(a) Attribution. All final products removed from or consumed within a petroleum refinery subzone must be attributed to feedstock admitted into said petroleum refinery subzone in the current or prior manufacturing period. Attribution must be based on records maintained by the operator. Attribution may be made by applying one of the authorized methods set forth in this section. Records must be maintained on a weight or volume basis.

(1) Producibility. The producibility method of attribution requires that records be kept to attribute final products to feedstocks which are eligible for attribution as set forth in this section during the current or prior manufacturing period.

(2) Actual production records. An operator may use its actual production records as provided for under §146.95(b) of this subpart.

(3) Other inventory method. An operator may use the FIFO (first-in, first-out) method of accounting (see §191.22(c) of this chapter). The use of this method is illustrated in the appendix to this part.

(b) Feedstock eligible for attribution. Only a feedstock that has been admitted into the refinery subzone is eligible for attribution. For a given manufacturing period, the quantity of feedstock eligible for attribution may be computed as beginning inventory, plus receipts less shipments of feedstock out of the subzone, and less ending inventory.

(c) Consumption or removal of final product. Each final product that is consumed in or removed from a refinery subzone must be attributed to a feedstock eligible for attribution during the current or a prior manufacturing period. Each final product attributed as being produced from the separation of a privileged foreign status feedstock must be assigned the proper relative value as set forth in paragraph (d) of this section.

(d) Relative value. A relative value calculation is required when two or more final products are produced as the result of the separation of privileged foreign status feedstock. Ad valorem and compound rates of duty must be converted to specific rates of duty in order to make a relative value calculation.

(e) Privileged status after admission. Nonprivileged status feedstock is eligible for privileged status only if the request shows to the satisfaction of the Customs Service that there was no manipulation or manufacture of the feedstock to change its tariff classification before the request is granted. The absence of such manipulation or manufacture can be shown by demonstrating that the feedstock was placed in an empty tank, in a tank that contained only feedstock with the same nominal specifications or providing a sample which shows there was no change in tariff status. The existence of negligible amounts of other feedstocks may be disregarded only in accordance with §146.95(b). A request for after-admission privileged foreign status shall be denied unless the feedstock's tank records from admission to the time that the request is made accompany the request. A refiner who makes such a request shall not put any other feedstock having different nominal specifications into the tank until the request for privileged status is granted. The Customs Service will deny or revoke a post-admission request if a refiner fails to retain the integrity of the feedstock in the tank.

(f) Consistent use required. The operator must use the selected method, measurement (weight or volume), and the price of product consistently (see §146.92(g) of this subpart and paragraph (a) of this section).