So: will an N95 mask keep the virus out?(Y/N)
It is tested againt 0.3 micron particles, but how will it keep out virus that are 0.1 micron?!
A lot has been mentioned about the inexpensive N-95 masks, but they are wholly inadequate for this application. Government officials should really stop recommending this mask to the general public because it will not stop a virus consistently. Go online with NIOSH and see what they say. Their standard for N-95 is that it will filter out 95% of all particles that are .3 microns or larger. So, this mask will effectively filter out only 95% of the airborne droplets from a cough or a sneeze. That leaves you vulnerable to the other 5%. Another liability with this mask is that it lacks an exhaust valve. Therefore, when you exhale into it, you tend to lose contact temporarily between the edge of the mask and your skin. This condition becomes worse if you are breathing hard.
Rather than bet your life that the N-95 is adequate against flu, invest in several N-100 masks. These are all equipped with exhaust valves and you can get reusable ones as well as the disposables. First, however, check out the inflated prices online, then stop by an industrial supply store, such as Grainger, Fastenal, or Whitecap. You will be impressed with how cheap they can be over the counter.
For those of you who would also like to prepare for other forms of respiratory assault, the highest standard in respirators is P100. The P100 will not only filter out particles, but it also filters out smoke, aerosols, and hazardous vapors, such as chlorine, toluene, etc. These can be reused and the filter media can be replaced.
I read somewhere that the virus will likely have to attach itself to droplets, that are larger than 3 microns. I am not any kind of scientist or technician, just passing along what I read. BTW I have both N95 and half mask p100.
NJ Jeeper
I read the same thing. Whatever large droplets that are discharged from a cough or a sneeze will eventually settle somewhere, but maybe not before someone close by has inhaled some. Regardless of the particle size, the fit of the mask will be of critical importance. The N-95 disposables are not very form-fitting and the vapor you exhale tends to degrade the filter membrane.
What if you have the masks with the exhaust valve to let the vapor out. My latest additions also have the foam fitting face mask.
Will a P100 filter out virus of 0.1 micron?
NJ Jeeper
I have a supply of N100 disposables that are sort of form-fitting and they do have the exhalation valve. I will use these outdoors in conjunction with social distancing. However, if I absolutely must come close to people, I will use my North 7700 half-mask P100 in conjunction with a face shield.
(Y/N)?
I can see myself going into the bank with a half mask and goggles on. Yeah, then time in the back of the enclosed squad car.
Blue,
I guess the question is one of conveyance. How did the particle get airborne? My understanding is that the greatest risk of inhaling a virus when it is transmitted through the air within droplets that have been expelled via coughs or sneezes. For that, a P100 mask will work, as long as you can also protect your eyes from the mist.
For those who would like more information on respirators:
http://www2.cdc.gov/drds/cel/cl.htm
Ultimately, even the P100 is only 99.9% effective and that level of protection assumes that the user is doing everything else 100% right.
So it will block 99.9% 0.1 micron virus even though it has only been tested against material that are 0.3 micron?
My asumption is that a P100 mask would have very little effect against anything smaller than .3 micron. However, it is still my understanding that the virus does not float freely through the atmosphere. It is bound to some particles (water, mucous, feces, dust, skin flakes, etc.)that are well over 1 micron in size. If this were not the case, no medical professional could ever be safe around a flu patient. Maybe someone out there can enlighten us on this facet of the discussion.
NJ Jeeper – at 09:53 wrote:
I can see myself going into the bank with a half mask and goggles on. Yeah, then time in the back of the enclosed squad car.
If it reaches the point you need a mask to go into the bank. Chance are only the ATM’s will still be open.
So, then an N95 will keep out 95% of 3 microns? If so, then I can go with those odds.
Blue – at 04:44 wrote”
So: will an N95 mask keep the virus out?(Y/N) It is tested againt 0.3 micron particles, but how will it keep out virus that are 0.1 micron?!
