a mask is needed daily, then 10 masks will be needed for the rotation. If one does not have enough masks to rotate, drenching the mask directly might be necessary. If alcohol is used, letting it air dry would be possible, as alcohol would do less damage than bleach. If 25% bleach is used, only 30 seconds of contact is needed, and then the mask can quickly be rinsed with water to remove the bleach that might otherwise degrade the material. However This will likely reduce the effectiveness of the mask. Another option is to remove the elastic, and bake in a conventional oven at 160F for one hour. The elastic can be reattached with a standard paper stapler. Even if the effectiveness of the mask to filter air is reduced to less than that of brand new N95 mask, the seal to the face is not 100% anyways.

    The another important function of mask is to keep the hands from making contact with nose and mouth, and to protect against spittle, and droplets. Another and perhaps more important function of the mask is to keep the user from infecting others. That is why every one needs to wear a mask. With this low level of protection the risk of infection is reduced by 80% . A reduction of 10% in the mask’s ability to filter is not significant in my book, as there are other problems that can pose a risk, such as the use of googles that do not seal to the face.

    Protecting the eyes with googles that seals, reduces the risk more than using a new mask each and every time. Also, I will spray my face with alcohol with googles and mask on. I will also spray my gloved hands before removing the protection from the face, and then strip away the tyvek suit. And before removing the gloves, I would spray or dip my gloved hands with a alcohol, or bleach solution. I will use x-large gloves that slip off my hands that can also be reused in the same way a mask can be reused. I would then remove the clothes in a designated area, and soak them, and the tyvek suit in a 25% bleach solution outside for 30 seconds, then let them soak in water. And after all that, I’d have and nice long hot shower.

    1. Addendum to the previous post on recycling masks.

      If we are going to attempt to reuse the N95 mask by storing them in plastic bags for 9 days, they need to be store some place as warm as possible, preferably as warm as 98F, or 37C, as the virus degrades in about 3 days at that temperature. Other temperatures, lower than 98F degrees, are untested. At 40F degrees, the virus might be viable for longer than 9 days. Recycling masks can be risky business and done with great attention to detail and procedure. And only done as a last resort.

      We are well acquainted with Chris Martensen’s work, but we should also check in with Dr. Campbell. Unfortunately he accepts the disinformation put out by China.

      Tuesday 10th March Research and update

      1. Tunnel Rabbit, your common sense is uncommon but appreciated. All of this needs to be in the construct of simply removing ourselves from all people to the greatest extent possible.

        Quick question. Would microwaving a mask without metal parts work to decon masks ? Or UV lights overnight in the basement ?

        1. Rabbit to Squirrel,

          Probably, yet there is no way to verify the effectiveness. Perhaps you can find verification. Also removing the metal that is necessary to conform the mask to the face, would ruin the mask.

        2. “Or UV lights overnight in the basement ?”

          Again, maybe. If the virus was embedded between within the layers of material that comprise the mask, it might be protected. It only takes one virus to infect.

          1. A problem I see here is that the article is about surgical masks and their re-use, not about N95 masks. The material used in each is quite different. Is that not an issue?

          2. I am materials engineer. Not an issue typically. I would not over do the salt and clog the pores in the filter. What your doing is enabling the mask to kill virus on it so you can use again without “as much fear”. I don’t see how it can hurt anything to try if you can keep breathing. Key on masks anyway is tightness so if that suffers in reuse Is a bigger problem. If you have an extra mask you could try.

          3. Just keep in mind that if you make a change that overly restricts airflow, then either you will choke or the mask will flex/distort, allowing the air that you breathe in will take the path of least resistance. Read: Breaking the seal of your mask on your face–bypassing the mask media, and rendering the mask ineffective.

          4. Further comment. That article about salt in the mask enables reuse. It even killed H1N1 in their study. The recipe was not made simple for the layman but it used table salt in a solution with some liquid surfactant (tween) but likely liquid dish detergent could be a substitute. Dry it out and you are good to reuse. This is what our govt should be telling us so that people don’t hoard masks for a supply to using a fresh one every day. This is a chance for us who are prepared to save others in charity. Keep one mask and prepare the others with salt the others to conserve mask use. I am sure that if you only gave one mask per citizen and told the correct recipe we could knock it out. I am sure FEMA is hoarding million of mask for the govt military and medical personnel. If the release them to The People who paid for them. One mask for all, not 1000 per govt worker. I am already planning to give away my masks when I figure this out more.

          5. Further comment. That article about salt in the mask enables reuse. It even killed H1N1 in their study. The recipe was not made simple for the layman but it used table salt in a solution with some liquid surfactant (tween) but likely liquid dish detergent could be a substitute. Dry it out and you are good to reuse. This is what our govt should be telling us so that people don’t hoard masks for a supply to keep using a fresh one every day. This is a chance for us who are prepared to save others with charity. Keep one mask and prepare the others with salt the others to conserve mask use. I am sure that if you only gave one mask per citizen and told the correct recipe, we could do a lot to help out. I am sure FEMA is HOARDING millions of masks for the govt, military, and medical personnel. If they release them to The People who paid for them. One mask for all, not 100 per govt worker. Only GOD knows how many masks they have. I am already planning to give away my extra masks masks when I figure this out more. I will post more here when I take the science article recipe and and translate for the common man to use

      2. Moving away from masks to another vector. Very informative article about handwashing:

        The money quote: 2/25 The soap dissolves the fat membrane and the virus falls apart like a house of cards and “dies”, or rather, we should say it becomes inactive as viruses aren’t really alive. Viruses can be active outside the body for hours, even days.

        3/25 Disinfectants, or liquids, wipes, gels and creams containing alcohol (and soap) have a similar effects but are not really quite as good as normal soap. Apart from the alcohol and soap, the “antibacterial agents” in these products don’t affect the virus structure much at all.

        4/25 Consequently, many antibacterial products are basically just an expensive version of soap in terms of how they act on viruses. Soap is the best but alcohol wipes are good when soap is not practical or handy (e.g. office receptions).

        You may enjoy the rest, too.

        Carry on

    2. The N95 should turn after 20 minutes of use from an asset to a liability, i cannot say if the mask will protect others then from an infected wearer, the protection is gone after that time because the mask gets wet from the wearers breath

      To my Knowledge filters of “Gas masks” are no longer valid to use after 30 minutes and ´ve opened not a very Long shelf life.

      I cannot say how Long actually because we´re discarding every filter after one use, every gar mask will be changed after one use and professionally cleaned for years.

      1. Hi ThoDan,

        Good points we should consider. The use of these masks are fraught with complications. One would be wise to study up. I imagine that a mask with the an exhaust valves would reduce the rate of moisture build up, yet most N95 masks to not have such a valve and the moisture builds up, greatly inhibiting the flow of air through the Hepa filtering material, and force in the inhalation of air from around the already inadequate seal on a face. In an environment where the humidity is very low, this is perhaps less of a problem.

        About gas masks. I chose the Czech M10 gas mask because the replacement filters rated for biological hazards were at the time, just 2 months ago, were only $2 per filter set, cheaper than N95 masks! The filters are however difficult to change, but we should reduce our exposure time, and the number of exposures to an absolute minimum, especially if we are a person who is at greater risk, and inclined to use that level of protection. A young and healthy person need not bother if there is no family member is also at greater risk.

