This interpretative rule concerns the applicability of the NESHAP for secondary aluminum producers, 40 CFR part 63, subpart RRR, to a specific type of facility which thermally delaminates aluminum foil from paper and plastic and then mechanically granulates the recovered metal. We decided to reconsider this matter after reviewing two applicability determinations which were issued by EPA regional offices for facilities of this type operated by the U.S. Granules Corporation in Plymouth, IN, and Henrietta, MO. We concluded that these applicability determinations reflected conflicting constructions of subpart RRR, and that the determinations should be vacated while we undertook a review to develop a uniform national construction of the rule. In today's interpretative rule, we conclude that a delamination chamber of the type operated by the U.S. Granules facilities is a "scrap dryer/delacquering kiln/decoating kiln" as that term is defined in 40 CFR 63.1503. Accordingly, we believe that the facilities operated by U.S. Granules in Plymouth and Henrietta, and any other facilities which may engage in similar operations, are subject to the emission control requirements of subpart RRR.