16 CFR 500.26 – Representations of servings, uses, applications
(a) The label of any packaged consumer commodity which bears a representation as to the number of servings, uses, or applications of such commodity contained in such package shall bear in immediate conjunction therewith, and in letters the same size as those used for such representations, a statement of the net quantity (in terms of weight or mass, measure, or numerical count) of each such serving, use, or application: Provided, that such statement may be expressed in terms that differ from terms used in the required statement of net contents (e.g., cupsful, tablespoonful, etc.), when such differing terms describe a constant quantity. Such statement may not be misleading in any particular.
(b) Representations as to the total amount of object or objects to which the commodity may be applied or upon which or in which the commodity may be used, will not be considered to be representations as to servings, uses, or applications, if such amount is expressed in terms of standard units of weight or mass, measure, size, or count.
(c) If there exists a voluntary product standard promulgated pursuant to the procedures found in 15 CFR part 10, by the Department of Commerce, quantitatively defining the meaning of the terms serving, use, or application with respect to a particular consumer commodity, then any label representation as to the number of servings, uses, or applications in such packaged consumer commodity shall correspond with such quantitative definition. (Copies of published standards will be available upon request from the National Institute of Standards and Technology, Department of Commerce, Washington, DC 20899.)