The active ingredient found in pepper spray is OC (Oleoresin Capsicum). The spray comes in 10% or 15%, with a heat rating of 2 million. OC is non toxic, non flammable, and comes from the well known cayenne peppers.
When used as a spray, OC acts as an inflammatory agent, causing immediate dilation of the nose, throat, lungs, and eyes - resulting in constricted breathing and temporary blindness.
Although it doesnt lead to death, the effects will last up to 45 minutes, and make attackers feel as if they are dying. The effects will take place immediately, giving victims plenty of time to escape and seek help.