Cal. Code Regs. tit. 19 § 1584.1
Unmixed plosophoric compounds shall be transported subject to their classification in accordance with U.S.D.O.T. regulations governing hazardous materials. When permitted and where unmixed plosophoric compounds are transported with cargoes containing classified explosives such transportation shall be regulated by applicable permits to transport explosives. When the quantity or class of initiating devices are deemed to be explosives under the regulations of the U.S.D.O.T., an appropriate permit to transport such explosives with unmixed plosophoric compounds shall be required. Any vehicle transporting plosophoric compounds shall be capable of providing reasonable security for the safeguarding of the material in a manner consistent with the requirements for safeguarding explosives.
Cal. Code Regs. Tit. 19, § 1584.1