[Code of Federal Regulations]
[Title 40, Volume 23]
[Revised as of July 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR158.167]

[Page 103-104]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 158_DATA REQUIREMENTS FOR REGISTRATION--Table of Contents
 
              Subpart C_Product Chemistry Data Requirements
 
Sec. 158.167  Discussion of formation of impurities.

    The applicant must provide a discussion of the impurities that may 
be present in the product, and why they may be present. The discussion 
should be based on established chemical theory and on what the applicant 
knows about the starting materials, technical grade of active 
ingredient, inert ingredients, and production or formulation process. If 
the applicant has reason to believe that an impurity that EPA would 
consider toxicologically significant may be present, the discussion must 
include an expanded discussion of the possible formation of the impurity 
and the amounts at which it might be present. The impurities which must 
be discussed are the following, as applicable:
    (a) Technical grade active ingredients and products produced by an 
integrated system. (1) Each impurity associated with the active 
ingredient which was found to be present in any analysis of the product 
conducted by or for the applicant.
    (2) Each other impurity which the applicant has reason to believe 
may be present in his product at any time before use at a level equal to 
or greater than 0.1 percent (1000 ppm) by weight of the technical grade 
of the active ingredient, based on what he knows about the following:
    (i) The composition (or composition range) of each starting material 
used to produce his product.
    (ii) The impurities which he knows are present (or believes are 
likely to be present) in the starting materials, and the known or 
presumed level (or range of levels) of those impurities.
    (iii) The intended reactions and side reactions which may occur in 
the production of the product, and the relative amounts of byproduct 
impurities produced by such reactions.
    (iv) The possible degradation of the ingredients in the product 
after its production but prior to its use.
    (v) Post-production reactions between the ingredients in the 
product.
    (vi) The possible migration of components of packaging materials 
into the pesticide.
    (vii) The possible carryover of contaminants from use of production 
equipment previously used to produce other products or substances.
    (viii) The process control, purification and quality control 
measures used to produce the product.
    (b) Products not produced by an integrated system. Each impurity 
associated with the active ingredient which the applicant has reason to 
believe may be present in the product at any time before use at a level 
equal to or greater than 0.1 percent (1000 ppm) by weight of the product 
based on what he knows about the following:
    (1) The possible carryover of impurities present in any registered 
product which serves as the source of any of the product's active 
ingredients. The identity and level of impurities in the registered 
source need not be discussed or quantified unless known to the 
formulator.
    (2) The possible carryover of impurities present in the inert 
ingredients in the product.
    (3) Possible reactions occurring during the formulation of the 
product between any of its active ingredients, between the active 
ingredients and inert ingredients, or between the active ingredients and 
the production equipment.
    (4) Post-production reactions between any of the product's active 
ingredients and any other component of the product or its packaging.
    (5) Possible migration of packaging materials into the product.
    (6) Possible contaminants resulting from earlier use of equipment to 
produce other products.
    (c) Expanded discussion. On a case-by-case basis, the Agency may 
require an

[[Page 104]]

expanded discussion of information of impurities:
    (1) From other possible chemical reactions;
    (2) Involving other ingredients; or
    (3) At additional points in the production or formulation process.