Pepper Spray

Pepper spray, Oleoresin Capsicum (OC) is fairly widely used and legal in many countries to subdue an individual. It's used by law enforcement as a means of crowd control, and is available for purchase to be carried by citizens for use as a crime/attack deterrent. It's made by processing the pepper and grinding it into a fine powder, then combined with Ethanol and evaporated to make the concentrate. That mixture is then combined with Propylene Glycol and water, and pressurized into an aerosol can.

Use of the aerosol is highly effective when aimed anywhere at a person's face. Direct contact with the eyes works by dilating capillaries in the eyes and additionally, causing inflammation of mucus membranes. This produces a burning sensation that is quite unbearable and unfortunately it's not so easy to quickly alleviate. Flushing eyes out with water, or milk diluted with water can help, but the most important thing to remember if you ever get hit with it, is DO NOT TOUCH OR RUB YOUR EYES. If you don't have either of those within reach, your best bet is leaning your head forward and allowing your own tears to start flushing it out.