California Air Resources Board

In January 2009 the Board approved the mobile air conditioning (MAC) regulation to reduce emissions associated with the use of small containers of automotive refrigerant. Do-it-yourself (DIY) practitioners can purchase HFC-134a refrigerant in small containers holding between 2 ounces and 2 pounds of refrigerant to recharge their MAC system. Typically a traditional container is not fully emptied during the recharging process since the air conditioning system may only require a portion of the container. With a traditionally designed container, any unused refrigerant is almost immediately vented to the atmosphere.

This regulation applies to the sale, use, and disposal of small containers of automotive refrigerant with a Global Warming Potential (GWP) value greater than 150. The regulation achieves emission reductions through implementation of four requirements: 1) use of a self-sealing valve on the container, 2) improved labeling instructions, 3) a deposit and recycling program for small containers, and 4) an education program that emphasizes best practices for vehicle recharging. This regulation went into effect on January 1, 2010, and has been improved through amendments over the years. The latest amendment to the regulation was approved on May 17, 2024.