  3. I personally find very worrisome the reports of how low our stockpile is of suitable protective masks(N95) for our healthcare workers. Someone was definitely asleep at the wheel by not assuring that we wouldn’t find ourselves in this situation, with much of our mask making factories located overseas where they will reserve their production for their own citizens. See article linked here- sounds like a good use of whatever N95 masks we own will be to bring some with us should we need to get checked at the hospital for suspected Covid-19 so that whomever is examining or treating us has adequate protection and can do their job!

  4. Some thoughts on your article. N95 means that the filter traps 95% of particles of a given size. All N95 filters are depth type filters like the paper media in your car air and oil filters. Here is what OSHA says about use and reuse.

    “One important addition to your respiratory protection plan should be reuse of N95 respirators during a shortage. The OSHA directive indicates that a respirator can be reused as long as it “maintains its structural and functional integrity and the filter material is not physically damaged or soiled.”

    Here is a piece about filter testing.

    A depth type media captures particles in a bell shaped curve size range. For example, older cars had oil filters with a nominal rating of 40 microns. That means the middle of the bell curve of particles captured was 40 microns. The filters would also pass some 60 micron particles and capture some particles as small as 10 microns. That is very different from a sieve type filter with a single layer of openings of a given size (think window screen openings only smaller) which have an absolute rating related to the opening size.

    A depth type filter actually tends to improve during use because the filter material becomes blocked with particles making the openings and pathways through the media smaller. The problem is that over time the plugging will adversely effect the vehicle (or the person trying to breath).

    Given the size of virus particles does a mask provide absolute protection from particles as small as a virus? The answer is NO. Does the mask reduce the possibility that you will inhale a virus particle? YES. Usually the virus is hitching a ride on a larger object like a tiny water droplet. In that case the mask works really well provided you have a good mask fitment. Anyone with a beard or mustache pretty much will NOT have a good edge seal due to the facial hair. A filter that leaks is not much better than no filter at all.

    Do not forget about eyes. Wearing a mask without goggles to protect eyes is a lot like no protection at all to the wearer. Those little virus particles riding water droplets will land in unprotected eyes and be just has happy as if they had been inhaled via the nose or mouth.

    Bottom line. Masks and eye protection help, but not very much. Spend some time reading about level 4 bio facilities and the protection used. There are a LOT of health care providers infected with (and have died from in China) COVID 19 and resultant secondary infections. Many were wearing N95 masks, disposable clothing, and eye protection. Outside of level 4 lab protocols the chances of being infected with a virus are high no matter how well you attempt to protect yourself with 1/2 measures, which is what masks and goggles amount to with a virus.

    1. Frank, the masks don’t filter viruses, they’re far too small. They filter the saliva and mucus droplets that the viruses are in. The masks CAN stop those.

  5. Consider a spray of peroxide 3%. Avoid elastic. Or try
    Dilute bleach 10-1 and spray. Or try cleaners with ammonium chloride [Zep DZ-7 concentrate is a listed virucide].
    Dry with hair dryer. The longer and hotter the better. Hold the mask outside the window and close down to your arms to avoid blowing things in the house.
    The mask is only part of your protective gear. Gloves are very important, as are goggles or glasses.
    Light some candles to burn off floating organics in small areas.
    I took JWR advice and ordered an oxygen concentrator instead of another firearm. Oxygen is what your flooded lungs need, and what you would get in the overcrowded hospital.
    In perspective, the seasonal flu kills 98 people a day in a normal year. China’s heavy pollution and 5G may be contributing factors in the claimed fatality rates. What better reason to give up our freedoms based on fear!

  6. Not to be a party pooper but the n95 mask does not protect against small particulates. It is good for large particulates and liquid.
    The n95 is effective for people who have the virus in that it will help them not spread the virus.
    The n95 surgical respirator is what you want but it has to be fitted and you need to be trained in its use.
    So let’s be rational people think before you spend your hard earned money , that paper mask your staking your life on is not what you think it is.

    1. B Rhoades, there’s more to protecting yourself than just buying the gear. Maybe the biggest part of this is good hand hygiene. And knowing when to wear a mask – my daughter was probably exposed yesterday by walking into a small waiting room with ONE guy in it who was coughing like crazy the whole time.

      People wear masks in one setting and then fail to wear them in other settings. They wear masks but don’t even think to wear goggles! And they aren’t disciplined enough to keep their hands away from their faces, or to have (or make) hand sanitizer for when they can’t just wash up with soap and water.

      Don’t blame the masks…

      1. I was just explaining that there are two type’s of n95’s , the one we buy at drug stores ,auto parts places etc are not going to offer much protection.
        With everyone buying these things up thinking it going to save them might want to research before spending money on them. You are right about hygiene though that will be your saving grace.

  7. I don’t know if this would be effective, but for those who didn’t have the foresight or maybe the ability to purchase the N95 or similar masks, a “better than nothing” approach could be to use a layered method. Maybe a basic dust mask (with admittedly bad sealing), covered by a kerchief? Its only a guess, but I’m thinking it would stop the particulate borne stuff anyway.

  8. Please be advised, N95 masks are only “N95” when properly fitted. I am a career FF and SCBA Technician who helps train and test our department with respirator use. I have been doing this for over 25 years. Our fire department fit tests both our SCBA masks and N95 masks every year. Even with coaching about 50% of the people that use these things on a regular basis do not get a fit able to pass on the first try. For casual contact? They will probably work just fine. Close contact over an extended period? You better learn how to put them on properly and even then I wouldn’t do a lot of chatting or fast movements. Bottom line, knowledge weighs nothing…spend some time learning how these work and how to properly wear them or don’t waste your money. If there is interest out there, I could put together a quick article on these masks and proper fitting etc. if readers think it would be beneficial.

    1. TK,
      Your experience is sorely needed. IHMO, these masks are inadequate and I prefer my military gas mask, or the P100 respirator that I’ve painted cars with, and know that the fitment is superior. It filters 99.97%, and has a tight seal. And it is easily reused. If you can highlight the short comings of using the N95, that would greatly improve the effectiveness of the mask as users would be aware of the pitfalls.

      I would also protect my eyes with tight fitting googles as well, and wear a tyvek suit. If I must use PPE, I will conduct my business and leave quickly. Exposure over time is also a risk. This virus is airborne. It does not necessarily need a water droplet to travel from one person to the next. Where it can become concentrated in the air as within a building with continual traffic, the odds that it can slip by one’s protective gear increases. Again for the record, I am already self isolated, however, there could be an occasion where I might have to use this stuff. Few people will be able to truly self isolate.

    2. TK, what a brilliant insight.

      Bottom line, knowledge weighs nothing…spend some time learning how these work and how to properly wear them or don’t waste your money.

      I appreciate the simplicity of that statement.

      Carry on

    3. TK, please do think about putting together an article about proper use!

      Beans, bullets, bandaids, and MASKS are useless with the skill and experience to use them correctly.

