Twelve words I didn't think I'd be saying tonight

Today, I set a table on fire in an elementary school library.

Don't worry, I didn't burn down the school or anything. Still, it was kind of scary for a minute, and I wasn't sure if I was going to be able to get it under control. The fire started as the reaction of potassium permanganate with glycerin, which is a rapid oxidation that gives off a lot of heat and a brilliant purple flame. Usually, the reaction is done on aluminum foil, both to contain the waste and to keep the heat off the table. Not having any aluminum foil, I did the reaction on a Ziploc bag and used an extra-large pile of the permanganate, thinking that it would keep the heat far enough from the bag and table that no damage would be done.

Wrong.

The reaction rapidly heated and then melted the bag, which had two consequences. First of all, it made a mess and spread the permanganate onto the wood tabletop. Second, it spread out the glycerin and exposed it to fresh permanganate, which made the reaction go to an extent that normally doesn't happen under more stable circumstances. There were a series of pops, and all the sudden a lot of smoke started coming off the table. Realizing that the wooden surface of the table was now on fire, I grabbed a heavy insulated glove and tried to beat out the fire. The glove caught on fire and burned for a couple seconds before I could put it out, and then use it to beat out the rest of the fire on the table and stop the oxidation reaction.

When I looked up from the table, I peered through a haze to see six teachers and a hundred and fifty fourth graders giving me horrified stares. Cool.

Tags: chemistry fire explosion chemistry accident

Cross-posted from TDC