United States
Protection
Office of Pesticide Programs
Washington, DC 20460
EPA 540/9-36-'31
June 19S6
Agenev
Hazard Evaluation Division
Standard Evaluation Procedure
Pesticide Spray Drift Evaluation:
Droplet Size Spectrum
Test and Drift Field Evaluation Test
Support Document 59
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EPA 540/9-86-131
June 1986
HAZARD EVAL-UATION DIVISION
STANDARD EVALUATION PROCEDURE
PESTICIDE SPRAY DRIFT EVALUATION-:
DROPLET SIZE SPECTRUM TEST AND DRIFT FIELD EVALUATION'TEST
Prepared by
Robert W. Hoist, Ph.D.
Standard Evaluation Procedures Project Manager
Stephen L. Johnson
Hazard Evaluation Division
Office of Pesticide Programs
United States Environmental Protection Agency
Office of Pesticide Programs
Washington, D. C . 20460
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TABLE OF CONTENTS
Page
I. INTRODUCTION '
A. Purpose of the Standard Evaluation
Procedure 1
B. Background Information 1
1. Droplet Size Spectrum Test 1
2. Drift Field Evaluation Test 1
C. Objective of the Pesticide Spray Drift
Evaluations ,. . . . 2
1. Droplet Size Spectrum Test 2
2. -Drift Field Evaluation Test 2
II. INFORMATION TO BE SUPPLIED 2
III. DATA INTERPRETATION . 3
iv. 'THE DATA EVALUATION PROCESS
A. Identify Data Gaps 3
B. Assess the Appropriateness and Adequacy
of the Data 4
C. Report Preparation 4
D. Conclude if the Requested Action is
Supportable 4
V. APPENDICES
Appendix 1: Information Requested of the
Registrant 5
Appendix 2: Specific Questions for the
Revi ewe r 9
Appendix 3: Sample Standard Format for
Preparation of Scientific
Reviews 13
REFERE NCES 14
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PESTICIDE SPRAY DRIFT EVALUATION;
DROPLET SIZE TEST SPECTRUM AND DRIFT FIELD EVALUATION. TEST
I. INTRODUCTION
A< Purpose of the Standard Evaluation Procedure
This Standard Evaluation Procedure is designed to aid Exposure
Assessment Branch (EAB) data reviewers in their evaluations of drop-
* let size spectrum and pesticide drift field evaluation studies sub-
mitted by registrants in the assessment of pesticide exposure.
B • Background Information
Droplet size spectrum studies and drift field evaluation stu-
dies are designed to provide off-site transport data on a pesticide.
These -off-site transport data are needed to. evaluate the effect of
pesticide exposure to .humans, plants, fish and wildlife by products
?n?fn£?d t? ^ applied by ^rial, air carrier, mist blower, overhead
sprinkler irrigation and other outdoor application equipment. These
studies are_ required by 40 CFR § 158.142 to support the registration
of any pesticide intended for outdoor use under the Federal Insecti-
cide, Fungicide and Rodent icide Act (FIFRA), as amended.
Pesticides with outdoor use patterns where aerial transport of
the pesticide to off-site locations is not likely to occur d™ not have
caMon Tf ^H- ^ USS Patterns include ground-hydraulic appli*
cations. If this or other use patterns do readily expose non-taraet
ofTnnr^0^1^1"9 hUmnS t0' the Pesticide through aerial transit
of droplets, the- pesticide drift potential may need to be evaluated.
!• Droplet Size Spectrum Test
the in$?,,*™le* 'SiZS spectrum studies are performed to determine
an! ini^Ti a nUmber, °f equipment and formulation parameters
and initial environmental factors on the formation of the droplets
™t™^r*-i^eHPeSticide diSPersal equipment. The major para-
meters that will be tested are type of nozzle, orientation to the
wind shear- and formulations. By studying this part of the applic
have" ?o°hTS ^ ^t' the m°re ^pensive field evaluations^! 1
have to be performed less frequently.
