California Code, Business and Professions Code - BPC § 3502.5

Notwithstanding any other provision of law, a physician assistant may perform those medical services permitted pursuant to Section 3502 during any state of war emergency, state of emergency, or state of local emergency, as defined in Section 8558 of the Government Code, and at the request of a responsible federal, state, or local official or agency, or pursuant to the terms of a mutual aid operation plan established and approved pursuant to the California Emergency Services Act (Chapter 7 (commencing with Section 8550) of Division 1 of Title 2 of the Government Code), regardless of whether the physician assistant's approved supervising physician is available to supervise the physician assistant, so long as a licensed physician is available to render the appropriate supervision.  “Appropriate supervision” shall not require the personal or electronic availability of a supervising physician if that availability is not possible or practical due to the emergency.  The local health officers and their designees may act as supervising physicians during emergencies without being subject to approval by the Medical Board of California.  At all times, the local health officers or their designees supervising the physician assistants shall be licensed physicians and surgeons.  Supervising physicians acting pursuant to this section shall not be subject to the limitation on the number of physician assistants supervised under Section 3516.

No responsible official or mutual aid operation plan shall invoke this section except in the case of an emergency that endangers the health of individuals.  Under no circumstances shall this section be invoked as the result of a labor dispute or other dispute concerning collective bargaining.