      I have a family member (elderly, on chemo, with compromised lung capacity) that I am particularly concerned about protecting, so I greatly appreciate any additional information and tips about how to correctly use the N95 masks and respirators. Fortunately, I already had both stocked in my supplies, thanks to SB articles about emergency medical supplies I read a few years ago when I began prepping. 🙂

      Thank you for volunteering to share your expertise with us. Much appreciated!

  9. Since the virus can only survive 9 days on inanimate surfaces under ideal conditions, and hours to days under non ideal conditions, I will safely assume they would die in 7 days in my warm vehicle.

    Take 7 N95 filters and number them 1-7 or Monday- Sunday, or 14 filters for Saturday AM, Saturday PM, etc. I want to keep all chemicals, microwaves, and UV light off mine, so after use, I merely hang them up in my vehicle to dry for 7 days. My SUV has bailing twine strung up inside for use as a dryer when my solar dryer gets overloaded during peak drying season. The twine is near the ceiling so will keep the N95 filters out of direct sunlight. There is no rush on sanitizing these. Time is my friend, chemicals and sunlight my enemy with N95 filters.

    Perhaps numbered quart mason jars will work for other folks. There are lots of variations on the idea but I personally would avoid all chemicals, UV, microwaves, and heat extremes. But I’m not an expert.

    The N95 mask in the photo accompanying this article is improperly fitted, as are most in modeled photos. Be sure to use the nose clip and squeeze it to fit around your nose. Otherwise you only have an N85 mask.

    1. I’ve seen a report where in cool temperatures of 40F, it remains viable for about 2 weeks on some surfaces. At temperatures of 86F and upwards, I believe it is safe to say that it would not last more than 9 days. Unfortunately there is no confirmation, and I’ve lost track of that information. Test results are almost none existent. I do know of a recent test that found that the virus degrades after 3 days at 98F or 37C. Here is the testing cited:
      Dr. Campbell
      Tuesday 10th March Research and update

      1. Hey Tunnel Rabbit, thanks for the heads up. I did a little research and that “9 days” number we keep hearing is actually just from a literature review, not an actual study. (Link below.) The same study indicates that some of the veterinary CoV’s can remain viable for up to 28 days on inanimate surfaces so I question whether we can safely conclude that Covid-19 is only viable for 9 days just because the other human CoV’s are.

    2. First step, make sure everyone has practiced proper donning and removal of PPE. My plan is to label a gallon size Ziplock type bag with the name of the person and date they wore it. The worn mask will be dropped into the bag (gallon size will make it easier to simply drop it in) and sealed. Individual masks will be stored in the bags (1 mask per bag) in a designated area away from our house for a minimum of 9 days (I would prefer 14 days). This will allow for time for surface decontamination. The masks should be inspected for degradation before re-use. We have enough masks and if able to keep to our social distancing protocols, we expect to be able to make it work. While this isn’t ideal and carries some risk, it may become necessary in a prolonged pandemic event.

  10. Can You Reuse N95 Face Masks During Pandemic Emergencies?? By Dr. Joe Alton
    (YouTube Video)
    DrBones NurseAmy
    Mar 7, 2020
    Duration – 5:13

    “DR. Alton discusses when dire emergencies, like pandemics, the supply flow may be disrupted. What are your options? Some are better than others. Be safe and be prepared. Knowing the difference will help you keep your family healthy. By Joe Alton, MD of

  11. Hey folks,

    Particulate masks can be used until they are too hard to breathe through. They actually get *more* efficient during use, because particles jam up the media and prevent other particles from slipping through.

    Many medical and otherwise knowledgeable people have commented here before that trying to decontaminate a N95 mask would likely compromise or destroy it. No offense, but not liking the answer is not the same as not being provided an answer. They are designed to be disposable, specifically to counter re-contamination concerns. If you want re-usable, you’re going to need a gas mask or respirator. Now, when you use one, the filter media is going to be swimming with viruses. They are not going to jump off and strangle you in your sleep, but if you touch the filter you’re going to spread the virus around. If you think the risk is worth it, then by all means keep using the filters/ cartridges.

    No manufacturer is going to tell you it’s ok to re-use a contaminated cartridge because of liability concerns.

  12. Im a retired critical nurse. My experience has been what you might expect.
    Some nurses get sick by being exposed to patients AND other nurses and some don’t get sick. Despite being diligent about masks and other PPE. And also what you might expect the nurses that were younger and didn’t smoke and had healthier lifestyles do not get sick as much and recover faster. What a Shock.

  13. The longer you use/reuse a N95 mask, the more the filters will “felt up” and clog, just from humidity if nothing else. Trying to decon them will probably make this worse. The harder they are to breathe through, the more likely they are to leak around the seals/edges. So, the benefit of trying some of this stuff may be largely psychological. But, if the alternative is going “bare”, why not try it and hope for the best.

    Also, maybe everybody knows this, but you have to be clean-shaven to get a good seal. Back in the olden days, some guys would try to cheat and shave down close and smear the contact edges with vaseline. Based on personal experience, that can actually work on CS and CN, but I seriously doubt it could protect against virus-sized particles.

    Lots of good thoughts, everybody.

    1. Hoping for the best is not a strategy, TJMO.

      If/when a mask gets damp from your respiration then it’s time to switch to the extra dry mask you’re carrying. Having a mask with an exhalation valve will prevent most of the problem.

      Don’t have enough masks? NOBODY has “enough” – you’re going to have to sanitize them. There are a few good ideas here, and a few bad ideas here. We’ve opted for UV-C and have the medical research to prove it. Not guessing, not hoping – research.

      Sanitizing our family’s masks will give us the equivalent of an $800 supply of masks.

      1. Hi ShepherdFarmerGeek,

        Please help us get started on our own research about UV-C. Other than the low tech ‘tincture of time’ method that is based upon mostly unverified testing, sounds like a fantastic way to go.

      2. We, too, have selected UV-C to sanitize everything that comes into the house, including mail and packages. I selected this item from Amazon: UVP 95-0016-14 Model UVG-11 Compact 4 Watt UV Lamp, 254nm Wavelength, 115V.

        The manufacturer’s website is hopeless in finding the specs for this UV lamp, but an internet search found this: “1120 microwatts per sq. cm of 253.7 nm radiation at a distance of 152 mm [6″], with filter in place Uses 4 watt, mercury vapor tube (6286M30). Another source gave the distance as 3”.

      3. Hoping for the best is what all the ad hoc methods provide. No reason not to try whichever fits your fancy, but no NIOSH or OSHA data says they will work. Using or adapting a respirator may work and would be my option, but I’d stick with manufactured filters and not “hillbilly” a solution with cut up N95s. If you get too much pass-through, you defeat the purpose.

  14. My opinion. Here’s part of the broiled up sentiment. Is the CDC telling you not to wear a mask because they are ineffective ? Or is the CDC telling you not to wear a mask because we don’t have any to purchase.

    That’s a big bet. If its a demand side problem, and the Haz Mat suits being worn by S. Korea and China and France and Italy and so on are really needed….then the USA people will be torked with serious spill over.