2- Drift Field Evaluation Test
t-ho - evaluation studies are performed to determine
the influence of a number of equipment and formulation parameters
e0
ciderom^ aaC.°rS °n the disPersal °f the formulatepest i -
cide from the application equipment to the intended surface(s). The
tnwnd h s) of nozzl orienta-
rative favors ' forTOulations' cross-wind velocity . and evapo-
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C. Objective of the Pesticide Spray Drift Evaluations
The objective of the pesticide spray drift evaluat-ions is' to
determine if a pesticide formulation applied as directed has the
potential to be transported to off-site, non-target areas and thereby
cause -'detrimental effects on non-target plants, animals and humans.
The extent of possible detrimental effects on plants, animals and
humans will be determined by various scientists evaluating phytotox-
icity, fish, wildlife and insect toxicity, and human and domestic
animal toxicity. These tests are required by 40 CFR § 158 and the
Pesticide Assessment Guidelines, Subdivisions E, F, J and L: Hazard
Evaluation.:'"~~
1. Droplet Size Spectrum Test
The droplet size spectrum test provides information on the
effects of pesticide application equipment and formulations on drop-
let sizes which in turn influence the extent of pesticide droplets
being carried by air currents to non-target areas. Quantification
of the pesticide movement by air currents is evaluated in the suc-
ceeding study' on pesticide drift field evaluation.
2. Drift Field Evaluation Test
The drift field evaluation test provides information on the
effects of the environment and application equipment on the extent.
of off-site, off-target transport of pesticides by air currents
immediately following release from application equipment. The ex-
tent and quantity of drift will be determined in order that it can
be compared to toxicological study information for possible effects
on non-target plants, wildlife and humans. It is important to note
that it is not the purpose of the drift field evaluation study to
evaluate the extent of aerial movement of a pesticide as a result
of evaporation of the material from plant, soil or other substrate
surfaces after deposition.
II. INFORMATION TO BE SUPPLIED
The registrant's reports on droplet size spectrum and drift
field evaluation studies should include all information necessary
to provide: 1) a complete and accurate description of the treat-
ments and-procedures, 2) sampling'data, 3) data on storage of the
samples until analysis, if so performed, 4) any chemical analysis
of the collection surfaces as to chemical content, if so performed,
5) recovery efficiency, 6) reporting of the data, rating system and
statistical analysis, and 7) quality control measures/precautions
taken to ensure the fidelity of the operations.
A guideline of specific information that should be included" in
the registrant's report on droplet size spectrum and drift field
evaluation studies is provided in Appendix 1 of this document.'
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This list of requested information and reviewer aids is derived from
the Pesticide Assessment Guidelines, Subdivision R; Pesticide Spray
Drift Evaluation, which is complemented by this Standard Evaluation
Procedure.
III. DATA INTERPRETATION
The acceptability of the study results will depend upon whether
the test requirements/standards are followed. If a deviation is
made, a determination must be made as to whether the deviation has
changed the quality of th_e_results in such a manner that the results
cannot be extrapolated to the natural environment. There should be
little or no deviation from the liberalized standards prescribed
in this study. - - • •
The results of the droplet spectrum study for the chemical
formulation with respect to the quantity of pesticide applied and
nozzles used are important. The concentration of the chemical in
the carrier is important in that varying concentrations can lead to
large variations in droplet size spectrums. The results of the
drift field evaluation study for the chemical formulation with
respect to the quantity of pesticide applied and nozzles used are
also important. This will help quantify the pesticide off-target
movement due to equipment and environmental conditions and enable
the Agency to prepare exposure assessments for the chemcial and that
use pattern.
There is no decision point for the droplet size spectrum with
respect to performing the drift field evaluation study. There is
also no decision point for the drift field evaluation study with
respect to performing additional studies.
