Since the N95 mask is designed to keep things outside from coming in, how long does anyone think I could use a single mask? In other words, if I had to venture out into the world and say my mask prevented exposure to the virus on a given day, must I throw that one away and use a fresh one the next time I go out? Just trying to figure out how many masks I should buy.
Nobody that I know of will tell you that you can reuse a mask. However the fact is that H5N1 will not live longer than 48 hours on porous or nonporous items (as long as we are not talking about a pool of liquid…or lump of feces). If I go out, I plan to isolate my mask for over 48 hours, and then reuse it. I would be interested to find out if anyone has any idea how many days these masks are functional at 95% (the N95 masks).
Also, you must realize that your eyes may come in contact with this airborne virus (it is not just in droplets from sneezing). Therefore if you do not wear airtight goggles, you won’t keep the airborne virus out of your eyes.
Also, your clothes may come in contact with this virus. It is a real consideration to isolate those clothes for 48 hours if you go out.
Washing your face and hands well (all the rest of you) after you remove your mask etc. would remove virus from your skin. You have to completely understand that this mask just covers your nose and mouth. The virus hopefully would be stopped there, but may easily stick to the rest of the skin on your face.
When you go out, the further you stay away from crowds or just people, the less chance you will have of encountering this virus in droplets from sneezes or in the airborne form.
My plan is to stay indoors completely when this pandemic hits. If I do go out when there are very few cases (inbetween waves), I may not wear goggles (I will just have to see how fearful I am), and I will stay far away from crowds (like going shopping when very few people are there). I will take the above precautions when I come home.
One additional strategy I have discussed with others is the possibility of venturing out only during a pouring rainstorm, and then only to go to someplace like a self service gas station to top up fuel stocks. I don’t think this bug could stay airborne in, for instance, a thunderstorm’s torrential downpour. If we count forward from now, assuming it is still a while yet until the critter starts running, that would put us well into spring/summer when fuel stocks for generators, cooking will start to be an issue. Just the right time for a nsaty thunderstorm to was out the air and keep others far away from me.
The virus can live in the environment on hard surfaces for several days. In water it can survive for 4 days at 72 deg F and 30 days at 32 deg F. In manure it can survive over 3 months. http://www.who.int/csr/disease/avian_influenza/avian_faqs/en/
I estimate masks not directly exposed to a high risk environment may be reused after sitting for 6 days. This is not to say you should only have 6 masks. Of course no one knows if a mask was exposed to a virus. I am just saying I would be less likely to reuse a mask used near a sick person (bird, etc).
fredness - In my comments relating to the length of time the virus may live on surfaces, I referred to this article: www.nycosh.org/specific_industries/Healthcare/Influenza_transmission.pdf
It states: Both influenza A and B viruses were cultured from experimentally contaminated, nonporous surfaces, such as steel and plastic, up to 24–48 h after inoculation, and from cloth, paper, and tissues up to 8–12 h after inoculation. However, viruses could be recovered from hands for only 5 min and only if the hands were contaminated with a high viral titer. Viable virus could be transferred from nonporous surfaces to hands for 24 h and from tissues to hands for 15 min.
This was published in Oct 2003. Perhaps there is new scientific evidence to the contrary. I would be quite interested if anyone has a differing scientific reference. Re the WHO reference you cited, I did not see scientific references for a time frame. I really want to know if anyone has evidence other than what I have cited. Please help me out.
JV, it is believed that this H5N1 virus can survive quite a bit longer in the open than typial flu viruses. See: http://www.who.int/foodsafety/fs_management/No_07_AI_Nov05_en.pdf
There was an earlier discussion thread about recycling masks and some doubts and caveats from medical people though you’d have to look back for the details
Name - The reference you gave me related to poultry. I think there may be two different issues. The H5N1 virus has even been recovered for three months in a cool environment in bird feces on the ground. The data I referred to was human to human spread, and nothing involving feces, or the poultry house environment. I was trying to relate the article I cited to reusing masks, or even the concern of clothing worn if someone ventures out during a pandemic. I was thinking of the city air environment where the overwhelming concern would be human to human spread of the virus in airborne or droplet form, not really of encountering the poultry environment. Of course, if a person stepped in bird feces, that is certainly a different matter concerning the shoes.
