Requires companies and other persons to notify the FDA when they claim a substance is "generally recognized as safe" (GRAS), creates a public FDA list of those substances, and sets deadlines and procedures for FDA decisions and listing. Establishes a formal process for the FDA to reopen and reassess the safety of food additives, color additives, and GRAS substances when safety concerns are raised by a citizen petition, a State official, or the agency itself, including public notice, career-staff scientific review, and notice-and-comment rulemaking.