Urine - Effective smoke filter?

Me and some friends were watching Spiderman 2, and there’s a scene in which Spidey goes into a burning building to save someone. That got us into a big discussion about “would you go into a burning building to save someone?”, in which someone said that if you’re going into an area with a good deal of smoke, you should piss on a hanky or some kind of fabric and tie it around your face covering your nose and mouth; the urine being a good filter against smoke.

Is that true?

I doubt if the urine, per se, has anything to do with it. Now, a WET cloth does filter out smoke better than a dry one, and if you have no other source of water nearby, I suppose a pee-soaked rag will give you a marginally better chance of sucessfully rescuing someone.

The filtering is done by cotton fibers (I’m not sure what other frabrics would work) which have swelled by absorbing water. The fact that there’s urine in the water doesn’t make it a better filter, though it makes it a lot less pleasant to use than if clean water were used. As ** Q.E.D.** suggests, urine might be the only water source if one’s in a jam, but it sure wouldn’t be the preferred one.

“Urine is a good filter against smoke” strikes me as rather nonsensical.

In WWI when gas warfare began, soldiers would use urine-soaked rags as improvised gas masks until actual ones were issued.

Sounds like the writers picked up on this, ignorant of the soldier’s belief that the urine neutralized chlorine gas.

Makes about as much sense as wearing a surgical mask during flu season, even though a flu virion goes thorugh a mask’s mesh like a golf ball tossed through the doors of a zeppelin hangar.