修车的空调系统要有EPA Section 609 Certificate

THE EPA REGULATIONS 
Since January 1, 1993, any person, repairing or servicing motor vehicle air conditioners shall certify, to the EPA that such person has acquired, and is properly using, approved equipment, and that each individual authorized to use the equipment is properly trained and certified under Section 609 of the Clean Air Act. In addition, only Section 609 Certified Motor Vehicle A/C technicians can purchase refrigerants in any size container from an auto supply house for use in cooling the passenger compartment of vehicles, including containers of 20 pounds or less.

拿certificate 并不难也不贵，考试是开卷邮寄。请遵守法律。