Dougwalkabout, Nicely said about Workplace Safety being the responsibility of the employer.
The other trouble with Pepperspray comes after you use it. It is not a "pinpoint" weapon, especially the type that comes out in a mist or cone shape.
In a confined space like a bar you have few problems:
First you have the bad guy to deal with, he will usually be a very angry, slobbering idiot for a while. Who remembers he has a cousin who is a lawyer, just about the time he regains the ability to speak.
Then you have the bad guys friends who want to stick-up for there buddy, and may have caught a hit of pepperspray themselves.
Finally you have everyone else in the building, pepperspray can be dispersed throughout the room and even through the air conditioning/heating system. I have seen an accidental discharge of pepperspray clear out an entire office building. This is especially bad for people with any type of breathing disorder.
Using pepperspray in a crowded enclosed area will cause a significant disturbance that I am sure the management of the establishment will not welcome.
Your friend needs a more tactical, precise and effective tool to combat harassment in the workplace, I suggest some verbal-judo training, a big mean bouncer and the police on speed-dial.
Mike