Federal Register / Vol. 79, No. 19 / Wednesday, January 29, 2014 / Notices 4691 

ENVIRONMENTAL PROTECTION 

AGENCY 

[EPA–HQ–OPP–2013–0676; FRL–9903–12] 

Pesticides; Consideration of Spray 

Drift in Pesticide Risk Assessment: 

Notice of Availability and Request for 

Comment 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Notice. 

SUMMARY: EPA is announcing the 

availability of two draft guidance 

documents for public comment. These 

documents describe how off-site spray 

drift will be evaluated for ecological and 

human health risk assessments for 

pesticides. Once final, these guidance 

documents will be posted on EPA’s Web 

site, to ensure consistent risk 

assessment practices and provide 

transparency for pesticide registrants 

and other interested stakeholders. 

DATES: Comments must be received on 

or before March 31, 2014. 

ADDRESSES: Submit your comments, 

identified by docket identification (ID) 

number EPA–HQ–OPP–2013–0676, by 

one of the following methods: 

• Federal eRulemaking Portal: http:// 

www.regulations.gov. Follow the online 

instructions for submitting comments. 

Do not submit electronically any 

information you consider to be 

Confidential Business Information (CBI) 

or other information whose disclosure is 

restricted by statute. 

• Mail: OPP Docket, Environmental 

Protection Agency Docket Center (EPA/ 

DC), (28221T), 1200 Pennsylvania Ave. 

NW., Washington, DC 20460–0001. 

• Hand Delivery: To make special 

arrangements for hand delivery or 

delivery of boxed information, please 

follow the instructions at http://

www.epa.gov/dockets/contacts.htm. 

Additional instructions on 

commenting or visiting the docket, 

along with more information about 

dockets generally, is available at 

http://www.epa.gov/dockets. 

FOR FURTHER INFORMATION CONTACT: For 

the ecological risk assessment guidance 

document, Faruque Khan, 

Environmental Fate and Effects 

Division, (7507P), Office of Pesticide 

Programs, Environmental Protection 

Agency, 1200 Pennsylvania Ave. NW., 

Washington, DC 20460–0001; telephone 

number: (703) 305–6127; email address: 

khan.faruque@epa.gov. 

For the human health risk assessment 

guidance document, Jeff Dawson, Health 

Effects Division, (7509P), same address; 

telephone number: (703) 305–7329; 

email address: dawson.jeff.@epa.gov. 

SUPPLEMENTARY INFORMATION: 

I. General Information 

A. What is the Agency’s authority for 

taking this action? 

Pesticides are regulated under both 

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 Act (FFDCA) 

21 U.S.C. 346a. 

B. Does this action apply to me? 

you may be potentially affected by 

this action if you are a producer of 

pesticide products (NAICS 32532), 

importers of such products, or any 

person or company who seeks to obtain 

a tolerance for such a pesticide. The 

North American Industrial 

Classification System (NAICS) code is 

not intended to be exhaustive, but rather 

provides a guide to help readers 

determine whether this document 

applies to them. Other types of entities 

not listed could also be affected. 

C. What should I consider as I prepare 

my comments for EPA? 

1. Submitting CBI. Do not submit this 

information to EPA through 

regulations.gov or email. Clearly mark 

the part or all of the information that 

you claim to be CBI. For CBI 

information in a disk or CD–ROM that 

you mail to EPA, mark the outside of the 

disk or CD–ROM as CBI and then 

identify electronically within the disk or 

CD–ROM the specific information that 

is claimed as CBI. In addition to one 

complete version of the comment that 

includes information claimed as CBI, a 

copy of the comment that does not 

contain the information claimed as CBI 

must be submitted for inclusion in the 

public docket. Information so marked 

will not be disclosed except in 

accordance with procedures set forth in 

40 CFR part 2. 

2. Tips for preparing your comments. 

When submitting comments, remember 

to: 

i. Identify the document by docket ID 

number and other identifying 

information (subject heading, Federal 

Register date and page number). 

ii. Follow directions. The Agency may 

ask you to respond to specific questions 

or organize comments by referencing a 

Code of Federal Regulations (CFR) part 

or section number. 

iii. Explain why you agree or disagree; 

suggest alternatives and substitute 

language for your requested changes. 

iv. Describe any assumptions and 

provide any technical information and/ 

or data that you used. 

v. If you estimate potential costs or 

burdens, explain how you arrived at 

your estimate in sufficient detail to 

allow for it to be reproduced. 

vi. Provide specific examples to 

illustrate your concerns and suggest 

alternatives. 

vii. Explain your views as clearly as 

possible, avoiding the use of profanity 

or personal threats. 

viii. Make sure to submit your 

comments by the comment period 

deadline identified. 

