United States Prevention, Pesticides EPA712-C-96-189
Environmental Protection and Toxic Substances August 1996
Agency (7101)
&EPA Residue Chemistry
Test Guidelines
OPPTS 860.1900
Field Accumulation in
Rotational Crops
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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 860.1900 Field accumulation in rotational crops.
(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 (FFDCA) (21 U.S.C. 301, et seq.).
(2) Background. The source material used in developing this har-
monized OPPTS test guideline is OPP 165-2. Field Accumulation Studies
on Rotational Crops (Pesticide Assessment Guidelines, Subdivision N,
Chemistry: Environmental Fate, EPA Report 540/9-82-021, October
1982). This OPPTS guideline should be used in conjunction with OPPTS
860.1000, Background.
(b) Purpose. Data from field accumulation studies on rotational crops
will enable the Agency to determine under actual field-use conditions the
amount of pesticide residue uptake in rotational crops. Such data are used
to establish realistic crop rotation restrictions (time from application to
a time in which crops can be rotated) and to provide information for deter-
mining whether tolerances are needed in rotational crops.
(1) General considerations, (i) Studies on confined rotational crops
and field rotational crops are conditionally required under 40 CFR part
158 for uses of pesticides on food crops. A rotational crop use is any
field-vegetable crop use or any other site use on which it is reasonably
foreseeable that any food or feed crop may be planted after harvest of
a treated crop. The purpose of field studies is to determine the amount
of pesticide residue uptake into rotational crops. The study uses a typical
end-product applied to a field plot. Results of these studies are used to
determine whether residues occur in rotational crops grown under actual
field conditions. Based on these data, appropriate crop rotation restrictions
(time from application to planting of rotational crop) may be established
and the need for tolerances on the rotated crops determined.
(ii) The Agency has determined that rotational crop studies will not
be required for uses of pesticides on the following commodities or crop
groups: Asparagus, avocado, banana, berries crop group, citrus fruits crop
group, coconut, cranberry, dates, fig, ginseng, globe artichoke, grapes,
guava, kiwi fruit, mango, mushrooms, olives, papaya, passion fruit, pine-
apple, plantain, pome fruits crop group, rhubarb, stone fruits crop group,
and tree nuts crop group. Refer to 40 CFR 180.41 for complete lists of
the crops in each crop group.
(2) Scientific considerations, (i) If the level of the total radioactive
residue (TRR) in the confined rotational crops is equal to or exceeds 0.01
parts per million at the desired rotational interval or at 12 months, and
once the nature of the residue in the rotational crops is understood, Reg-
istrants should consider the Agency's position regarding the residue to be
regulated in the primary crop (see OPPTS 860.1850 and the following
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Figure 1) to decide whether the first tier of field trials should be initiated.
That is, if the composition of the TRR in the rotational crops is such that
residues which need to be are regulated are found at levels greater than
or equal to 0.01 ppm in the rotational crop (following the criteria set forth
in OPPTS 860.1300), field trials should be performed. If residues of con-
cern in the confined study are greater than or equal to 0.01 ppm but less
than the limit of quantitation (LOQ) of the analytical method to be used
on field trial samples, the Agency will consider waiving the need for field
trials on a case-by-case basis.
Figure 1.
Pesticide to applied to crept that on be rattled.
o
MstabofcmCcmrtttBe
B) -ORES Hun
14-C Study- 1xApplication Rate
<0.01 ppm In crap parts
uasd lor toed/bed aa
defined In Tabte I,
860.1000.
at the desired plant-beck
Interval
(12 months max).
No tolerances required. A
rotational crop restriction
may be needed.
£0.01 ppm In craps after 12 month
pknHiack (or shortsr Interval <
detfred).
Cnaractertee/raenllfy
(See QjkMkK 800.1300).
Residues of concsm are observed.
observed.
Umtad FMd TrUs (Odd)
Residues of concern
at quantifiable levels.
Extended FMd Trials
0-*
Tolerances Required
(See SukMlma«).1iOO].
nookjuss of concsm at non-
quanWIeble levels.
No tolerances required. Plant-fcack
No tolerances required.
