Poultry Farmers At Risk With N95 Mask

This was sent to me by a microbiologist in Washington and he has informed me that N95 masks being used by poultry farmers although very cost effective is completely useless against H5N1 virus. He refers it to trying to filter sand with a pasta strainer! The H5N1 virus is so much smaller than .3um. Why on earth would anyone want to wear a N95 mask which is only 95% effective? Would it not be more prudent to wear a mask that is 99.99% effective? Would it not be wiser to actually use a mask that's been tested with biological agents instead of salt particles? It's kind of like building a boat and spraying it with a hose then telling everyone it will float. I understand that N95's are inexpensive and yes better than nothing. But why is everyone so quick to accept it as being the best or only solution. Their are masks out there that will give you 99.99% protection. I've read that the H5N1 virus is attached to droplets and that the N95 will stop it from passing through. What about the 5% that might get through. How long will the 95% efficiency of the mask last? Not all face masks provide the same level of performance hour after hour of use. Studies show that when subjected to bio-aerosols, the performances of most face masks deteriorate significantly over time unless there is a antimicrobial agent which protects it against microbial deterioration of the filtration media.

What is N-95?
Filters and infectious particles
Particles greater than 5 microns fall out of the air
Particles 1 – 5 microns in diameter can enter upper airways
0.1 – 1 micron particles enter lower lungs and alveolar ducts
Examples of particle size:
 Viruses 0.02 to 0.3 microns - N95 mask not effective
 Bacteria 0.5 to 10 microns - N95 mask effective
 Mold spores 1 to 70 microns - N95 mask effective
 Fungi 2 to >200 microns - N95 mask effective
Particulate filter efficiency is based on ability to remove particles greater > than 0.3 microns in diameter (medial aerodynamic diameter of 0.3 um)
It is also very important to note, that although the CDC recommends these products as suitable levels of protection against the H5N1 virus, the testing criteria used to certify these products does not include any biological agents.

NIOSH only tests the filtration efficiencies of N95 facemasks against salt particles, and does not currently employ any standards to test against live agents.

http://www.cdc.gov/niosh/pt84abs2.html 42CFR part 84
Under the new particulate filter tests, NIOSH will certify three classes of filters, N-, R-, and P-series, with three levels of filter efficiency, 95%, 99%, and 99.97%, in each class. All filter tests will employ the most penetrating aerosol size, 0.3 µm aerodynamic mass median diameter. The N-series will be tested against a mildly degrading aerosol of sodium chloride (NaCl). The R- and P-series filters will be tested against a highly degrading aerosol of dioctylphthalate (DOP):

http://www.health.state.mn.us/divs/idepc/dtopics/infectioncontrol/ppe/comp/n95.html
http://www.cdc.gov/niosh/npptl/usernotices/pdfs/Nanoguard062906.pdf Nanoguard Mask Warning

http://www.viraldefender.com/index.htm
This is a mask I found on the net that has been tested with biological agents as well as having an antimicrobial property in the filtration media.

Post edited by: Booboo, at: 2006/07/28 04:03

Post edited by: Booboo, at: 2006/07/28 05:26