For buildings that allow smoking, common problem areas that may require sealing to prevent room-to-room transfer of environmental tobacco smoke (ETS) include bathroom exhaust vents, doors and locks, shared drain risers, electrical and telecommunications r

For buildings that allow smoking, common problem areas that may require sealing to prevent room-to-room transfer of environmental tobacco smoke (ETS) include bathroom exhaust vents, doors and locks, shared drain risers, electrical and telecommunications receptacles, plumbing and heating chases, at the floorplate behind baseboards, under doors leading to shared hallways.