The mask (N95) stops about 95% of all water droplets on which the virus hitches a ride on. There is information based on the experiences of SARS nurses, that if N95′s were used with proper precautions, hand-washing etc., that the risks of exposure were significantly reduced. Keep in mind that N95 are not the easiest to breath through and the problem increases with N100.
In a controlled home enviroment (caring for someone sick), you can increase the the efficiency of the N95 respirator significantly with the temporary use of an, off the shelf ionizer. Buried in the CDC website is an extensive scientific paper about this. The paper is easy to understand.
If this were not the case, no medical professional could ever be safe around a flu patient. Maybe someone out there can enlighten us on this facet of the discussion.
That is the question, I suppose!!
quoth:Dr Dave – at 08:39
“ The P100 will not only filter out particles, but it also filters out smoke, aerosols, and hazardous vapors, such as chlorine, toluene, etc. These can be reused and the filter media can be replaced. “
NO NO NO. P100 is only for particulates, hence the ‘P’. It most assuredly will NOT protect from hazardous vapors such as chlorine and toluene. And none of the professional P100 filters are reusable; they are all disposable. For organic vapors, there is a separate cartridge, with a charcoal filter, I think it is yellow. The P100 filters are pink. Combo filters with both have a yellow and a pink stripe. Make sure you understand the difference.
quoth Blue– at 21:40
“this were not the case, no medical professional could ever be safe around a flu patient. Maybe someone out there can enlighten us on this facet of the discussion. “
Perhaps part of the explanation is that by the time the patient hits the hospital, they are no longer contagious. There is more danger from the family member beside them, who is still vertical, and shedding virus.
? Perhaps ?
You are saying that these masks are probably useless then?!
Blue - read up on masks from the CDC/Niosh website @ http://www.cdc.gov/niosh/docs/2005-100/chapter3.html: A filter series (N, R or P) that will provide protection against exposure to the particulate in question is recommended.
a. The selection of N-, R-, and P-series filters depends on the presence or absence of oil particles, as follows:
• If no oil particles are present in the work environment, use a filter of any series (i.e., N-, R-, or P-series).
• If oil particles (e.g., lubricants, cutting fluids, glycerine, etc.) are present, use an R- or P-series filter. Note: N-series filters cannot be used if oil particles are present.
• If oil particles are present and the filter is to be used for more than one work shift, use only a P-series filter
Note: To help you remember the filter series, use the following guide: N for Not resistant to oil, R for Resistant to oil P for oil Proof
b. Selection of filter efficiency (i.e., 95%, 99%, or 99.97%) depends on how much filter leakage can be accepted. Higher filter efficiency means lower filter leakage.
Additional information on selecting the appropriate filter certified under 42CFR84 can be found at http://www.cdc.gov/NIOSH/userguid.html. Proceed to Step 9.3.
Because virus particles are normally suspended in water droplets (expelled from the respiratory tract through coughing or sneezing) and not OIL, the relevancy of the N, R, P masks is relatively irrelevant because efficacy of the mask does not increase or decrease based on water exposure, but on oil exposure. However, it is most effective to use a N,R,or P 100 mask as it filters smaller particulate matter than the 95 masks do. Any mask is certainly better than no mask, IMO. You’ll probably only get a better result if you bottle your own clean oxygen now and glue yourself to a regulator should TSHTF.
I like to look on the positive side of adversity. As I heard someone say, “What doesn’t kill us makes us stronger.” Words to “live” by. hehe.
No. But masks might not always work the way you think they do. One way the mask protects you is by preventing you from touching your nose or mouth with your contaminated hands. Any mask will do this, even a cloth one. Another way is by trapping droplets, which again, even a cloth mask will do. Not everybody will be intubating patients or or be exposed to hours on end of high-concentration aerosol virus. Most everyone else might do OK with a simple mask. The type and cost of the mask should be proportionate to the concentration, exposure time, and particle size of the expected exposure. And there should be a schedule for changing out a mask, too. They don’t work forever. And note that a lesser mask might make you be more careful, while a better mask might make you careless.
