How does bear pepper spray work as a determent??

Capsaicin elicits an intense burning sensation when it comes in contact with skin, causing pain receptors to send the same impulses as those generated by burning heat.  Bear pepper spray is a very effective defense because of the way it effects the mucous membranes of the eyes, nose and lungs.  This spray immediately causes these tissues to swell and the result is a nearly total, yet temporary, loss of sight and severe restriction of breathing. 

To be most effective using it, aim for the eyes and nose of the aggressive bear. You always want to be aware of and avoid:  Wind speed and direction an affect your spraying of the bear pepper spray.   If the wind is at your back, you may be able to spray the bear repellent a greater distance than otherwise.   Always keep in mind that the wind is not blowing towards you.  You may have to maneuver until you have the wind just right.  You never want to accidentally inhale this.  Many people have been caught in the effects of bear pepper spray by testing it out.

I guess it says a lot that so many experts carry this bear pepper spray over firearms. Seriously consider this product before you take any outdoors trip. You never know...