I've heard that Sluggo or Escar-go will do the trick. They both seem to be the same active ingredient, Iron Phosphate, which looks pretty mild in comparison to other chemicals. You just sprinkle it on the beds according to the directions, the slugs eat it and then they starve.

I haven't tried it yet since the slugs are just getting bad now around me and I think I'll try to go with putting a copper strip or wire around the raised beds as the primary defense.

Sluggo works like magic - the slugs stop eating immediately and crawl off somewhere to die. Not poisonous to pets, people or wildlife - you just sprinkle it around and in a couple of weeks it turns into fertilizer. I use it around hosta and in the vegetable garden around tomatoes and peppers.

I have always used Escar-go and it works quite well...Good luck!