Even against a backdrop of heightened vigilance over potential domestic terrorism, sounding an alarm over school-age “pranks,” even if they get out of hand, may seem to be overdoing a bit. But it is exactly the scenario of explosive adolescence that is raising concern at the Agency for Toxic Substances and Disease Registry (ATSDR), a branch of the federal Centers for Disease Control.
Under the disturbing banner “Homemade Chemical Bomb Incidents – 15 States, 2003-2011,” the ATSDR reported data for 53 persons injured in 134 separate events over nine years (http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6224a4.htm). In one of the most dramatic incidents, “A high school janitor found students mixing calcium hypochlorite and other chemicals in a bottle. The janitor seized the bottle, which exploded, releasing chlorine gas. The janitor became ill and vomited, and 12 students and three school workers were treated for respiratory problems. Approximately 1,640 persons were evacuated for 5 hours while a hazardous materials team cleaned and ventilated the school.” In addition to the hypochlorite (that is, bleach) recipe, another common scenario involves combining a strong acid or caustic (typically household products) with a metal such as aluminum. Two thirds of the injured in the ATSDR series were youths and 4 in 10 were students at school at the time of the misadventure.
The ATSDR report was more a less a sequel to a previous accounting they had made in 2003 of similar events (http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5228a3.htm). Hypochlorite bleach was also a recurring theme that time, especially in the more severe events, such as a 2001 explosion in Rhode Island in which “a high school student placed a chemical bomb in a vacant classroom. The bomb, made with sodium hypochlorite, released chlorine gas on explosion. A total of 23 persons (five teachers and 18 students) in the vicinity of the explosion sustained respiratory irritation and were transported to a hospital for treatment and released. The school was evacuated, and a HazMat team conducted decontamination and debris removal.” The CDC suspects that the trend over time is increasing, but it’s hard to know for sure because only a relatively small group of States has been tracking the problem and, even then, it hasn’t been all the same ones over the entire period.
Unfortunately, the potential problems with hypochlorite bleach go beyond rigged-up bombs. That’s because whenever you mix hypochlorite with an acid of some sort (it can even be vinegar), chlorine, the original World War I war gas, can be released. Frequently this is just a result of an over-zealous attack on bath-tub scum, not any other form of extremism. This is a really common mishap. Often, when I give a talk to a medical audience on this problem, I ask how many practitioners in the audience have treated someone who suffered such a homemade gas attack. Typically, quite a number of hands go up. As a follow-up, I enquire how many have actually done this to themselves. I am always surprised at how many it is.
Luckily, regular “good old” household bleach is fairly dilute solution in water, coming in at 5 to just over 6 percent hypochlorite. This sets a limit on the damage one can do. Not so luckily, the latest thing on the market is a newfangled “Concentrated Bleach.” This can be up to 12% hypochlorite, that is, with more than double the chlorine kick of the classic. In a really creative example of spin, one of the major bleach manufacturer’s touted this product innovation as nearly green, sort-of: “The newer formulation of bleach will improve whitening on clothes and significantly reduce the amount of water and plastic used, ultimately helping minimize Clorox Bleach’s and The Clorox Company’s environmental footprint” (http://www.clorox.com/our-story/press-and-media/clorox-introduces-new-concentrated-bleach/). It may make for a bigger post-detonation footprint, too.