I think there is a difference then in the viaility of the virus, or is there anyone else who may have other info on this topic?
Yes, I understand JV, but I think this is the same discussion we had the last time. It’s currently mainly a poultry virus, yes, but this is the virus we’re dealing with in terms of the anticipated human pandemic, so this is the best available information on how well it can survive outside of a warm body—whether bird or human. Note that this WHO article is aimed at preventing human infection although, as you correctly note, this is still essentially a poultry virus.
Now we don’t know if this property or any other will change when H5N1 goes H2H. It might, but there’s no more reason to expect it to behave like a regular human influenza A virus in terms of environmental survival than there is to expect it will have other typical human influenza properties (i.e mild symptoms, same incubation period etc). Some of these properties may change as the virus mutates, but we can’t say if or how.
Bottom line, we don’t know for sure at this point, but the present behaviour of H5N1 is the best we have to go on, and by all indications it has a unique ability to survive very well in the open. Other than that, we’ll have to wait & see.
Another thing, some people mentioned having trouble finding these masks (i.e. on back order.) I just stopped by a tool rental store and they had boxes & boxes of the “3M N95 particulate respirator” masks ($24,95 Cdn or about $20 US retail for a box of 20).
Rather than medical supply sources, perhaps try paint stores, hardware, anywhere that people get supplies for renos.
Would steam-cleaning the masks kill virus? I have one of those Steam-buggy steamers that shoots a strong spray of steam. I understand, I would need to have electricity for it. How about a boiling kettle or pot, put mask on rack across top of pot, then cover with lid. Just a thought.
Name - I appreciate any information re this virus. I am neither an epidemiologist nor a virologist. I have a background in science, so I am just trying to read the literature and understand it. I read the article I cited as I was buying my masks because I felt I didn’t understand well enough what I was doing. For historical reference, I think the article I mentioned is good scientifically because it addressed all influenza viruses as they have been studied and understood as of 2003, in reference to human to human spread in the hospital setting. The article in no way addressed poultry to human infection.
You are correct that anything truly can happen re H5N1 when it becomes H2H. I made assumptions based on all past viruses. If and when H5N1 becomes H2H, everyone will have to watch and see how it behaves. It will be a new virus. Tamiflu and Relenza, and Amantadine may or may not work. The death rate may be 2% or 10% or 0.1%. The incubation period may be 1 day or 10 days.
In talking about what we know from the past, and what we will have to observe as this virus becomes H2H, I think we are all learning something. I simply want to understand what the truth is, however, I am afraid we don’t know that yet, and we will have to wait and see.
Thanks for your input. I do appreciate it. I think I may have made too heavy an assumption on the past behavior of influenza viruses.
I just had an idea: suppose you had 7 cardboard shoe boxes with lids, marked with the days of the week, monday, etc. When you come in you drop the mask in that day’s box where it can be dry and isolated until the same day next week. Maybe something similar with the clothes, if washing them is not an option.
Lorelle - Exactly what I have decided to do. Or maybe ziplock bags. As I stated above, we will have to see whether 48 hours isolation for a mask will be enough or not. Also, shoes may be a problem because they may have walked though bird feces. I am not sure the best option re the shoes. Maybe just leave them outside.
Also, the further anything (clothes and masks) come inside a house, the more problematic for infection.
I honestly don’t plan to go out except between waves, and only then very infrequently.
mr Detail – at 10:39 “how long does anyone think I could use a single mask?”
JV – at 11:03 “I would be interested to find out if anyone has any idea how many days these masks are functional at 95% (the N95 masks). “
The useful life span of a single disposible N95 mask is a total of 8 hours of use OR LESS depending on the environment. After several hours wear, the filtering material becomes clogged up with virus, dust, dirt, pollen, anything in the air.
