"This edition of NFPA 55, Compressed gases and cryogenic fluids code, was prepared by the Technical Committee on Industrial and Medical Gases. It was issued by the Standards Council on June 16, 2022, with an effective date of July 6, 2022, and supercedes all previous editions" -- Page 1.
"This edition of NFP 55 was approved as an American National Standard on July 6, 2022" -- Page 1.