Except as provided in subsection (b), no State or political subdivision of a State may establish or continue in effect with respect to a device intended for human use any requirement-
Upon application of a State or a political subdivision thereof, the Secretary may, by regulation promulgated after notice and opportunity for an oral hearing, exempt from subsection (a), under such conditions as may be prescribed in such regulation, a requirement of such State or political subdivision applicable to a device intended for human use if-
21 U.S.C. § 360k
June 25, 1938, ch. 675, §521, as added Pub. L. 94-295, §2, May 28, 1976, 90 Stat. 574.