Given the fact that some manufacturers are using one million Scoville Unit oleoresins to manufacture super-hot sauces, the question comes up about the dangers of capsaicin. The biggest danger, of course is death. Is it possible? Can capsaicin kill you in high enough dosages?
In order to determine the lethal toxic level of capsaicinoids in animals, and to extrapolate that level for humans, researchers in 1980 performed a rather gruesome experiment with mice, rats, guinea pigs and rabbits. Pure crystalline capsaicin (16 million Scoville Units) was administered intravenously, subcutaneously, in the stomach, and applied topically until the animals died. The lethal toxic doses of capsaicin, measured in milligrams per kilogram of animal weight ranged from a mere .56 milligrams when administered intravenously, to 190 milligrams when consumed, to 512 milligrams when applied topically--which means that the poor animals were drowned in it. Indeed, the probable cause of death in all cases was presumed to be respiratory paralysis. Guinea pigs were the most sensitive to capsaicin, while rabbits were less susceptible. The author of the study, T. Glinsukon, concluded that the acute toxicity of capsaicinoids as a food additive in mankind was negligible. If humans are about as sensitive as mice, the acute fatal toxicity dose for a 150 pound person would be about thirteen grams of pure, crystalline capsaicinoids, which frankly, sounds high to us. We think that less than that would be lethal.
There have been investigations of dangerous doses for humans of the various substances that have capsaicin as an ingredient. For example, C.L. Winek conducted a study that was published in Drug and Chemical Toxicology that examined the overdose potential of Tabasco® Sauce. He concluded that a person of average weight would have to consume nearly a half gallon of the sauce to overdose and become unconscious.
In a related study, rats were fed large amounts of Tabasco® Sauce and suffered "no gross or microscopic pathological changes or any significant biochemical changes in the animals." Their growth rate also remained normal. In a similar study, rats were fed crude extracts of chile pods and crystalline capsaicinoids by stomach tube while allowed access to normal food and water. None of the rats died and they all appeared normal throughout the study. Of course, the rats were killed and then autopsied, but no gross pathological changes were detected.
Humans have also acted as guinea pigs with oleoresin capsicum, which is the concentrated heat ingredient in super-hot sauces with names using words like "insanity," "death," and "suicide." These sauces are tasted at food shows by people who have no idea of how hot they are. Some people, with few tastebuds in the mouths, are not bothered by the extreme heat. But most people react very negatively to the super-hot sauces, experiencing severe burning and sometimes blistering of the mouth and tongue. Other immediate responses have included shortness of breath, fainting, nausea, and spontaneous vomiting. People should be very careful of commercial hot sauces that list oleoresin capsicum as an ingredient, and taste them in small quantities.
Aside from the above possible adverse effects, the super-hot sauces will not seriously harm you. "Comprehensive nutritional studies have not shown any adverse effects of chile or capsaicinoids even at ten times the maximum use levels," wrote the one world’s experts on capsaicin, V.S. Govindarajan, author of the mammoth study, Capsicum--Production, Technology, Chemistry and Quality. But even if you do overindulge in super-hot sauces, do not worry, for they are quickly metabolized in the liver and excreted in the urine within a few hours. (Excerpted from The Chile Pepper Encyclopedia, by Dave DeWitt, William Morrow & Co., 1999).