IV. THE DATA EVALUATION PROCESS
Upon careful examination of the information/data supplied by
the registrant in his submission to the Agency, the reviewer shall
evaluate the data as follows.
A. 'Identify Data Gaps
Using Appendix 1 of this document as a guide, the reviewer
should look for data gaps - omissions in the information supplied
by the registrant in his report. These should be duly noted in the
reviewer's report and a judgment made as to which are considered
significant enough to adversely affect the review process. Those
so identified should be communicated back to the registrant by the
Product Manager for corrective action.
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B> Assess the Appropriateness and Adequacy of the Data
The data reviewer then considers the appropriateness, i.e.,
the intended use pattern, and adequacy of the data/information that
has- been supplied. Appendix 1 of this document is a useful guide
to the various parameters that need to be considered. Appendix 2
provides specific questions that should be answered by'the 'reviewer'
during the study evaluation process. Statistical treatments of the
data should be independently verified and the quality control ore-
cautions noted. • ,
As an adjunct to these, the reviewer should-draw upon the tech-
nical guidance in the reviewer aids materials that are available.
(See also the recommmended references in Subdivision R - Pesticide
Spray Drift Evaluation.) A listing of additional source materials
is located in the References section of this document.
In addition to the data gaps noted above, any perceived defici-
encies in the data/information supplied should also be identified
A statement as to these deficiencies should be made in the reviewer's
report and corrective action to resolve them should be provided
This information can be relayed to the registrant by the Product
Manager for appropriate action. •
C. Report Preparation
The Agency reviewer prepares a standard review report followino
the standard format for preparation of scientific reviews as provided
in Appendix 3 of this document. All important information provided
by the registrant including the methodology and results is to be
summarized in order that future evaluations can be made. The results
may be expressed in the form of tables where specific values are
rela.ted. t igures (graphs) may be provided but are not to be the sole
source of the values needed for future evaluations.
D' Conclude if the Requested Action is Supportable
Lastly, the reviewer considers the results of the droplet size
whhrUm^hr Sld evaluation studies and makes a judgment as to
whether they support the requested registration action of the data
^ Kata arS ^ s^P°rtive, possible alternativf '
maY 6/^en. ^ the registrant, such as label modifi-
tte d ^9gested- If Deficiencies /omissions exist in the sub-
mitted data, the reviewer may have to defer judgment until such time
as appropriate corrective action has been rendered by the registrant
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APPENDIX 1
INFORMATION REQUESTED OF THE REGISTRANT
The registrant's report on droplet size spectrum and drift
field evaluation studies should include all information necessary
to provide: 1) a complete and accurate description of the treat-
ments and procedures, 2) sampling data, 3) data on storage of the
samples until analysis, if so performed, 4) any chemical analysis
of the collection surfaces as to chemical content, if so, performed ,
5) recovery efficiency, 6) reporting of the data, rating system and
statistical, analysis, and 7) quality control measures/precautions
taken to ensure the fidelity of the operations.
