If it's a wide spray there is less velocity and more chance you'll get yourself. Even with bear spray, you don't want to be directly down wind. I know a guy who tried spraying a mama bear and just got himself. I'm amazed he's still alive, honestly..
I picked some up a while ago for my girlfriend that was for sale at a bike shop. She has a lab pup she is doing the basic training for guide service, so takes it where ever she goes (lucky). Needless to say she gets assaulted by off leash dogs all the time, or those on the super duper extendo leashes (..oh he's harmless..), or people that are ignorant enough to just start petting her dog without asking (.. I have a dog, where can I get one of those vests.., umm, no! this is serious what she does, it's not a pet!)
Sorry, anyway, it's called "Halt!" No idea if it's still available. The packaging looked like it could have been twenty years old.