Thread: Face masks
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Old 05-24-02, 05:51 PM
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John C. Ratliff
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I have used one on occasion here in the Portland area. My main concern is two-fold:

--Diesel fumes
--Wearing the right respiratory protection

Diesel fumes have been shown to be carcinogenic, and for a small while there was a move during the Clinton administration to have OSHA regulate them. This did not happen; there are too many economic factors coming to play.

The problem I see with some of the responses is that the respiratory protection some are using really don't filter out the "bad actors" in diesel fumes. These are very, very tiny particles which will go through the regular handkerchief or around an ill-fitting mask. The mask needs to seal, and should be approved (if you're in the US) to NIOSH standards for "hazardous dust."

Some masks sold (usually with only one strap) state that they are for either "Non-hazardous dust," or "Road dust." These quite simply don't filter anything but very huge (on a microscopic level) dust particles. The problem is that we already filter these dust particles in our upper respiratory system. So basically, these are "feel good" masks which don't really do much good at all.

The hazardous dust (containing things like silica, asbestos fibers, etc.) are particles so small that we cannot filter them out in our respiratory system. They therefore go deep into the lung, into the air sacs themselves, and imbed there. Our lungs cannot get rid of them, so they stay there. Our lungs try to do something, and many times (with silica, for example) form scar tissue. If our lungs cannot encapsulate the fibers (such as asbestos), then the fibers continue with each lung movement to abraide and tear at tissue on a microscopic level, and can thereby induce cell changes, including inducing a rare form of cancer (mesothelioma).

So respiratoy protection must filter these particles out, and they must also filter chemicals and gases. Diesel smoke has many different gases which won't be filtered out by any particle mask. To filter these, you need some media to absorb the gas, usually activated charcoal. There are some masks out there which do filter these out. I'll try to attach a web site which illustrates these types for you.

http://www.cdc.gov/od/ohs/manual/respprot.htm

Good luck,

John

PS--I've been in the Safety Profession for 25 years now.
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