  15. If I cut a 6” wide strip of flannel, wrap it twice around the lower part of my face and secure it with a binder clip or two…hmm.
    After use pour boiling water over it, put it in a 250 degree oven for a few minutes, or wet it with a disinfectant of choice. Seems like it would work fine.

    1. Dean Ing highly recommended flannel for radioactive particles in his nuclear war survival novel, Pulling Through. (It’s very good.)

      It should be very thick flannel. Cheap shirt flannel that you can pretty much see through when you hold it up to the light won’t do much. Multiple layers might help.

  16. Wonder if one could run an N95 mask, or similar, ( WITHOUT any metal tabs ) in the microwave a certain amount of time? Maybe microwaves and the airflow through it could help? Maybe not…..

    1. I also wondered if the microwave would kill the virus but as a side note the fan may spread the virus around the room ,,,, when cooking micro popcorn does the smell fill the room ,,, virus has no smell swift, silent and deadly,,?? also cross contamination from the outside of machine to food or whatever . it would have to be a dedicated unit in outside open-air environment with no one close by not in containment suit ,,then risk if microwave do not kill virus,,, same as heat if oven baked in safe environment for set period of time ,,,,

  17. My experience with “taking precautions early” has been, like the author’s, viewed as being paranoid by family and friends. I just call it being smart. I have changed my routine and travel plans, postponing my attendance at a weekly gathering of about 20 people, no longer shake hands, use hand sanitizer even more than my normal OCD tendencies required, and cancelled plans for a road trip to visit a family member in an out of state nursing home.
    While I don’t understand all the technical advice on masks, I am of the “something is better than nothing” camp, and as mentioned by a previous respondent, at least a mask helps to keep me from touching my nose and mouth. Do what you can do.
    I am continually amazed by the number of people who are out in public coughing, sneezing, and constantly wiping their nose. Last week at the gathering I mentioned earlier, I noticed an attendee coughing and wiping her nose. That convinced me then and there that people are stupid, and it is up to me to protect myself. If that means my staying at home to avoid stupid people, so be it. Anyone with cold-like or flu-like symptoms should self- isolate at home. It is the best thing for everyone. Skip school, skip work, skip going to the store.

  18. Does anyone know if Ozone will kill the corona virus, I think it should. It seems that putting used masks in a container with an ozone generator blowing into it would disinfect the mask. (Of course it will break down the rubber compounds in the elastic.)

    But at least it will keep the mask dry and maybe last longer this way.

  19. The virus is reported to survive for 9 days on hard surfaces but not sure on soft fibrous surfaces such as filter media. My thought would be to have 9 or more mask. Number them then hang them up separated from each-other after the days use in a dry area in direct sunlight on a line for 9 days or more before reuse. As long as the material is not compromised it may work but no guarantee.

    1. Andrew, this may address your questio: 16/25 These tiny droplets end on surfaces and often dry out quickly. But the viruses are still active! What happens next is all about supramolecular chemistry and how self-assembled nanoparticles (like the viruses) interact with their environment!

      17/25 Now it is time to introduce a powerful supramolecular chemistry concept that effectively says: similar molecules appear to interact more strongly with each other than dissimilar ones. Wood, fabric and not to mention skin interact fairly strongly with viruses.

      18/25 Contrast this with steel, porcelain and at least some plastics, e.g. teflon. The surface structure also matter – the flatter the surface the less the virus will “stick” to the surface. Rougher surfaces can actually pull the virus apart.

      19/25 So why are surfaces different? The virus is held together by a combination of hydrogen bonds (like those in water) and what we call hydrophilic or “fat-like” interactions. The surface of fibres or wood for instance can form a lot of hydrogen bonds with the virus.

      20/25 In contrast steel, porcelain or teflon do not form a lot of hydrogen bond with the virus. So the virus is not strongly bound to these surfaces. The virus is quite stable on these surface whereas it doesn’t stay active for as long on say fabric or wood.

      21/25 For how long does the virus stay active? It depends. The SARS-CoV-2 coronavirus is thought to stay active on favourable surfaces for hours, possibly a day. Moisture (“dissolves”), sun light (UV light) and heat (molecular motions) all make the virus less stable.

      22/25 The skin is an ideal surface for a virus! It is “organic” and the proteins and fatty acids in the dead cells on the surface interact with the virus through both hydrogen bonds and the “fat-like” hydrophilic interactions.

      23/25 So when you touch say a steel surface with a virus particle on it, it will stick to your skin and hence get transferred onto your hands. But you are not (yet) infected. If you touch your face though, the virus can get transferred from your hands and on to your face.

      24/25 And now the virus is dangerously close to the airways and the mucus type membranes in and around your mouth and eyes. So the virus can get in…and voila! You are infected (that is, unless your immune system kills the virus).

      Entire article here:

      Carry on

  20. Knowing how to properly fit a mask and maintain a good seal is very important. Do leave how without knowing how to perform this step:

    “There is also an informative discussion of leakage and fit testing:

    Fit testing is time consuming, and in the health care setting, requires a technician. The test typically involves molding the mask until a seal is accomplished. Coffey et al found that most persons cannot be adequately fit tested to commercially available N-95 respirators.

    Furthermore, it is uncertain if the utility of fit testing extends to beyond a single use. We could find no measurement of filtering efficacy with removal and immediate reapplication of the respirator, nor were we able to find any data to support the supposition that fit testing in 1 model of mask carries over into other masks of the same make and model. We also were unable to find assessments of efficacy after sustained use. The face is not a static surface; for example, motion of the jaw from swallowing, facial grimacing, or talking likely alters the seal. Even if all of these variables are negligible, there is still the effect of gravity pulling down on the mask. (Weiss et al., AJPH)”

  21. A similar discussion to that we are having here is also occurring elsewhere.

    I have a problem with using UV-C not because it is not proven to kill virus such as SARS-Cov2 on surfaces, or in the air, but because of the layered filter that is the N95 mask that is designed to trap particles between layers. The wavelength of UV-C is about 100nm, and cannot penetrate an eye lid. The N95 mask and filter, although less dense, is thicker.

    The bullet proof method that I am comfortable with at this time, and until more information is available, although it has it’s own issues, is the safest for most people to use. Soaking the mask in a 25% solution of bleach for more than 30 seconds, and then quickly and thoroughly rinsing in the mask in water to remove the bleach solution is a low risk, high reward process. If chlorine can be detected in a sniff test, then it should rinsed again, and quickly dried using a heat source, and possibly a fan to hasten the drying process that off gases chlorine at an accelerated rate. A hair dryer would do the job the fastest. If one has an adequate quantity of alcohol for this job, it would be preferable as the process would be easier, and potentially do less damage to the mask, thereby increasing the number of times it may be reused. A 70% or greater concentration of alcohol should be used for 30 second contact times, and 30 minutes and longer times should be used as the percentage of alcohol is less than 70%, and decreased to as low as 50%, or 100 proof. No extended times, or duration is available for concentrations of alcohol that are less than 50% alcohol.

