SNAP Rule 26 marks an important milestone in the transition from commercial refrigeration to new refrigerants. The rule lists refrigerant substitutes that provide a spectrum of technological solutions to meet required performance, global warming potential (GWP), safety, and environmental standards.
SNAP stands for Significant New Alternatives Policy, a program by the U.S. EPA (Environmental Protection Agency) under the Clean Air Act. In general, the program aims to evaluate and regulate substitutes for ozone-depleting substances, considering their overall risks to both human health and the environment.
Impact of SNAP Rule 26
Final SNAP Rule 26, Protection of Stratospheric Ozone, lists acceptable substitutes in commercial and industrial refrigeration. SNAP Rule 26 will be effective July 15, 2024. The incorporation by reference of certain material listed in the rule is approved by the Director of the Federal Register as of July 15, 2024.
The incorporation by reference of certain material listed in the rule is approved by the Director of the Federal Register
“To date, the SNAP program has provided a very effective framework for evaluation and approval in support of innovation and the transition to new technology,” says Andrew Pansulla, Technical Service Engineer, The Chemours Company, a global chemistry company that provides a range of refrigerant products. We asked Pansulla to elaborate further on the impact of SNAP Rule 26 and what lies ahead.
Q: How will the Rule’s finalization impact various commercial refrigeration sectors?
Pansulla: The rule’s finalization will impact commercial refrigeration in several ways. Areas, where impact will likely be seen, include providing more acceptable refrigerant options, adherence to updated standards, new equipment design standards, and the exemption of propane from the venting prohibition for refrigerated food processing and dispensing equipment. These impacts could trigger changes in operational, manufacturing, and environmental compliance strategies in the commercial refrigeration sectors. SNAP Rule 26 will enable the adoption of the listed substitutes, including Chemours Opteon™ refrigerants, with global warming potential (GWP) lower than existing refrigerants. This rule does not require any changes to existing equipment and will impact only new equipment that uses the specific substances referenced in the SNAP rule.
Q: What is the outlook for additional requirements for safe handling and use of alternative refrigerants? What specific safety standards are expected or appropriate?
Pansulla: As part of the comparative risk framework used by the EPA to assess new alternatives, the EPA considers and implements use conditions that will ensure the safe use of products. These use conditions rely upon existing safety standards (e.g., UL and ASHRAE) which are available at the time the rule is finalized. In the case of SNAP Rule 26, many of the use conditions require adherence to UL 60335-2-89 and ASHRAE-15-2022. These standards are reviewed and updated periodically to maintain relevance with the products subject to the standards.
Q: What are any limitations of the use of A2L refrigerants under SNAP Rule 26?
Pansulla: There are two main categories of limitations under SNAP Rule 26. The first, as mentioned above, is the adherence to specific safety standards that apply to refrigerants that are designated as mildly flammable (A2L). The second is based on the GWP of the refrigerant. In the case of the A2L refrigerants subject to SNAP Rule 26, the EPA imposed conditions on the type of equipment and specific circumstances in which the substitute may be used. For example, the EPA is permitting the use of R-454A in supermarket systems, but only on the high side of a cascade system, or when the refrigerant charge capacity is less than 200 pounds.
Q: Which new-generation A2L refrigerants are fit for which commercial refrigeration applications?
Pansulla: Under SNAP Rule 26, the EPA deems R-1234yf, R-1234ze(E), R-454C, R-455A, R-457A, and R-516A as acceptable subject-to-use conditions for various commercial refrigeration applications. This selection is primarily driven by these refrigerants having GWPs under 150. However, certain applications necessitate refrigerants with higher GWPs due to unique performance characteristics. For example, R-454B and R-32 were listed for industrial process refrigeration with exiting fluid temperatures below minus 30 degree Celsius because these two specific refrigerants have lower boiling points than the other six less-than-150-GWP alternatives. However, it is critically important to consider the additional use conditions when designing equipment with refrigerants that have a GWP greater than 150.
Q: So various equipment needs different refrigerants?
Pansulla: The EPA purposefully lists several different refrigerants in each application to allow for equipment manufacturers to consider a variety of different factors that go into refrigerant selection, such as energy efficiency, capacity, normal boiling point, temperature glide, cost, safety, and use conditions. There is no one-size-fits-all solution for the entire commercial refrigeration industry.
Q: How can commercial refrigeration businesses achieve a smooth transition to A2Ls?
Pansulla: Keys to a smooth transition to A2Ls include understanding what refrigerants the EPA has approved as acceptable substitutes under the SNAP program, the sector-based GWP limits imposed by the Technology Transitions Program under the American Innovation and Manufacturing (AIM) Act, and which refrigerants provide the best combination of technical performance and environmental characteristics. Many resources are available to navigate the regulatory landscape and select the best low-GWP refrigerants to meet the needs of this industry. Working with companies like Chemours, who has nearly a century of refrigerant innovation and experience, is a great first step in the transition process.
Q: What is the “staying power” of A2Ls — based on their chemistry, sustainability, and other attributes, combined with regulations such as SNAP Rule 26?
Pansulla: The identification, selection, and development of new refrigerants that deliver required performance while meeting increasingly stringent environmental standards is a challenging process. With the identification of certain hydrofluoroolefin-based (HFO) refrigerants as an alternative to meet these criteria came a new safety classification. These HFO-based refrigerants are classified as A2Ls. While slightly more flammable than existing hydrofluorocarbon-base (HFC) refrigerants, HFOs are much less flammable than hydrocarbons, which are classified as A3 (two categories higher on the ASHRAE flammability spectrum). Moreover, such refrigerants offer an excellent alternative to substances with higher toxicity, such as R-717. The listing of A2L refrigerants in SNAP Rule 26 clearly indicates that such refrigerants can be used safely in commercial refrigeration as well as many other applications, which are subject to the SNAP Program, when adhering to the applicable safety standards.