United States Prevention, Pesticides EPA712-C-96-243
Environmental Protection and Toxic Substances February 1996
Agency (7101)
&EPA Occupational and
Residential Exposure
Test Guidelines
OPPTS 875.2200
Soil Residue Dissipation
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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.).
This guideline, along with the others in Series 875.2000 through
875.2900, is being substantially revised for publication in 1997. However,
the current guidelines are still official. Before initiating any studies for
post-application exposure registrants should contact EPA's Occupational
and Residential Exposure Branch (within the Office of Pesticide Programs)
at 703-305-6094.
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 875.2200 Soil residue dissipation.
(a) Scope—(1) Applicability. This guideline is intended to meet test-
ing requirements of the Federal Insecticide, Fungicide, and Rodenticide
Act (FIFRA) (7 U.S.C. 136, et seq.).
(2) Background. The source material used in developing this har-
monized OPPTS test guideline is OPP guideline 132. This guideline should
be used with OPPTS 875.2000 and 875.2900.
(b) Purpose. Requirements of 40 CFR 158.390 and described in this
guideline are confined to the measurements of pesticide residues which
are deposited on and remain on surfaces after pesticide application. These
surfaces are limited to those that can be touched or disturbed by people,
and from which residues can be dislodged during the performance of var-
ious tasks and subsequently deposited on human skin and clothing or in-
haled.
(c) Test standards—(1) Test substance. A typical end-use product
should be used for this study.
(2) Sites for conduct of tests. Since climate strongly influences the
dissipation of pesticide residues, the applicant should perform dissipation
study at a site representative of the climatic conditions expected in the
intended use areas. The Agency will provide guidance on the choice of
site upon request.
(3) Substitutions for sites. In certain cases, data from one site (when
available) may be substituted for data from another site when surface char-
acteristics are generally similar or nearly identical (e.g., orange and grape-
fruit orchard applications). For those cases, available residue data should
demonstrate that dissipation rates at the two sites do not differ significantly
for similar use patterns.
(4) Method of application. The test substance should be applied by
application methods recommended for the end-use product. Application
of the test substance to the site, area, or objects should be at the least
dilution and highest rate permitted for that end-use product.
(5) Timing of application. The test substance should be applied at
the time of year or season that would normally be recommended to achieve
satisfactory pest control by the product.
(6) Meteorological conditions. Daily meteorological conditions at or
near the site of application should be recorded as part of the data in this
study. Such data would include, as appropriate, temperature, wind speed,
daily rainfall, humidity, and similar information.
(7) Standards for sample collection—(i) Duplicate samples. Dupli-
cate foliar samples should be collected periodically for the development
of dissipation curves. The first samples should be taken as soon as the
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spray has dried or the dust has settled. The intervals at the start of sampling
should be relatively short and may increase with time. For example, sam-
ples taken as soon as the spray has dried or the dust has settled, and at
1, 2, 5, 7, 14, 21, 28, and 35 days after pesticide application would prob-
ably be appropriate for some pesticides. Comparable control or baseline
samples should be collected immediately before the pesticide application.
If analyses of samples reveal dislodgeable residues above the reentry level,
sampling and analyses should continue until a level at or below the reentry
level is reached.
(ii) Additional standards for soil samples. (A) Whenever the ap-
plied pesticide deposits on, is incorporated into, or diffuses into soil at
the site of application and whenever tasks at the treated site will involve
exposure of workers to large amounts of soil, duplicate soil samples for
pesticide residue analysis should be collected from the soil surface or from
not more than the upper 1 cm of soil in the test plot.
(B) The fine material should be isolated from the soil samples without
grinding to give all of the material having particle sizes of 147 (im or
less without particles larger than 147 (im. The fine material will be ex-
tracted for residue analysis.
(iii) Sample storage. Samples and sample extracts may be stored for
later analysis only if fortified controls are included to permit evaluation
of possible residue deterioration during storage. Such samples should be
stored under conditions which will minimize deterioration.
(8) Procedures for chemical extraction and analysis. The
dislodgeable pesticide residues should be extracted from the foliar material
and soil, isolated from interfering materials by suitable cleanup procedures,
and quantified.