    Yes, the masks ability to filter 95% of particles would be reduced, yet as discussed, this and other issues in my first post on this thread. Given the balance of trade offs, this is the best method for persons with few masks to rotate, and where time and attention to detail grow thin, and the risk of infection becomes unacceptable during the decontamination process. In the long run, the KISS principle rules, especially in large groups, where no formal training is possible. Fitment problems, exposure times, and other issues are bigger contributors to the overall risk, than a small reduction in the filters ability to filter the smallest particles.

    Again, we are attempting to develop an SOP (standard operating procedure) for a large audience, or group of diverse persons, including families with children. In time, we may discover a better method. A complicated method can work for individuals, but can fail when many persons are involved.

    1. Rabbit, this is Squirrel again. I called a few physicians whom I know well. The Chinese research asserts the virus lingers airborne for up to 30 minutes (see JWR link above on the Wednesday edition of SB).

      One can find Jackson V90 series full face shields (either clear under shield or blue, listed on amazon) with googles and solve several problems. Do not wear contact lens, remove those for the immediate future. Trim stray hair strands or better yet, trim hair well back (for those who fiddle with their hair).

      The face shield can be worn over any mask – it’s certainly better than zero. And the unit is a combined shield with VERY comfortable googles.

      Northern Tool also has a number of face shields as well. Basically anything that offers another line of defense for misted airborne particles. The Jackson V90 is 100% shielded over the full face, nose, mouth area. Any mask can go underneath, even a home grown mask.

      1. Rabbit to Squirrel,
        Roger that. Good idea to protect the whole face, yet if airborne for even only 30 minutes, it could float and enter through the mucus membranes of the eyes. I would opt for a face shield, and still use googles that seal to the face that are similar to ski googles as final protection. The face shield is a great addition that provides yet another layer to a system that needs all the help it can get. Ideally we would want level 3 at a minimum, or at least a full face mask respirator.

    2. In the spirit of KISS, this:

      From a member of the Stanford hospital board. This is their feedback for now on Corona virus

      1. If you have a runny nose and sputum, you have a common cold
      2. Coronavirus pneumonia is a dry cough with no runny nose.
      3. This new virus is not heat-resistant and will be killed by a temperature of just 26/27C degrees (or roughly 80F ). It hates the Sun.
      4. If someone sneezes with it, it takes about 10 feet before it drops to the ground and is no longer airborne.
      5. If it drops on a metal surface it will live for at least 12 hours – so if you come into contact with any metal surface – wash your hands as soon as you can with a bacterial soap.
      6. On fabric it can survive for 6-12 hours. normal laundry detergent will kill it.
      7. Drinking warm water is effective for all viruses. Try not to drink liquids with ice.
      8. Wash your hands frequently as the virus can only live on your hands for 5-10 minutes, but – a lot can happen during that time – you can rub your eyes, pick your nose unwittingly and so on.
      9. You should also gargle as a prevention. A simple solution of salt in warm water will suffice.
      10. Can’t emphasis enough – drink plenty of water!

      1. It will first infect the throat, so you’ll have a sore throat lasting 3/4 days
      2. The virus then blends into a nasal fluid that enters the trachea and then the lungs, causing pneumonia. This takes about 5/6 days further.
      3. With the pneumonia comes high fever and difficulty in breathing.
      4. The nasal congestion is not like the normal kind. You feel like you’re drowning. It’s imperative you then seek immediate attention.

      Serious excellent advice by Japanese doctors treating COVID-19 cases: Everyone should ensure your mouth & throat are moist, never dry. Take a few sips of water every 15 minutes at least. Why? Even if the virus gets into your mouth, drinking water or other liquids will wash them down through your throat and into the stomach. Once there, your stomach acid will kill all the virus. If you don’t drink enough water more regularly, the virus can enter your windpipe and into the lungs. That’s very dangerous. Please send and share this with family and friends. Take care everyone and may the world recover from this Coronavirus soon.

      The new Coronavirus may not show sign of infection for many days. How can one know if he/she is infected? By the time they have fever and/or cough and go to the hospital, the lung is usually 50% Fibrosis and it’s too late (Fibrosis is not reversible). Taiwan experts provide a simple self-check that we can do every morning. Take a deep breath and hold your breath for more than 10 seconds. If you complete it successfully without coughing, without discomfort, stiffness or tightness, etc., it proves there is no Fibrosis in the lungs, basically indicates no infection. In critical times, please self-check every morning in an environment with clean air.

      I just added some new behaviors.

      Carry on

      1. Hi Once a Marine,
        Wonderful! We are finally get information from outside China that is more trustworthy.
        As it is the first I’ve seen like this, this is exciting and refreshing stuff. And valuable. Not liking report about the fibrosis issue however. Hope we will see more like this, opinions from the field that confirm, is very important. Other reports from Italy is that it tends to hit those 45 and up, with, and without other health problems. In other words, an otherwise 50 year old may have the same chance of dying as a healthy, or even a 70 year old with co-morbitities such heart disease, or whatever.

        I suspect there are many surprises yet ahead, and many strains that will effect the population in different ways. There is much more to learn about the thing. I am glad I can self isolate, yet if I pop some bubble wrap made in Asia, it could get me then….

        And from your post there is more reason to believe that my alternative prevention, or treatment plans might just be helpful after all. I just received all the parts to make high quality nano silver that can be used in a nebulizer. I would also use a pocket carried nose, and throat spray. And one could use an iodine made for the purpose, but it is expensive stuff. sells iodine for that job called X-3 and x-2 that is selling out. Iodine is a powerful antiseptic that I would trust over nano silver for the nose and throat. 5% hydrogen peroxide could work too, or perhaps a shot of the hard stuff, but that would be tough in the nose. This is one of the few instances I would condone it… for medicinal purposes only! One can of Bud light is now too much for me.

      2. Hi Marine,
        Need to add some info that runs counter to some of this information. Forgot I had it. We’ve been drinking out of a fire hose for about 2 months now. It’s good to compare notes. I believe this a good study to refer to. Here is some of the meat.

        ” On different types of materials it can remain infectious for from 2 hours up to 9 days. A higher temperature such as 30°C or 40°C reduced the duration of persistence of highly pathogenic MERS-CoV, TGEV and MHV. However, at 4°C persistence of TGEV and MHV can be increased to ≥ 28 days. Few comparative data obtained with SARS-CoV indicate that persistence was longer with higher inocula (Table I). In addition it was shown at room temperature that HCoV-229E persists better at 50% compared to 30% relative humidity [8].”

        “Inactivation of coronaviruses by biocidal agents in suspension tests
        Ethanol (78–95%), 2-propanol (70–100%), the combination of 45% 2-propanol with 30% 1-propanol, glutardialdehyde (0.5–2.5%), formaldehyde (0.7–1%) and povidone iodine (0.23–7.5%) readily inactivated coronavirus infectivity by approximately 4 log10 or more. (Table II). Sodium hypochlorite required a minimal concentration of at least 0.21% to be effective. Hydrogen peroxide was effective with a concentration of 0.5% and an incubation time of 1 min. Data obtained with benzalkonium chloride at reasonable contact times were conflicting. Within 10 min a concentration of 0.2% revealed no efficacy against coronavirus whereas a concentration of 0.05% was quite effective. 0.02% chlorhexidine digluconate was basically ineffective (Table II).”

