In accordance with the provisions of M.G.L. c. 146, § 2, the Board adopts ASHRAE 15-2022 Safety Standards for Refrigeration Systems and ASHRAE 34-2022 Designation and Safety Classification of Refrigerants for the Installation of Refrigeration Systems and ANSI/IIAR Standard 4-2020, American National Standard for Installation of Closed-circuit Ammonia Refrigeration Systems.