[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: 40CFR425.03]

[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. 425.03  Sulfide analytical methods and applicability.

    (a) The potassium ferricyanide titration method described in 
appendix A to part 425 shall be used whenever practicable for the 
determination of sulfide in wastewaters discharged by plants operating 
in all subcategories except the hair save or pulp, non-chrome tan, 
retan-wet finish subcategory (subpart C, see Sec. 425.30). In all other 
cases, the modified Monier-Williams method as described in appendix B to 
part 425 shall be used as an alternative to the potassium ferricyanide 
titration method for the determination of sulfide in wastewaters 
discharged by plants operating in all subcategories except subpart C.
    (b) The modified Monier-Williams method as described in appendix B 
to part 425 shall be used for the determination of sulfide in 
wastewaters discharged by plants operating in the hair save or pulp, 
non-chrome tan, retan-wet finish subcategory (subpart C, see Sec. 
425.30).

[53 FR 9181, Mar. 21, 1988]