Food Chemical Reassessment Act of 2021 This bill establishes the Office of Food Safety Reassessment within the Center for Food Safety and Applied Nutrition and addresses related issues. The office must conduct reassessments of additives, food contact substances, and other related substances to ensure that such substances are safe. Specifically, every three years, the office must reassess the safety of at least 10 substances or classes of substances, including those that are generally recognized as safe for use in food. The office must issue final regulations relating to the safety of each reassessed substance. The bill also specifies 10 substances that the office must assess in its first review. The Food and Drug Administration (FDA) must reestablish the Food Advisory Committee to advise the FDA on issues related to the substance assessments required by this bill.