California Code, Health and Safety Code - HSC § 1799.103

(a) An employer shall not adopt or enforce a policy prohibiting an employee from voluntarily providing emergency medical services, including, but not limited to, cardiopulmonary resuscitation, in response to a medical emergency, except as provided in subdivisions (b) and (c).

(b) Notwithstanding subdivision (a), an employer may adopt and enforce a policy authorizing employees trained in emergency services to provide those services. However, in the event of an emergency, any available employee may voluntarily provide emergency medical services if a trained and authorized employee is not immediately available or is otherwise unable or unwilling to provide emergency medical services.

(c) Notwithstanding subdivision (a), an employer may adopt and enforce a policy prohibiting an employee from performing emergency medical services, including, but not limited to, cardiopulmonary resuscitation, on a person who has expressed the desire to forgo resuscitation or other medical interventions through any legally recognized means, including, but not limited to, a do-not-resuscitate order, a Physician Orders for Life Sustaining Treatment form, an advance health care directive, or a legally recognized health care decisionmaker.

(d) This section does not impose any express or implied duty on an employer to train its employees regarding emergency medical services or cardiopulmonary resuscitation.