California Code, Health and Safety Code - HSC § 12603

No person or employee holding a pyrotechnic license shall be required to obtain a manufacturer's license to design, assemble, compound, use, discharge, fabricate, construct, or erect any fireworks of any class or any combination thereof when such person or employee of such person is engaged in the business of producing television, motion picture, theater, or opera productions if the fireworks are for a specific use in a particular production or are used to maintain a reasonable inventory of special effects by a special effects independent contractor.