Compressed Natural Gas (CNG) Vehicular Fuel Systems Rules  effective January 13, 1996, apply to the design and installation of CNG engine fuel systems on vehicles and associated fuel-dispensing systems.  

The National Fire Protection Association pamphlet No. 52, 1992 edition, entitled "Standard for Compressed Natural Gas (CNG) Vehicular Fuel Systems," referred to in these rules as "the standard," is adopted by reference as part of these rules. For a copy of the referenced documents contact the National Fire Protection Association,  11 Tracy Drive, Avon, MA 02322, 02269, phone 800-344-3555 (ask for the library).    

Informational Memorandum No. 12: Storage of Compressed Natural Gas for Vehicle Fueling.