Specifically, each report should include the following informa
1 1 o n • "-
I. General
° Cooperator or researcher (name and address), test location
(county and state; country, if outside of the U.S.A.), and date of
s t UQ y j
' title, organization, address and
) ***V°™^* «« Panning/super-
0 Trial identification number;
assurance indicating: control measures/precautions
Mdd re ^ fidelifcy of the droplet size and/or drift
innhonv! ^^ ?nS: reC°rd-keeping Procedures and availability of
logbooks; skill of the laboratory personnel; equipment status of
°rator of adherence to good laboratory practices;
^ fl°°d ^'^tu.al practices for applica-
° Other information the registrant considers appropriate and
° S« t'lf.*
Test Substance (Pesticide)
» ' Identification of the test pesticide active ingredient (ai)
including chemical name, common name (ANSI, BSI, ISO, WS!A" and
Company developmental/experimental name; ****)-, and
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ctivVngrdient percentage by weight in the formulated
°r Subst^uted (with, reasons for substitution
able powdr l^uSi^e?"?? (e*g" «BUl8i.fl«"e concentrate, flow-
land or fnSe,iriate(S) ln termS °f acti.ve ingredient per unit area of
, land or in gal Ions -per -minute (gpm) (liters-per-minut e [1pm]); and
.-A. Droplet Size Spectrum Tests
hlnwJi Method of droplet testing (wind tunnel, aircraft, mist
UJ. Omr L ) •
B- Drift Field Evaluation Tests
Identification of the use of dyes or other indicators; -an d
cides.° Identification of adjuvants used, and other tank mixed pesti-
IIZ- Collection Surfaces
A- Droplet Size Spectrum Tests
0 Identification of the collection surfaces. The collect ion
Identification of the number of replicates; and
device. °iStanCe between nozzles and collection surface/detection
B* Drift Field Evaluation Tests
Identification of the number of replicates; and
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IV. Site of the Test
A. Droplet 'Size Spectrum Tests
^ ! ^TYPe °f SitS °f the dr°Plet size spectrum study as to whether
durin^T^/?^ *" ^ '°Ut °f * "^
during the drift field evaluation study; and
Climatological data (records of applicable conditions for the
^ flow or velocity- wind d
B. Drift Field Evaluation Tests
0 Location of the test site;
of fo..ed 6 ™™ ^ « type
tvoe of data (records of applicable conditions for the
type of site, i.e., temperature, thermoperiod, rainfall or' water! nn
reP 0t°Peri0d' alr V6lOCit a "
V6lOCity and Wnd Direction retve
°- Field lay-out (graphic display is encouraged).
V. Application Equipment
Nozzle type, orifice size, and core identification;
and ° N°22le Pressure' flow «te' and orientation to the airstream;
° For drift field evaluation tests, identification of i-h^
VI. Results
A* - P^oplet Size Spectrum Tests
B- Drift Field Evaluation Tests
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VI I. Evaluation
A. Droplet Size Spectrum Tests
0 The 10th, 50th and 90th percentile of the size distributions
with respect to droplet volume and number and standard deviations,
where possible.
B. Drift Field Evaluation Tests
0 .The overall movement of the pesticide formulation as a result
of aerial transport.
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APPENDIX 2
SPECIFIC QUESTIONS FOR THE REVIEWER
The following questions are provided to aid the reviewer in
performing the standard evaluation procedure in a scientific manner
and to complete a scientific review.
I. General •
-..- — o were the name of the cooperator or researcher (name and
address)/ test location (county and state; country, if outside of
the U.S.A.),.and date of study provided?
0 Were the name (and s ignature ), title, organization, address,
and telephone number of the person(s) responsible for planning/super-
vising/monitoring and, for small field plot studies, applying the
pesticide provided?
0 Was the trial identification number provided?
0 Were quality assurance control measures/precautions indicated?
II. . Test-Chemical
0 Was the test.chemical being used the proposed formulated
end-use product or of the same formulation category as the end-use
product to be registered?
0 Was the active ingredient percentage or degree of purity of
the chemical given?
0 Was the application rate given in quantity per unit area (of
plant or land surface) or in quantity per minute (galIons-per-minute
or li ters-per-minute) ?
0 Was the application rate the maximum label-recommended rate?
0 Were the physical properties of the total formulation given
including surface tension, viscosity, density and vapor pressure?
A. Droplet Size Spectrum Tests
0 Were diluents and extent of dilution identified along with
possible adjuvants, tank mixtures with other pesticides?
.B. Drift Field Evaluation Tests
0 Were diluents or carriers, and the extent of dilution identi-
fied along with possible adjuvants, tank mixtures with other pesti-
cides, and tota.l spray volume?
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Were tank mixes evaluated, i.f so specified, for the intended
use pattern that was being evaluated?
0 Were controls used to note any possible decay or other loss
of pesticide during the collection, transport, storage ajid analysis?
