# R-421A — HVAC refrigerant replacements: retrofit compatibility, safety class, GWP and lubricant

For R-421A, trade name(s) is Choice R-421A; retrofit / new is R/N; ashrae safety class is A1; gwp is 2,630; listing status / notes is Acceptable, verified against its source on 2026-08-11.

- **Refrigerant:** R-421A _(verified: appears in the quote below)_
- **Trade name(s):** Choice R-421A _(verified: appears in the quote below)_
- **Retrofit / new:** R/N _(verified: appears in the quote below)_
- **ASHRAE safety class:** A1 _(verified: appears in the quote below)_
- **GWP:** 2,630 _(verified: appears in the quote below)_
- **Listing status / notes:** Acceptable _(verified: appears in the quote below)_

## What the source says

> R-421A | Choice R-421A | R/N | 0 | 2,630 | A1 | <https://www.govinfo.gov/content/pkg/FR-2006-09-28/pdf/E6-15833.pdf> September 28, 2006 (pdf) (183 KB) | Acceptable |

## Source

- https://epa.gov/snap/substitutes-residential-and-light-commercial-air-conditioning-and-heat-pumps

Last verified: 2026-08-11. Review by: 2027-08-11.
Part of [HVAC refrigerant replacements: retrofit compatibility, safety class, GWP and lubricant](https://referencesource.org/hvac-component-refrigerant-compatibility/).