Any idea how long the standard N95 masks should be okay in storage (normal temp conditions, in cardboard box, no/minimal exposure to light)?
Disgruntled, I do not mean to be argumentative, but it appears that you have been misinformed about respirators:
No, the P designation does not stand for particulate. Yes, the P100 respirators are available as reuseables, as are the N100s and R100s. Yes, the P100 respirators will filter out organic vapors, such as Toluene.
Please refer to the NIOSH web page I referenced earlier for clarification of the codes, ratings, capabilities, durability, and practical applications. After that, visit an industrial supply store, such as Grainger, and see the wide variey of reuseable P100 respirators. Compare them to the disposable N95s. Buy one of each and then test them at home. You will find it enlightening.
Although I commonly use a cheap disposable N95 particle mask for benign applications like sanding or tilling, I am not willing to bet my life that it will protect me from the flu. Based upon the amount of dirt and sawdust that still ends up in my nostrils, I would have no confidence whatsoever that a disposable N95 would protect me from the flu. By contrast, when I wear my reuseable P100 half mask respirator while painting or staining, I never smell a thing. Even when I have worked with epoxy solvents, such as Xylene and Toluene, I have never smelled anything.
You will get the protection you pay for: a disposable N95 respirator can be purchased for $1, whereas a high-end reusable P100 respirator, such as the North 7700, will cost over $25. Are you willing to bet your life that N95 is adequate? Not me. Not after seeing how inadequate they are for filtering out garden dirt and gypsum dust. So, for anyone who is about to invest in respirators, ask yourself this hypothetical question: if you had to crash into a light pole, would you rather be in a Yugo or a Hummer?
Keep in mind that some people can afford Yugos and some can afford Hummers.
I neglected to mention two important factors in respirator selection and application:
1. Exposure Limits. Each respirator is rated for exposure limits, based upon the type of hazard and the amount of time the respirator will be used on a specific hazard. For example, a P100 half-mask respirator can be used all day for exposure to particulates, but not for organic vapors. The amount of time that any respirator can protect you from organic vapors will vary widely, so this is very case specific.
2. Respirator Selection. Disposable respirators are usually mass-produced as “one size fits all” items. Therefore, they tend to fit poorly on a lot of people. Reuseable respirators, on the other hand, are available in varying sizes, from small to extra large.
Here is a tip for the selection of reusable respirators: try on a medium mask, put plastic sandwich bags over the filters to block the air flow, and attempt to inhale. If you can draw any air past the perimeter seal, this is not the mask for you. (Another reason not to buy these online.)
NJ Jeeper,
The Hummer is actually cheaper than the Yugo. The Yugo could cost you your life.
Certainly, for those who live from paycheck to paycheck having a few disposable N95 particle masks would appear to make economic sense, but it is false economy. Apart from the limited protection factor (N95 versus N100, poor fit, etc.), this is a single-use mask that must be discarded after a few hours of use.
How long will the pandemic last? Several months? How many disposable masks are you going to need? Several dozen? After you have stocked up on several dozen disposables, you will have spent more than you would have on a single P100 half-mask.
O.K.
Next question.
Will a P100 keep the virus out?
They, too, are only tested for 0.3 micron.
Virus are about 0.1 micron, and virus can be found alone.
I understand your point. Question, though, the p100 filters are usable for a day then are contaminated, so this would also be an expense to have lots of the filters on hand. You also have to be careful when taking all masks off your head. There is a procedure to do this.
I read about a suggestion that they be taken off and allowed to sit for a few days for the virus to die off. Then recycle them a few times. Your comments?
Blue, I really hope you are mistaken, but if that is the case, then you will need a full hood with its own air supply.
NJ Jeeper, you raise an interesting complication. But, as long as your air flow does not seem impeded by a build up of dust, the reusable P100 respirator filters can be used for months. All you would have to do to refresh them between uses would be to dry them out or heat them to a temperature that effectively kills the virus. The mask itself can be sanitized with bleach and reused indefinitely.
