Since reading that H7N9 can defeat a regular surgical mask, a P-100 mask is needed. There aren't too many P100 surgical masks around, and may be worse: Pissin' On The Roses: CDC Requiring Face-Seals On ALL Approved Masks And Points To H7N9; Shortages Imminent! Looking around for things I have on hand, I have an old (but perfectly useable) North Safety 7700 series half mask respirator with a couple of organic vapor cartridges. I don't see why this would not be able to be utilized in a pinch, with proper cleaning of the respirator before and after use. Unfortunately, I haven't changed filters in the thing since I painted my Jeep in the garage with a LPHV gun a few years ago, and they are quite caked up. I went to the local hardware store, but they don't sell filter cartridges for this respirator, only 3M products. The 3M respirators use a bayonet attachment for their filters, and not a screw on type, so trying to adapt them will be difficult. Any adaptions would be temporary at best, anyway. It figures that manufacturers use their own style of filter attachment, and that nothing is standard. Maybe this is from a liability standpoint, but for a guy like me it just makes things more difficult. All the manufacturers that I've looked at make light, flat style P100 filters for their respirators, and some even have hepa filter cartridges. I do have a few questions about protocol. When and where to use the respirator- when going outside, or just when around people, or just around patients? How often do you change cartridges- every time you are done, or every other time- or until it gets harder to breath through it? Can you clean a P100 cartridge with some hexadine glucanate and water solution, let it dry, and reuse them? I would change the filters only with a gloved hand and then spray down with some hexadine glucanate and water solution. When donning the mask, I would probably also rub a little bit of the HG+water solution on the seal of the mask, or rub it on my face where the seal would land. Any other ideas?