The first thing to do is to check your state laws regarding OC/CS/chemical defense spray
whatever they want to call it.
If your laws jive with you carrying it: you want to find something with at least 1 to 2 Million SHU, in a concentration of 5%. 10% is too heavy and anything higher is considered bear repellant.
The best spray pattern is cone shaped mist or a fogger type. BUT, the problem is that wind does affect it more than stream or foam. You want the bad guy to inhale it. That is where you get best results. OC is considered an inflammatory agent, so inhaling, inflames the mucos membrane, throat, nasal passages and eyes.
Stream works better in windy enviroments but takes to long to work. Had a stream tested on me and it took 22 seconds before I went "OMG!" Too long, especially in a serious altercation.
Foam is ok but you don't get the inhalation.
Buy a cone shaped mist and always be consious of your surroundings. If your state will allow you to carry something marked LE, go for Punch II or CapStun. Liquid Napalm in a can. This stuff sucks. Plus your propellants are not considered toxic in these two. If your propellants are isobutane/propane, (Same stuff used in shaving cream and hair spray), you won't have a problem with it leaking out. Your agent carrier is best if it's isopropayl alcohol. Some get in a tizzy about it being flammable. Yeah, only if your hosing someone down who is standing at BBQ grill or next to a house fire. A cigarette, won't set it off! That's why I much prefer Punch or CapStun
Avoid the OC/CS concentrations. CS manufactures, realized that their products are not great in handheld size units so they tried to make up for it and added OC.
I have used OC on many occasions. It is not 100%, like anything is, but in a right formula and spray pattern, it is very effective and a very good deterrant. Do your homework, check the manufacture's MSDS for any bad ingrediants like Dymel 22 or 122. This will help if you get sued.
Hope this helps. Good luck!
ps -
for some really good info, go to
www.zarc.com