46 C.F.R. § 169.703
(c) The use of liquefied petroleum gas (LPG) or compressed natural gas (CNG) is authorized for cooking purposes only.
(5) If Chapter 6 of NFPA 302 is used as the standard, then the following additional requirements must also be met:
(7) If ABYC A-22 is used as the standard for a CNG installation, then the following additional requirements must also be met: