# R-456A — HVAC refrigerant replacements: retrofit compatibility, safety class, GWP and lubricant

For R-456A, ashrae safety class is A1, verified against its source on 2026-08-11.

- **Refrigerant:** R-456A _(verified: appears in the quote below)_
- **ASHRAE safety class:** A1 _(verified: appears in the quote below)_
- **Retrofit / new:** retrofit _(per federalregister.gov, not stated by the source above)_
- **Listing status / notes:** acceptable, subject to use conditions _(per federalregister.gov, not stated by the source above)_

## What the source says

> ASHRAE 34-2024 categorizes HFO-1234yf and R-444A as being in the A2L Safety Group and R-453A, R-456A, and R-480A in the A1 Safety Group.

## What federalregister.gov says

> List the blend R-456A as acceptable, subject to use conditions, in retrofit LMDV MVACs, retrofit HD pickup trucks and van MVACs (complete and incomplete), retrofit HDOH MVACs, and retrofit MVACs on buses and trains;

Source: https://www.federalregister.gov/documents/2025/11/10/2025-19812/protection-of-stratospheric-ozone-listing-of-substitutes-under-the-significant-new-alternatives

## Source

- https://www.federalregister.gov/documents/2025/11/10/2025-19812/protection-of-stratospheric-ozone-listing-of-substitutes-under-the-significant-new-alternatives

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/).