Okla. Stat. tit. 59, § 59-1000.30
Federally accepted refrigerants not to be prohibited
or limited in use.
No provision of a building code, any other law, regulation, or
other requirement in Oklahoma may prohibit or otherwise limit the
use of a refrigerant designated as acceptable for use pursuant to
and in accordance with 42 U.S.C. 7671K; provided, any equipment
containing such refrigerant is listed and installed in accordance
with safety standards and use conditions imposed pursuant to such
designation.