49 U.S.C. § 45106: Relationship to other laws, regulations, standards, and orders

A State or local government may not prescribe, issue, or continue in effect a law, regulation, standard, or order that is inconsistent with regulations prescribed under this chapter. However, a regulation prescribed under this chapter does not preempt a State criminal law that imposes sanctions for reckless conduct leading to loss of life, injury, or damage to property. shall establish only requirements applicable to foreign air carriers that are consistent with international obligations of the United States; and shall consider applicable laws and regulations of foreign countries. The Secretaries of State and Transportation jointly shall request the governments of foreign countries that are members of the International Civil Aviation Organization to strengthen and enforce existing standards to prohibit crewmembers in international civil aviation from using alcohol or a controlled substance in violation of law or a United States Government regulation. This section does not prevent the Administrator from continuing in effect, amending, or further supplementing a regulation prescribed before October 28, 1991 , governing the use of alcohol or a controlled substance by airmen, crewmembers, airport security screening employees, air carrier employees responsible for safety-sensitive functions (as decided by the Administrator), or employees of the Administration with responsibility for safety-sensitive functions.