The topic of pepperspray for personal protection occasionaly comes up in the forums asking about effectiveness and strength. Well, here's a new product that clocks in at 15,000,000 SHU which is the same strength as pure capsaicin (the active ingredient in pepperspray) . Presumably it doesn't get any stronger than this.

http://www.vexor.com/

This is not a Shameless Promotion! Just passing the word along.