Commercial stocks of smokeless powder in quantities over one hundred (100) pounds (but not to exceed seven hundred fifty (750) pounds) and commercial stocks of black sporting powder in quantities over five (5) pounds (but not to exceed twenty (20) pounds) shall be stored in separate storage cabinets constructed of minimum one (1) inch nominal thickness lumber. Not more than four hundred (400) pounds of powder shall be permitted in any one cabinet.
Cal. Code Regs. Tit. 19, § 1574.7