Cal. Health & Safety Code § 78455

If the owner or the owner’s authorized representative does not voluntarily grant access to a place, establishment, or property pursuant to this article, the officer, employee, representative, or designee shall first obtain a warrant pursuant to Title 13 (commencing with Section 1822.50) of Part 3 of the Code of Civil Procedure. However, if there is an emergency posing an immediate threat to public health and safety, the officer, employee, representative, or designee may enter the place, establishment, or property without the consent of the owner or owner’s authorized representative and without the issuance of a warrant.