California Code, Business and Professions Code - BPC § 8505.12

A registered company performing fumigation shall use an adequate warning agent with all fumigants which lack those properties.There may be circumstances in which the use of chloropicrin is not possible due to its unknown effects on sensitive items, including, but not limited to, artifacts in museums or in police evidence storage. In these circumstances, waiving the use of chloropicrin shall be approved by the state regulatory authority and documented in advance and shall include alternative safety precautions which address initial clearance of the site to be fumigated, potential movement of the fumigant to unattended areas, and continued site security. When conditions involving abnormal hazards exist, the licensee exercising direct and personal supervision shall take those safety precautions in addition to those prescribed by this chapter as are reasonably necessary to protect the public health and safety.