      3. @once a marine

        This information is totally bogus, fake- I checked this out last night. Here is the Hospital board link refuting this nonsense. Pays to recheck, does it not ?

        Stanford warns public about bogus coronavirus breathing test, calling it ‘misinformation’

        One wag posted this reply………… ” In other news….Researchers have found that holding your breath for 20 minutes will protect one permanently from contracting all diseases. But, it only works for liberals. So….please, protect yourself as soon as possible!

        I like ! ( not suggesting you are liberal at all )


        1. Good catch, neighbor. Oh, and I don’t consider “liberal” a dirty word. When I make choice, some would be seen as liberal and others as conservative. I have friends who are lefty liberals and lovely human beings. My test for friendship doesn’t include complete agreement on politics.

          Carry on

  22. Microwave ovens use a radio wave frequency that resonates with water molecules and energizes them causing them to heat up. You could theoretically steam an item in the microwave, much like baking a potato, but it in practice this would be difficult. The other consideration is the components of the masks themselves, and how exposure to high temperatures would affect the filtering capability of the filtration media.

    I found an article from 2006 regarding reusability of masks. Their conclusion was It’s an interesting read that basically anticipated the issue being discussed.

    Some of their findings:

    “Finding 1: The committee could not identify or find any simple modifications to the manufacturing process that would permit disposable N95 respirators to be reused without increasing the likelihood of infection.

    Finding 2: Any method of decontaminating a disposable N95 filtering facepiece respirator must remove the viral threat, be harmless to the user, and not compromise the integrity of the various elements of the respirator. The committee found no method of decontamination that met all three criteria.”

  23. Lots of good comments on here already, so like the rest of us online I’ll add my two cents.

    I’m neither a doctor nor a virologist, but I did 20 years as a CBRN specialist in the Marines–so I have a good general knowledge of protection. Please recall, N95 is just a rating based on testing of various masks to a standard where 95% of contaminants 0.3 microns in size don’t pass through. Some look like surgical masks, some like painter’s respirators. These will not protect your eyes or open wounds, and frankly we still haven’t got much info on how CoVid19 spreads. Masks are probably better than nothing, goggles added are maybe a bit more protection. The only way to fully protect yourself would be a plastic (Level A or Level I suit) with SCBA; have fun walking around in that for the 40 minutes to an hour of air you have.

    Also, decontamination is NOT a perfect science. Not to mention, the military doesn’t even have immediate detection capabilities for random biologicals (unless something drastically changed in the 2 years since I retired). You can argue and debate on the best decontamination methods, but you have no way of knowing how clean you are. Not to mention, does anyone have any idea how many virus strands are necessary to infect someone successfully? Honestly washing hands and being generally hygienic are the best bets. Sure, bleach will kill the heck out of any biological, but it can also burn your skin and is a respiratory irritant at best.

    So am I just saying don’t worry? Well, kindof. First, I think this CoVid19 is an over-hyped media sensation. Right now 0.0000158% of Earth’s population are infected with CoVid19 (according to John’s Hopkin’s regularly updated operations dashboard as of 10 March 2020). I follow the news every day, as soon as ONE patient is confirmed in the US, the entire state is labeled as infected. That’s ridiculous. What I suggest is be aware. You cannot know who is infected, but sites such as the CSSE of John’s Hopkins are good relatively trustworthy bits of intel. Personally, unless the numbers go up more than a thousand fold, I’m not going to change my personal habits. The death rate may be somewhere around 10 fold higher than the common flu, but it might not be. We simply do not have enough information.

    If things do get bad, the most intelligent, cheapest, and safest method of protection is self quarantine. That’s a personal judgement call. Frankly, anyone on a site like this should not be concerned about having to rush to town to get some groceries.If numbers of infection do go up dramatically, and I need to get fuel or some milk, I may put a respirator on (I would prefer a painter style respirator with P100 filters rather than an N95, more protection and a much better seal). If numbers go up significantly, maybe 100 to 1000 fold, I may make it a point to not go to large towns or cities (the largest city I regularly go to is about 20,000 as it is). Other than that, there isn’t a lot to do or worry about.

    Trust me, you will NEVER be perfectly protected or perfectly decontaminated. There are plenty of simple tests which have been conducted (even in classes I’ve taught in the Marines) over and over to prove that. One of the best I recall is using an invisible tracker which is visible under UV…put it in a small place in a room and tell people there is contamination and they should decontaminate. Then, turn on a UV light, there will be signs of the tracker everywhere. Don’t panic, God created you with a great immune system, all anyone in the medical community can do right now is provide comfort care, there is no vaccine and there is no such thing as a virus killing medicine.

    Thats my two cents, take it or leave it,

    1. Clinton,

      Given your CBRN background, I will ask you some of the questions I asked the CDC:

      6. Paint respirators that are rated P95 use replaceable filters. Given that these filters are meant for use over substantial periods for industrial use, can they likewise be used for virus protection for protracted periods of time?

      7. If the answer to No. 7 is in the affirmative, if the paint respirator’s filter(s) is not visibly contaminated, can the user reasonably rely on the fact that it is easy to breathe through the respirator a reasonably good indication that the filter is still “good to go” and is effective?

      8. Surplus military gas masks appear to have been snapped up in the last month. One vendor a month ago probably sold 20 types. Only one type is left in stock now. These masks, being military issue, were originally certified for nuclear, biological, and chemical warfare protection, so their usefulness when new is not of concern. Yet, is it reasonable to assume that even used filters in these masks, if providing sufficient air flow, are adequate substitutes for N95 and N100 masks?

      9. If the answer to No. 8 is in the affirmative, should the user have any concerns about the age of the used filters in the gas masks?

      10. If the answer to No. 9 is in the affirmative (i.e., there is a concern about the prior use of the filters), should the user have any concerns about using sealed and unissued filters for the gas masks, even if they were manufactured quite some time ago?

      1. I’ll give this my best shot, but this is off the cuff–if I find out anything is clearly in error I’ll re-post. Unfortunately, I don’t think my answer is going to satisfy you..but this is all to the best of my knowledge.

        7a) Filter lifetime is a sketchy thing. I did some digging a few weeks ago, my father was discussing this situation and was asking similar questions. What I found was probably what you found, the N, R, and P before a number describes the resistance to oil (N=none, R=some, P=resistant). The number refers to percentage of particulates removed. What you’re not going to find is what I would refer to as burn through time or how long the filter is good for. There will be general guidelines, one use, multiple use, etc. but I would be surprised if a manufacturer guarantees a specific time. The reason is there are way too many variables. Humidity, temperature, and concentration levels of substances play a big role in this. The CDC will probably not give you any specifics because they don’t make masks, they just follow NIOSH guidelines and regurgitate them. The best source is NIOSH or a manufacturer, and I haven’t seen anything concrete from either of those sources. Current military masks have a sort of indicator on the back of the filter elements, but as I recall it is more of a humidity check than anything (military filters tend to use activated charcoal which degrades with humidity).

