As regards N95 masks and influenza, a number of folks in the Flu Thread have indicated they don't work or don't give a good seal -- whatever. I've seen a number of news photos of folks wearing their masks with their nostrils exposed. What's the point of wearing a mask if you leave your breathing holes on the outside? Maybe they don't breathe through their noses.

The isolation masks we have here (99% EFF at .1 Microns) can be shaped around the bridge of your nose and they provide a good fit.

I'm no expert on this but, as I understand it, any sort of regular dust mask is really only effective to the extent that it prevents the wearer from touching their own mouth and nose. A mask plus glasses or goggles would be the complete package to keep you from picking up the virus and infecting yourself with it.

That could be true, virus' are pretty small critters and can get through some fairly small gaps when motivated. That said, when I wore these masks during the last wildfire here (SOCAL) it cleaned up the air a lot. As I understand the H1N1 virus is dependent on droplets and isn't "in the air". The mask will stop you from inhaling those droplets. . . maybe, I think, not sure but it won't hurt.

"Sciency"? There you go again, Izzy, using all those big words again!

But seriously, we're all here to share and learn, so don't sweat it. I appreciate your many contributions.

In the workplace, N95 masks are required to be fit tested just like any other respirator. Facial hair and face shape can make that difficult or impossible, so an N95 will not work for everyone.

That said, N95s or Pappers are what all of our hospital staff use in isolation areas.

Greg

The N95 masks we use at work (3M) also come with an adjustable noseclip. I've seen the same model available in hardware stores and it works well for what it does. If adjusted properly the seal is pretty tight. The fit should be identical to your N99 masks, though of course the N95 standard offers somewhat inferior protection.

I like them as they are, cheap and they pack flat. We have them in bags and vehicles just in case. So far I've only needed them for wildfire smoke (probably way overkill) and so far haven't seen a need to wear them for the phase 5 influenza pandemic alert.

N95's are not overkill for wildfire smoke. The tiniest soot particles from a hot wildfire are so small that they can evade your body's normal airway defenses and get down deep into your lungs, which is bad for you. A dust mask or bandana won't filter out these tiniest particles, but an N95 can. This is a separate problem from any sort of fumes a wildfire can generate from combustion, like carbon monoxide.

Actually, even when the skies clear after the fire, the air can still be loaded with these tiniest of soot particles. The air looks clear because the particles are so small that they don't block the light like larger soot/ash particles do. The only way to know if these smallest particles are around is to check an official air quality report and look at the PM2.5 and PM10 levels (well, or you may be able to "feel it" in your lungs). Since they are so small, they can stay suspended in the air for a while unless there's a breeze to blow them away.

I have a couple boxes of N95's at home (purchased from fellow ETSer Red Flare, too!), not for pandemics, but for wildfires. A big wildfire was upwind of me and poured smoke down on us for almost a week, and I only had two N95's to get me through that week. By day 6, I had to go see a doctor because I was having trouble breathing from all the irritation from the particulates even though I had tried to stay indoors pretty much continuously during that week. I even wore the N95 indoors during the day, but not when I slept, which is probably when my lungs would get irritated. The PM2.5 and PM10 levels stayed sky high for maybe 10-14 days even though the skies had been clear after day 6 or so.

Actually, if you haven't already read it, Wildfire Smoke: A Guide for Public Health Officials, is a very readable source of information.

OK, OK, I've tried to avoid the ensuing over-panic about "swine flu."

From my school's dean, a pulmonologist:
Masks over the healthy do NOTHING. Viruses are small enough to pass through the pores. Since you need to touch the virus on a surface, or breath it in, just wash your hands.

Masks over the SICK make sense: the virus is in the droplets that they sneeze and cough up. Block the drops, you keep it better contained.

Remember, N95 masks block Tuberculosis - still way, way bigger than a virus!

