Section NR 257.31 - Specialized definitionsIn addition to the definitions set forth in s. NR 257.03, the following definitions apply to the terms used in this subchapter:
(1) "Ancillary operation" means any operation which is not a core operation but which is performed on-site following or preceding the extrusion operation, such as direct chill casting, press or solution heat treatment, cleaning or etching, degassing, and extrusion press hydraulic fluid leakage.(2) "Core operation" means extrusion die cleaning, any wet scrubber associated with the die cleaning, dummy block cooling, stationary casting, artificial aging, annealing, degreasing, and sawing.(3) "Extrusion die cleaning" means an operation in which the steel dies used for aluminum extrusion are cleaned by dipping the dies into a concentrated caustic bath to dissolve the aluminum and then rinsing the dies with water.Wis. Admin. Code Department of Natural Resources § NR 257.31
Cr. Register, November, 1989, No. 407, eff. 12-1-89.