09-16-10 - Gasoline

Is it actually dangerous to keep your gas can near your furnace? Or is it just one of those paranoid wives' tales.

I remember a MythBusters where they showed that making gasoline explode is actually really difficult, like it has to be perfectly aerosolized and everything.

My only storage area is my basement where my heater is, but it does make me a little nervous.


ryg said...

Depends on how full they are, whether the cans are airtight or not, and on which scenario you're worrying about. Getting a full gas can to explode is nigh impossible - not nearly enough oxygen to make that happen. Airtight cans (provided they're closed properly) prevent the fumes from oxidizing with more than the air that's inside the container, which again doesn't have nearly enough oxygen to get an explosion going.

I wouldn't worry about explosions at all. But the stuff is highly flammable so it's still a fire hazard - though I'm having a hard time imagining how you'd get a closed gasoline can to burn from the outside without there being a serious fire already.

ryg said...

Oh, Wikipedia has the specifics: "If the concentration is below 1.4% the air-gasoline mixture is too lean and will not ignite. if the concentration is above 7.6% the mixture is too rich and also will not ignite. However, gasoline vapor rapidly mixes and spreads with air making unconstrained gasoline quickly flammable."

So: Store in an airtight container, keep it closed, almost-empty cans are way more dangerous than full cans, and most importantly: DO NOT try to douse a gasoline fire by pouring water over it. Not only does gasoline float on water, it burns at >470°C - at that temperature, water will instantly evaporate, expand, and spray the stuff all over the place. At best, you'll make the fire bigger. At worst, you get a small cloud of water vapor and gasoline in a concentration low enough to actually explode.

old rants