Following receipt of information from two industry groups, in addition to a lawsuit mounted by the groups, the EPA has removed a 90-day reporting requirement for persons intending to manufacture, import, or process the refrigerant 1-Propene, 2,3,3,3-tetrafluoro- (trade named HFO 1234yf).  

The rule change applies when the HFO 1234yf is manufactured or processed for consumer use to recharge motor vehicle air conditioning systems in passenger cars and vehicles in which the original charging of the motor vehicle AC system was done by the original equipment manufacturer (OEM) for the vehicle. According to the Agency, the new information submitted by the groups indicates that exposure to HFO 1234yf for this specific use does not trigger the toxicity criteria listed at 40 CFR 721.17(b).

Developed by Honeywell and DuPont, HFO 1234yf is intended as a replacement for the refrigerant R-134a, a powerful greenhouse gas.  R-134a has a global warming potential (GWP) of 1,430 while HFO 1234yf has a GWP of 4. 

Significant new use

The rule change is implemented under Section 5 of the Toxic Substances Control Act (TSCA), which provides the EPA with the authority to issue and withdraw significant new use rules (SNURs).  A SNUR requires a person to notify the Agency at least 90 days before beginning the manufacture or processing of a substance for a new use if the EPA has determined that the substance meets the concern criteria.  Section 5 then empowers the Agency to regulate the manufacture (including import) or processing of that chemical substance before the initiation of the significant new use. 

Industry suit

In December 2010, the Automotive Aftermarket Industry Association (AAIA) and the Automotive Refrigeration Products Institute (ARPI) filed a lawsuit against the EPA, claiming that the restrictions imposed by the Agency’s SNUR for HFO 1234yf were neither necessary nor supported by health and safety data. 

In their petition to the court, AAIA/ARPI claimed that EPA’s conclusions about the risks of HFO 1234yf were based on a variety of implausible and unwarranted assumptions that led to unnecessary restrictions on the ability of individual consumers to service and maintain AC systems that utilize the new refrigerant.

Data developed by the associations indicated that laboratory animals showed no toxic effects from 1 hour of exposure to HFO 1234yf at concentrations as high as 100,000 parts per million (ppm); a human equivalent to this would be 190,000 ppm.  Also, test conditions with specified air conditioning fittings demonstrated that the highest 30-minute exposure was 1,789 ppm.  The EPA accepted the validity of these data, resulting in the final amendment withdrawing the SNUR.

In the action, the Agency also clarifies that the removal of the SNUR for commercial and consumer use of HFO 1234yf is not intended to allow only one recharge of automotive AC systems originally charged with HFO 1234yf.

According to the AAIA and ARPI, General Motors has already begun using HFO 1234yf in some of its vehicle lines and others are expected to follow suit soon.

EPA’s final rule was published in the November 1, 2013, FR.