Various news bulletins from the FD I volly for suggest this is still not much of a "panic" bug. Really, the death toll from regular old flu is 36K annually in the US. This is, what, 1 in the US to date? Does it have the potential to reach 1918 levels? Maybe... but we have Tamiflu which helps decrease duration of disease, as well as symptoms.

As one of the CDC officials pointed out, the reason we're "seeing" more cases as the days go on is that we're now testing folks for it. By looking for something, we're finding it. That doesn't mean we haven't had swine flu in the US before, it's just that we didn't look for it. The normal "flu" swabs that most docs use just test "a" or "b" strains. Swine flue is still in the "a" category, so it's entirely possible we've been treating it like any other strain.

Personally, I'm not worried just yet, until the death toll starts to get higher (in proportion to number of sick). Avian flu/SARS seemed a much bigger threat.

Edit: Having said all this, the EMS guidelines I'm seeing currently are recommending N95 masks, gloves, gown, eyes for CONFIRMED cases only. Otherwise, suspected cases are still OK with gloves, eye shields, and surgical mask only if close contact is anticipated during procedures. Then just wash hands before and after.
http://www.cdc.gov/h1n1flu/masks.htm

Just wanted to add that the N95, R95 and P95 are the same level of filtering. The letters only specify how resistant to oil the filters are (N=not oil-resistant, R=oil-resistant, P=oil-proof). So as far as pandemic flu is concerned, they all provide the same level of protection. (Whatever level that might be is up for debate.)

I think the Wilson brand masks do have the neoprene (I think) gasket around the edge. Also, the Triosyn (blue, iodine-impregnated) masks have a gasket around the edge, if I remember correctly.

I first read this last night and thought, "Wow, that's a rather provocative statement," so I slept on it.

It would be nice if I had been there to hear the entire context of the statement but that's not important. I do agree that hand washing is far more important to protect most of us from any flu bug than having a mask.

For average folks, better to stock up, carry, and frequently use hand sanitizer than stocking up on N95 masks if you're worried about the flu (among the other suggested steps, like cough etiquette).

I was curious about when the N95/99/100 standard started, and while I was doing some reading, I discovered that the new standard was adopted in 1995 primarily in response to protecting workers against TB. Actually, that's not that long ago, when you think about it.

If you recall, there was an upsurge in infectious TB in the early 90's. Workers in the healthcare setting and also in jails/prisons were very concerned about their safety. Before then, it seems that surgical masks on the patients and workers were the norm, but workers were getting infected so the CDC came up with a new standard. Prior to that, masks were regulated primarily for situations like manufacturing or mining, so those standards didn't necessarily fit well to biological threats.

Anyway, if you ever search the medical literature on masks/respirators, you see TB mentioned a lot, and now you know why.

Probably the most likely path to infection is from hand to mouth/nose/eye contact. Most influenza/rhino viruses aren't strong enough to penetrate the epidermis directly, but will contaminate the hands fairly easily, and then we wipe our face or touch food or drink or some such that then contacts our mouth etc and then we get infected. Wearing a mask is actually beneficial as a barrier against self infection by keeping our hands out of our mouths, off our noses, etc. You are more prone to decontaminate first before doffing the mask this way, and greatly reduce the risk of infection. Wearing a mask and eye protection would be quite desirable in this respect. Of course airborn vectors are always a factor to consider (the theater scene from the movie "Outbreak" exemplifies such a problem), and in this way a mask and eye protection are a definite advantage as well.

Personally, if we had a really virulent disease running rampant, I would opt for an enviro suit (level B at the least), kinda like what the stormtroopers wear, only better sealed and more air conditioned. If we get an "Andromeda Strain" variant, I'll just go to ground and close the lid.

Viruses don't travel alone. The current understanding is that they are almost always contained in body fluids. That if they are not protected by some sort of biological goo not created by the virus itself they die. These virus containing fluids can form an aerosol when people cough or sneeze that can drift on the air for a good distance. If you breath these droplets you get the virus. If you stop contact with these droplets by preventing them from being breathed or from physical contact after they are on surfaces you have stopped the virus.