(d) Reporting of test results. (1) In addition to meeting the general
reporting requirements of 40 CFR 158.390 the test report should also meet
the following requirements: For residues on soil, the analytical results
should be expressed in terms of micrograms per gram of fine material.
The fine material should be reported in milligrams or micrograms per
square centimeter of surface of the soil area from which the sample was
obtained. Soil and water methods should identify and quantify the total
toxic residue, including the parent compound, toxicologically significant
metabolites and degradates. This guideline does not include those environ-
mental chemistry methods from studies that use radioactive isotopes.
(2) These methods may be validated in an EPA laboratory to deter-
mine if they identify and quantify the pesticide parent compound,
toxicologically significant metabolitess and degradates at the level indi-
cated. The results from the soil and water method validation program may
be used to support regulatory decisions regarding the reliability and valid-
ity of the chemistry data sent to the Agency with exposure, environmental
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fate, and ecological effects studies. Registrants should immediately send
5 gm of the active ingredient analytical grade standard and 1 gm, or a
reasonable amount, of any toxicologically significant metabolites and
degradates to the EPA repository at Research Triangle Park, North Caro-
lina. Registrants shall also send 1 gm, or a reasonable amount, of any
stable derivative that is used to identify and quantitate the target analytes
to the EPA repository. All environmental chemistry methods should be
stamped nonconfidential.
(3) Registrants must provide EPA with accurate and precise data on
the performance of those soil and water chemistry methods that are used
to develop laboratory and/or field residue data to support exposure, envi-
ronmental fate, and ecological effects studies for registration and rereg-
istration. This includes all single or multianalyte methods for the parent
compounds, toxicologically significant metabolites, and degradates in each
environmental matrix.
(4) Registrants shall provide EPA with clearly written and complete
analytical methods that describe the exact procedure, materials, and equip-
ment to be used by regulatory chemists to validate their methods. Analyt-
ical methods shall be practical, rapid, and quantitate analytes of interest.
The Agency will accept best available methods for those parent com-
pounds, toxicologically significant metabolites, and degradates that have
significant risks and require state-of-the-art equipment to measure trace
amounts of analytes. Both practical and rapid and best available methods
must use equipment that is commercially available in the United States.
If methods use conventional gas chromatography, liquid chromatography,
etc., registrants shall submit confirmatory methods using GC/MS, LC/MS,
second column or other suitable procedures. Well established confirmatory
methods that are used to generate study data do not require another con-
firmatory procedure.
(5) Regulatory chemists should be able to validate practical and rapid
analytical methods using a standard set of samples in 24 hours (e.g., three
8-h working days); however, EPA recognizes that best available methods
may require additional time. Each set should have an appropriate number
of samples with quality control samples intermingled. EPA regulatory
chemists should be able to quickly validate soil and water methods for
each test level and matrix.
(6) Registrants shall submit performance data to EPA demonstrating
that an adequate number of samples for each test level were extracted,
cleaned up, and analyzed. This data should support the established limit
of quantitation (LOQs) and precision and accuracy for each method. Target
levels for the mean recoveries should be distributed between 70 and 120
percent of the known quantity of the pesticide/ metabolite spiked into the
matrix blanks at the LOQ or above during the method validation, but reg-
istrants should report individual values for recoveries and standard devi-
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ations for known quantities of pesticides and metabolites in fortified sam-
ples at each spiking level.
(7) The relative standard deviation (RSD) of replicate measurements
of recoveries should not exceed the target level of 20 percent at the LOQ
or above in any set. EPA recognizes that some methods may not be able
to meet these precision requirements. The LOQ may be determined as de-
scribed in paragraph (g)(4) of this guideline. If they are determined in
any other way, registrants shall identify the source of that information and
provide EPA with a clearly written explanation of how they calculated
those values.
(8) Registrants shall not correct sample values for recoveries. Reg-
istrants shall also describe any matrix or solvent effects that result in signal
enhancement, masking or suppression and the impact those effects have
on the test results.
