Chili peppers, such as jalapeño, cayenne, and habanero peppers, contain capsaicin, which is the main ingredient in pepper spray. Capsaicin can add flavor and spiciness to food, but can also cause an extreme burning sensation which can last for minutes or even hours. Capsaicin is a natural oil found in all chilies, what we have come to call peppers. Cool off that burning mouth or skin by neutralizing the capsaicin with a variety of liquids such as milk or sugar water.