Good point. I don't load using real black powder, only an occasional BP substitute (treated the same as smokeless powder). I did find that CA has laws pertaining to smokeless and black powder and they equate one pound of black powder with 50 pounds of smokeless. I also found some OSHA regulations that offer guidance -->
http://www.osha.gov/pls/oshaweb/owad...able=STANDARDS, but I am not sure how binding OSHA regs are for private individuals in their residences.