1.5 SNAP Program and Refrigerant Transitions
Key Takeaways
- SNAP program evaluates and lists acceptable substitute refrigerants for ozone-depleting substances
- R-410A is being replaced by R-454B (GWP 466) and R-32 (GWP 675) in new residential/commercial AC
- R-404A (GWP 3,922) is a primary phasedown target in commercial refrigeration
- A2L means lower toxicity, mildly flammable — no separate EPA certification required
- Never mix different refrigerants — even when both are A2L classified
1.5 SNAP Program and Refrigerant Transitions
The Significant New Alternatives Policy (SNAP) Program is the EPA program that evaluates and lists acceptable substitutes for ozone-depleting substances. Understanding SNAP is important for the EPA 608 exam because it determines which refrigerants can legally be used in new and existing equipment.
How SNAP Works
EPA reviews substitute refrigerants based on:
- Ozone depletion potential (ODP)
- Global warming potential (GWP)
- Toxicity and exposure risks
- Flammability characteristics
- Atmospheric lifetime
- Available alternatives for the specific application
SNAP classifies substitutes into four categories:
| Category | Meaning |
|---|---|
| Acceptable | Approved for the listed end-use without restrictions |
| Acceptable, subject to use conditions | Approved with specific safety, handling, or application restrictions |
| Acceptable, subject to narrowed use limits | Approved only for specific limited applications |
| Unacceptable | Prohibited for the listed end-use |
Key Refrigerant Transitions (2026)
The industry is in a period of major transition. Here are the most important refrigerant changes:
Residential and Light Commercial AC/Heat Pumps:
- R-410A (GWP 2,088) → Being replaced by R-454B (GWP 466) and R-32 (GWP 675)
- R-454B is marketed as "Opteon XL41" by Chemours
- R-32 is widely used internationally and gaining U.S. adoption
Commercial Refrigeration:
- R-404A (GWP 3,922) → Being replaced by R-448A (GWP 1,386), R-449A (GWP 1,282), and natural refrigerants
- R-404A has an extremely high GWP and is a primary target for phasedown
- CO2 (R-744) transcritical systems are growing in supermarket applications
Chillers:
- R-134a (GWP 1,430) → Being replaced by R-1234ze (GWP 7) and R-513A (GWP 631)
- HFO-based refrigerants offer dramatically lower GWPs
A2L Refrigerants: The New Normal
Many replacement refrigerants are classified as A2L — mildly flammable:
| Refrigerant | ASHRAE Class | GWP | Replacing |
|---|---|---|---|
| R-454B | A2L | 466 | R-410A |
| R-32 | A2L | 675 | R-410A |
| R-454C | A2L | 148 | R-404A, R-22 |
| R-1234yf | A2L | <1 | R-134a (MVAC) |
For the Exam: A2L means "lower toxicity, mildly flammable." These refrigerants have a lower burning velocity (below 10 cm/second) than Class 2 or 3 refrigerants. Existing EPA 608 certifications remain valid for A2L refrigerant service — no separate certification is required.
Impact on Technicians
- Existing certifications are still valid — no new EPA certification is required for A2L refrigerants
- Safety procedures are evolving — UL/CSA 60335-2-40 updates address A2L safety for new equipment
- Recovery equipment must be compatible — ensure recovery machines are rated for the specific refrigerant being handled
- Never mix refrigerants — A2L refrigerants must not be mixed with each other or with legacy refrigerants
What does the SNAP program evaluate?
Which refrigerant is the primary replacement for R-410A in new residential AC and heat pump equipment?
What does A2L mean in ASHRAE refrigerant classification?