United States Prevention, Pesticides EPA712-C-08-024
Environmental Protection And Toxic Substances October 2008
Agency (7101)
&EPA Fate, Transport and
Transformation Test
Guidelines
OPPTS 835.8100
Field Volatility
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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
(OPPTS), United States Environmental Protection Agency for use in the testing
of pesticides and toxic substances, and the development of test data to meet the
data requirements of the Agency under the Toxic Substances Control Act (TSCA)
(15 U.S.C. 2601), the Federal Insecticide, Fungicide and Rodenticide Act
(FIFRA) (7 U.S.C. 136, et seq.), and section 408 of the Federal Food, Drug and
Cosmetic (FFDCA) (21 U.S.C. 346a).
OPPTS developed this guideline through a process of harmonization of
the testing guidance and requirements that existed for the Office of Pollution
Prevention and Toxics (OPPT) in Title 40, Chapter I, Subchapter R of the Code
of Federal Regulations (CFR), the Office of Pesticide Programs (OPP) in
publications of the National Technical Information Service (NTIS) and in the
guidelines published by the Organization for Economic Cooperation and
Development (OECD).
For additional information about OPPTS harmonized guidelines and to
access this and other guidelines, please go to http://www.epa.gov/oppts and
select "Test Methods & Guidelines" on the left side menu.
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OPPTS 835.8100 Field volatility
(a) Scope—(1) Applicability. This guideline is intended for use in meeting testing
requirements of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) (7 U.S.C. 136, et
seq.). It describes procedures that, if followed, would result in data that would generally be of
scientific merit for the purposes described in paragraph (b) of this guideline.
(2) Background. The source materials used in developing this OPPTS test guideline are
OPP 163-3 Field volatility studies, OPP 160-4 General test standards, and OPP 160-5 Reporting and
evaluation of data (Pesticide Assessment Guidelines, Subdivision N - Chemistry: Environmental
Fate, EPA report 540/9-82-021, October 1982).
(b) Purpose. Volatilization can be a major mode for the movement of pesticides from
treated areas. The field volatility study provides realistic estimates of volatility when the pesticide is
applied as it is intended to be used. The vapors resulting from volatilization of some pesticides can
cause adverse effects to man via inhalation exposure at sites of application or biological effects in
non-target organisms at some distance from the treated site.
(c) General considerations. (1) Field volatility studies should be performed for those
pesticides that demonstrate a significant rate of volatilization from soil based on the results of the
laboratory study.
(2) Data from volatility studies are used to support the registration of end-use products
intended for terrestrial and greenhouse uses.
(3) Endangered species. Field volatility studies should not be conducted in critical habitats
or areas containing or suspected to contain endangered or threatened plants or animals which may be
threatened by the test to be conducted.
(d) Test method.—(1) Test substance, (i) The test substance should be a typical end-use
product. If the applicant's product is a manufacturing-use product which could be used to make an
end-use product, the test substance should be a product representative of major formulation category
which includes that end-use product.
(ii) If the end-use products that could be made from the manufacturing-use product belong to
two or more major formulation categories, a separate study should be performed for each such
category.
(2) Location. Field volatility studies should be conducted in areas considered representative
of major areas where the pesticide is intended to be used.
(3) Application, (i) The test substance should be applied to a site which is typical of one of
the sites to which the product would be applied.
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(ii) The test substance should be applied to soil at the rate and by the method stated in the
label directions for the pesticide.
(4) Test design. The following factors should be addressed in designing a greenhouse or
field volatility study:
(i) Properties of the pesticide such as vapor pressure and water solubility, which can
influence the trapping medium and air sampling rates.
(ii) Properties relating to the soil, such as adsorption to soil and soil texture, to avoid
untoward reduction of the rate of volatility (e.g., sandy soil is preferred).
(iii) Environmental factors, such as air temperature, humidity, and movement, to avoid
untoward dehydration or flooding of the soil, and to assure efficiency of sampling.
(5) Air sampling. Air samples should be monitored for residues at treated sites at intervals
which increase with time after pesticide application. For example, the following schedule of
sampling times might be appropriate for some situations: 0 and 12 hours, 1, 2, 4, 7, 14 and 21 days.
Sampling should be continued until the nature of the dissipation curve has been clearly established.
