According to the National Fire Protection Association, smoking is the leading cause of home fire deaths in America. Most smoking-related fires start inside the home, often originating from upholstered furniture, bedding, or mattresses. Always smoke outside, thoroughly extinguishing cigarettes in an ashtray when finished. Soak cigarette butts in water before tossing them—never just toss a butt into a trash can! Also, smoking should never be allowed in any home where medical oxygen is in use, because of its explosive properties.