        7b) Protecting against viruses specifically is something I haven’t seen any credible air purifying filter guaranteeing either. Plenty of advertisements suggest that, but again, too many variables. Is the virus able to promulgate individually in the air or is it passed in water droplets (larger size with many more virus strands) from coughs? There is a huge size difference there, the test size for filters is small, current standards reference 0.3 microns (which is tiny), but virus strands can be smaller. You also get into the concept of air movement through a filter, I’ve heard (but not seen direct information) that particles smaller than what is tested for have a significant difficulty traveling in predictable ways through filters. Basically your breath and the air keeps them moving without landing somewhere in your lungs if the particles are too small. I can’t give you a source for that its too long since I got that info.

        7) Final Answer. If you’re using your mask to go into town rarely to get some supplies and get out, its probably good for a few uses with the same filters, maybe a few days to a couple weeks but you aren’t going to find anyone who can guarantee that. This is assuming you’re taking care of the face piece and cleaning it after each use. Its also assuming CoVid19 isn’t so dangerous that surface contamination on the outside of a mask is going to cause you to get sick. Interestingly enough, no one is worried about their clothes causing latent infection. Think of how great they are for sucking up particles of dirt when you’re walking around.

        8) I would be SUPER wary of surplus military masks. I worked with serviceable masks for two decades, and you have to regularly inspect them for damage, dry rot, etc. The ones you get in a surplus store probably haven’t been tested in ages. We regularly tested batches randomly selected by test centers when we used to store them (in the Marines, at least, the gear is stored in centralized facilities now). We would regularly have relatively new masks fail, need new components, or need to be de militarized. I suspect (but can’t be sure) that most of what you find at a surplus store is just that, failed masks that were purchased from what used to be called DRMO.

        8b) The filters on the masks are very different from what you see in the civilian market. They filter down to a certain micron size (I can’t recall this anymore, and I think the most detailed info was confidential). However, they are designed to absorb vapors as much as they are filtering. They are typically full of charcoal–no joke you can take a punch and make a hole and charcoal will fall out. They are designed primarily for chemical weapons. I never got too much hard information even in the military on specifically what biologicals they would filter other than the ubiquitous discussion of anthrax spores (they filter anthrax), mainly because of all the variables. Yes, they filter radiation, but not much better than a thick cloth over your face. You can only filter Alpha and Beta particles, not EM radiation, and a cloth tightly wrapped over your face provides similar protection from that, although it wouldn’t be fitted as well.

        8c) Fit is another thing, this I can speak to for military masks. Often times, they are worn with a poor fit. This is regularly demonstrated when true fit tests are done. A clean shave, proper positioning and tightening and size of mask and the proper maintenance and cleaning of the mask all have to be tested. Yeah, that will never happen in the field, but its also not going to be perfect in the field.

        8) Final answer. I would really inspect a mask, using the manual, before I purchased a surplus one. The filters probably provide similar protection to maybe an N 95 or R 95, maybe more, maybe less, depending on the country of origin. Just remember, these were discarded by the military, or remade in some factory with no onerous bureaucracy even pretending to check standards for civilian sale.

        9) Yes, you need to be concerned about surplus military surplus filter shelf life. Each NATO canister has a lot and manufacture date. They also have a specific shelf life (something like 10 or so years, I can’t remember). They get tested in the military and discarded if they fail tests. You have no clue what the lot number you find at a surplus store had in its testing history. If it comes in a sealed container, its a better chance of being good than in an unsealed one, and that’s as far as I’d take that to the bank.

        Put it this way, I would trust new civilian masks and filters over surplus military ones any day. You can get full face piece civilian masks too. The ONLY thing I’d use a surplus military mask for is tear gas/pepper spray. IMHO, military surplus masks are a crapshoot at best and probably better for a decoration than defense (other than tear gas, CS is pretty easy to filter. I’ve seen some crap masks work fine in the gas chamber. So if its police use of CS against riots from food shortages you’re worried about, an old military mask with filters should be just fine so long as it isn’t falling apart and you have it on tight).

        I guess the sad truth is, a particulate filter is not going to be 100 percent effective no matter what, and there is no way of telling how long it will be good for just by looking at it, other than seeing one in terrible shape and not using it. If this gets bad, which I still am not convinced of, I would rather stay home than try to cobble a reliable protective ensemble together.

        My last bit of advice. Lets assume CoVid19 is really bad and spreads all over. Wear a good respirator with new (within a few days of opening) filters as well as some safety goggles and gloves. Don’t get close to people, and when you get home, shower, wash clothes and the mask, and stay there most of the time. I don’t want to be crude, and don’t intend this in that manner, but think of all these masks and whatnot as prophylaxis for intimate relations. Sure, it will help reduce disease likelihood, but even though you use the prophylaxis, I still wouldn’t bet the farm on coming home clean from someone I KNOW to be carrying a disease…getting back to masks and such, if you KNOW the area is disease ridden don’t go there. The masks, filters, goggles, long sleeves, gloves, etc. are good to reduce likelihood, but they will NOT be foolproof at all.

        1. For some clarification, for all the civilian stuff, I’m specifically talking about respirators with removable filters. I would NOT reuse a facemask (the ones that look like the typical surgical masks but have the NIOSH qualification on them).

          I am also incorrect for bashing CDC, they put out the NIOSH, so I guess they aren’t regurgitating info, they are promulgating it. Thinking back I guess I forgot NIOSH was part of CDC, but when I looked at my NIOSH Pocket Guide for Chemicals I realized it had CDC stamped right on there. This is what I get for commenting at 2 am.

          Also, if the moderator allows it, the following is a pretty good explanation of everything respirator from the US Navy medical branch, and it isn’t too old, 2013. Its simple to read and has some good diagrams and pictures in it:

          1. Clint,

            Brilliant response! Thank you! Clear, concise, either you want it or you don’t, in your face, truth. Bravo. Far too often, we in the survival community get wrapped around the axle about trivial things when the answer is clearly, right in front of us. Like so many things in life, people tend to skirt around harsh truths because they are seeking confirmation of what they already believe, not facts.

            From my own experience: No manufacturer, government agency, or expert in the field is ever going to tell you to ignore the instructions for the recommended use of a product if you expect to realize maximum effectiveness from that product. Period.

            To summarize:
            1. For maximum effectiveness, N95 masks are designed to be one-time use, i.e. disposable, and were never designed or intended to be re-used. Period. No matter how you word or phrase the question, no matter how many variables you introduce, after use, throw the thing away.
            2. If it is so imperative that you co-mingle with possibly infected people, you should have bought hundreds of masks, no matter the price, long ago.
            3. No mask, suit, or other preventative measures taken are 100% effective, 100% of the time.
            4. The only method that even comes close to being 100% effective is complete isolation. No “ifs”, “and’s”, “ buts”, or “what if I do this” about it. If you do not want to be infected, stay home.

            Thank you!

  24. I’ve been using 3M n95 masks for years, specifically the ones with the valve in the front.

    My problem is I raise hay and have terrible allergies, so I use them from about May till August not only in the field changing sprinklers but also when I buck the hay bales in the summer.

