United States Prevention, Pesticides EPA712-C-96-186
Environmental Protection and Toxic Substances August 1996
Agency (7101)
&EPA Residue Chemistry
Test Guidelines
OPPTS 860.1550
Proposed Tolerances
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INTRODUCTION
This guideline is one of a series of test guidelines that have been
developed by the Office of Prevention, Pesticides and Toxic Substances,
United States Environmental Protection Agency for use in the testing of
pesticides and toxic substances, and the development of test data that must
be submitted to the Agency for review under Federal regulations.
The Office of Prevention, Pesticides and Toxic Substances (OPPTS)
has developed this guideline through a process of harmonization that
blended the testing guidance and requirements that existed in the Office
of Pollution Prevention and Toxics (OPPT) and appeared in Title 40,
Chapter I, Subchapter R of the Code of Federal Regulations (CFR), the
Office of Pesticide Programs (OPP) which appeared in publications of the
National Technical Information Service (NTIS) and the guidelines pub-
lished by the Organization for Economic Cooperation and Development
(OECD).
The purpose of harmonizing these guidelines into a single set of
OPPTS guidelines is to minimize variations among the testing procedures
that must be performed to meet the data requirements of the U. S. Environ-
mental Protection Agency under the Toxic Substances Control Act (15
U.S.C. 2601) and the Federal Insecticide, Fungicide and Rodenticide Act
(7U.S.C. I36,etseq.).
Final Guideline Release: This guideline is available from the U.S.
Government Printing Office, Washington, DC 20402 on The Federal Bul-
letin Board. By modem dial 202-512-1387, telnet and ftp:
fedbbs.access.gpo.gov (IP 162.140.64.19), internet: http://
fedbbs.access.gpo.gov, or call 202-512-0132 for disks or paper copies.
This guideline is also available electronically in ASCII and PDF (portable
document format) from the EPA Public Access Gopher (gopher.epa.gov)
under the heading "Environmental Test Methods and Guidelines."
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OPPTS 860.1550 Proposed tolerances.
(a) Scope—(1) Applicability. This guideline is intended to meet test-
ing requirements of both the Federal Insecticide, Fungicide, and
Rodenticide Act (FIFRA) (7 U.S.C. 136, et seq.) and the Federal Food,
Drug, and Cosmetic Act (21 U.S.C. 301, et seq.}
(2) Background. The source materials used in developing this har-
monized OPPTS guideline are OPP 171-6 Proposed Tolerances, OPP 171-
8 Exemptions from the Requirement of a Tolerance, and OPP 171-9 Toler-
ance for Foreign Uses (Pesticide Assessment Guidelines, Subdivision O:
Residue Chemistry, EPA Report 540/9-82-023, October 1982). This
OPPTS guideline should be used in conjunction with OPPTS 860.1000
Background.
(b) General—(1) Determining the tolerance level. To obtain a toler-
ance, the petitioner proposes a tolerance level, based on residue field trial
data, which reflects the maximum residue that may occur under worst-
case conditions as a result of the proposed use of the pesticide. The toler-
ance must include significant metabolites of toxicological concern and
must be high enough to cover all components of the total toxic residue
(TTR). The pesticide active ingredient and any significant metabolites to-
gether comprise the TTR. If one component of the residue is significantly
more toxic than other components, two levels may be included in the toler-
ance expression.
(2) Significant metabolites of concern and tolerance expression.
(i) Using the results of plant and animal metabolism studies, EPA deter-
mines which metabolites are of concern and need to be included in the
tolerance expression. In each case, this decision is based on the toxicity
of the metabolite and the magnitude of its residue. Metabolites that are
toxicologically significant and occur at significant levels require a suitable
analytical method.
(ii) In some cases, tolerances may be based on only a portion of the
residue of concern in order to ease enforcement or to harmonize with inter-
national tolerances. This may be referred to as an indicator compound,
which typically would be the parent pesticide. However, residue data are
still required on all residues of concern so the latter can be included in
dietary risk assessment.
