California Code, Health and Safety Code - HSC § 12689

(a) It is unlawful for any person to sell, give, or deliver any dangerous fireworks to any person under 18 years of age.

(b) It is unlawful for any person who is a retailer to sell or transfer any safe and sane fireworks to a person who is under 16 years of age.

(c) Except as otherwise provided in subdivision (d), it is unlawful for any person who is a retailer to sell or transfer to a person under the age of 18 any rocket, rocket propelled projectile launcher, or similar device containing any explosive or incendiary material whether or not the device is designed for emergency or distance signaling purposes. It is also unlawful for a minor to possess such a device unless he or she has the written permission of, or is accompanied by, his or her parent or guardian while it is in his or her possession.

(d) Model rocket products including model rockets, launch systems, and model rocket motors designed, sold, and used for the purpose of propelling recoverable model rockets may be sold or transferred pursuant to regulations, adopted by the State Fire Marshal which the Fire Marshal determines are reasonably necessary to carry out the requirements of this part.