California Code, Health and Safety Code - HSC § 101080

Whenever a release, spill, escape, or entry of waste occurs as described in paragraph (2) of subdivision (b) of Section 101075 and the director or the local health officer reasonably determines that the waste is a hazardous waste or medical waste, or that it may become a hazardous waste or medical waste because of a combination or reaction with other substances or materials, and the director or local health officer reasonably determines that the release or escape is an immediate threat to the public health, or whenever there is an imminent and proximate threat of the introduction of any contagious, infectious, or communicable disease, chemical agent, noncommunicable biologic agent, toxin, or radioactive agent, the director may declare a health emergency and the local health officer may declare a local health emergency in the jurisdiction or any area thereof affected by the threat to the public health. Whenever a local health emergency is declared by a local health officer pursuant to this section, the local health emergency shall not remain in effect for a period in excess of seven days unless it has been ratified by the board of supervisors, or city council, whichever is applicable to the jurisdiction. The board of supervisors, or city council, if applicable, shall review, at least every 30 days until the local health emergency is terminated, the need for continuing the local health emergency and shall proclaim the termination of the local health emergency at the earliest possible date that conditions warrant the termination.