(6) Protocol development. Volatilization studies call for methods for the trapping,
extraction, cleanup and quantitation of pesticides in Lewis (paragraph (f)(l)). Soderquist et al
(paragraph (f)(2) in a study of pesticide photolysis in air describes procedures for measurement of
volatilization of a pesticide from soil. Cliath et al (paragraph (f)(3)) is a well-designed and well-
executed field study of volatilization with simultaneous study of other modes of dissipation of a
pesticide. Harper et al (paragraph (f)(4)) provide an example of the use of ethylene glycol vapor
traps and non-specific GLC quantitation used in this study. The influence of water in soil and thus
rainfall during the study on volatilization of a pesticide are illustrated, as are effects of wind,
turbulence and temperature. Parmele et al (paragraph (f)(5) used hexylene glycol vapor traps and
sampling periods adjusted to compensate for decrease in pesticide vapor concentration during the
study. Pesticide vapor flux from soil was calculated and related to micrometeorological
measurements.
(e) Reporting and evaluation of data. Reporting units should be in the metric system, but
the English system may be used in addition. The systems should not be mixed (e.g.,
kilograms/acre).
(1) Test method. A statement regarding the test method used, including a full description of
the experimental design and procedures.
(2) Test substance. The test substance should be identified including: (i) Chemical name
and percentage of active ingredient, molecular structure of the active ingredient, and qualitative and
quantitative description of the chemical composition, and the names and quantities of known
contaminants and impurities.
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(ii) Manufacturer and lot and sample numbers of the test substances.
(iii) Properties of the test substance, including physical state, pH, and stability.
(3) Control values. Due to the wide diversity of pesticide properties, use patterns, and
organisms likely to be exposed in the field environment, specific reporting elements for control
values (as to source, sampling regime, and total number submitted) will depend upon the complexity
and variability of the environment in which the test is to be conducted.
(4) Test equipment. A description of the test equipment used, and photographs or detailed
descriptions of nonstandard equipment.
(5) Calculation and tabular, graphic information. The principal mathematical equations
used in generating and analyzing data, as well as representative calculations using these equations.
When rates of formation and decline of parent compounds or their degradates are reported in any
test, data should be expressed as amounts, concentrations, and corresponding percentages. Rate
constants, when appropriate, should be reported in conjunction with rate data. Tabular data, as well
as graphs for decline curves and soil sorption, should be submitted.
(6) Analysis and identification of degradation products. Analysis and identification of
pesticide residues in field studies should be reported only for those degradation products that were
found to form in the laboratory studies. This position is taken because the purpose of field studies is
to derive levels of degradation products as a result of pesticide use under field conditions.
(7) Media characteristics. Characterization of soils sampled at all field use sites should be
reported, including texture (percent sand, silt, and clay), percent organic matter, moisture content,
pH, cation exchange capacity, and bulk density under field conditions. Field studies are to be
conducted in the United States.
(8) Volatility. Volatility data expressed as g/ha/day.
(9) Air concentrations. Air concentrations expressed as ug/m3 or ng/m3.
(10) Vapor pressure. Vapor pressure expressed as torr (or the equivalent expressed in other
conventional units).
(11) Meteorologic conditions. Meteorologic conditions (temperature, relative humidity,
wind velocity and direction, and cloud cover) during the time of the field study.
(f) References. The following references contain supplemental information for developing a
protocol to conduct field volatility studies:
(1) Lewis, R.G., 1976. Sampling and Analysis of Airborne Pesticides, pp. 51-94 in Air
Pollution from Pesticides and Agricultural Processes. R.E. Lee (ed.). CFC Press, Inc.,
Cleveland, Ohio.
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(2) Soderquist, C.J., D.G. Crosby, K.W. Moilanen, J.W. Seoner, and J.W. Woodrow.
1975. Occurrence of trifluralin-and its photo-products in air. J. Agr. Food Chem. 23:304-309.
(3) Cliath, M.M., W.F. Spencer, WJ. Farmer, T.D. Shoup, and R. Grover. 1980.
Volatilization of S-ethyl N, N-dipropylthiocarbamate from water and wet soil during and after
flood irrigation of an alfalfa field. J.Agr. Food Chem. 28:610-613.
(4) Harper, L.A., A.W. White, Jr., R.R. Bruce, A.W. Thomas, and R.A. Leonard. 1976.
Soil and microclimate effects on trifluralin volatilization. J. Environ. Qual. 5:236-242.
(5) Parmele, L.H., E.R. Lemon, and A.W. Taylor. 1972. Micrometeorological
measurement of pesticide vapor flux from bare soil and corn under field conditions. Water, Air,
and Soil Pollut. 1:433-451.
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