(a) General. Except as provided in paragraph (b) of this section, when metal-bearing ores and other metal-bearing materials which are classifiable under Chapter 26, Harmonized Tariff Schedule of the United States (HTSUS) (19 U.S.C. 1202), are entered for consumption or warehousing at the port of first arrival, they shall be sampled for assay and moisture purposes in accordance with § 151.52. If proper facilities for weighing or sampling are not available at the port of entry, the merchandise shall be transported under bond to the place of sampling. The sampling or weighing of metal-bearing ores or materials at any place other than the port of entry shall be at the expense of the parties in interest.

(b) Ores of low metal content. When, on the basis of invoice information, the nature of any available sample, knowledge of prior importations of similar materials, and other data, the Center director is satisfied that metal-bearing ores entered under heading 2617, HTSUS, as containing less than 1 percent of metals dutiable under headings 2603, 2607, and 2608, HTSUS, are properly entered, he may liquidate the entry on the basis of the assay information contained in the entry papers. However, the sampling and testing procedures prescribed in §§ 151.52 and 151.54 shall be followed at random intervals for verification purposes.

(a) Commercial samples taken under Customs supervision. Representative commercial moisture and assay samples shall be taken under Customs supervision for testing by the Customs laboratory. The samples used for the moisture test shall be representative of the shipment at the time the shipment is weighed for Customs purposes. When a shipment is made up of a number of lots a composite sample of the shipment shall be drawn for assay, providing composite sampling is feasible and assays of the individual lots are not required for tariff classification or other Customs purposes. The composite sample shall consist of proportional parts by weight of the prepared sample drawn from the various lots represented and shall be thoroughly mixed.

(b) Commercial samples furnished by importer. When commercial samples cannot be taken under Customs supervision, the importer shall be required to furnish a verified commercial moisture sample and prepared assay sample certified to be representative of the shipment at the time the shipment was weighed for Customs purposes. The samples shall be in appropriate containers, properly labeled, and shall be accompanied by a statement including:

(1) Entry number,

(2) Lots represented,

(3) Kind of ore or material,

(4) Date and place where sampling occurred, and

(5) The name and address of the sampling concern.

(c) Samples taken by Customs. Where no commercial samples have been taken, an authorized CBP official shall take representative samples from different parts of the shipment.

A suitable place or containers shall be provided for the safekeeping of all Customs samples under Customs lock or seal.

Samples taken in accordance with § 151.52 shall be promptly forwarded to the appropriate Customs laboratory for testing in accordance with commercial methods. An authorized CBP official may secure from the importer a certified copy of the commercial settlement tests for moisture and for assay which shall be transmitted with the commercial samples to the Custom laboratory. If the Customs tests are not in substantial agreement with the settlement tests, the Customs laboratory director shall review his tests. The Customs tests shall be used in determining the final duties on the merchandise, except that the settlement tests shall be used if, in the opinion of the Customs laboratory director:

(a) The settlement and Customs tests differ by no more than is to be expected between qualified laboratories, and

(b) The use of the settlement test results will not require a different tariff classification or rate of duty than is indicated by the Customs test.

Deductions for the loss of copper, lead, or zinc content during processing, as authorized by Chapter 26, Additional U.S. Note 1, Harmonized Tariff Schedule of the United States (19 U.S.C. 1202), shall be made by the Center director in the liquidation of any entry only if the importer has followed the procedures set forth in that headnote. See §§ 19.17 through 19.25 of this chapter for procedures applicable to bonded smelting and refining warehouses.