I did some research, post 9/11, so it’s somewhat dated . Based upon that research, I chose and continue to choose the Xcaper smoke mask in my EDC backpack emergency kit. It is very compact and lightweight and the manufacture asserts that it absorbs CO. It is my choice to get me out of the smoke-dust-debis filled air in a high rise or train tunnel fire/ explosion. Since it is a half mask, I also carry a largish pair of swim goggles to give full eye protection. I would have to remove my eyeglasses if “masked-up”. But at 0’ to 50’ that’s almost a non-issue, as my unaided vision is adequate at those distances. Note, I also have 2 flat-fold N-95 masks with extra exhale valve, for less lethal situations.

I’d be interested to know if anyone uses a similar set-up for such urban challenges ? Details desired.