[Code of Federal Regulations] [Title 40, Volume 29] [Revised as of July 1, 2005] From the U.S. Government Printing Office via GPO Access [CITE: 40CFR467.21] [Page 626] TITLE 40--PROTECTION OF ENVIRONMENT CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PART 467_ALUMINUM FORMING POINT SOURCE CATEGORY--Table of Contents Subpart B_Rolling With Emulsions Subcategory Sec. 467.21 Specialized definitions. For the purpose of this subpart: (a) The ``core'' of the rolling with emulsions subcategory shall include rolling using emulsions, roll grinding, stationary casting, homogenizing, artificial aging, annealing, and sawing. (b) The term ``ancillary operation'' shall mean any operation not previously included in the core, performed on-site, following or preceding the rolling operation. The ancillary operations shall include direct chill casting, solution heat treatment, cleaning or etching, and degassing.