Cal. Pub. Util. Code § 4452

(a) On or before July 1, 1995, the commission shall undertake a propane safety inspection and enforcement program for propane distribution systems to ensure compliance with the federal pipeline standards by propane operators within the state. The commission may adopt rules, which shall be at least as stringent as the federal law, in order to protect the health and safety of customers served by propane distribution systems. Nothing in this chapter prohibits the commission from adopting more stringent standards than those in the federal pipeline standards.
(b) As part of this propane safety inspection and enforcement program, the commission inspectors may:
1. (1) Enter public or private property as is necessary to carry out this chapter.
2. (2) Enter and inspect all propane distribution systems, wherever situated, and inspect all documents (including those records listed in subdivision (a) of Section 4453), accommodations, equipment, or paraphernalia used in connection with or related to the distribution system.
(c) The commission’s propane safety inspection and enforcement program shall not cover propane used by any of the following:
1. (1) Single customers served by single tanks.
2. (2) Distribution systems, other than mobilehome parks, that serve less than 10 customers, unless any portion of the system is located in a public place.
3. (3) Recreational vehicles and appliances.
4. (4) Vehicular fuel.
5. (5) Agricultural, commercial serving less than 10 customers, unless a portion of the system is located in a public place, industrial, and refinery systems.
6. (6) Cylinder exchange operations.