I will be wearing disposable nitrile gloves. I can easily grasp my reusable respirator by the two filter housings and avoid contacting my skin with my gloves.
That is my plan also. I also have some N95 vented (8211) to wear. Not sure when I would wear these, maybe at the 24 hour market at 3am if I have to go there at all. If they are open and if they have food.
NJ Jeeper, I admit to having a lot of N95, N99, and N100 disposables for use in low risk situations.
As you prepare to care for someone who has the flu, don’t forget to buy a couple of face shields. Sick people cough and sneeze unexpectedly. A face shield could provide some protection to your eyes.
Another important thing to remember regarding any sort of respiratory hazard:
Respirators are inferior to engineering and environmental controls. OSHA and NIOSH guidance is that respirators are to be used when engineering controls are impractical or inadequate, not in lieu of them. This is why pathogens are handled within biological safety cabinets, rather than out on an open lab table with the laboratory worker garbed in PPE. The same is true of chemicals in a fume hood, painting in a paint booth, etc.
Think about what engineering and environmental controls can be applied to reduce the load and shorten the viability of the virus in air. Influenza does best in conditions of relative humidity between about 55 and 70% - can the RH be controlled? Higher or lower, and the viability drops greatly. Contact with contaminated surfaces and fomites is a prime cause of infection with many diseases, flu included. The bug is picked up on the hand and transferred by unconscious touching of the face, eyes, etc. Frequent hand washing, gloves and liberal use of disinfectants are indicated. Sunlight is a great disinfectant - most bugs die quickly when exposed to sunlight or ultraviolet light.
Maybe maintain negative atmospheric pressure in the sickroom relative to the rest of the building, exhausting to the outside? Change clothing and shower out like in BSL III labs? Red bag all potentially contaminated waste? The point is, there a whole lot of precautions that can and should be taken in addition to just worrying about the particulars of respirator efficiency.
A good reminder about the workplace and home, but if you need to go out somewhere, you can not control these things you mentioned. But we can and should control all of the things you mentionr to the best of our ability. And I agree masks are the last line of defense.
quoth Dr Dave – at 07:55 “Disgruntled, I do not mean to be argumentative, but it appears that you have been misinformed about respirators:
No, the P designation does not stand for particulate. Yes, the P100 respirators are available as reuseables, as are the N100s and R100s. Yes, the P100 respirators will filter out organic vapors, such as Toluene. “
Here is what the label says: P100 High-efficiency Filter : Approved for respiratory protection under the 42, CFR P100 classification (99.97% efficient against all particulate materials including oil-based aerosols).
It does Not include organic vapors. The yellow cartridge does that. What you are describing sounds like the combination cartridge.
And I use a respirator at work, and just last week completed my annual 8-hour Hazmat refresher training. And in the class we covered respirator cartridges, and there was even a quiz. I think you need to check out the fine print.
Disgruntled,
While you are correct that not all P100 filters can be used for all organic vapors, some can used for a limited range of vapors. And yes, the yellow and pink is the combination filter that pretty much does it all. That’s what I use in my North 7700s.
Say, how come after 8 hours in a haz-mat class you didn’t learn what the P stood for and how come you didn’t know that P100 filters are reusable? You were pretty adamant about those two points.
quoth Dr Dave – at 12:19 “Say, how come after 8 hours in a haz-mat class you didn’t learn what the P stood for and how come you didn’t know that P100 filters are reusable? You were pretty adamant about those two points. “ Well, I looked into it a bit. It turns out that our Industrial Hygenists made the selection of what to stock, and they chose the P100 for particulates, the combinations, and the organic vapor cartridges for the rest. In the class, they use the mnemonic, pink=particulate=p100. So perhaps I was misled. It was Calandriel who pointed out the differences, not you. I still think it should be made clear that not all particulate filters are good for organic vapors, as your first post stated. And not all P100s are reusable. Ours certainly aren’t. Perhaps we could agree to say, “Read the specifications and use only as directed.”
