[Code of Federal Regulations]
[Title 40, Volume 27]
[Revised as ofJuly 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR467.31]

[Page 632]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 467--ALUMINUM FORMING POINT SOURCE CATEGORY--Table of Contents
 
                    Subpart C--Extrusion Subcategory
 
Sec. 467.31  Specialized definitions.

    For the purpose of this subpart:
    (a) The ``core'' of the extrusion subcategory shall include 
extrusion die cleaning, dummy block cooling, stationary casting, 
artificial aging, annealing, degreasing, and sawing.
    (b) The term ``extrusion die cleaning'' shall mean the process by 
which the steel dies used in extrusion of aluminum are cleaned. The term 
includes a dip into a concentrated caustic bath to dissolve the aluminum 
followed by a water rinse. It also includes the use of a wet scrubber 
with the die cleaning operation.
    (c) The term ``ancillary operation'' shall mean any operation not 
previously included in the core, performed on-site, following or 
preceding the extrusion operation. The ancillary operations shall 
include direct chill casting, press or solution heat treatment, cleaning 
or etching, degassing, and extrusion press hydraulic fluid leakage.