Masks may be more effective at keeping the disease contained if used on an infected individual but they are not ineffective when worn by the healthy person. Ideally both would wear them. there is also the simple fact that many diseases can be spread by people who don't, may not ever, show symptoms.

Putting a mask on sick people can help. But seeing as they may have been shedding virus for 24 hours prior to their showing symptoms your closing the barn door after at least some of the horses have left.

I just got 40 for my dad last month from amazon... $16/shipped for 20 can't beat that... He uses them for EVERYTHING. mowing the grass to sanding or dusting the house. Totally allergic to it all.

Me? They do not seal good AT ALL even if you contour them aroudn your nose you still get contaminated goop in.. sure they may have good filtration but not if it doesn't close up the gaps good

I have one of those 3M with the filters onthe side, and the plastic around tnhe face with the straps you adjust.. that thing is great! I use it for painting and other dirty jobs.

I think for most people, most of the time(obviously not counting health care workers and such), wearing masks is simply not necessary at this point, and wearing them in public may lead to alarm or panic on others, and would probably cause a lot of uncomfortable stares and such. That said...

N95 respirators are great, they're multipurpous, cheap, never go bad, and you can keep them everywhere. My favorite are the flat pack, individually wrapped, 3M model 9211, which include an exhale valve for comfort. Note that for patients suspected of being infected, they should definitely NOT wear a mask with an exhale valve, as that defeats the purpose. The biggest flaw of disposable N95(or N99, p100, etc) masks is that they will not make a perfect seal with your face, but as noted above that's less of an issue if you only need to filter water droplets.

If you want/need a mask with a better seal, especially if you have facial hair, the best way to go is a reusable rubber respirator with replaceable filters. None of them are especially comfortable, especially in hot weather, though neither are disposable masks, especially cheap ones. I use the North 7700 silicone half-mask, which is about as light and comfortable as you can get when you use a lightweight, pancake style P100 filter. The highly flexible silicone creates a better seal than other types of rubber and way better than paper masks. You can find these online for under $20, and if you buy a lot of filters the best deal I've found is at AlexGS.com. I wear a respirator almost everyday at work(mainly for fiberglass, dust, and crawlspace nastiness), and these are the best I've used, though I use their full-face respirator more often. Not to get too off-topic, but I like the wide variety of filters and cartridges I can use with these.

You're right, it IS provocative. I'm actually suprised no one else called me on it. I think I'm just irked that this disease is getting so much attention - it's a "WOW!" factor in the media, with totally biased info. It's the flu. It's not like Ebola suddenly became airborne and we're getting 90% death rates.

Since you wanted the entire context, I pulled the quotation out of the email sent to our campus. If I get contacted to remove it, I will, but I'll also leave it anonymous for now. The info he is referencing is the bit about hand washing, staying home, stop picking your nose and rubbing your eyes, etc.

"One other piece of advice from an old pulmonologist, who dealt with these sorts of things on more than a few occasions, all of the above are the best that can be done. Wearing masks if you think YOU HAVE the Swine Flu helps you from spreading it to others. Wearing a mask to protect yourself does NOT help you from catching the flu from others, however. [ It has to do with the difference in size of the virus enveloped in moisture coming out of the diseased person and the virus particle floating freely in the environment dehydrating and becoming small enough to pass through all but HEPA filters. It gets pretty technical but it is pretty interesting (as I define interesting).] Bottom line if you are feeling well don't waste money on buying masks."

Here's some fun reading I saw just after hitting "Post"
http://www.cnn.com/2009/HEALTH/05/02/worried.well.hospitals/index.html

The headline on CNN. com for the above article: "Emergency rooms hit with flu 'hysteria'"

Ironically the "surgical masks' are not all that good at filtering air. Their main job is preventing sprayed spit from the wearer traveling to others. This they do pretty well.

