California Code, Health and Safety Code - HSC § 109975

(a) Any device the composition, construction, or properties of which are such that the device is not generally recognized, among experts qualified by scientific training and experience to evaluate the safety and effectiveness of devices, as having been adequately shown, through scientific investigations to be safe and effective for use under the conditions prescribed, recommended, or suggested in the labeling or advertising thereof.

(b) Any device the composition, construction, or properties of which are such that the device, as a result of such investigation to determine its safety and effectiveness for use under these conditions, has become so recognized, but which has not, otherwise than in the investigations, been used to a material extent or for a material time under the conditions.