    I need eye protection too because the pollen will effect my eyes as well so I wear these:

    Between these 2 items I don’t have any problem with my allergies unless I don’t change my clothes after I get in from the field, as the pollen sticks to my clothes as well.

    Here is the color: Its 95 degrees outside, I’m stacking 1000 bales of hay into my enclosed barn, its hot, its dusty as hell, I’m sweating like a pig, and working harder than any day of the year.

    And I am still wearing the same N95 mask that I started with in the spring. It is discolored from all the dust and pollen it has filtered, I mean really dirty but it still works. I like the valve on the front because it keeps the mask sealed when I am exhaling and cuts down on the moisture.

    In a Cov-19 climate I would zip lock the used mask for a week to let the virus die and then reuse it. Several hours of use a day and I doubt you will have any degradation of the filtering until it just quits fitting.

  25. As this started I’ve never been comfortable with the protection of the N95 mask. I read the expert opinion not the wear the masks unless you were sick/contagious. This implies the purpose of the mask is to capture virus particles coming out of the sick person. This seems possible since the air with moisture will have velocity towards the mask coming out of the sick person wearing the mask. On the inhale side is where my concerns are. I’ve done my share of varnishing and my rubber mask must be tight against my face with the vent working or I smell the fumes of the varnish. How can a flexible fabric mask make that same kind of seal? Experts say it requires training for the fit, and even with training many masks apparently aren’t installed properly (see link below). Next question, can the masks actually capture the viral particles? How effective is it against incoming viral particles that might be lighter from evaporation between the infected person and the new victim. How does the fabric actually capture the particles? How does water or water vapor affect the mask material? How the mask captures the particles will also affect if the viral particles can be killed on the mask and how it might be done without damaging the filter material. How might chemicals that kill the virus damage the mask material reducing effectiveness? I found the following link that describes how the masks capture particles. It’s interesting.

    I’m still looking for more technical information on how long the mask might remain effective, how its effectiveness degrades over time, and how moisture or chemicals might degrade the mask. It’s possible the masks might be disposable because of contamination risks through reuse. I could also see moisture or cleaning chemicals matting down the fir on the fabric threads reducing effective surface area of the mask to capture particles.

    For masks, my plan is to carefully take the mask off while wearing gloves, keep it secure where no one can touch it, and then to wait 21 or some number of days for the viral particles to naturally degrade. Storage temp and humidity will be adjusted as possible if they can speed up the degradation.

    Some people have mentioned UV to degrade the viral particles. I’ve read some about diesel engine air intake filters and talked with manufacturers. My questions were about how the filters worked and if caked on dust from off road settings could be banged off the filters. Their answer was somewhat. Apparently some of the dust (it should be the finer dust) penetrates deep into the filter material where it becomes physically trapped. The outside dust will frequently fall off with vibration, but the dust deep in the filter is trapped. The N95 mask should be no different. I worry that the UV rays may not penetrate deep enough into the filter to degrade the virus. You would need a translucent filter material that didn’t absorb UV rays.

    I think the best option is to avoid going out, self isolation to the maximum extent possible. I am a knowledge worker so I can work from home. Just supply me electricity and internet, I have food. How easy self isolation is will really depend on what my employer, other employers and the government do to keep people apart. We’ll see. I feel for the people who physically need to be at their place of work to actually work and for all the people in industries that aren’t going to have customers because the normal customers are not going out.

  26. Montana Rancher has the right idea by using a mask and goggles. I use the RZ Mask and bought lots of the 12 pack filters. My son used the mask for sanding projects. I bought enough for the family at the local ace hardware store and hundreds of filters direct from RZ Mask. I have the Dewalt goggles for the family that Montana Rancher provided. The RZ masks filter .1 microns and can be worn comfortably for hours.
    Here is a recent example. Drove to Costco. In the parking lot, donned my mask, goggles, gloves, place my credit card in my shirt pocket. I go in, buy stuff, return to the truck of my car. I assume i am contaminated. Open trunk, place clean towel on ground with the side i touched down. I remove boots and spray top and bottom with Lysol while standing on towel. I pull out my credit card and disinfect it. Next i remove sweat pants and outer shirt, and old ball cap, place in garbage bag. Next i hold my breath, remove goggles and mask into garbage bag #2, then gloves in bag #3. I garb a disinfectant wipe to wile my face, neck. I put on clean clothes in another bag. Now i’m decon’d. I go home, don new gloves, mask, goggles. I dispose of old gloves (bag 3). I disinfect the goggles, remove the filter from the mask and place in mason jar form 10 days. Change gloves again and disinfect the RZ Mask that holds the filter. Contaminated clothes get washed.
    I’m a medic near ground zero in WA and this is close to what we do on the job. It’s a matter of knowing what is a cold (safe) zone, what is a hot (contaminated) zone, and avoiding cross contamination, which requires a well thought out procedure from start to finish and then practiced first before you enter the hot zone. I’m also a HAZMAT TECH, and this is just what we do. But if requires enough of the right equipment, the right procedure, and the right execution attained only from training.
    Getting through the oncoming sh$t show will not be fun, it will not be easy.
    Plan, practice, and learn from every mistake. It’s trial and success in the new paradigm.
    Good luck.

  27. I apologize for all the typos in the earlier post. I should have been sleeping instead of writing on my kindle in the dark with reading glasses.

    In reference to reusing the mask, I believe letting the mask remain in an open mason jar for 10 days should be long enough for the virus to die. Basically disinfecting with time, which will not degrade the filter.

    And frequent glove change to prevent cross contamination means using a lot of gloves. Disposable gloves.

    Cross contamination is extremely difficult to avoid.

    Once your gloved hand touches a contaminated surface, every thing you touch thereafter becomes contaminated. Before you touch something clean, like your phone, wallet, glasses, etc., you should remove the contaminated gloves, use your hands on clean items, then put on new gloves to continue. That’s why gloves are disposable. That’s also why the N95 is designed to be disposable. However the shortage of N95’s is a serious problem for everyone.

    I told my sister-in-law to put on a pair of disposable gloves, go outside, pick up some mud, then take off the gloves without getting any mud on her. It’s not as easy as you may think.

    Start now to practice donning and doffing any PPE you think you will be wearing on the next Costco trip.

    Obviously the best practice is to just stay at home. Limit exposure.

    Otherwise, if you live in western Washington or any other community break out area, at this point, you must consider all stores and basically everything outside your home as contaminated.

    Choose safe, be prepared.

  28. During the Bush senior and Clinton years laws were passed that said a company doing business that had product on the shelf would be taxed as if said product were profit.
    Since all hospitals are now medical associations and groups they are not there to serve you. They are conducting business. Their are no stockpiles of insulin, no caches of penicillin. And there is no more than a month, week, or days worth of face masks or the medical business will have to write it off as profit on their leadgers and pay tax on it.
    Everything is ordered on computers last minute. When there’s something like this pandemic situation, the whole process grinds to a halt. The system gets overloaded and takes time to ramp back up.

  29. Been reading about common table salt applied to a breathing mask to kill corona virus….some team up in Canada onto this. Why not try a combination of salt and zinc? Talking about being desperate and out of n95 gear…trying to “upgrade” a surgical mask if possible…?

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