On the other side a N-95 or better mask is fairly good job at filtering air. It isn't perfect but far better than nothing and a good bit better than a surgical mask. The ones with an exhalation valve are much more comfortable for hot weather or extended wear. A really big improvement. Trust me. Spend the extra money.

Either of these masks will offer some protection from sprayed spit coming at the wearer and will also serve to help keep the wearer's potentially contaminated hands away from their mouth and nose.

Using these two different masks some consideration needs to be taken to use the right one. A surgical mask will help prevent you from inhaling aerosols but not as well as a filter mask. A filter mask can help keep spit confined to the wearer but it is using a $7 mask to do what a $.50 surgical mask will do. And, it should be obvious, you wouldn't use a mask with an exhalation valve when the person is infected because the valve bypasses the filter when air is going out.

I was using an N95 mask today. It specifically stated it was not rated for Asbestos or silica dust.

If cannot be used to keep me from getting asbestosis, then I don't see how it can stop a virus.

I think asbestos or silica requires an N100 (or was it a P100). It may also require a half-face respirator.

those using N95 like me have been sized and tested for fit.
I'm a ER nurse so having mask like these are normal. many who don't know how to use them just think they don't seal properly.
its just they never been fitted and hood tested. yep i was put into a smoke hood and tested for proper fit.
i use a small for i have a long nose and my nose and mouth close small chin.
most people have difficulty breathing threw them for they tend to be thick with some type of rubber inside so they tend to be hot and uncomfortable. so many patients only use the ordinary surgical mask for they tend to be applied and kept correctly on longer. surgical mask have to be tided both strings. surgical masks are good for those coughing up microscopic droplets. still they in the CDC newsletter are unsure of disease spreading by airborne or droplets. so having both mask handy would be very practical just check for size with the N95. they come in small and med that i know of.
prizm63 wife of cousinit.

Large too. Never seen an XL, but I assume they exist.

Unfortunately, I still have questions about what exactly your dean is referring to. If he was talking about the surgical/procedure masks that you see many people wearing on TV, then I would totally agree with his statement which is why I didn't really say anything about it the first time without more information. But, from that quote, it sort of seems like he is referring to N95's, in which case, I guess I take issue with the statement that they provide NO protection at all. It sounds like he's comparing an N95 to someone trying to use a bridal veil as respiratory protection against the flu.

But, again, context makes all the difference. For example, since an N95, by definition, lets 5% of the test aerosol through, some may consider that result to be the same as being useless since 5% may be enough to infect someone. <shrug> Not to be argumentative. I'm genuinely interested in the logic of what he's saying since on its face, it seems counter to everything things I've heard/read.

The point about the viral shape inside the droplet is interesting, although I have never heard any mention of that ever being an issue with filtration. If the droplet itself is much bigger than the individual virus particles, how the virus is folded doesn't seem like it would affect the shape or characteristics of the droplet itself. That's another potentially interesting piece to this puzzle.

I think it's interesting that in the two different media visits I have seen on TV to the operations center at the CDC or even in the microbiology lab at the CDC doing active testing on the H1N1 virus, there's not a single face mask to be seen on anyone working there. Anyone else notice that?

Has to be stock footage. Most of the ones I've seen with surgical masks are probably to just avoid contaiminating the sample, not to protect the user.

No, not stock footage. In both segments I saw from different networks, the reporter was on-camera, talking to CDC people in those locations and you could see the operations center or lab folks working in the background.

Unless...they are all just actors...and the real work is being done at some "secret, undisclosed location" recently vacated by you-know-who.

Work with N1H1 is recommended at a Biosafety Level 2 (BSL2), which is generally working under a certified BSL2 biosafety cabinet. No mask is required, as the containment feature is engineered into the biosafety cabinet. You may see laboratory workers wearing additional protection of masks and/or Tyvek clothing, which can be added if the worker is entering and exiting the hood frequently.

Pete