16 CFR § 303.14 - Products containing unknown fibers.
(a) Where a textile fiber product is made from miscellaneous scraps, rags, odd lots, secondhand materials, textile by-products, or waste materials of unknown, and for practical purposes, undeterminable fiber content, the required fiber content disclosure may, when truthfully applicable, in lieu of the fiber content disclosure otherwise required by the Act and regulations, indicate that such product is composed of miscellaneous scraps, rags, odd lots, textile by-products, secondhand materials (in case of secondhand materials, words of like import may be used) or waste materials, as the case may be, of unknown or undetermined fiber content, as for example:
(b) Where a textile fiber product is made in part from miscellaneous scraps, rags, odd lots, textile by-products, second-hand materials or waste materials of unknown and, for practical purposes, undeterminable fiber content together with a percentage of known or determinable fibers, the required fiber content disclosure may, when truthfully applicable, in lieu of the fiber content disclosure otherwise required by the Act and regulations, indicate the percentage of miscellaneous scraps, rags, odd lots, secondhand materials (in case of secondhand materials, words of like import may be used), textile by-products, or waste materials of unknown or undetermined fiber content and the percentage of known fibers, as for example:
(c) No representation as to fiber content shall be made as to any textile product or any portion of a textile fiber product designated as composed of unknown or undetermined fibers. If any such representation is made, a full and complete fiber content disclosure shall be required.
(d) Nothing contained in this section shall excuse a full disclosure as to fiber content if the same is known or practically ascertainable.