Modifies provisions relating to smoking regulations

HB 1280 modifies Missouri's smoking regulations by banning smoking (including tobacco and marijuana) in most indoor public spaces like restaurants, hospitals, schools, and child care facilities. It allows exceptions for private events, limousines with passenger consent, and small bars/restaurants (under 50 seats) that post "no nonsmoking areas" signs. The bill also prohibits smoking in all indoor areas of public elementary/secondary schools (excluding colleges) and child care facilities during operating hours, and bans workplace discrimination against employees who use tobacco or marijuana off-premises during non-work hours. Employers may still offer lower health insurance rates to non-users but cannot fire employees for off-duty use unless it directly impacts work performance.