If this weekend's attack on students had you wondering how bad pepper spray really is, science writer Deborah Blum has you covered. Answer: It's five times more intense than the hottest natural pepper in the world. (Commercial pepper spray is twice as intense, but the police-grade stuff is supercharged.) That's because it's made of capsaicin, the compound that gives peppers their bite by acting directly on heat- and pain-sensing neurons. "Pepper spray" sounds like a condiment, but this should probably be called "sheer pain spray."

What does that mean for you and your mucus membranes? Well, pepper spray causes tissue inflammation, which means it can damage your eyes or swell your airways shut. There's plenty of scientific evidence that pepper spray can cause respiratory failure, especially in people with conditions like asthma, and it's been implicated in a number of deaths in police custody.

The dangers of pepper spray are well-established enough, says Blum, that any police department should know about them. Which means that if police really did force pepper spray directly down students' throats (where the windpipe is, if you're keeping track at home), they may — or should — have known they could end up killing someone.

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