A good rule of thumb is when you notice that it is getting more difficult to breathe thru the mask, toss it out and put on a new one. Once it gets harder to breathe, even if you waited for the virus to die off, the filter material will still be clogged up.
anonymous – at 19:42 “Would steam-cleaning the masks kill virus? I have one of those Steam-buggy steamers that shoots a strong spray of steam. I understand, I would need to have electricity for it. How about a boiling kettle or pot, put mask on rack across top of pot, then cover with lid. Just a thought. “
DO NOT steam, soak, or spray liguidof any type on your disposible N95 masks. Also keep it away from any products that contain oils (ladies, that means no makeup, moisturizer, etc when wearing a mask and gents, no “moisture rich” shaving cremes”.)
Water, steam, etc will warp and wilt the mask so that it will no longer fit your face and will not provide the expected protection. Water, cleaners, disinfectants and oils will damage the filter material and allow nasty things to pass thru.
Your best bet if you MUST reuse a mask (and don’t ever tell my boss I said this) is to expose it to strong sun light for at least 3 days.
This allows the mask to dry out, allows time for the virus to die of, AND the sunlight will help kill the virus…also, pay attention to the temperature…all of these “virus only lives for 48 hours on nonpourous mateial” statements etc, generally only apply to standard room temperature (about 68 degrees) or higher, at lower temperature the virus can live much longer. So if you have to put mask outdoors in winter to reach sunlight, better leave it out there for a much longer time before reuse.
BTW, reuse should be an absolute last resort, not a primary plan as you can never truely be sure that the reused mask is providing propper protection or that all of the virus from last wearing is dead.
Don’t plan to go out? At all? How will you keep a job? Are you retired? I know money isn’t everything, but it’s still pretty important! If you aren’t retired, are you in a job that you are comfortable just not showing up for…for up to a year or more?
luv2cmwork - I am retired. My husband will do his work on the computer at home. It will nto be a problem for him. My son will do his school work on the computer, and send it in to his teacher via computer. He goes to a school where they communicate homework on the computer already. This will not be so different, but very weird for him being home all the time.
I absolutely do not want to stay at home for 3 months or a year. I also do not want to die or have my family die. I will simply have to see how this pandemic plays out as to whether I go out at all or just between waves. I won’t know till I see what happens.
Hey folks, while better than nothing, the ubiquitous 3M-N95 mask that most everybody uses is really nothing more than a low cost industrial particulate filter. It is rated to filter 95% of all particles that are 300nm or larger. While this is OK for drywall dust, mold, mildew, and bacteria, it is too large for most virus that aren’t aggragated on mucous - like when someone sneezes. Bird Flu is an oblong influenza virus that is only 80 – 120nm in diameter, less than half the size that a N95 mask totally filters. Additionally, a typical N-95 mask has a poor facial seal which allows the inhaled and exhaled breath to follow the path of least resistance - around the sides of the mask. If you want a truly effective mask (to tend to sick family members or go out in public with H5N1 running around) you need something better. Allegedly, the Nanomask by Emergency Filtration Products is one of the few products that will filter out H5N1.
FYI: buy wine and vitamin D.
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=170457
Pfwag - The information I referred to when I bought my masks was from NIOSH: www.cdc.gov/NIOSH/appndxe.html
As you can see in the first paragraph, a 100 nm particle (as this H5N1 is), should be filtered out at 95% for N95, 99% for N99, and 99.7% for N100. This is for NIOSH certified masks. As you can see, nothing is 100%. The facial seal is important. It can take a 95% efficiency mask down to 30% if there are gaps. Also, airborne viruses can enter through the eyes, therefore, airtight goggles are a consideration.
As you can see, masks and goggles help, but nothing will be 100%. Therefore either staying at home, or if you do go out, staying away from crowds or other people will reduce your chance of being infected no matter what mask you wear.