III. Collection Surfaces
A. Droplet Size Spectrum Tests
0 Were tne collection surfaces or devices identified along
with the equipment limitations? Equipment "limitations include the
resolution of tne microscopes, particle measuring systems, or air
samplers, and the spread factor of the droplets on the various
collection surfaces (cards).,
0 Were at least three replicates, of each test produced or
were multiple samples taken from only one replicate, i.e., were
several different sets of nozzles of the same type tested?
B. Drift Field Evaluation Tests
Were at least two replicates of each sample position produced
or were multiple samples taken from only one replicate?
Were the distribution of the collection surfaces of suffi-
cient number to establish a definitive uninterrupted picture of
deposits across the treated swath as well as outside the target
area?
Did the collection pattern extend 1000 feet downwind for
aerial and air carrier applications and 500 feet for other ground
applications?
0 Were the collection surfaces placed at the soil surface or
at the height of the surrounding canopy?
Were air samplers employed, and if so, were they at least
three downwind locations (one preferrably at the farthest downwind
site)?
IV. Test Procedures
A. Droplet Size Spectrum Tests
Was the test site specified-, i.e., wind tunnel, or field
evaluation?
Were the environmental conditions that prevailed during the
test (temperature, relative humidity, air velocity) .provided?
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0 Were the environmental conditions/ especially wind velocity,
steady throughout the evaluation?
B. Drift Field Evaluation Tests
0 Was the test site specif ied,- i .e. , open field, cropped field,
forest, grove,.etc.? .
0 Were the environmental conditions that prevailed during the
test' (temperature at two levels, relative humidity, air velocity
and direction, rainfall or .watering regime [overhead irrigation
systems]) provided?' '
. ° Were the environmental condi-tions that prevailed during at
least one field test those conducive to the extensive drift of the
pesticides? .
0 Were the environmental conditions, especially wind velocity,
steady throughout the evaluation?
V. Application Equipment
0 Were the nozzles those most likely to be used for the appli-
cation of that pesticide or the intended use pattern?
0 Were the nozzle pressure, flow rate and orientation to the
airstream given?
A. Droplet Size Spectrum Tests
0 Were the nozzles tested the same as those most likely to be
used in the application of that pesticide?
B. Drift Field Evaluation Tests
0 Was at least one test run performed with nozzles and other
equipment configurations that would result in conditionk conducive
to the extensive drift of the pesticides?
•°" Was the speed of the equipment over the ground given?
0 Was the estimated minimum and maximum nozzle-to^target
height provided? i
VI. Reporting
A. Droplet Size Spectrum Tests
Were the particle size distribution versus cumulative percent
volume and versus droplet number (frequency) given?
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B. Drift Field Evaluation Tests
0 Were the particle size distribution versus cumulative percent
volume given and versus droplet number (frequency) given if the drop-
let size spectrum study was performed.as part of the field evaluation?
0 Was a diagram of the plot or area provided indicating north,
swath width, and orientation, prevailing wind direction, and location
of the collection stations?
0 Was the Barad stability ratio calculated?
0 Were the quantities of pesticide at each collection station1
and quantity of pesticide per area (g/ha) given?
VII. Evaluation
A. Droplet Size Spectrum Tests ' -
0 Were the results tabulated to indicate a luth, 5Uth and 90th
percentile of particle size distribution with respect to droplet
volume and number? s
B. Drift Field Evaluation Tests
0 Was the extent of downwind spray drift evaluated with respect
to possible exposure to the non-target organism(s) that may be
detrimentally affected?
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APPENDIX 3
SAMPLE STANDARD FORMAT FOR PREPARATION OF SCIENTIFIC • REVIEWS
The following format shall be used in documenting the review
of the Subdivision R: Pesticide Spray Drift Evaluation - Droplet
Size Spectrum and Drift Field Evaluation Studies.
