Grandparent help

Hi ladies, I need advice. My little one is currently 16 months old. My problem is, my step dad smokes cigarettes. My mom & him are obsessed with my daughter, which is great. But the smoking just drives me out of this world insane. So much to the point that I avoid seeing my mom if I know he’ll be around. I avoid going over there. I have told him from day one to wash his hands before touching my baby. He doesn’t always respect that. And my mom, gets SO defensive if I tell her anything about his smoking, or IM making a big deal about it. I don’t know what to do. What can I say to her to get my point across without being a bitch?