California Code, Business and Professions Code - BPC § 19504

(a) No racehorse shall be ridden at a racetrack unless the rider is equipped with a safety helmet and safety vest.

(b) No later than July 1, 2006, the board shall conduct an investigation, including at least one public hearing, to determine whether the use of safety reins would provide jockeys and exercise riders greater protection from accidents and injuries than conventional reins.  Should the board determine that the use of safety reins would provide greater protection for jockeys and exercise riders than conventional reins, it shall adopt a regulation no later than July 1, 2007, mandating the use of approved safety reins whenever a racehorse is ridden at a racetrack.  The regulation adopted by the board may phase in the use of safety reins, but in the event safety reins are mandated, the board shall not permit the use of conventional reins in a parimutuel race for longer than 18 months following the adoption of the regulation.

(c) The board shall approve any model of safety helmet, safety vest, and mandatory safety rein, if required, in use at a racetrack.

(d) For the purposes of this section, a “safety rein” is a type of rein that is reinforced with a wire cable, nylon strap, or other safety device or material that is attached to the bit and designed to maintain control of the horse should the rein break.

(e) For the purposes of this section, a “conventional rein” is any rein other than a safety rein.