California Code, Vehicle Code - VEH § 353

“Hazardous material” is any substance, material, or device posing an unreasonable risk to health, safety, or property during transportation, as defined by regulations adopted pursuant to Section 2402.7. “Hazardous material” includes explosives and hazardous wastes or substances as defined by regulations adopted pursuant to Section 25141 of the Health and Safety Code and medical wastes, as defined in Section 117690 of the Health and Safety Code.