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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