D. What action is the Agency taking? 

Pesticide drift can be characterized as 

the physical movement of a pesticide 

through the air at the time of application 

or soon thereafter from the target site to 

any non- or off-target site. This does not 

include pesticide movements by 

erosion, migration, volatility, or 

windblown soil particles after 

application. Drift is dependent on the 

design of application equipment, size of 

spray droplets or dry particles, weather 

conditions, and other factors. 

Once off-target, pesticide drift can 

potentially deposit in unintended areas 

or directly onto people or nontarget 

species. To provide guidance to EPA 

staff and stakeholders, EPA has 

developed two documents describing 

EPA’s approach to assessing pesticide 

drift in human health and ecological 

risk assessments. Both documents are 

available in the docket for this action 

using the docket identifier EPA–HQ– 

OPP–2013–0676. 

• Guidance on Modeling Offsite 

Deposition of Pesticides via Spray Drift 

for Ecological and Drinking Water 

Assessments for the Environmental Fate 

and Effects Division (Draft dated 11/1/ 

2013) (Ref. 1), and 

• Residential Exposure Assessment 

Standard Operating Procedures (SOPs), 

Addenda 1: Consideration of Spray Drift 

(Draft dated 11/1/2013) (Ref. 2). 

The draft Ecological and Drinking 

Water Assessment Guidance provides 

information on estimating spray drift 

fractions of liquid sprays for modeling 

offsite deposition of a pesticide for 

ecological and drinking water 

assessment and on estimating distances 

from the treated field where adverse 

effects may be observed due to exposure 

to spray drift. The draft guidance also 

provides default assumptions for 

modeling inputs to use when estimating 

spray drift in terrestrial and aquatic 

assessments. 

The Residential Exposure Addenda 

describes a screening approach for 

defining when assessments are needed 

and the methodology for estimating 

risks for indirect exposures to pesticide 

drift, such as children playing on a lawn 

that has pesticide residues that drifted 

from a nearby treated field. The draft 


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4692 Federal Register / Vol. 79, No. 19 / Wednesday, January 29, 2014 / Notices 

guidance describes when quantitative 

risk assessments for spray drift are 

generally needed, and also provides the 

modeling inputs needed to complete the 

exposure and risk assessments. 

EPA expects the model-generated 

values for spray drift fractions to 

provide realistic exposure and risk 

estimates for both ecological and human 

health assessments. These policies will 

promote consistency within EPA, as 

well as with other federal agencies and 

international regulatory partners that 

rely on predicted spray drift values. 

II. Spray Drift Estimates Used for Risk 

Assessment 

EPA uses two peer-reviewed spray 

drift models (AgDRIFT and AGDISP) to 

estimate the contribution of spray drift 

to ecological and human health risk 

assessments. Both models estimate drift 

fractions, as applicable to spray of 

liquid materials. In general, OPP uses 

the AgDRIFT model to assess spray drift 

from agricultural applications, whereas 

AGDISP is used for other types of 

pesticide applications, such as aerial 

application of mosquito adulticides. It is 

noted that AGDISP has limited 

capability to estimate drift fractions 

from dry materials application. 

EPA has prepared a support 

document (Ref. 3), which is available in 

the docket for this action, explaining the 

scientific basis for AgDRIFT and 

AGDISP, and providing information on 

this harmonized approach for estimating 

spray drift fractions. 

III. Consideration of Spray Drift in 

Ecological Risk Assessment 

To enhance consistency and provide 

more realistic risk estimates, the Agency 

has developed the draft ecological 

guidance (Ref. 1) to apply a uniform 

approach for estimating drift fractions 

for all tiers of ecological risk 

assessments. Unit III. provides historical 

information on OPP’s approach for 

estimation of spray drift. 