Ptent-btck restriction maybe
(ii) The limited field trials should be conducted on a representative
crop (as defined in 40 CFR 180.41) at two sites per crop for the following
three crop groups: Root and tuber vegetables, leafy vegetables and small
grains (wheat, barley, oats, rye) for a total of six trials. As with confined
studies (OPPTS 860.1850), soybeans may be substituted for the leafy vege-
table. The six trials should be conducted on crops which a registrant in-
tends to have as rotational crops on the label. If there is no uptake of
residues of concern in one or two of the representative crops in the con-
fined study, the Agency still requires six field trials. The trials may be
distributed at the petitioner's discretion among the representative crops
showing uptake. In addition, some of the six trials could be conducted
using other crops that are typically involved in crop rotation such as alfalfa
and soybeans.
(iii) The soil should be treated at the maximum label rate and the
maximum number of applications and the appropriate crops should be
planted after the minimum aging interval. However, if the pesticide is only
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to be applied to foliage, the treatment in the field studies may be carried
out in the same manner. The crops should be harvested and all the plant
parts (including leaves of the root and tuber vegetables) prescribed as raw
agricultural commodities (RACs) in Table 1 of OPPTS 860.1000 should
be analyzed for the residues of concern observed in primary crops as well
as any other residues of concern specific to rotational crops which fulfill
the criteria set forth in OPPTS 860.1850. Quantitation limits for rotational
crops should be comparable to those for primary crops. The petitioner
should describe how the values for the LOQ were calculated and cite any
appropriate references.
(iv) The methods employed to analyze the rotational crops should
be specific for all pesticide residues of concern in the subject commodities.
If the analytical procedure determines interfering compounds it will be
considered to be deficient and this would be a cause for rejection of the
studies. It would also be desirable to employ sites on which the test pes-
ticide had not been previously applied. If residues are found in control
crop samples, the Agency will not automatically reject the field studies.
The total study will be examined and consideration given to factors such
as the relative levels of residues in treated and control samples. As in
the case of the confined accumulation in rotational crops study, analysis
of the soil is not required.
(v) If no residues above the LOQ are observed in RACs in the limited
field trials, no tolerances will be needed. However plantback restrictions
will normally be needed unless the confined study shows no residues of
concern at a 30-day plantback interval.
(vi) If the limited field studies in paragraph (b)(2)(ii) of this guideline
indicate that quantifiable residues will occur, rotational crop tolerances will
be required. The requirement for number of trials would be the same as
that to establish primary tolerances on all crops or crop groups which a
registrant intends to have as rotational crops on the label. If a registrant
desires to allow the universe of crops to be rotated, magnitude of the resi-
due data are required on representative crops (see 40 CFR 180.41) for
all crop groups which could be planted in a typical crop rotation sequence.
With respect to treatment, these trials should be conducted in the same
manner as discussed in paragraph (b)(2)(ii) of this guideline for the limited
trials. If a registrant believes that fewer crops would be rotated because
of the nature of the pesticide or due to the way it is used, guidance should
be obtained from the Agency regarding specific data requirements in that
case. If tolerances exist on the crops to be rotated as a result of a primary
use, rotational data on these crops would be required only if residues in
rotated crops are significant in comparison to those in the primary crop.
(c) Test standards—(1) Test substance. The test substance should
be a typical end-use product. If more than one formulation type is reg-
istered, several factors need to be considered as to which types should
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be used. If one formulation has a significantly higher application rate than
the others, it should be applied to the plots in which the rotational crops
will be grown. If all formulations have similar application rates but one
has been specifically designed to have a longer half-life in the environment
(e.g. controlled release product), the latter should be the test substance.
The discussion in OPPTS 860.1500 on formulations for crop field trials
should also be consulted. That guidance notes that for target crops, residue
data can be translated among formulations which are diluted in water and
applied early in the growing season. Such translation would also be appro-
priate for rotational crop field studies. Therefore, rotational crop data re-
flecting use of a wettable powder would cover formulations such as emul-
sifiable concentrates and water dispersible granules. However, as with tar-
get or primary crops, separate studies will normally be required on rota-
tional crops reflecting uses of granular formulations unless data are avail-
able to show the relative soil half-lives of the active ingredient as a func-
tion of formulation.
(2) Test procedure—(i) Sites. Field accumulation studies should be
conducted on at least two different sites per crop. These sites should be
representative of the areas where rotated crops are expected to be grown.
If possible, the soil type at one of the test sites should be the same as
that used in the confined accumulation study of OPPTS 860.1850. For
restricted use patterns where only one typical area is involved, data from
two similar sites should be submitted.
(ii) Application. (A) The soil at the test site should be treated with
the test substance applied by the method stated in the directions for use
specified on the product label and at the highest recommended label rate.
