Saturday, July 23, 2011

Chemistry Kits - Getting Your Hands Dirty

Many science bloggers bemoan the disappearance of the chemistry set, a seemingly anachronistic toy for the Millenials, who might rather Skype, LARP, Geocache, or Tweet (Note: All real activities with very little risk of injury or mess). Scientists especially detest the new “Chemical-Free Chemistry Kit” by Elenco, an educational products company that also sells models of Julius Caesar’s head, a color-in-the-countries globe, and an aluminum triceratops (who was real, btw).  JAYFK and Speakeasy Science jumped into the fray, suggesting that the Kit enhances public fears over the words “chemicals” and “chemistry,” making them synonymous with “evil.”
Should these fears deprive our youth of the chance to make beautiful alum crystals or basement fireworks?
Playing with dangerous things at an early age has a special place in my heart, a flame rekindled in a recent Collectors Weekly article by Lisa Hix. She recounts the laundry list of potentially dangerous compounds the pre-WWII generation could experiment with: potassium nitrate (explosives), sodium ferrocyanide (dyes), sulfuric acid (batteries), and even uranium ore (radioactivity). Most of the cases include hand-drawn images of young boys dressed in ties and lab coats, pouring liquids at eyeball-scorching closeness with no goggles.
Well, I may never have been that cavalier, but I was allowed a certain leniency to play with dangerous things as a child. Whenever thermometers would break, my brother and I would scoop the mercury (yup, mercury) into a little jar and play with it, watching the tiny spheres break apart and glom back together on the glass surface. Cyanoacrylate polymers (Superglue) could stick anything to anything, especially your hands to your face. When we learned that peroxide solution would make blood foam up, we would intentionally pour it on all sorts of things (much parental dismay) to see if we could duplicate the effect. A middle-school experiment to demonstrate how color of transition metals depended on ligation environment went horribly wrong, blasting bright green liquid all over the floor (and us), but I recall being fascinated how the metal complex color changed back to blue when it hit the floor (Readers: Can you guess the metal?). I also discovered that the same compound could permanently stain my lab apron and the concrete floor. Today, much of my current lab attire has holes, stains, and smudges that won't come out with any measure of bleach.
Perhaps my favorite example of theory - experiment - practice came from the day I discovered urushiol, one of the oily components of poison ivy leaves that produce an allergic skin response.  I had a theory based on “like dissolves like” that I could perhaps pick the poison ivy barehanded, and then wash away the urushiol with a suitable solvent, such as isopropyl alcohol (rubbing alcohol). Well, you can guess where this story goes: I went to the doctor with horrific, oozing, itchy bumps all up and down both hands. I had successfully taught myself about skin absorption of common chemicals, which I remember every time I accidentally get some methylene chloride on my lab gloves.

Update (July 30, 6:30PM) - Changed, at commenter gippgig's suggestion, the words "toxic and deadly" in para. 3 to "potentially dangerous." Gippgig correctly points out that potassium nitrate is not itself toxic (its danger comes from potential to construct explosives), and both uranium ore and thiocyanides are not themselves highly poisonous.


  1. Of those 4 "toxic and deadly compounds", potassium nitrate is only slightly more toxic than table salt, "ferrocyanides have a low order of toxicity" (Merck Index), and uranium ore is darn near harmless (unless you eat it or inhale powder). By the way, concentrated sulfuric acid was, and may still be, sold in hardware stores as a drain opener with nothing more than a standard warning label. Considering the ready availability of large quantities of hazardous chemicals such as gasoline, sodium hydroxide (again, drain openers - by the way, chemical drain openers don't work all that well; try one of the gas (i.e., difluoroethane) pressure openers instead), propane, etc. people shouldn't be too concerned about the small quantities of moderately hazardous chemicals likely to be found in chemistry sets.

  2. I'm with you on most of this. If you've never heard of hormesis, I encourage you to Wikipedia / Google's thought that a lot of synthetic chemists live well into their 80s and 90s simply because of exposure to low level toxins over much of their lives.