A few years ago while living in Vancouver we returned to our basement apartment from a day’s shopping. After about 5 minutes we felt our throats were very scratchy and our eyes were burning and we couldn’t really work out why. There was no obvious odour in the apartment although it was perhaps colder than usual. We opened the outside door and all the windows and ventilated the place for an hour or so. A few hours later, our neighbour came back. Both apartments shared the same outside door and hallway. He looked a bit sheepish as he explained that he’d been camping and while unpacking his backpack had let off a can of bear spray.
Bear spray is an aerosol form of Oleoresin Capsicum which is an oily residue from chili peppers, preferably hot ones. It contains compounds like capsaicin, the substance in chili peppers that burns. Bear spray affects the bears in much the same way we were affected but hopefully to greater effect if sprayed into the face. Pepper sprays are similar in nature using oleoresin capsicum and may be called OC sprays. They are supposedly non-lethal weapons and may be used in crowd control in some countries but are illegal in others. They are related to tear gasses which make use of lachrymators (chemicals that cause tearing). OC spray may cause tearing amongst other effects. All are technically chemical weapons so consider that the next time you need bear spray for a camping trip.
What Am I this week was indeed a form of pepper spray – bear or OC spray, take your pick. The large organic molecules are capsaicin and derivatives, propylene glycol as an emulsifier and water as a base.
Capsaicin has other uses and may be used medically as a topical ointment. For example some of the LaKota products use capsaicin. These products may be used for relief of pain from arthritis and other conditions. Not bad going for a substance that is usually a major irritation to people preparing chilli peppers for dinner.