Pepper Spray

One hundred years ago, an American pharmacist named Wilbur Scoville developed a scale to measure the intensity of a pepper’s burn. The scale – as you can see on the widely used chart to the left – puts sweet bell peppers at the zero mark and the blistering habanero at up to 350,000 Scoville Units.

I checked the Scoville Scale for something else yesterday. I was looking for a way to measure the intensity of pepper spray, the kind that police have been using on Occupy protestors including this week’s shocking incident involving peacefully protesting students at the University of California-Davis.

As the chart makes clear, commercial grade pepper spray leaves even the most painful of natural peppers (the Himalayan ghost pepper) far behind. It’s listed at between 2 million and 5.3 million Scoville units. The lower number refers to the kind of pepper spray that you and I might be able to purchase for self-protective uses. And the higher number? It’s the kind of spray that police use, the super-high dose given in the orange-colored spray used at UC-Davis.

Deborah Blum, Scientific American