Is it bad to store an empty gasoline container in my car?

March 4, 2004 1:46 PM

An empty gasoline container stored on the carpeted floor of a vehicle: good idea or forthcoming explosive disaster?
posted by keli to travel & transportation (15 comments total)

Empty as in "containing no vapor," or empty as in "containing no fluid, but plenty of vapor?" It's the vapor, not the fluid, which is explosive. It's probably safer to fill the container with gas.
posted by majick at 1:50 PM on March 4, 2004

Chances are very good that it won't actually explode, but I wouldn't take the chance, if I were you. If you have another, uncarpeted place to store it, or you can buy a cheap new container that hasn't had gas in it yet, that might be better.
posted by vorfeed at 1:53 PM on March 4, 2004

and don't use it as an ashtray...I'd say put it in the trunk or trash it.
posted by amberglow at 1:53 PM on March 4, 2004

Containing no fluid, but plenty of vapor.

I think I'll just trash it. Thanks!
posted by keli at 1:58 PM on March 4, 2004

majick is (as usual) absolutely correct.

For effect, my grandfather once threw a lit match into an open container full of gasoline. Nothing happened. That whole fire triangle...
posted by trharlan at 2:20 PM on March 4, 2004

The only reason gasoline explodes in your engine is because its vaporized, then compressed, then treated to an electric arc. You can literally douse a match in bucket of gas, as tharlan says, and a container full of fumes isn't going to hurt you much more than a lit fart at worst.

If you want to keep it there for out-of-gas situations (many gas stations will no longer lend you a container, for liability reasons) just open the cap and let it dry out. It should be absolutely no problem.
posted by scarabic at 2:30 PM on March 4, 2004

Usually leave the cap off the container after using it, prior to storing. It may be wrong, yet throwing the container out seems worse.
posted by thomcatspike at 2:34 PM on March 4, 2004

"a container full of fumes isn't going to hurt you much more than a lit fart at worst."

Wrong. Gasoline has a flashpoint of about 95 Farenheit. That's the temperature at which any spark will ignite the fumes, and that's a temperature easily reached inside a car in the summer. If a gas-can full of fumes flashed over, it would be more like a grenade than a lit fart.

If the fumes have a chance to dissipate, then you're fine.
posted by adamrice at 3:19 PM on March 4, 2004

Come on, flammable is flammable, yes, but explosive is something different. A lit fart (if you've never gotten that drunk) is definitely a fair bit of fire. Don't get me wrong. But toilet paper is flammable fer gad's sake. I think "grenade" is quite an overstatement, however attainable the flashpoint is.
posted by scarabic at 4:55 PM on March 4, 2004

The vapor produced by about 1/5 of a teaspoon of gasoline (1 ml) has enough energy to propel my 4300 lb truck about 14 feet (this based on, ugh, 10 miles per gallon).
posted by TimeFactor at 5:33 PM on March 4, 2004

If you feel the need to carry the container in the car in case of emergency, fill it with water. This keeps it safe (no gasoline vapors) and you can use the water if the car's engine overheats.
posted by mr_crash_davis at 5:55 PM on March 4, 2004

I work with fire and fuel routinely. The accepted wisdom is that the fumes in a gallon tank of gas can explode with the force of a stick of dynamite. I admit I'm not sure who worked that out or how, but I'm not going to mess with it.
posted by adamrice at 8:09 PM on March 4, 2004

Oh, okay. Not a grenade but a stick of dynamite. Cool. Well, from what you said it still needs ignition. Anyway, letting the fumes dry out sounds like the best idea. I think there's enough material here to get said can out of the back seat completely anyway.

I'll admit, I don't work with fuel at all, and the worst back seat explosion I've heard of personally is a friend of mine who left an Odwalla in his back seat during the warm months.

/bows and exits
posted by scarabic at 10:28 PM on March 4, 2004

I'm a fuel chemist (among other things). Adam is spot on. Either leave the can to evaporate outside (until you cannot smell gas at the mouth), or chuck the can (with the lid off). You can reuse the can without trouble, but you should store them full with a minimum of free space (headspace) at the top, OR empty, with both caps loose/undone. Mostly empty cans are an accident waiting to happen.

Gasoline fumes are very dangerous. People get worked up about "explosive" hydrogen, but gas is worse: higher energy content (about 2x) and much easier to ignite.

Static electricity discharge is the way most of these things get set off, incidentally. We use special shoes and lots of grounding wire when we handle fuels.
posted by bonehead at 7:57 AM on March 5, 2004

Random fact: When you go to your local hardware store to get your propane filled, it is technically illegal to put the tank inside your car because law mandates its illegal to have a propane tank in an enclosed area.
posted by jmd82 at 11:01 AM on March 5, 2004