Could a virologist help with this further?
JV - great link. Thanks!
http://www.fluwikie.com/index.php?n=Forum.MasksN95AndOthers
Lots if discussion on this previous thread re: N95 masks and how to fit them.
re: Nanomasks…IIRC, Nanomasks have not yet passed any of the NOISH tests, have not yet been rated and a number people on a number of flu sites have asked for specific info on the technology from the manufacturer and have yet to get a useful answer…bottom line, so far, there is no independent info to prove nanomask works as they claim.
Re masks
All masks should be replaced frequently - min 3 −4 times a day.
Take them off to drink, eat what ever increases the risk that bacteria will enter the masks inside when it is replaced.
Personally that makes for an expensive 3 - 6 months.
I believe for internal use in the house good quality, 3 ply, high filtration antifog surgical masks are the go. About one tenth of the cost of eaven the most basic N95 mask.
Pfwag,
Anne?
Pfwag,
Never mind about the “Anne” question. That vitamin D link threw me.
Anyone have good information on goggles or willing tp make recommendations?
The best goggles will be air-tight. You don’t want the virus to come in through vent holes.
a couple of weeks ago a came across an article (see http://www.sciencedaily.com/releases/2006/02/060214080834.htm ) on effects of copper on flu viruses, including h5n1. apparently, the life expectancy of a virus is pretty limited on the surface of a regular sheet of copper. so, if i place a n95 mask between 2 copper sheets, it’s suppossed to get killed in a few hours. same could be done with clothes etc.
I’ve been away and am behind in my reading, so if this has been answered, sorry….could one microwave a mask and make it reuseable in any way? I know you can microwave sponges and cutting boards to make them safe after use.
regarding the microwaving…
when you stick anything in the microwave and turn it on, the first thing that kicks on is the microwave’s exhaust fan. Before any germs can get “cooked”… some that were on the outside of the mask may come blowing out into the room I would think.
I”m looking into finding some UV light (short-wave length) fixture that one could rig into a “decontamination” box, much like is used for sterilizing safety goggles in school laboratory situations. Remove masks throw into the box, close box, run the UV light for 1–2 minutes…voila…
Don’t run the risk that you have high temps of ruining the elastic bands, or increasing the porosity by spraying with “wet” disinfectants.
any thoughts on this scenario?
3M 1862 respirators cost about 6 dollars a piece in the UK if they are bought in boxes of 20. Many websites offer N95 masks at around 1 dollar per piece. I checked a site in the US for 3M masks and there was a mention that these masks could not be purchased by customers outside of the US. What gives ?
Not sure about why that may be the case. Have you tried the website masksnmore.com ? I have had good luck with them but I’m in the US. It’s worth a try anyway.
Albert, I saw that too…that they couldn’t be purchased outside the US. I thought that was really weird! Maybe there are just different regulations in the different countries. I actually bought a package of 20 for my husband and me, and a package of the small size for my kids. They were only about $18/package. The peace of mind is worth the it to me. I got them at www.gallawaysafety.com. They have them in stock. Several sites were out of stock and couldn’t get more until the end of April.
I just figured that an N95 or N100 particulate mask is better than no mask at all and there is no shortage of them. I got the kind with the exhale valve (very important if you aren’t the sick one) at Gemplars. Have probably posted this link before but forgive me because I am getting old. Oh! The disposable masks are spread out among 7 pages so don’t think that flimsy thing on the first page is all they have. I got the kind with the inner flaps that mold around the nose and cheeks for a better fit. You will see which ones they are. http://tinyurl.com/opwqd They also have all kinds of interesting items (huge catalog) that might be useful in a crisis. Spayer things, things to test soil, tanks, weather instruments, good heavy duty clothing etc.
And don’t forget about those bung wrenches and siphon pumps if you have 55 gallon water barrels. They have those too.