(9) Registrants shall clearly identify those laboratories that developed
the data for the soil and water methods they submit to EPA. Registrants
shall use an independent laboratory to validate soil and water methods
that are used to support appropriate exposure, environmental fate and eco-
logical effects studies. Methods will not be rejected outright for failure
to comply with each and every aspect of this guideline but will be re-
viewed on a case-by-case basis to determine their suitability by chemists
at OPP's Analytical Chemistry Laboratories.
(e) Evaluation and use of data. Data obtained from this study are
for the development of dissipation curves which can be used in the calcula-
tion of reentry intervals according to the approaches described in OPPTS
875.2900.
(f) Data report—(1) Information to be reported to the Agency.
The following information should be submitted by registrants:
(i) Name, address, telephone number of the study director and lead
chemist for the laboratory that developed the method and the laboratory
that validated the analytical methods.
(ii) Detailed stepwise description of the analytical methods developed
for each environmental matrix.
(iii) An example of sample calculations and an explanation of how
the LOQ was determined.
(iv) Precision and accuracy data, including recoveries, control charts,
and other performance data for each method,
(v) Representative chromatograms/spectra for each analyte measured
in each matrix and at all spiking levels, including method and matrix
blanks. Copies of the chromatograms/spectra are also required for the
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standards that were used to quantitate the analytes in the representative
matrix chromatograms/ spectra submitted to EPA.
(vi) Description of the supplies, materials, and instruments used for
each method (these must be commercially available in the United States).
(vii) Description of any problems encountered with each method and
any steps considered critical, i.e. steps where little variation is allowed
and where directions must be followed precisely.
(viii) The number of worker-hours required to extract, cleanup, and
analyze one set of samples.
(ix) Registrants or their representative shall keep 10 Ib, or a reason-
able amount, of each type of blank soil tested until the product has been
registered with EPA. This soil will be available to EPA on request.
(x) A statement of adherence to the FIFRA Good Laboratory Practices
Standards (GLP), which should be used to support both the ecological ef-
fects, exposure, environmental fate study data, and the validation data that
demonstrate the performance of each soil and water method. This informa-
tion should be sent to EPA/OPP Registration Division and a complete hard
copy with a computer floppy disc that can be used on a personal computer
with Word Perfect 5.1 or newer should be sent to: Environmental Protec-
tion Agency Environmental Chemistry Section Building 1105 Stennis
Space Center, Mississippi 39529-6000 ATTN: Lab Chief.
(2) Evaluation of the environmental chemistry methods sent to
EPA. (i) EPA plans to evaluate a certain number of the written soil and
water methods that are used by registrants to support appropriate ecologi-
cal effects, exposure, and environmental fate studies.
(ii) The first phase involves an evaluation of the written soil or water
method and data sent to EPA by registrants. During this phase an EPA
chemist will determine if the written method and data meet all of the re-
quirements described in this guideline. That evaluation will determine if
there are any minor or major deficiencies in the method. If there are minor
deficiencies, such as the need to substitute one item for another, the EPA
chemist will call the registrant to clarify those points. If there are major
deficiencies, such as the entire cleanup procedure being left out, the EPA
chemist will send comments to the technical reviewer in headquarters with
a recommendation that the package be returned to the registrant. If the
chemist determines that the registrant has submitted a complete method
that meets all the requirements, it may be further evaluated in an EPA
laboratory.
(iii) Priority for evaluating the methods will be determined by the
needs of the Pesticide Program and the issues associated with pesticides
undergoing registration and reregistration. The more detailed standard
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evaluation procedure (SEP) that EPA plans to use to evaluate the written
methods and the standard operating procedure (SOP) to be used in the
laboratory evaluation have been developed and are available at the ECL
at Bay St. Louis, MI. Please call 601-688-3253. The effective data for
the submission of soil and water methods, and performance data for
those methods, is 12 months after the date of this guideline. This in-
cludes soil and water methods sent to the Agency for registration and/
or reregistration.
(3) Format for reporting environmental chemistry methods. The
following format should be used in writing up the results of testing.
(i) Title/Cover Page.
(ii) Certification. (A) Certification of authenticity by the study direc-
tor (including signature, typed name, title, affiliation, telephone number,
and date, etc.)
(B) Statement of adherence to the FIFRA GLP.
(C) Statement of claims for nonconfidentiality, trade secrets, or pro-
prietary data.