Respirator Performance with Infectious Agents
(Studies with Simulants) Center for Health-Related Aerosol Studies University of Cincinnati Cincinnati, OH 45267–0056, USA Sergey Grinshpun, PhD CDC Workshop, November 30, 2004
‘’‘Enhancement of the respirator performance by the unipolarion emission is governed by the electrostatic “shield”mechanism.’‘’ (use of ionizers)
Disgruntled,
I already acknowleged that not all P100 filters are good for all vapors, but every P100 filter is good for some vapors, in addition to all particles. However, it was not my intention to advise anyone on how to cope with hazardous fumes. I am sorry if I gave you that impression.
When this discussion began, the issue was one of absolutely blocking something that is smaller than the smallest filter available. For that, I have no answer. I always thought that the virus would be carried through the air on a tiny droplet of about 5 microns in size, so my biggest risk would have been in coming into contact with someone who was coughing or sneezing. I do not really know if I am at risk for inhaling a bare .1 micron virus through any mask, but my odds of preventing such an occurance increase if I protect myself with something better than a disposable N95. Do you agree?
Since you and I both have experience wearing respirators, you probably know what I’m getting at, and I’m sure people could benefit from your real-world experience, too. I mean, if you can get drywall dust up your nose while wearing a disposable N95, what is to stop a contaminated 5 micron droplet of saliva? We both know from practical experience that there is a huge difference between the fit and seal of a “one size fits all” disposable N95 and a reuseable elastomeric or silicone N100.
I may be jaded on this issue, but I see the widespread recommendation of the disposable N95 as essentailly similar to the old “duck and cover” nuclear attack drills from elementary school.
I don’t think that absolutely blocking all particles is a reasonable goal. The mask is there to reduce risk, not eliminate it completely. As you have observed, the N95 mask doesn’t eliminate particles, it just reduces their number. Same with P-100: they will reduce levels further than an N95, but not eliminate them completely.
So what we need to know is the particle size distribution in a sneeze, and the minimum number of virions needed to produce an infection. It seems clear from the poultry workers’ seroconversion that low levels of exposure do not produce fatal disease, even without masks, gloves, or other equipment. However, being in an enclosed space with a high concentration of particles does cause fatal disease in susceptible persons.
So the worst case scenario is being stuck on an airplane with someone who is coughing. And logic suggests that controlling the source will protect more people more efficiently than dealing with the consequences. So any kind of mask on the perpetrator, and a good mask on you, would be a reasonable response.
Filtration in the sickroom is another issue. Here, a furnace filter duct-taped to a box fan would reduce the aerosol viral load.
I disagree on the N95s being useless as I described above. Aerosol particles are not the only way to get the virus, and an N95 on a sick person will help control it at the source. In Dave Barry’s book, he cites an example of a city being told to take off masks too soon, with a poor outcome. And they were using cloth masks, probably equivalent to N95 or less.
Another observation is that killing the virus on the mask might be an option. The gentian violet filter has been discussed before, and I can’t see why it wouldn’t work. I think copper sulfate was also suggested.
As you can see, I think in terms of multiple directions of risk reduction, not just one. Going from N95 to N100 probably is about one order of magnitude risk reduction. Source control is probably good for 2–4 orders of magnitude reduction. Handwashing another order of magnitude. Air filtration another order of magnitude. They add up after awhile.
OK, experiment time: Here is something google brought up:
“”DEPOSITION OF PARTICLE ON TYPE N95 RESPIRATOR.
