(Denis Freitas/)
While chili pepper extract was used by samurai to temporarily blind enemies at least 500 years ago, the current aerosol format appeared in the US in 1973. Initially used by postmen and hunters to incapacitate animals, today the spray is more widely used by police to quell riots. Like tear gas, pepper spray is considered a form of torture by Amnesty International, but its use is legal in most countries. In theory, the use of spray by police is only for self-defense or submission of individuals who resist police intervention.
– (Denis Freitas/)
1. The spray works like any other. Inside it is a liquid under high pressure. At the top, there is a valve that, when tightened, puts this liquid in contact with the environment. As the external pressure is lower, the liquid expands and escapes through the plastic tube, being expelled at high speed.
two. The spray contains capsaicin, the active component of chili peppers. In mammals, when ingested, this substance activates nerve endings sensitive to pain and temperature. Inside the pepper spray can we find an extract made from the plant itself, pressurized and mixed with a kind of synthetic oil, which makes it difficult to remove the substance after application.
3. On the skin, the spray stimulates the release of anti-inflammatory substances and vasodilators, which can cause redness and facial swelling. In the eyes, there is tearing and possible blindness for 30 minutes. Constant exposure can change the sensitivity of the cornea. On the mucous membranes of the nose and mouth, the duration and intensity of the effects vary according to the affected area and the time of exposure. The burning sensation can last for hours. Finally, during breathing, depending on exposure, the bronchial tubes constrict, limiting lung capacity.
– (Denis Freitas/)
4. The potency of capsaicin is measured by the Scoville Heat Units Scale or SHU. The higher the value, the greater the amount of capsaicin and therefore the greater the intensity of the pepper effect.
SOURCES The New Yorker and HowStuffWorks