D.C. Mun. Regs. tit. 18, r. 18-738
The term "air conditioning equipment" as used in this section means mechanical vapor compression refrigeration equipment which is used to cool the driver's or passenger compartment of any motor vehicle.
Air conditioning equipment shall be manufactured, installed, and maintained with due regard for the safety of the occupants of the vehicle and the public, and shall not contain any refrigerant which is toxic to persons or which is flammable.
The Director may adopt and enforce safety requirements, rules, and specifications consistent with the requirements of this section applicable to such equipment which shall correlate with and, so far as possible, conform to the current recommended practice or standard for such equipment approved by the Society of Automotive Engineers.
No person shall operate on any highway any motor vehicle equipped with any air-conditioning equipment unless the equipment complies with the requirements of this section.
D.C. Mun. Regs. tit. 18, r. 18-738