K. Lee, University of Kentucky, Lexington, KY; W. Zhong, G. Sun, University of California, Davis, CA.
The Type N95 filtering-facepiece respirator is most likely used by health care workers attending bioterrorism victims with airborne infectious diseases, and by some emergency personnel responding to a large bioterrorist incident. A previous study showed that a Type N95 respirator filter can remove at least 99.5% of microbial particles larger than 1 µm. Because a filtering-facepiece respirator tends to be reused throughout a work shift before being discarded, it is possible that handling the respirator can free trapped pathogens and resuspend them in the user’s breathing zone or cause the mechanical transfer of pathogens to mucous membranes or cuts on the skin. Therefore, we investigated the deposit of particles on an N95 respirator. Congo red was used as an indicator for examination of particle deposition on N95 respirators. The dye was mixed with NaCl in a particle generator. Size distribution of the red dye-NaCl particle was similar with pure NaCl particle. A person wore a N95 respirator while red dye particle was generated. Deposit of the red particle was observed by GretagMacbeth Color-eye 7000A Spectrophotometer. K/S (ratio of absorption K and Scattering S) versus wavelength of light is supposed to be proportional to the concentration of dye-salt particles deposited. The first (outmost) layer of the respirator had most of the dye particles. While only a small portion of particles deposited on the second layer, deposition on the rest of the three layers was negligible. This deposition trend was observed in different deposition times from 5 min to four hours. It is concluded that particles are deposited on respirator surface. Such particles deposited may be available for resuspension or mechanical transfer.”“
OK. Let’s do an artificial sneeze. Take a household sprayer, some red koolaid powder, and some salt, and make up a strong solution. Put on the mask, spray the air, and breathe some in. Can you taste salt? Can you taste cherry koolaid? Cut the mask across, peer at with magnifying glass. How far does the red go into the filter material? How does this compare with a bandana, and a t-shirt mask?
disgruntled:
A word of caution on your experiment. A sneeze generates air velocities of about 100 mph and a mixed but small droplet size. It is very effective as a way to generate an infective aerosol. There isn’t enough energy in a spray bottle to realistically simulate a sneeze.
That being said, if a mask fails your spray bottle test, it surely won’t work for the aerosol from a sneeze.
How about an ultrasonic nebulizer? That might generate the right size particle.
That would do it, I think.
Here is what I am doing-
For general preparation before the formal start of a pandemic, and for ‘out and about’ protection I use the disposable N95.
Once a pandemic starts anywhere in the world, I wear hospital grade N95 and gloves.
For wear on the RARE occasions when I go out into the general populace after the pandemic starts here, I use a fitted half-face N100 with N95 prefilter, face shield and gloves.
For wearing while caring for those ill with the flu during a pandemic, I wear a gas mask with n100 filters, full coverage biohazard suit, booties, hood and double gloves.
Match the response to the threat, I say.
…
(Y/N)?
This topic relates to the current discussion of aerosol transmission.
By the way, for anyone who thinks they will be relatively secure behind a mask, have you thought about the virus entering your body through your eyes? I do not know if this is possible, as I believe it is with a cold virus, but you can offer your eyes some protection with a face shield. You can wear these lightweight items like a headband. They will fit over respirators and prescription glasses, too.
I believe the virus can be ingested through the eyes!
O.K. Well the N100 WILL NOT WORK because it cannot keep the virus out of the eye’s.
So, now which mask/respirator should we all buy…ahem…all health care worker’s be supplied!?!
Although, I can’t recall seeing people being treated for TB with any form of Goggles on!
(Food for thought!)
What is the manufacturing capacity of N95s and N100s worldwide?
And Dr. Dave, I apologize for mistaking your dissertations for something I saw at Current Events. : )
Disgruntled is correct about the masks for the most part. Hospitals or buildings full of flu patients will need the N100 mask as appropriate, and the N95 inappropriate. Even if a flu patient expels in the air on the side walk and you’re walking behind him this is less of a viral load exposure than a flu patient in a room with you. Hospital rooms for the most part vent out—this helps exposure loads but it depends on how well the patient can be controlled. I can tie a surgical mask on a flu patient to lessen the viral load in the open air and if he is compliant the air is less infective. My experience with coughing and sick patients is they rip them off. So unless your home becomes a pest house N95 should work for you if you don’t go into hospitals or flu designated buildings.
