This blog has been updated to incorporate information from ACR and reflect Calyx Global’s latest review process.

In February 2023, ACR updated its methodology for the destruction of ozone-depleting substances (ODS) in the U.S. and Canada, and later published an explanatory FAQ doc in February 2025. The new methodology (v2.0) changes some of the default parameters used to calculate the emission reduction claims of ODS destruction projects and expands eligible host locations to include Canada. In this blog, we explain the context behind these changes and their impact on projects’ GHG integrity, aiming to shed light on some of the uncertainties implicit in the baseline assumptions for ODS destruction projects. For a deeper dive into methodology-level risks for ODS projects, see Calyx Compass for ODS refrigerant destruction.