Tuesday, July 10, 2012

Inadvertent chemists

I just finished another Thesis column for Nature Chemistry (about chemistry sets). While writing I wondered how many accidents there are in home labs (not counting home meth labs). It turns out that in the US, the Agency for Toxic Substances and Disease Registry (ATSDR) keeps track of hazardous substance events. The data, nicely collected in a spreadsheet, suggests there are around 1000 chemical incidents in private homes each year, and the vast majority involve carbon monoxide (nearly all the fatalities are caused by CO, if you don't have a detector, get one!) or people who inadvertently do chemistry by mixing what they likely think are two innocuous common household solutions. Bleach and ammonia. Bleach and pool acid. Bleach and pesticides. There's a pattern here. Do not mix bleach with anything. It will not make it stronger, and it may kill you, or cause your apartment building to be evacuated. Really.

There are no narratives included with the spreadsheet, but as a chemist I enjoyed reading between the lines. The accident where the primary chemical was table sugar? Someone with dreams of space? or darker desires? a dedicated Star Trek fan1? You can make rocket fuel or smoke bombs from sugar and saltpeter2. The video posted here shows a gummi bear being rapidly oxidized by a chemical relative of saltpeter, potassium chlorate. Watch closely and you can see the charcoaled bear being popped out of the tube!

1. In an episode of the original Star Trek (Arena), Kirk grabs various rocks to make an explosive mixture and an improvised bazooka. Watch it here.
2. sal petrae, "salt of rock, " otherwise known to chemists as potassium nitrate, KNO3

A version of this post appeared on The Culture of Chemistry


  1. Bleach is just dang scary. I showed my students that splendid video

  2. Julianne4:13 PM

    In the church kitchen today, I spotted a spray bottle with a hand written label on it. It said "Bleach Mix". A mix of bleach and what? I thought and then had to stopped myself evacuating the church prior to mass. Nothing happen so I guess maybe it was mixed with water?

  3. Probably bleach and water! Great for disinfecting counters and such...

    You get the bad stuff as soon as you mix things, so anything that has been in a bottle for a long time isn't likely to cause an evacuation!

    But glad you thought of it!