Not that I don't like it when non-violent protesters get permanant lung damage, but...

December 10, 2009 1:36 AM

NoveltyUseOnlyFilter: Chemists- do you think it would be possible to develop a chemical compound (aerosol? liquid?) which could counter tear gas by causing it to break down/change phase?

Like I said, this is a PURELY theoretical question. I would never actually want to subvert any kind of authority. That said, I am rather curious. Compounds commonly used as tear gas:

CS Gas

CN Gas

CR Gas

Do you think the development of a counter-agent could be possible?

posted by Truthiness to Science & Nature (6 answers total)

I think Sudecon Decontamination Wipes remove OC and CS, while CN and CR are banned by the U.N. anyways. They'd make great stocking stuffers for people who protest often, the down side being that Fox Labs makes the Pepper Spray too.
posted by jeffburdges at 2:21 AM on December 10, 2009

If you're talking about pulling it out of the air, I'd say probably yes, but it would surely be just as bad for you as the tear gas itself, if not worse.
posted by Dr.Enormous at 3:07 AM on December 10, 2009

I don't think that's necessarily the case.

I've never had the pleasure of trying it myself, but all of the stick-it-to-The-Man anarchist info pages talk about just soaking a bandana in vinegar to reduce the effects of CS gas. Not that breathing acetic acid is a bunch of fun either, of course, but speaking as someone who once spent a few hours dissolving rock from around microfossils with glacial acetic acid, it really ain't that bad.

The very cheapest supermarket "white vinegar" has, I think, pretty much nothing in it but water and commercial-grade acetic acid, so you could cheaply fill a backpack sprayer with that. Don't expect the dudes with the polycarbonate shields and four-foot truncheons to ignore your Super-Soaker experimentation, though.

I've also got some weak Web evidence suggesting that sodium metabisulfite may neutralise CS. That's similar in toxicity to table salt, so I wouldn't be very bothered about having a solution of it sprayed in my face, especially if I'd just been tear-gassed.
posted by dansdata at 5:22 AM on December 10, 2009

I doubt the cops will notice if your just handing out spray bottles in the crowd before any confrontation. It looks like there are various decontamination spray products too, so maybe you can just read their ingredient lists and/or patent applications.
posted by jeffburdges at 6:57 AM on December 10, 2009

It is absolutely possible to do this. The products already exist and are called decontamination agents. They are typically applied as foams and are applied using pressure washers or fire hoses. The active ingedients are usually stabilized oxidisers (like Fenton's regent) and stong soaps.

There isn't a lot of public information out there that I can point you to, but you can be certain that most NATO militaries and most national police organizations (eg FBI, Scotland Yard, the RCMP) keep it on hand for ready use. Decon foams have been in active and continuing development for the past decade and are aimed at being multi-spectrum, that is effective against biological and radiological threats as well as just chemical ones.
posted by bonehead at 7:07 AM on December 10, 2009

I have heard of protesters rubbing toothpaste around their eyes in an attempt to reduce the effects of tear gas, but cannot vouch for its efficacy.

dansata, breathing in vinegar might not be particularly pleasant, but the response to the first military use of chlorine gas at Ypres was to use of urine-soaked handkerchiefs as primitive gas masks.
posted by James Scott-Brown at 9:57 AM on December 10, 2009