When you take a bite of spicy salsa or Szechuan stir-fry, the heat you sense comes from capsaicin, the chemical found in all chili peppers that gives them a fiery flavor. People around the world have found ways to use a variety of peppers in foods, adding levels of spiciness that range from subtle to painful. Whether cooking Thai, Mexican, African, Italian or other regional specialties, you will likely incorporate the heat of one or more types of chili pepper into the flavor palette.
It may not be surprising that pure capsaicin is used as a biochemical pesticide and animal repellent. Aerosols, pellets and liquids are available to apply to plants and soil, deterring pests and beneficial insects as well as pets and wildlife. Interestingly, birds aren’t repelled by capsaicin. Pepper sprays are also made to ward off attack from bears, dogs and humans. When breathed in, capsaicin irritates the lungs and mucous membranes of the nose, mouth and throat. It is highly irritating to the eyes, and can cause skin inflammation. Capsaicin is broken down quickly by soil bacteria and can be composted.
As thrilling and zesty as the flavor of chilis can be, the pain of inadvertent contact isn’t easily forgotten. There are precautions you can take to limit your exposure to capsaicin when working with chili peppers. Wear thin latex or nitrile gloves when handling fresh or dried peppers, and leave them on until you have washed the knife and cutting board. Be careful not to touch your face, hair or clothing until you’ve cleaned up and removed the gloves. Since capsaicin isn’t absorbed by the skin but remains active on the surface, if you don’t wear gloves and later rub your eyes, eat something with your bare hands, or smoke a cigarette, you’ll feel the effects. If charring or roasting peppers over coals or an open flame, be aware the smoke can contain capsaicin. Keep pets and people, especially children and yourself, out of the smoke. Long-term effects of high capsaicin exposure haven’t been studied extensively and it’s wise to avoid it if possible.
Eating too much capsaicin can cause serious irritation of the mouth, stomach and intestines. It’s smart to know your own limits and be cautious when cooking for others. Fortunately, additional hot peppers can be mixed in or sprinkled on after cooking, so consider making a recipe with only moderate spiciness for a crowd and letting people add pepper sauce, sliced raw serranos, or crushed red chiles to their own servings. To get an idea of how hot a particular pepper is consult the scoville scale. Serve a traditional firefighting food as part of the meal. Creamy dairy foods like tzatziki and raita made with full-fat yogurt, or super premium ice cream, are rumored to soothe that lingering heat.