Originally published at http://www.yearofscience2009.org/ (November 2009) in a month long series of articles about chemistry during the 2009 Year of Science celebration. An original essay by Barbara Belmont. All rights reserved.
Part Four: It's ALL Chemistry
If you're interested in science, you probably already suspect what I'm about to say. Just in case you are new to science and chemistry in particular, however, you'd better hold on to your chair, because I am going to reveal something that may shock you. Ready? Hold on now: THERE ARE CHEMICALS EVERYWHERE!
Before you run screaming from the room for a hot shower, I'd better warn you that your soap on a rope, your shampoo, the bath water, your loofah, your hair gel, and your flip-flops are all chemicals. Even your all-natural energy drink is full of chemicals (sugar, caffeine, water, flavoring). If you can see it, smell it, or taste it, or if it takes up volume, it is a chemical - a chemical element, a chemical compound, a chemical mixture, or a product of a chemical reaction.
Looking around my work space, I see a wooden desk (cellulose) with a melamine laminate top, piles of paper (more cellulose), a polyacrylonitrile-butadiene plastic computer keyboard, a polypropylene bottle of hair product that I've been analyzing (alcohol, cyclopentasiloxane, silk protein), some flashlight batteries (zinc and manganese dioxide in a plastic-coated cardboard cylinder with metal electrodes), nitrile rubber gloves, loose-leaf notebooks (polyvinyl chloride, cardboard, steel), and a hard-surface cleaner I've been analyzing (water, detergent, sodium citrate, sodium carbonate).
When I leave work, I'll get into my ultra-low emissions vehicle, a rolling metal carriage with plush upholstery (polyester fibers) and a lovely silver exterior finish (polyurethane with aluminum pigment, top-coated with clear acrylic to give it permanent gloss). My vehicle runs on regular gasoline, generically known as C4-C12 hydrocarbons with ethanol, benzene, toluene, ethyl benzene, naphthalene, trimethyl benzene, and some detergents. I like the way gasoline smells in the air at the gas station, but am quick to wash my hands when I spill some on me.
When I get home, we'll be going out to dinner with some out-of-town guests. I expect there to be quite a lot of chemicals in my dinner: protein, cellulosic fiber, vitamins, amino acids, spices, and yes, even food coloring. As long as they don't add any sodium chloride to my meal, I'm happy. Sodium chloride makes my food taste too, well, salty. Since we'll be dining on Mexican food, I'll also want to be careful that the food doesn't have too much chile oil (capsacin), since that tends to give me acid indigestion. It's nothing that a couple of Maalox can't handle, though (calcium carbonate, silicone oil).
You get the picture. It's all chemistry.
Yet, many people are very afraid of chemicals. Part of this fear is because some chemicals are indeed very dangerous, and they've made the news. These types of chemicals are acutely hazardous. That is, a single exposure to a very small amount will cause death; ricin, cyanide, dimethyl mercury, and polonium have all made the news. These are sensationally acutely toxic hazards that you will never ever encounter thanks to the vigilance of Homeland Security.
Most acutely hazardous chemicals that we encounter in every day life are physical hazards, such as corrosive or flammable. Corrosive examples are: toilet bowl cleaner, laundry bleach, and paint stripper. Flammable examples are: charcoal lighter, hair spray propellant, and gasoline. You get one of these things on your skin, you wash it off. You get it in your eyes, you rinse it out and go to the doctor. Better yet, always handle the corrosive things with protective wear, and keep the flammables away from ignition sources. If you take precautions, you can use these chemicals without injury.
Then there are the chronic-exposure hazards - the chemicals that tend to accumulate in the body and cause harm after years of repeated exposure. Examples are asbestos, coal dust, cigarette tar, benzene, carbon tetrachloride, bisphenol A, and phthalates. Heavy metals. It took a long time for scientists to understand the effects of chronic exposure, and now we have laws that prevent accidental exposure of known hazards. Chronic hazard chemical safety is ever evolving as testing and evaluation procedures become more sophisticated. It is this final category of chemicals that people worry about the most. What is considered safe today might be discovered unsafe next year. This is an uncertainty of modern life.
When I was running the testing lab, I frequently got phone calls from concerned people who had been near an unknown substance. Perhaps it's that white film that accumulates on their windshield interior, that efflorescense on their cement porch, or that bone shard in their sirloin burger they bit into. They wanted me to analyze it for its ingredients, so they could find out whether any harmful chemicals are in it. After I explained that all substances are chemicals, and too much of any chemical could be harmful - even water - they told me what they really want to find out. What they REALLY wanted was to find out if this one exposure is going to manifest itself in some harmful way 20 years from now. Unfortunately, this question can't be answered, even if the substance composition is known.
Nevertheless, the societal benefit from chemical innovation far outweighs the risks. Chemicals change lives and save lives more than they do harm. Here are some that come to mind: broad-leaf herbicide that doesn't kill your grass, combination shampoo-conditioner, ozonation of drinking water, lithium ion batteries powerful enough to move a car, wash and wear microfiber clothing, retractable gel pens, solvent-free paints, disposable contact lenses, artificial hips, birth control, tooth-whitening strips, no-lick postage stamps, and antibody chemotherapies.
It's all chemistry. What would we do without it?