My early years were spent in Hungary so it should come as no surprise that my first venture into the world of chemistry involved paprika. Bread smeared with goose fat was a popular childhood delight, always topped with a sprinkling of paprika. No worries about cholesterol back then! One day, however, I got a spicy surprise as I bit into my snack. The paprika practically set my mouth on fire. My mother, it seems, had bought hot paprika instead of the usual sweet version. I was about seven years old, but it got me thinking. The hot stuff looked exactly the same as the sweet. What was the difference I wondered? I didn’t realize it at the time, but I was actually dipping my toes into the deep pool of chemistry. Many times since I have thought about how that paprika incident sparked my chemical curiosity, which eventually would burst into a flame. 

I became more and more enthralled by the wonders of chemistry. I remember visiting the DuPont pavilion at the New York World’s Fair in 1964 and being thrilled by a Broadway-style musical entitled the “Wonderful World of Chemistry.” What a great show it was. Everything in the DuPont theatre was made of some newly invented material. Doors featured alkyd resin paint and polyacetal doorknobs, the ceiling was made of polyvinyl fluoride, floors were carpeted with nylon and seats covered with polyvinyl chloride. The polyester curtain went up to reveal dancers in colourful spandex costumes, tapping their polyurethane shoes on an acrylic-glossed stage.

Next to the DuPont pavilion was a NASA display of rockets and an exhibit that featured the planned trip to the moon, including samples of the special fabrics and plastics that chemists had designed for the fledgling space program. Chemistry was flying high! Nobody took issue with DuPont’s slogan of “Better Things for Better Living Through Chemistry.” The word chemical was not seen to be synonymous with poison or toxin.

By the time I graduated with a chemistry degree in the 1970s, the winds of change were blowing. Chemistry went from being a heroic science that furnished us with new medicines, fibres and plastics, to one associated with napalm, Agent Orange and pollution. Rachel Carson’s Silent Spring called attention to the misuse of pesticides and before long “chemical” became a dirty word, with some chemists even suggesting that when communicating with the public it be replaced by the term “substance.” Somehow, “substance” was seen to be more benign than “chemical.” By 1982 the image of chemistry had been so tainted that DuPont felt the need to drop the “through chemistry” phrase from its slogan. Too bad, because our understanding of the world around us really comes “through chemistry.” For instance, it explains hot versus sweet paprika; the difference lies with the amount of capsaicin each contains. An interesting compound, capsaicin, when blended into a cream, is an effective pain reliever, even for the terrible pain of shingles.

There’s more. Construction workers have been known to prevent frostbite by sprinkling cayenne pepper, which also contains capsaicin, into their socks. Apparently blood rushes to the irritated skin and warms the cold extremity. A novel venture in Florida involves incorporating capsaicin into paints used on the hulls of boats. In warm water areas, encrustation with barnacles, tube worms and zebra mussels is a common problem.  Antifouling paints, based on cuprous oxide, can pollute the water. However, capsaicin-laced paint is more environmentally friendly and doesn’t kill marine creatures. The capsaicin just irritates them enough to encourage them to look for refuge elsewhere. Even the police have seized upon the irritant potential of capsaicin.  If it can get rid of zebra mussels, might it not deter criminals?  In some cities, police officers have been issued a cayenne pepper spray which, when aimed at the eyes, encourages criminals to instantly drop their weapons. Talking about burning sensation, on a visit to New Orleans I tried a hot sauce made with “Carolina Reaper.” The name should have been a clue. This is the hottest pepper that exists! As I found out so many years ago, chemistry really is a hot subject. 

Joe Schwarcz is the director of McGill­ University­’s Office for Science and Society. Read his blog at www.mcgill.ca/oss.