How Kiera Wilmot's School Bomb Could Have Killed Her
Drano is a crystal that can clear clogged drains.
If you ever made a volcano with vinegar and baking soda as a child, then you know the appeal of using science to make things explode. Florida teenager Kiera Wilmot's affinity for explosions recently got her in trouble: After constructing what's called "Drano bomb," she found herself expelled from school and facing felony charges.
While critics have questioned this harsh penalty, Drano bombs are more dangerous than their simple chemistry would suggest, and can easily inflict lacerations and chemical burns.
A Drano bomb is a nasty little contraption that consists of a bottle, some drain cleaner and a little tinfoil. Given a few minutes, it will explode — often quite spectacularly — and launch shrapnel and lye (a strong base used in making soap, so corrosive it was once used to dissolve dead bodies) at unlucky targets. Not only is the device easy to make, but the chemistry underlying this weapon is quite simple.
Backlash against Wilmot's expulsion was both severe and immediate. In addition to a perceived disconnect between crime and punishment (Wilmot's bomb hurt no one, and she was a model student), the issue of race reared its ugly head (Wilmot is black, which has led some commenters to speculate that the sentence would have been more lenient for a white student). The scientific community pushed back right away, claiming that explosions happen — with alarming frequency — in the pursuit of good science.
"Random twitter poll," tweeted Dr. Andrew Thaler, a North Carolina-based marine scientist. "How many of y'all accidentally blew something up in high school during science?"
Thaler received responses from M.D.s and Ph.D.s of every stripe, from medical doctors to astrophysicists. "Dude," wrote Jacquelyn Gill, a paleoecologist at Brown University, "I blew something up in grad school doing science. Concentrated sulfuric acid and acetic anhydride plus water equals BOOM!"
Other stories involved creating jets of flame with pure oxygen, blasting apart beakers with sodium and blowing up plastic bottles with liquid nitrogen. None of the respondents was ever expelled.
Drano bombs (also called "works bombs") are a perfect example of what an Internet-savvy public can accomplish in improvised weaponry. Snopes verified a 2010 email warning of their destructive potential, and since then, finding plans, police reports, or YouTube activities for Drano bombs is as easy as Googling the term.
Even though there's not much information available about what inspired Wilmot to build and test a Drano bomb, how it works is no mystery: It's simple chemistry. Drano is comprised primarily of four chemicals: sodium hydroxide (lye), sodium nitrate (a kind of saltpeter, used to make gunpowder), sodium chloride (table salt) and aluminum. [See also: Top 10 Disruptive Technologies]
They key ingredient in this reaction is aluminum: When added to water, both the sodium in lye (NaOH) and the aluminum (Al) bind preferentially to the oxygen that water (H2O) provides. This creates a reactive white crystal called sodium aluminate (NaAlO2), but more importantly, it creates a large quantity of hydrogen (H2) gas.
Pouring Drano into a sink or toilet bowl is one thing: Drano boils and releases hydrogen gas when exposed to water, which is excellent for cleaning clogged pipes or clearing sediment buildup. However, Drano contains only a very small amount of aluminum. Add more aluminum to the equation, and you'll get more hydrogen gas as well.
Add Drano and a few balls of aluminum foil to an empty plastic (or worse, glass) bottle, and you have an improvised explosive device just waiting to blow. As the aluminum dissolves, hydrogen gas fills the bottle, eventually shattering it. Plastic or glass can slice across skin (or even through fingers), and lye burns the victim.
Although communities stumble on Drano bombs every so often, usually set up by pranksters, they're not a terribly common way of harassing people. Sergeant David Wyant of the Bartow Police Department (which arrested Wilmot) told TechNewsDaily that the department had never encountered a Drano bomb before last week.
Still, Wyant explained that it's best to leave any bomb scares to the police. "I would urge [civilians] to leave [a Drano bomb] alone and call the authorities," he said. "It can burn you. If it's swelling, back away."
Wilmot was either smart or lucky enough to avoid hurting herself, but Drano bombs can be much more harmful than a simple science experiment. If you want to make one, think carefully about how attached you are to your fingers first.