In addition to the exemptions allowed under the Clean Air Act , the EPA has established a narrow exemption to allow owners of existing inventory of virgin HCFC-124, HCFC-225ca, HCFC-225cb, or mixtures thereof to continue using their inventory after the January 1, 2015, Clean Air Act prohibition on use and introduction into interstate commerce took effect. These exemptions allow anyone who owns: 

• HCFC-124 as of January 1, 2015, to use that HCFC-124 as a sterilant for testing biological indicators.
• HCFC-225ca and HCFC-225cb (collectively referred to as AK-225), or mixtures thereof, as of January 1, 2015, to use that material as a solvent.

EPA’s stratospheric ozone regulations at 40 CFR 82.15 prohibit introduction into interstate commerce of virgin HCFCs for sterilant and solvent uses, beginning January 1, 2015.

EPA has developed a fact sheet with more information on AK-225.