California Code, Health and Safety Code - HSC § 25500

(a) The Legislature declares that, in order to protect the public health and safety and the environment, it is necessary to establish business and area plans relating to the handling and release or threatened release of hazardous materials. The establishment of a statewide environmental reporting system for these plans is a statewide requirement. Basic information on the location, type, quantity, and health risks of hazardous materials handled, used, stored, or disposed of in the state, which could be accidentally released into the environment, is required to be submitted to firefighters, health officials, planners, public safety officers, health care providers, regulatory agencies, and other interested persons. The information provided by business and area plans is necessary in order to prevent or mitigate the damage to the health and safety of persons and the environment from the release or threatened release of hazardous materials into the workplace and environment.

(b) The Legislature further finds and declares that this article and Article 2 (commencing with Section 25531) do not occupy the whole area of regulating the inventorying of hazardous materials and the preparation of hazardous materials response plans by businesses, and the Legislature does not intend to preempt any local actions, ordinances, or regulations that impose additional or more stringent requirements on suppliers of hazardous materials or businesses that handle hazardous materials. Thus, in enacting this article and Article 2 (commencing with Section 25531), it is not the intent of the Legislature to preempt or otherwise nullify any other statute or local ordinance containing the same or greater standards and protections.