However, if the pesticide is only to be applied to foliage, the treatment
in the field studies may be done in the same manner.
(B) Following treatment, the pesticide should be aged under aerobic
conditions in the soil for a time approximating the anticipated agricultural
practice (e.g., 1 year for crops rotated the following year, 120 days for
crops rotated immediately after harvest, and 30 days for assessing cir-
cumstances of crop failure). Growing a primary crop in the soil during
the aging period is not precluded.
(iii) Sampling. (A) Representative root and tuber vegetable, small
grain, and leafy vegetable crops should be planted as rotational crops. Soy-
beans may be substituted for the leafy vegetable.
(B) If a registrant is proposing a tolerance for residues in a rotated
crop, that crop should be planted, harvested, and analyzed for residues
at test sites selected in accordance with the requirements described in detail
in OPPTS 860.1500.
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(C) The rotational crop RACs (including the foliage of the root and
tuber vegetable) as prescribed in Table 1 of OPPTS 860.1000 should be
analyzed for residues at appropriate harvest times.
(D) Test duration. Residue data should be collected in rotational crops
until the time that the mature portions of the crops are normally harvested.
(d) Reporting and evaluation of data. In addition to the applicable
reporting requirements specified in OPPTS 860.1000, the following data
should be reported:
(1) Field test data including:
(i) Dates of planting and harvesting of primary and rotational crops.
(ii) Amount of rainfall and irrigation water (accumulated from appli-
cation to harvest).
(iii) Temperature monitoring data and a description of the general
climatic conditions at the test site during the study.
(iv) Planting, culture, and harvesting techniques.
(v) Pesticide application dates and method.
(vi) Sampling techniques for primary (if applicable) and rotational
crop RACs.
(vii) Stages of crop development at times of sampling.
(viii) Weight of each sample taken for analysis.
(2) Analysis for residues of parent compound and metabolites in the
crops. Separate analyses should be conducted on different portions of the
plant as outlined in Table 1 of OPPTS guideline 860.1000. In addition,
analysis of both the aerial and root portions of root crops should be con-
ducted.
(e) Format of data report. The following format is provided as an
example. Other formats are acceptable provided that all the information
is included.
(1) Title/cover page. Title page and additional documentation require-
ments (i.e. for data submission and statement of data confidentiality of
data) if relevant to the study reported should precede the content of the
study. These requirements are described in PR Notice 86-5 (see paragraph
(2) Table of contents. The table of contents should follow the title,
data confidentiality, and GLP pages. This page should provide the overall
organization of the report, including tables and figures.
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(3) Abstract. Give a summary of the study addressing the following
points:
(i) The chemical name and formulation of the pesticide and the meth-
od of application to the primary (treated) crop. Structures of the pesticide
and metabolites may be included in this section.
(ii) Maintenance of the treated plots.
(iii) A narrative or a table (with an appropriate title) that provides
the following information:
(A) Days between treatment and planting of the rotational crops.
(B) Age of crop (in days) at each sampling point (e.g. at forage, hay,
grain stages).
(C) Total residues in parts per million. Parent compound and
metabolites of concern should be reported separately if so determined by
the method.
(iv) Indication of problems (such as technical difficulties or unusual
weather) resulting in necessary deviations from the intended test protocol.
Describe the effect of the deviations on the results of the study.
(v) The name and phone number of a contact person should be pro-
vided in the event the reviewer has technical questions about the study.
(This is optional. However, providing this information will facilitate effi-
cient review in case of questions.)
(4) Introduction. This section should open with a description of the
purpose of the study, what requirement it is intended to satisfy, and (if
applicable) how it supports the position of the registrant. Background and
historical information relative to the study should appear in this section.
(5) Materials/Methods. This section should be in narrative form in
the following order and should contain all details with regard to the mate-
rials, equipment, experimental design, field plots and procedures used in
conducting the study. Registrants are encouraged to include drawings and
photographs of the plot, equipment and of different phases of the study.
(i) Chemical. (A) Active ingredient and type of formulation.
(B) Include the percent (by weight) of the active ingredient and for
liquid formulations, the weight of the active ingredient per unit of liquid
measure.
(ii) Site. (A) Include a map of the test plots indicating their location,
topography and size, and location and size of the control plots in relation
to the test plots; the soil characteristics (percent sand, silt, clay, and or-
ganic matter, pH, water holding capacity).