Chemical: (Common Name)
Formulation: (Percent Active Ingredient and Formulation Type)
. Study/Action: -(Purpose of the Submission)
Study Identification:
(Subdivision R Test Title)
(Reference or Registrant Data Information with
Study Number)
(EPA Accession Number)
Reviewer: (Name and Address of Reviewer; Date of Review)
Approval: (Quality Control Reviewer)
Conclusions: (Summary and Conclusion of Tests)
Acceptability and Recommendations:
(Decide as to (1) the scientific validity of the
study, (2) compliance to the Subdivision R - Droplet
Size Spectrum Test or Drift Field Evaluation Test
guideline, (3) data gaps, and (4) additional infor-
mation required by Agency.)
Background: (Introductory Information and Directions for Use)
Discussion: 1. Study Identification
2. Materials and Metho'ds
3. Reported Results
4. Reported Conclusions
5. Reviewer's Interpretation of Results and Conclusion
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REFERENCES
Akesson, N. B., W. E. Yates. 1984. "Predicting and controlling
flagged and extended aircraft swaths." Ame r. Soc. Agric. Engin.
Paper No. ASAE-AA-84-003
Amberg, A. A., B. J. Butler. 1970.. "High-speed photography as
a tool for spray-droplet analysis." Trans. ASAE 13:541-546
Bache, D. H. 1975. "Transport of Aerial Spray III. Influence of
microclimate on crop spraying." Agric. Meteor. 15:379-383.
Bode, L. E., B. J. Butler. 1981. "The three D's of droplet
size: diameter, drift, and deposit." Aner. Soc. Agric. Engin.
Paper No. AA-81-004
Draper, W. M., R. D. Gibson, J. C. Street. 1981. "Drift from and
transport subsequent to a commercial, aerial application of
carbofuran: An estimation of potential human exposure." Bull.
Environ. Contam. Toxicol. 26:537-543.
Goering, C. E., D. B. Smith. 1978. "Equation for droplet size
distributions in sprays." Trans. ASAE 21:209-216.
Haq, K., N. B. Akesson, W. E. Yates. 1983. "Analysis of droplet
spectra and spray recovery as a function of atomizer type and
fluid physical properties." pp. 67-82 i_n T. M. Kaneko and
N. B. Akesson (eds.) Pesticide Formulations and Application
Systems: Third Symposium. ASTM STP 828. Philadelphia, PA.
Himel, C. M. , .S. Uk. 1975. "The biological optimum spray droplet
size." Proc. 5th Internat. Agric. Aviation Conf.
Hoist, R. W. 1983. "Spray drift exposure assessment." pp. 83-91
in T'. M. Kaneko and N. B. Akesson (eds. ) Pesticide Formulations
and Application Systems; Third Symposium. ASTM STP 828.
Philadelphia, PA.
Kautz, J., R. B. Ekbald. 1984. Analysis of Spray Deposit Cards
Sensitive to Non-Dyed Mixes. Missoula, MT: U.S. Forest
Service, Equipment Development Center.
Matthews, G. A. 1979. Pesticide Application Methods. London:
Longman Publ.
Miller, C. 0. 1980. "A mathematical model of aerial deposition of •
pesticides from aircraft." Environ. Sci. & Technol. 14:824-831.
Reichard, D. L. , H.. J. Retzer, L. A. Liljedahl, F. R. Hall. 1977.
"Spray droplet size distributions delivered by air blast orchard
sprayers." Trans. ASAE 20:232-242.
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REFERENCES (Cont i nue d)
Yates, W. E., N. B. Akesson, D. Bayer. 1976. "Effects of spray ad-
juvants on drift hazards." Trans. ASAE 19:41-46.
Yates, W. E., R. E. Cowden, and N. B, Akesson. 1981. "Effect of
nozzle design on uniformity of droplet size from agricultural
' aircraft." Amer, Soc. Agric. Engin. Paper No. AA-81-002.
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