I’m a small town Fire Chief here. From considerable reading on the subject as I plan for our EMS personnel, I agree with your opinion that N95 is a lame attempt at respiratory protection from Ebola. However, I disagree strongly with anyone suggesting depending on a castoff “gas mask”, discarded decades ago by some 3rd world military, to protect your lungs. Obsolete military gear of unknown history was likely improperly stored and not maintained for years or decades and, equally important, has filters of unknown capability, age, and condition. All filters have a shelf life. How old are those filters in your stock? Dry rot in the inhalation or exhalation disks (valves) if present. Dry rot in the seal?
A better plan is to purchase Fire Dept surplus (or new) Scott brand SCBA (airpak) facepiece (mask), an adapter for filter cartridges, and current production filters. Why?
1. SCBA facepieces, even old, typically have been well maintained and stored in a dry, heated fire station during their life and not in a subzero warehouse, while sitting on a drum of avgas. A SCBA facepiece provides full protection of ALL your facial mucus/orifices and has a large viewing lens which provides much better visibility that military “gas masks”.
2. The same Scott SCBA facepieces, uniquely, are used for the full range of respiratory protection from airpaks, to supplied air, to various powered filter paks, et cetera. Scott facepiece models, in order of age, are: AV2000, AV3000, AV3000 Sureseal, AV3000HT. All have small, medium, and large sizes for a fit/seal for most face sizes/shapes. Each model has improved voice emitters. Electronic voice amplifiers are available if needed.
3. You can easily arrange for a “Quantitative fit test” for an SCBA facepiece. There is no way you are going to fit test that M___ or Chicom POJ for mom or the kids. Without a fit test to verify you have a leak-free respirator, you have nothing; you have NO respiratory protection. The test should cost you $25-35/person. Testing with a Quantifit tester (as by Scott dealer or industrial safety firm) will take about 5 minutes. Shave before you test or you will not pass. Most adults will use a size medium and pass in a higher % for new models, as the design of the seal (face to mask) has improved (reduced leakage). AV3000Sureseal is the most forgiving/easiest to fit. OSHA says a business is “supposed” to do test annual, but …..
4. A wide range of P100 (99.9%) filter cartridges are available. Basic P100 filters are $9/set (two). Higher capacity P100 filters with special capabilities run $15+/set. A 742 twin pack filter adapter is needed at approx. $30-35 to connect the filters to the facepiece. To change filters, make a ¼ turn to remove the old filter from the adapter and then install a new filter. Repeat for the other side of the facepiece. https://www.scottsafety.com/en/us/pages/ProductDetail.aspx?productdetail=Adapters
All the facepiece models listed use the same filter adapter. I would not recommend adopting the 40mm style filter, though Scott does have a 40mm adapter if that floats your boat (legacy cop equipment). Note that the AV2000 is obsolete, but thousands are used, or stored, at FD nation/world-wide. A new AV3000Sureseal will cost you around $210; a used AV2000 on ebay will be well under $100. If buying used, I’d recommend buying AV3000 (or AV3000 Sureseal) from a local FD so they can upgrade to AV3000HT. It might be tax deductible for you. Scott is by far the largest mfg of SCBA in the U.S. and the world, so you won’t have to go far. There is a good chance you can arrange to buy the filter adapter and filters through them and set up a fit test. It is good to have friends down at the local (volunteer) Fire Station; these guys are the opposite of the cops.
If you want to increase your protection with a positive pressure or supplied air source while working on a patient, then you can add on a Scott SCBA. Older used units are available for a few hundred $.
The other North American SCBA mfg is MSA, but they’re less common and their equipment is less flexible, facepieces are more expensive, less flexible and do not have most of the benefit described above. There are a couple of European SCBA manufacturers, but don’t bother.