Maced myself...
I used to have pepper spray attached to the end of my keychain. One day I cracked the sprayhead in the top. Before I threw it away, I thought I would see how far it squirted. About 8 feet. Next I squirted some on my finger. Nothing.
So, being more curious than smart, I sniffed my finger. Nothing. So I shrugged and walked back to the garage behind the house to throw the broken pepper spray canister in the trash. I had gone maybe 15 feet when my nose started to burn.
I quickly threw the pepper spray towards the trash can and headed back into the house. About the time I made it inside I was started to tear up and my face was on fire.
Not knowing what to do, I went to the sink and washed my face with soap and water. This made it worse for the moment, but 10 minutes later my sinuses quieted down and I was ok.
I would just point out that I never actually touched the spray to my face. This was all off of fumes.
Also, someone asked about how people on drugs would react to a stungun. My old law partner was a bouncer at the biggest dance club in Memphis, TN during his college years. One time they had some trouble with this medium-sized, muscular guy. Several bouncers surrounded the disorderly guy and he starts trading blows with the bouncers. The disorderly guy had obviously had some training in boxing. There were 6 or 7 bouncers beating on this guy and he was giving it right back to them. My old law partner sees this happening and runs over with his stun gun. He grabs the guy on the shoulder and gives him the stun gun in the lower back. The disorderly guy immediately drops to his knees. Unfortunately, because of the handhold, my friend is also getting shocked. So when the guy drops to his knees, my friend takes the stun gun off. This bastard springs right back to his feet and knocks my friend down. By this time, every bouncer in the place is teeing off on this guy. Nothing fazes him. My friend grabs this guy by the belt and with some help drags the guy to the front door and throws him down the steps. The guy lands at the foot of the steps and pops right up. Punchs the first person he sees. This happens to be a cop. There were four cops total and the other three cops start clubbing this guy in the head. My friend says the last time he saw the guy was when he was in the cop car, the guy was smearing the face (and his blood) all over the window of the car. He never found out what the guy was on, if it was PCP or Meth or what. But that was the end of his career as a bouncer.
I think the morale of the story is don't touch your target when using a stun gun and make sure they are totally prone or running in the other direction before you left off the stun gun.