Also at some point the patient is not infectious. This is the time frame we need to monitor. How many days is the patient with H5N1 infectious? Those who read the Barry book will recall the young doctor who found himself on the really sick flu floor, but none of the HCW’s got sick? The patients infectious period was over by then, but remember the a lot of the patients did die. It wasn’tt luck, ok some luck. Does anyone know the infectious time frame for the cases right now? 3 days? 5 days?
what about this idea:
use a balloon, fill it with (safe) air from your home,
only always breath in/out from/into the balloon.
That should be safer than any mask, but you have to take the
balloon with you. How big a balloon is required for a short
10-minutes walk to the next shop or to your neighbor
to barter something ?
hmmn?
What about ingestion thru the eyes?
Blue: Eyes are mucous sponges—I don’t think there is a lot of research on flu transmission through them. Wear protective goggles when out around a crowd.
hmm, I tried it, you need about 1 m^3 for half an hour.
There could be balloons with a valve and a filter and a mechanism
which permanently fills the balloon with safe,fresh,filtered air.
This air could even be treated with additional UV-light or chemicals or heated.
Then you breath that air. This should be much safer than a normal masks.
The balloon and the other mechanics could be in a knapsack on your back.
Do such things exist ?
interesting - i think there has been some work around that in another thread - not “masks” but “respirators”
Thought you might be interested in this…comments?
ANON - YYZ Yesterday.
I posted this on the news thread. Notice the author, from Toronto Sick Kids Hospital. I am glad some one is speaking up. The Canadian Pandemic plan basically positions the surgical mask as the PPE of choice for pandemic protection for health care workers, stating that there is no scientific evidence that N95 is any more effective.
Review of Aerosol Transmission of Influenza A Virus
Raymond Tellier*†
Hospital for Sick Children, Toronto, Ontario, Canada; and †University of Toronto, Toronto, Ontario, Canada
Several authors have stated that large-droplet transmission is the predominant mode by which influenza virus infection is acquired (1–3). As a consequence of this opinion, protection against infectious aerosols is often ignored for influenza, including in the context of influenza pandemic preparedness. For example, the Canadian Pandemic Influenza Plan and the US Department of Health and Human Services Pandemic Influenza Plan (4,5) recommend surgical masks, not N95 respirators, as part of personal protective equipment (PPE) for routine patient care. This position contradicts the knowledge on influenza virus transmission accumulated in the past several decades. Indeed, the relevant chapters of many reference books, written by recognized authorities, refer to aerosols as an important mode of transmission for influenza (6–9).
…”recommend surgical masks, not N95 respirators, as part of personal protective equipment (PPE) for routine patient care.”
had to be re-itterrated
Parallel thread over here- http://tinyurl.com/pedbg “Review of Aersol Transmission of Influenza A Virus”
Good review article
More governmental disorganization than disinformation IMO
more food for thought…
it says that N95 masks are not tested specifically for flu viruses!?!
C’mon….and we landed man on the moon…maybe it was a fake!
Food for thought—and possibly running away:
http://www.sierratimes.com/archive/files/oct/03/arwh100301.htm
I am not endorsing this, but thought you’d like to see it.
Blue -
No manufacturer will warrant their product as protecting against flu because of this. Many factors come into play, including what constitutes a median human infective dose of virus. BTW - I am looking for such a figure if anyone can point me to a source. Also I would like to have data on the probit slope or dose-response curve, if such exists.
Bogus respirators and cartidges
far as eye protection goes…i’ve found swimmer’s googles (w/anti-fog) provide a great seal, a pretty decent view (as they’re clear on the sides as well), and fit fine in conjunction with a half-face reusable.
$12. at Dick’s Sporting Goods
(but i got em for half-price when i knew the cashier and mentioned i’d thought they were $5.99! i really did! :)
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Walgreens Pharmacy is selling kits now. 7 N95 masks, 10 gloves and sanitizing wipes. $9.99 for the box.
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