Cosmetic Fragrance and Flavor Ingredient Right to Know Act of 2021 This bill imposes disclosure and labeling requirements on cosmetics products that contain certain ingredients. A cosmetics product that fails to meet such requirements may not be sold. Within two years of this bill's enactment, a cosmetics product's labeling or packaging must indicate the use of any ingredient that (1) is identified on specified lists of harmful or potentially harmful chemicals, such as chemicals identified as carcinogenic to humans by the Environmental Protection Agency or toxic air contaminants under California regulations; or (2) must be disclosed under certain European Union laws and is present in a product above specified concentrations. The Food and Drug Administration must publish and periodically update on its website a list of the ingredients subject to this requirement. Within one year of this bill's enactment, a brand owner (i.e., the entity bringing a cosmetics product to market) must disclose certain information on its website if a cosmetics product contains any fragrance or flavor ingredient that is (1) present in the product above a certain concentration, or (2) subject to this bill's labeling or packaging requirement. The website must disclose the use of the ingredient in question and other information, such as the ingredient's functional purpose. The use of an ingredient subject to this bill's requirements shall not be treated as a confidential trade secret, but the concentration of such an ingredient shall be treated as confidential commercial information.