Prior to the adoption of AgDRIFT and 

AGDISP, for aquatic exposure 

assessment purposes, default values of 

5% were recommended to OPP for use 

as estimates for the spray drift loading 

from aerial and air-blast applications to 

a pond (Ref. 4). However, beginning in 

the 1990s, OPP’s practice was to use 

default drift values—developed using 

best professional judgement—of 5% 

(aerial application), 3% (airblast 

application), and 1% (ground 

application) in terrestrial and aquatic 

assessments. Then, to make more 

realistic calculations of exposure from 

spray drift deposition, EPA 

implemented the use of AgDRIFT 

model-generated values for spray drift 

fractions for: 

• Screening-level (Tier I) aquatic 

exposure model GENEEC (GENeric 

Estimated Exposure Concentration) for 

ecological exposure assessments, and 

• Tier I—FIRST (FQPA Index 

Reservoir Screening Tool) and Tier II— 

PRZM (Pesticide Root Zone Model)/

EXAMS (Exposure Analysis Modeling 

System) for drinking water assessments. 

However, the practice of using default 

drift values of 5% (aerial application), 

3% (airblast application), and 1% 

(ground application) in terrestrial and 

Tier II aquatic assessments continued. 

In 2004, EPA staff performed a 

comparison study of these previouslyspecified, percentage–based default 

spray drift deposition levels and 

AgDRIFT predictions. The comparison 

indicated these default values can 

potentially underestimate off-site 

deposition of spray drift under certain 

scenarios when compared to modelpredicted values (Ref. 5). 

Based upon continued model 

refinements, EPA is now revising its 

approach for terrestrial and Tier II 

aquatic assessments. As a result of these 

revisions, EPA has developed default 

model input parameters to estimate the 

spray drift fraction for all tiers of aquatic 

and terrestrial exposure assessments. 

Use of these inputs in the AgDRIFT 

model should result in more realistic 

estimates of exposure from spray drift 

deposition for all terrestrial and aquatic 

environments. 

IV. Consideration of Spray Drift in 

Human Health Risk Assessment 

The draft guidance for considering 

spray drift in human health risk 

assessment has been developed as an 

addendum to the EPA’s existing SOPs 

For Residential Exposure Assessment 

(SOPs), which are available at http://

www.epa.gov/pesticides/science/

residential-exposure-sop.html. EPA 

routinely uses the SOPs as the basis for 

evaluating the risks associated with 

residential exposures to pesticides, 

including residential turf assessments. 

The predominant sources of potential 

human health risks associated with 

spray drift is from direct contact with 

sprays and from contact with 

contaminated surfaces such as lawns in 

areas adjacent to pesticide applications. 

Direct contact with sprays is considered 

a violation of standard label language, 

and as applicable, EPA’s Worker 

Protection Standard (40 CFR part 170). 

This means that direct contact is not 

evaluated in risk assessment but is 

addressed through enforcement action 

against persons not complying with 

label prohibitions/directions, through 

applicator education, and through other 

means. The primary focus on spray drift 

in the human health risk assessment 

process is through indirect contact with 

contaminated surfaces such as lawns. 

The draft guidance document describes 

scenarios for which quantitative risk 

assessments for spray drift would 

generally be appropriate, and provides 

the information needed to complete a 

residential turf assessment using spray 

drift fractions predicted by AgDRIFT. 

Spray drift is governed by a variety of 

factors which govern how much of the 

pesticide application deposits on 

surfaces where contact with residues 

can eventually lead to indirect 

exposures (e.g., children playing on 

lawns that are next to treated fields and 

where residues have deposited). The 

potential risk estimates from these 

residues can be calculated using drift 

modeling coupled with methods 

employed for residential risk 

assessments for turf products. There is 

a regulatory precedent for this approach 

as it has been used by the Agency in a 

number of previous situations that 

include: 

• Response to a petition to cancel 14 

pesticides, (69 FR 30042; May 26, 2004; 

FRL–7355–7), 

• Development of buffer zone 

estimates for two organophosphate 

insecticides used on orchard crops in 

the Pacific Northwest, and 

• Development of a recent spray drift 

risk assessment for all uses of an 

organophosphate insecticide, available 

at http://www.regulations.gov/

#!documentDetail;D=EPA-HQ-OPP2008-0850-0105. 

