The 2 oz. Stream Inert Pepper Spray contains only water pressurized by nitrogen. Get used to firing it, so that if you ever need to use real pepper spray, you will not hit an innocent bystander accidentally.
You should train with a practice defense spray before getting out there to use pepper spray. If you do not practice, you probably will not be able to hit a real threat you encounter on the street, and you could get yourself injured or killed.
WARNING: Do not spray on anyone or yourself. Even though there is nothing in the sprays to do any permanent harm to anyone, the nitrogen can cause some skin irritation or burning if sprayed in the eyes.