Where conditions are such as to make smoking a hazard in any areas of piers, wharves, warehouses, stores, industrial plants, institutions, places of assembly and in open spaces where combustible materials are stored or handled, the Board of Fire Wardens, Chief of the Fire Department and the Fire Inspector are empowered and authorized to order the owner or occupant in writing to post "no smoking" signs in each building, structure, room or place in which smoking shall be prohibited. The Fire Inspector shall designate specific safe locations, if necessary, in any building, structure or place in which smoking may be permitted.