Using default assumptions, the 

AgDRIFT model is used to predict spray 

drift estimates (similar to the ecological 

assessment process described in Unit 

III.) in the absence of application 

parameters such as droplet size 

spectrum, release height, wind speed, 

and percent of swath displacement (i.e., 

the same Tier 1 input parameters are 

used to compute drift fractions for both 

human health and ecological risk 

assessment). In the human health risk 

assessment process, deposition 

estimates are integrated over 50 feet 

wide lawns to account for the fact that 

small children can play anywhere on an 

impacted lawn. In the draft guidance 

document (Ref. 2), drift estimates are 

then used to adjust deposition values for 

the standard methods for evaluating 

children’s exposure from treated turf. 

Small children are the focus of this 

methodology because they have the 

highest exposures. Values are calculated 

using lawns at different distances away 

from a treatment area—adjoining it to 

300 feet away. Also, additional spray 


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Federal Register / Vol. 79, No. 19 / Wednesday, January 29, 2014 / Notices 4693 

drift deposition values are included 

which account for more options 

available in the AgDRIFT model which 

allows for flexibility in the risk 

management process. These include: 

• All canopy types for orchard 

airblast sprayers, 

• All boom height and spray quality 

combinations available for groundboom 

sprayers, and 

• Different options for aircraft 

including consideration of helicopter 

use and differing spray qualities (e.g., 

coarse instead of fine to medium spray 

quality). 

V. Request for Comment 

EPA is providing an opportunity, 

through this notice, for the public to 

provide comments and input on any 

additional information that may impact 

the Agency’s assessment of spray drift 

in pesticide risk assessments. 

Specifically included within the 

Agency’s request for comments are the 

model-generated spray drift values as 

described in either or both of the draft 

guidance documents. 

With regards to the Ecological and 

Drinking Water Assessment Guidance, 

as discussed in Unit III., EPA currently 

uses spray drift estimates, developed in 

the 1990s, using best professional 

judgement: 5% (aerial application), 3% 

(air-blast application) and 1% (ground 

application) in selected terrestrial and 

Tier II aquatic exposure assessments. 

Based upon continued model 

refinements, EPA is revising this 

approach and is beginning to 

incorporate AgDRIFT model estimates 

in all tiers for terrestrial and aquatic 

environments to estimate more realistic 

exposure from spray drift deposition. 

This approach is more consistent with 

current approaches throughout OPP. 

EPA is seeking comment on this 

approach. 

While EPA does not intend to 

formally respond to all comments made, 

comments in response to this notice will 

be taken into consideration as EPA 

finalizes these guidance documents. If 

substantive comments are made that 

may substantially change the EPA’s 

consideration of spray drift in pesticide 

risk assessment, EPA will notify the 

public of these comments and describe 

how EPA has responded to them. 

VI. References 

As indicated under ADDRESSES, a 

docket has been established for this 

notice under docket ID number EPA– 

HQ–OPP–2013–0676. The following is a 

listing of the documents that are 

specifically referenced in this action. 

The docket includes these documents 

and other information considered by 

EPA, including documents that are 

referenced within the documents that 

are included in the docket, even if the 

referenced document is not physically 

located in the docket. For assistance in 

locating these other documents, please 

consult the persons listed under FOR

FURTHER INFORMATION CONTACT. 

1. USEPA. Guidance on Modeling Offsite 

Deposition of Pesticides via Spray Drift for 

Ecological and Drinking Water 

Assessments for the Environmental Fate 

and Effects Division (Draft dated 11/1/

2013). 

2. USEPA. Residential Exposure Assessment 

Standard Operating Procedures (SOPs), 

Addenda 1: Consideration of Spray Drift 

(Draft dated 11/1/2013). 

3. USEPA. Use of AgDRIFT and AGDISP in 

OPP Risk Assessments. 

4. RESOLVE. 1992. Improving Aquatic Risk 

Assessment under FIFRA: Report of the 

Aquatic Effects Dialogue Group. Published 

by World Wildlife Fund, Suite 500, 1250 

24th Street NW., Washington, DC 20037. 

