All retail sales of fire extinguishers which contain ozone-depleting substances are prohibited unless at the time of purchase the purchaser presents a valid permit for the purchase from the chief of a fire protection district. The chief of the fire protection district shall issue such permits for aviation use, use in protecting electrical equipment, and for other uses where the applicant demonstrates that there is no technically feasible, economically sound and environmentally safe substitute or alternative available. (Ord. 1990-18 § 2 (part))