Hot Car + Aerosol Cans = Ticking Time Bombs?

Alternate title: Will my frugal ways be the death of me? :eek:

In the summer, for my job, mosquito repellent is essential for anyone not wishing to die of anemia or West Nile virus(or itching so badly he/she might want to). I had made it my habit to carry a pump sprayer of it around, but I ran out. When I went to buy more at the Dollar General Store, all they had was a two for two dollar special of a reputable brand in aerosol cans(saving me at least eight dollars over the drug store price, thank you very much!), so I bought that.

However, yesterday when I opened the car and got a glimpse of the can sitting there, and simulanteously a classic case of furnace face, and it caused me to have a flashback to my quaint and provencial childhood, when we burned our trash because there was no pickup service. Whenever there was an aerosol can in the fire, the damned thing would go off like a small bomb, once nearly blowing a hole in the steel drum we used to burn trash in.

The can does say store in a cool place. The car gets pretty hot. How hot does a can need to get before turning into shrapnel with a bug spray chaser?

I am not sure of the exact conditions but it can happen. I have seen it happen to friends and family in a hot car in very hot Louisiana. The outside temperature was at least in the mid 90’s. One friend had a cigarette lighter blow up and ruin part of his truck.

Temperature inside a trunk or passenger compartment is a function of vehicle color, sunlight exposure, and ambient breeze. Although lacking a cite, I believe that can manufacturers have included a safety margin for their products, expecting the occasional can-in-car situation.

On a daily basis, my service truck has aerosol cans of hornet spray, degreaser, and various lubricants-other aerosol stuff carried on an as needed basis. No problems to date (mid atlantic location).

This situation was featured in a “Mythbusters” episode. The original was screened on the Discovery Channel, 8 June 2004, but I’ve only just seen it on Prime TV here in NZ. I could only find a summary of the episode, here, not a full rebuttal of the myth, but in summary, try as they might, they couldn’t get the aerosal cans to explode in any temperature that could be expected in a closed car. Their conclusion, “Busted!”

Kiw Fruit

One less thing to worry about, thanks to Kiwi Fruit and the Discovery Channel! :slight_smile:

Very recently, I placed a can of spray enamel paint in a pot of very hot (not boiling) tap water to improve the paint’s flow during application. After ten minutes in the hot water, the concave bottom of the can popped into a convex shape. No paint was released, and the can was fine. I took it out of the water immediately and went outside to apply the paint to relieve some internal pressure.

I chalk the can’s partial failure up to the higher heat capacity of water and the higher temperature. Since your car will not get as hot as the hottest tap water in my house, and since the can will be in air and not in water, I think you’ll be fine.

The can may have been designed that way. Many aerosol cans have a release point built in to prevent injury. For example, a can of Edge shaving gel has a rubbery plug in the bottom, made to leak in extreme heat.

In about 1959, I threw an empty aerosol paint can into a burning pile of leaves. I stood 20 feet back. When it blew, the sharp, jagged exploded can zinged about 50 feet. :eek: :smiley:

You build models?