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(B) A complete record of daily temperature and daily rainfall through-
out the study (refer to raw data discussion in OPPTS 860.1000) and how
they compare to average temperature and rainfall at the test site.
(iii) Crop. (A) Crop and pesticide use history on the plot for the
3-year period preceding the study.
(B) The date and technique of plot preparation prior to pesticide appli-
cation.
(C) The identity of the primary (treated) crop; a description of how
and when the primary crop was planted; how and when the subject pes-
ticide was applied; the weather (temperature, rainfall, windspeed and direc-
tion) and condition of the field at time of application; the formulation of
the pesticide applied, adjuvants or other compounds added to the spray/
application mixture; the application rate and the application technique.
Also, provide a similar description for each of any additional applications
made of the subject pesticide. Indicate how much pesticide was applied
in comparison to actual use rates; and if application technique differed
from label recommendations.
(D) A description of any posttreatment crop maintenance such as use
of fertilizers and other pesticides, irrigation (when applied, how much, and
source), tilling, weeding, etc.
(iv) Test method—(A) General. (7) Provide the date of harvest of
the treated crop; describe what was done to the plot after harvest in prepa-
ration for planting of the rotational crops.
(2) Provide the identity of the rotational crops planted in the study;
a description of the procedure used in planting the rotational crops; and
days elapsed between planting of crops and treatment with pesticide; a
description of all procedures used in the maintenance of the rotational
crops (as done for the treated crop), the sampling/harvest method and num-
ber of samples/replicates.
(3) Describe handling from the time of taking of the samples until
analysis with special attention to the conditions under which the sampled
rotational crops were stored and the thawing procedure (if frozen). Deter-
mine storage stability of pesticide residues. Provide dates the samples were
frozen, thawed, and analyzed.
(4) Describe any deviation from the intended test protocol and the
effects on the results.
(B) Analytical method. (7) Describe methods fully (or reference if
previously submitted), including method validation data, recovery and
method sensitivity data, sample chromatograms, and sample calculations.
Preparation and handling of the sample throughout the method should be
described in detail. Note that methods for metabolites may also be needed.
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(2) Identify instrumentation, equipment and reagents used and the op-
erating conditions of the instrumentation. If the extraction/clean-up proce-
dure is complex, a flow diagram should be submitted.
(3) Identify all plant fractions analyzed in the study, such as grain,
forage, hay, and straw in the case of small grains and root and aerial
(leafy) portions in the case of root crops.
(6) Results/discussion, (i) This section should contain the scientific
results of the study, for instance:
(A) Narrative and tables describing the steps taken in determining
the pesticide residues in crop samples. (Any graphical presentations of the
data should be accompanied by the tables of the actual values from which
the graphs were constructed.)
(B) A table of structures and chemical names/designations for the par-
ent compound and metabolites.
(C) Total residues of concern for all RACs as prescribed in Table
lofOPPTS860.1000.
(7) Conclusion. Provide discussion as to the significance of the resi-
dues (if any) taken up, at what intervals residues are taken up by rotational
crops (in which crop fractions and at what levels) and at what interval
no quantifiable residues of concern can be expected to be taken up by
rotational crops.
(8) Certification. Include:
(i) Signatures of each of the senior scientific personnel responsible
for the study.
(ii) Certification by registrant that the report is a complete and
unaltered copy of the report provided by the testing facility.
(9) Tables/figures. Use arabic numerals for figures and roman numer-
als for tables.
(10) References.
(11) Appendixes. Reprints of methods and other studies cited, actual
results of analyses (raw data), copies of relevant letters and memos and
other material not fitting in any of the other sections and that support
the registrant's case should be placed in this section.
(f) References. The following references should be consulted for ad-
ditional background material on this test guideline.
(1) Environmental Protection Agency. Pesticide Assessment Guide-
lines, Subdivision N, Chemistry: Environmental Fate, Field Accumulation
8
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Studies on Rotational Crops, Addendum 1, Series 165-2, EPA Report 5407
09-86-149, 1986.
(2) Environmental Protection Agency. Pesticide Regulation Notice PR
86-5, Standard Format for Data Submitted under the FIFRA and Certain
Provisions of the Federal Food, Drug, and Cosmetic Act (FFDCA), May
3,1986.
(3) Environmental Protection Agency. Pesticide Rejection Rate Anal-
ysis, Residue Chemistry/Environmental Fate: Followup Guidance for Con-
ducting Rotational Crop Studies, EPA Report No. 738-B-93-001, Feb-
ruary 1993.
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