i know this is late, but i've had some dealings with OC on numerous occasions.

OC has 3 seperate intended effects.
1. severe skin irritation
2. inflammation of mucus membranes
3. respiritory distress

You cannot build up a tolerance for OC. Thats like saying that given enough time, your skin will be impervious to fire. Also, as far a respiratory and the immflamation of the mucus membranes, thats the bodies natural way of removing the irritation. everything in your face comes out, and you *feel* like you can't breathe. albeit it is harder to breathe, your still normally capable. If you do spray someone, it is best advised to call 911 and try to make sure they don't die. wrongful death law suits = no fun. regardless of how righteous you are.

when it comes to animals, I would reccomend a big heavy object over OC any day of the week. even better, a firearm... ive heard of multiple occasions where even the strongest of OC hasnt stopped a motivated pit bull...now the business end of a ball-peen hammer or a brick should TCOB.


ps- i second the vote for FoxLabs..OCAT is good too.