Oh, this is what I originally meant to write (then I will shut up) I only have 30 respirator masks. If we ever have to use them, after using one I am going to spray them with a bleach/water solution and let them sit for a few days.
If you spray your disposable mask with anything it damage the materials and it will not filter properly anymore - they can’t get wet and they are not designed to be reused.
They are designed to be worn for only 20 minutes to an hour max and then be tossed.
Masks filter out the particles, the particles (anything in the air above a certains size) accumulate in the filter gradually clogging it. You won’t be able to resuse them after that, there isn’t anyway to ‘backflush’ the filters. Speaking of which, for those who think that they’ll need to filter water, the same thing will happen to the ceramic filter in those also.
Oh shucks!!! Then I will just have to stay home. Sigh. :-) Seriously, I will pick up more if possible. The masks that I got are for use and reuse for several days, but for a different purpose (not the flue) They are for mist, mold and that kind of thing along with dry particles. About the moisture thing - NO mask will remain dry for more than a minute or less. At least the exhale valves will minimize it a little bit. Sigh, time to shell out some more bucks! I might as well get the cheaper ones I guess. Gemplers had a permanent mask with disposable filters that you in it. Maybe that is the cheaper way to go in the long run. The filters are for the same things. I can clean the mask and change the filters in it.
Be very careful how you clean that reusable. You may have brought the virus into the very place you are trying to protect…..your home.
Deb - please read the above response to others. Thanks
also see the treads: http://www.fluwikie.com/index.php?n=Forum.MaskRecycling http://www.fluwikie.com/index.php?n=Forum.WouldLowHeatPermitReuseOfRespiratorMasks http://www.fluwikie.com/index.php?n=Forum.MasksN95AndOthers
conclusion is we still dont know of a nondestructive recycling way, but a there is common agrement that masks will be short. And that it has to be dealt with, even if mask effecicency decrases.
UV light from the sun or a tanning lamp seems to be the beste idea . The microven solution need viruses with water inside to work, I think dry viruses may survive, but I dont know.. A plastic box to keep the mask in will prevent any spread by the ovens fan.
My plan is spraying with pure isopropanol in an emergency, but don´t tell Pirate Girl I said that ;-)
Just came across this thread, and thought about the fact that I bought a high power UV light for Halloween; 400 Watts. Just go to www.Froogle.com, and put in “chauvet black shadow”; there will be several wattages. Don’t know if this would help anyone, but it’ll make your teeth glow in broad daylight from 10 ft. away!
VLPRONJ If you shined a high power ultraviolet radiation lamp at me on Halloween I’d be REALLY REALLY pissed at you. What do they teach in school these days?
You probably bought a highpower black light, which is just a really short wave blue light, or alternatively a very longwave purple (ultraviolet) light, close to 400 nanometers.
It doesn’t matter how high the wattage is, what makes an ultraviolet light germicidal is the wavelength.
A true germicidal ultraviolet light would emit at about 100–280 nano-meters, and would come with strict warnings to not expose your skin and to wear safety glasses.
If you are in the habit of shining a true shortwave UV light on your face I’d suggest you see a dermatologist at regular intervals.
I’m sorry, but I don’t understand a lot of the things being said in this thread. We have been using 3M N95 masks in our woodworking shop for quite some time, now. They do NOT break down in an hour, or a day—if anything, they pick up the fine micron sized wood dust particles and, like any of our other dust filters and dust collection systems, become more efficient the more clogged they become. Until, of course, air no longer passes through efficiently. Then it’s time to throw them away.
Eight hours a day, in constant wood dust, and we have to replace our masks about once every three to four weeks. Now obviously there are issues specific to the filtration of airborne viral particles, such as the need to isolate a mask after use for some amount of time. Fredness, for example, suggests 6 days as a possibility. But no company hoping to survive could produce and successfully market an N95 mask that you could only use for an hour or so before having to discard it.
What am I missing here?
It’s a good thing that wood particales and dust aren’t infectious…
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