(a) The importation of any merchandise as tea which is inferior in purity, quality, and fitness for consumption to the standards prescribed by the Act of March 2, 1897, as amended (21 U.S.C. 41 through 50), is prohibited. Customs officers and employees shall perform all duties required of them by the said act and regulations.

(b) The importation of tea is subject also to the provisions of the Federal Food, Drug, and Cosmetic Act and the regulations thereunder. See §§ 12.1 to 12.5.

(c) [Reserved]

(d) The port director may order such an examination of packages containing tea as will satisfy him that no dutiable goods are packed therein. For this purpose the customary designation shall be made of packages for examination in public stores.

(e) If the invoice has not been received, the importer may use an additional copy of the chop list and release permit required by the regulations of the Department of Health and Human Services as a pro forma invoice, marking “Pro forma invoice” across the face thereof.