(c) Proposed tolerances—section F of a petition). (1) Tolerances
should be proposed in terms that best represent the TTRs on the raw agri-
cultural commodity, whether it be the parent pesticide, altered forms of
it, or both. The proposed tolerance should not be based on an average
residue value but should be large enough to include any residue values
that could be reasonably expected based on the available data.
(2) The tolerance should not be larger than is needed for the proposed
use although some limited accommodation to this rule may be necessary
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in the interest of avoiding an inordinate multiplicity of tolerance levels
for a single pesticide on a number of different crops. When the analytical
method is based on measurement of a common chemical moiety, it will
usually determine one or more conversion products along with the parent
compound. In such cases, it may be appropriate to propose a combined
tolerance for all of the compounds calculated as the parent compound,
toxicological considerations permitting.
(3) The petitioner should consider whether the proposed tolerance can
be made compatible with maximum residue limits (MRLs) established by
the Codex Alimentarius Commission (an organization set up under the aus-
pices of the United Nations to facilitate international trade) or the toler-
ances established by Mexico or Canada. The tolerance comparison should
include compatibility of the numerical level proposed, the residue defini-
tion (i.e. the metabolites included in the tolerance), and the commodity
definition.
(4) An exemption from the requirement of a tolerance may also be
proposed when appropriate (see paragraph (d) of this guideline). When
an exemption is proposed, data should be presented to show the level of
residues to be expected.
(5) In the case of food additive regulations covering the use of pes-
ticides in food handling establishments, it is contemplated that the regula-
tion may or may not include a numerical tolerance on foods. However,
a numerical indication of the expected residue levels is preferred. In either
case, the proposed regulation should specify the conditions of use of the
pesticide. The determination of whether a numerical tolerance is needed
will be based on the toxicity of the residue and the level of possible con-
tamination.
(d) Exemptions from the requirement of a tolerance—(1) Active
ingredients. Exemptions from the requirement of a tolerance are appro-
priate for pesticides for which no enforcement action can be anticipated.
Since an exemption from the requirement of a tolerance means that there
is no limit on the level of residue that could occur, exemptions are limited
to relatively non-toxic pesticides. Examples of active ingredients for which
an exemption is appropriate are acetic acid and sulfur. Exemptions from
the requirement of a tolerance for an active ingredient should be requested
by submission of a petition. Normally, the only information/data needed
in such a petition are the data from petition sections A, B, E, F, and G.
The normal residue chemistry data requirements in section D will be
waived for toxicologically-innocuous active ingredients. An analytical
method is rarely needed for enforcement purposes.
(2) Inert ingredients. Inert ingredients of pesticide formulations have
been determined to be pesticide chemicals within the meaning of the Act
and are subject to the Pesticide Amendment (section 408) of the FFDC
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Act. A large number of these inert ingredients have been exempted from
the requirements of a tolerance (40 CFR 180.1001). Requests to add other
adjuvants should be submitted as petitions for exemption or as a letter
to the Director, Registration Division, Office of Pesticide Programs. Data
requirements for inerts will not ordinarily be as extensive as for active
ingredients. However, an analytical method may be required and a basis
for estimation of the level of residues likely to result must be provided.
Limitations on the use may be imposed in the exemption regulation. Any
clearances of the inert ingredient by the FDA as a food or feed additive
should be referenced. The amount of residue chemistry data needed for
the exemption of an inert ingredient will vary with the nature of the chemi-
cal. The minimum information required are a description of the identity
of the chemical and the possible uses involved. If the inert ingredient can-
not be deemed toxicologically-innocuous, then additional data will be re-
quired. In some cases, the full data requirements described for active ingre-
dient tolerances will be required, while in other cases, only an analytical
method and residue data for representative crops will be required. The
amount of data required will depend on the toxicity of the chemical and
the use restrictions imposed.
(e) Tolerances for foreign uses. Foreign uses are not subject to reg-
istration requirements. However, proposals for tolerances for residues in
any imported foods or feeds should be submitted under section 408(e) of
the FFDCA. Tolerances proposed in conjunction with requests for domes-
tic registration are submitted under section 408(d) of the Act. Petitions
submitted under section 408(e) should contain the same types of informa-
tion, including sample labelling, and data as those submitted under section
408(d).
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