Businesses and industries which must, in the conduct of their operation, start fire to combustible material or make fire of any description in the open air may make application to the Chief of the Fire Department for special permission to start fire to combustible material or to make fire in the open air. The Chief of the Fire Department or an authorized agent shall investigate the application and may, in their discretion, allow an exception to the prohibition against open burning as provided in this chapter; and then only upon receipt of special permission of the Chief of the Fire Department or an authorized agent, specifying the time and location at which the authorized burning will take place. Such burning, when authorized, shall take place no closer than 25 feet from any permanent structure unless the permission specifically allows it, nor shall any burning permitted under this section be carried on without one or more persons in direct attendance, and as may be specified by the Chief of the Fire Department or an authorized agent. (Code 1981 § 16-121. Code 1995 § 70-166.)