5. Birchfield N B. 2004. Pesticide spray drift 

and ecological risk assessment in the U.S. 

EPA: A comparison between current 

default spray drift deposition levels and 

AgDRIFT predictions in screening-level 

risk assessments. Aspects of Applied 

Biology 71: 125–131. 

List of Subjects 

Environmental protection, 

Administrative practice and procedure, 

Agricultural commodities, Pesticides 

and pests. 

Dated: January 13, 2014. 

Steve Bradbury, 

Director, Office of Pesticide Programs. 

[FR Doc. 2014–01234 Filed 1–28–14; 8:45 am] 

BILLING CODE 6560–50–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

[FRL–9905–98–OA] 

Notification of a Public Meeting of the 

Clean Air Scientific Advisory 

Committee (CASAC) Ozone Review 

Panel 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Notice. 

SUMMARY: The EPA Science Advisory 

Board (SAB) Staff Office announces a 

public meeting of the CASAC Ozone 

Review Panel to conduct a peer review 

of three draft EPA documents: (1) Health 

Risk and Exposure Assessment for 

Ozone—Second External Review Draft 

(January 2014), (2) Welfare Risk and 

Exposure Assessment for Ozone— 

Second External Review Draft (January 

2014) and (3) Policy Assessment for the 

Review of the Ozone National Ambient 

Air Quality Standards—Second 

External Review Draft (January 2014). 

DATES: The CASAC Ozone Review Panel 

meeting will be held on Tuesday, March 

25, 2014 from 9:00 a.m. to 5:30 p.m. 

(Eastern Time), Wednesday, March 26, 

2014 from 8:30 a.m. to 5:30 p.m. 

(Eastern Time) and on Thursday, March 

27, 2014 from 8:30 a.m. to 1:00 p.m. 

(Eastern Time). 

ADDRESSES: The public meeting will be 

held at the Carolina Inn at 211 Pittsboro 

St., Chapel Hill, NC 27516. 

FOR FURTHER INFORMATION CONTACT: Any 

member of the public who wants further 

information concerning the public 

meeting may contact Dr. Holly 

Stallworth, Designated Federal Officer 

(DFO), via telephone at (202) 564–2073 

or email at stallworth.holly@epa.gov. 

General information concerning the 

CASAC can be found on the EPA Web 

site at http://www.epa.gov/casac. 

SUPPLEMENTARY INFORMATION: The 

CASAC was established pursuant to the 

Clean Air Act (CAA) Amendments of 

1977, codified at 42 U.S.C. 7409D(d)(2), 

to provide advice, information, and 

recommendations to the Administrator 

on the scientific and technical aspects of 

issues related to the criteria for air 

quality standards, research related to air 

quality, sources of air pollution, and the 

strategies to attain and maintain air 

quality standards and to prevent 

significant deterioration of air quality. 

The CASAC is a Federal Advisory 

Committee chartered under the Federal 

Advisory Committee Act (FACA), 5 

U.S.C., App. 2. Pursuant to FACA and 

EPA policy, notice is hereby given that 

the chartered CASAC augmented with 

additional experts, known as the 

CASAC Ozone Review Panel, will hold 

a public meeting to peer review EPA’s 

draft documents referenced above. 

These EPA draft documents are 

prepared as part of the agency’s review 

of the National Ambient Air Quality 

Standards (NAAQS) for ozone. 

Section 109(d)(1) of the CAA requires 

that the Agency periodically review and 

revise, as appropriate, the air quality 

criteria and the NAAQS for the six 

‘‘criteria’’ air pollutants, including 

ozone. EPA is currently reviewing the 

primary (health-based) and secondary 

(welfare-based) NAAQS for ozone. The 

CASAC previously reviewed EPA’s 

Health Risk and Exposure Assessment 

for Ozone (First External Review Draft— 

Updated August 2012) and Welfare Risk 

and Exposure Assessment for Ozone 

(First External Review Draft—Updated 

August 2012). CASAC’s comments on 

both of these documents are reported in 

a letter to the EPA Administrator, dated 

November 19, 2012 (EPA–CASAC–13– 


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