United States Prevention, Pesticides EPA 712-C-98-319
Environmental Protection and Toxic Substances March 1998
Agency (7101)
&EPA Spray Drift Test
Guidelines
OPPTS 840.1000
Background for
Pesticide Aerial Drift
Evaluation
-------
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 submittedby 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), 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's World Wide Web
site (http://www.epa.gov/epahome/research.htm) under the heading "Re-
searchers and Scientists/Test Methods and Guidelines/OPPTS Harmonized
Test Guidelines."
-------
OPPTS 840.1000 Background for pesticide aerial drift evaluation.
(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 Toxic Substances
Control Act (15 U.S.C. 2601).
(2) Background. The source materials used in developing this har-
monized OPPTS guideline are OPP test guidelines Series 200-1 through
200-4—General (Pesticide Assessment Guidelines, Subdivision R: Pes-
ticide Spray Drift Evaluation, EPA report 540/9-84-002, April 1984). This
guideline provides an overview for spray drift evaluation and describes
in general terms the Spray Drift Data Base currently under development
and its potential uses.
(b) General—(1) Purpose. The guidelines in this series deal with
data submittal to support the registration of all outdoor use pesticides that
are to be applied by aerial application methods (fixed- or rotary-wing),
air carrier (mist blowers), overhead sprinkler irrigation devices, or other
ground application equipment. Data required to evaluate pesticide spray
drift may be derived from studies of droplet size spectrum and spray drift
field evaluations. These data can contribute to development of the overall
exposure estimate for use in assessing the potential hazard of pesticides
to humans, fish and wildlife, or plants.
(2) Definitions. Terms used in this guideline shall have the meanings
set forth in FIFRA 136, section 2 and OPPTS 830.1000. In addition, for
the purposes of this guideline:
Nontarget organism means any plant, animal, or human species not
considered to be pests. These species are not intended to be controlled,
injured, killed, or detrimentally affected in any way by a pesticide.
Primary drift refers to the physical process of movement of pesticide
particles or droplets through air at or near the time of initial deposition
on the target away from the site of application.
Target area means the area intentionally treated with a pesticide when
label use directions are followed.
(c) Data requirements. The drift potential of a pesticide applied ei-
ther by aircraft or ground equipment may be determined in two stages.
The initial stage involves the determination of possible detrimental effects
to nontarget organisms that may be produced through dermal (or foliar)
exposure to the pesticide. The second stage involves studies to determine
droplet size spectra and drift characterizations of pesticide product based
on proposed use limitations. The droplet size spectrum study would dem-
onstrate typical droplet size distribution. Determination of the spray droplet
size spectrum may be performed using wind tunnels or during the field
study evaluation using commercial equipment. The field studies involve
-------
commercial equipment to determine the extent of spray drift (droplet depo-
sition vs. distance) from application using typical equipment and environ-
mental conditions.
(d) Spray drift studies. Droplet size spectrum studies (see OPPTS
840.1100) and drift field evaluation studies (see OPPTS 840.1200) are de-
signed to provide an estimate of droplet deposition away from the target
site at or near the time of initial deposition. These off-site transport data
are needed to evaluate the potential risk from pesticide exposure to hu-
mans, plants, fish and wildlife by products expected to be applied by aer-
ial, air carrier, mist blower, overhead sprinkler irrigation and other similar
outdoor application equipment. These studies are required by 40 CFR
158.440 to support the registration of any pesticide intended for outdoor
use under the FIFRA, as amended. Studies are required on:
(1) Droplet size spectrum to aid in the determination of potential drift
from the proposed application methods.
(2) Field drift evaluation which determines the movement and deposi-
tion of droplets as a function of distance away from target site for the
proposed application methods under a reasonable "worse case" scenario.
Test data ordinarily are required to support the registration of each end-
use product that meets the criteria and each manufacturing-use product
used to make such an end-product.
(e) Test substance. The test substance is a typical spray mixture
using a formulated product. Generally, the test substance is prepared by
the basic manufacturer of a pesticide. The composition of the test sub-
stance shall be reported, including the name and quantity of adjuvants and
surfactants, in order to account for 100 percent of the test sample in ac-
cordance with OPPTS 830.1550.
(f) Spray drift data base. (1) An industry consortium has developed
a spray drift data base. The premise used in developing the data base was
that the physical properties of the spray and the mechanics of application
(i.e., equipment and meteorology) are the primary determinants of drift
rather than the chemical property of the pure active ingredient (except as
manifested through effects on physical properties. In developing the data
base, the consortium considered spray drift data already available from
submissions to EPA, published research, and other sources within industry,
government, and academia. Review of the data base and any corresponding
models by Agency and outside experts is underway. The data base and
the scope of its applicability to satisfy spray drift data requirements for
pesticide product registrations is being peer reviewed by the Scientific Ad-
visory Panel (SAP). Spray Drift Task Force (SDTF) and Agency scientists
are using the data to develop a series of methods to estimate spray drift
potential. The goals of this effort are to produce models for drift potential
from aerial application and other methods for the calculation of exposure
-------
to drift from airblast, ground hydraulic application and chemigation. The
Office of Pesticide Programs plans to use these methods for risk assess-
ment and risk management decision-making. Ultimately, these methods or
modifications of them may be available to applicators in the field to facili-
tate on-the-spot drift management decisions prior to applications.
(2) It is possible that some use patterns and uncommon formulations
for which the Agency might require separate spray drift studies would
not be included in the data base. For these use patterns, specific testing
would be required using OPPTS 840.1100 and 840.1200.
(g) Data reporting. See OPPTS 840.1100 for data reporting guidance
on spray droplet size spectrum and OPPTS 840.1200 for spray drift field
deposition.
(h) References. The following references may be consulted for addi-
tional background information.
(1) Environmental Protection Agency, Standard Evaluation Proce-
dure—Pesticide Spray Drift Evaluation: Droplet Size Spectrum Test and
Drift Field Evaluation Test, EPA report number 540/9-86-131, June 1986.
(2) Environmental Protection Agency, Pesticide Regulation Notice PR
90-3, Announcing the Formation of an Industry-Wide Spray Drift Task
Force, April 6, 1990.
------- |