[Code of Federal Regulations]
[Title 40, Volume 29]
[Revised as of July 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR425.02]

[Page 7]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 425_LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY
--Table of Contents
 
Sec. 425.02  General definitions.

    In addition to the definitions set forth in 40 CFR part 401, the 
following definitions apply to this part:
    (a) ``Sulfide'' shall mean total sulfide as measured by the 
potassium ferricyanide titration method described in Appendix A or the 
modified Monier-Williams method described in Appendix B.
    (b) ``Hide'' means any animal pelt or skin as received by a tannery 
as raw material to be processed.
    (c) ``Retan-wet finish'' means the final processing steps performed 
on a tanned hide including, but not limited to, the following wet 
processes: retan, bleach, color, and fatliquor.
    (d) ``Hair pulp'' means the removal of hair by chemical dissolution.
    (e) ``Hair save'' means the physical or mechanical removal of hair 
which has not been chemically dissolved, and either selling the hair as 
a by-product or disposing of it as a solid waste.
    (f) ``Chrome tan'' means the process of converting hide into leather 
using a form of chromium.
    (g) ``Vegetable tan'' means the process of converting hides into 
leather using chemicals either derived from vegetable matter or 
synthesized to produce effects similar to those chemicals.
    (h) ``Raw material'' means the hides received by the tannery except 
for facilities covered by subpart D and subpart I where ``raw material'' 
means the hide or split in the condition in which it is first placed 
into a wet process.
    (i) ``Monthly average'' means the arithmetic average of eight (8) 
individual data points from effluent sampling and analysis during any 
calendar month.
    (j) ``Interference'' means the discharge of sulfides in quantities 
which can result in human health hazards and/or risks to human life, and 
an inhibition or disruption of POTW as defined in 40 CFR 403.3(i).

[47 FR 52870, Nov. 23, 1982, as amended at 53 FR 9181, Mar. 21, 1988]