(iii) Table of Contents.
(iv) Summary. Provide a brief description of analytical procedures and
instrumentation.
(v) Materials. (A) Equipment (list and describe).
(B) Reagents and standards (list and describe source and preparation,
also MSDS sheets must be available for standards).
(C) Safety and Health (describe any special precautions that need to
be taken with solvents or reagents and any procedural steps that require
special precautions to avoid safety or health hazards).
(vi) Methods (A) Principles of the analytical methods.
(B) Analytical procedures (describe in a detailed stepwise fashion).
(7) Source and characterization of control samples, e.g., soil (textural
class, pH, percent organic matter, etc.).
(2) Preparation of samples.
(3) Extraction (demonstrate efficiency in relevant soils).
(4) Fortification, if applicable (i.e. during method validation runs).
(5) Clean-up.
(6) Derivatization (if any).
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(C) Instrumentation. (7) Description, e.g., make/model, type/specifity
of detectors, columns (packing materials, size), carrier gases, etc.
(2) Operating conditions, e.g., flow rates, temperatures voltage, etc.
(3) Calibration procedures.
(D) Potential interferences—describe the effects of the following on
signal enhancement, masking or suppression of signal and their impact
on the test results:
(7) Sample matrices.
(2) Other pesticides.
(3) Solvents.
(4) Labware.
(E) Confirmatory techniques—describe confirmatory techniques, i.e.
GC/MS, LC/MS, second column, etc.
(F) Time required for analysis—give the time required to take a sam-
ple/set completely through the analytical procedure, including sample prep-
aration, extraction, cleanup, derivatization, and determination steps.
(G) Modifications or potential problems—describe any unique steps
where little variation is allowed and any potential problems and/or modi-
fications that were made to the analytical procedures.
(H) Methods of calculation—describe calculations in a step wise fash-
ion and include calibration factors, calibration curves for parent compound,
metabolites, and degradates, etc.
(I) Copies of chromatograms and/or spectra—representative sample
should be submitted for each analyte measured in each matrix at all spiking
levels, including method and matrix blanks. Copies of chromatograms and/
or spectra are also required for the standards that were used to quantitate
the analytes in the representative matrix submitted to EPA.
(J) Other—describe any and all additional information the registrant
considers appropriate and relevant to provide a complete and thorough de-
scription of the soil and water method.
(vii) Results/Discussion. Describe expected performance of method.
(A) Method validation results and test levels.
(B) Accuracy (expected mean and range of recoveries).
(C) Precision.
(D) Limit of quantitation (provide definitions).
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(E) Ruggedness testing, if performed.
(F) Discussion of selectivity and specificity of method (if applicable).
(G) Limitations.
(H) Independent laboratory validation (if available).
(viii) Conclusions. Discuss applicability of the soil and water method
for measuring specific test compounds in various matrices, ranges, ex-
pected recoveries, interferences, etc.
(ix) Tables/Figures.
(x) References.
(g) References. The following references should be consulted for ad-
ditional background material on this test guideline.
(1) Spencer, W.F. et al. Worker reentry into pesticide treated crops.
II. Procedures for the determination of pesticide residues on the soil sur-
face. Bulletin of Environmental Contamination and Toxicology 18:656-
662 (1977). This paper contains a procedure for sampling of fine, dry par-
ticulate matter from the soil surface and a procedure for extraction of pes-
ticide residues from soil.
(2) Berck, B. et al. Worker environment research: Rapid field method
for estimation of organophosphorus insecticide residues on citrus foliage
and in grove soil. Journal of Agricultural and Food Chemistry 29:209-
216 (1981). The procedure for sampling fine surface soil material in this
paper may be appropriate for damp soils as well as wet soils.
(3) Smith, C.A. and F.A. Gunther. Rapid estimation of
organophosphorus pesticide residues in citrus grove soil. Bulletin of Envi-
ronmental Contamination and Toxicology 19:571-577 (1978). This paper
reports procedures for analysis in the field of pesticide residues sorbed
to surface soil.
(4) ACS Committee on Environmental Improvement. Principles of
Environmental Analysis. Analytical Chemistry 55:2210-2216 (1983).
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