California Code, Education Code - EDC § 17581

(a) The Legislature finds and declares that the quality of protective equipment worn by participants in high school interscholastic football is a significant factor in the occurrence of injuries to such participants and that it is therefore necessary to insure minimum standards of quality for the equipment in order to prevent unnecessary injuries to such participants.

(b) No football helmets shall be worn by participants in high school interscholastic football unless the equipment has been certified for use by the National Operating Committee on Standards for Athletic Equipment or any other recognized certifying agency in the field.

This section shall not be construed as relieving school districts from the duty of maintaining football protective equipment in a safe and serviceable condition.