; (B) a substance that is present by reason of having been added to a cosmetic during processing for the substance’s technical or functional effect; (C) a fragrance, flavor, preservative, or colorant (and the components thereof); and (D) any individual component that the Secretary deems to be an ingredient for purposes of this subchapter. (6) Professional use The term professional use means— (A) the application of a cosmetic to a human customer or client that is intended only for use by an employee or contractor, in settings such as cosmetology, nail care, barbering, esthetics, spa, and other professions as determined by the Secretary through regulation; or (B) the use by, or application to, a human of a cosmetic purchased from a hair salon, nail salon, beauty salon, spa, or other establishment that provides cosmetic treatment services for humans. .