I’m not gonna lie; when I first stumbled upon this I thought it was one of the dumbest ideas ever. “Oh no, bad dudes with riot control gas are coming, hurry and make some improvised gas masks…” You get the point. Now that I’ve made one and found that it actually holds a really good seal, although being a bit on the flimsy side; I realized it was fun as hell to make and I had to share the info. The major difference between mine and the diagram is that I used duct tape to hold everything together; the idea had seamed dumb so I wasn’t about to spend hours waiting for glue to dry that would probably just crack when the plastic flexed. Other than tape I used a soda bottle and an old respirator mask. I cut the elastic of the mask and used it for the entire mask. The respirator had to be turned upside down to get a good fit in the bottle. As is now I just have a glorified dust filter; as I doubt it would work in its current state, even against tear gas. But with a good seal, and any number of other filtration ideas, this might be a good improvised breathing apparatus. The first protective gas masks used crushed charcoal in the filters; so with that in mind there is not limit on what kinds filters could be improvised and screwed onto the soda bottle cap screw. The only real drawbacks were that it was flimsy, even after being cut to fit your face and lined with tape; and it had a tendency to fog up a little.
In regards to the vinegar mentioned in the diagram I pulled this up from About.com, Chemistry, Tear Gas Exposure: How to Deal with Tear Gas:
“The best defense against tear gas is a gas mask, but if you don’t have a mask there are still steps you can take to minimize damage from tear gas. If you think you might encounter tear gas you can soak a bandana or paper towel in lemon juice or cider vinegar and store it in a plastic baggie. You can breathe through the acidified cloth for several minutes, which should give you sufficient time to get upwind or reach higher ground. Goggles are a great thing to have. You can use tight-fitting swim goggles if chemical safety goggles aren’t available. Don’t wear contacts anywhere you might encounter tear gas. If you are wearing contact lenses, immediately remove them. Your contacts are a loss as is anything else you can’t wash. You can wear your clothes again after you wash them, but wash them separately that first time. If you don’t have goggles or any sort of mask, you can breathe the air inside your shirt, since there is less air circulation and therefore a lower concentration of the gas, but that is counterproductive once the fabric becomes saturated.”