UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

MAR 3 1 2014 

OFFICE OF CHEMICAL SAFETY 

.AND POLLUTION PREVENTION 

VIA EMAJ[L AND POST 

To Addressees Listed in the Enclosure to this Letter 

Subject: EPA Response to ·'Pesticides in the Air- Kids at Risk: Petition to EPA to Protect 

Children from Pesticide Drift" 

Dear Petitioners: 

Enclosed please find the Agency"s response to your petition. "Pesticides in the Air - Kids at 

Risk: Petition to EPA to Protect Children from Pesticide Drift.'' submitted in October 2009 on 

behalf of a number of health and enviromnemal organizations.' As you may recall. EPA posted 

the petition to the public docket (www.regulations.Qov, docket ID EPA-HQ-OPP-2009-0825) in 

November 2009 and opened a comment period that ran 120 days in its entirety. In summary, and 

as related more specifically in our response, the petition asked EPA to account for children's 

exposures t:o pesticide drift and volatilization in its risk assessments and to take certain steps to 

reduce the risks from these exposures. .· 

On July 24,2013, you filed a writ of mandamus lawsuit against EPA alleging that EPA bad 

unreasonably delayed responding to the petition. The parties agreed to stay the case as long as 

EPA promised to issue a final response to the Petition by March 31, 2014.2 The enclosed 

response fudfills that promise. 

During the several years that passed between the time the petition was submitted and the present. 

the Agency was actively developing drift and volatilization assessment methodologies, applying 

those meth•odologies to both fumigant and conventi011al pesticides, and finding ways to mitigate 

the risks to adults and children posed by pesticide drift and volatilization. 

Recently the Agency posted to the docket and solicited comments on the methodologies it has 

developed for assessing the risks from pesticide drift and volatilization. The comment periods 

1 The organizations were Pesticide Action Network of North America (PANNA), United Farmworkers, 

Pineros y Campesinos Unidos Del Noroeste, MomsRising, Sea Mar Community Health Center, California 

Rural Legal Assistance Foundation, Farm Labor Organizing Committee, and Physicians for Social 

Responsibility. 2 ln re: Pesticide Action Network North America, et al. v. EPA, No. 13-72616 (91

h Circuit) 

1 
for both mc:thodologies arc open at this time (at www.regulattons.gov; the docket ID for the drift 

methodology is EPA-HQ-OPP-2013-0676; for the volatilization methodology, EPA-HQ-OPP2014-0219). 

The enclosed response discusses background on the petition, the pending lawsuit, the statutory 

and regulattory framework for EPA's pesticide programs, how these programs are implemented, 

and how EPA assesses and manages the risks associated with pesticide use, including risks from 

spray drift and volatilization. The response also directly addresses the three major changes to 

current practices that were requested by the petitioners, that the Agency 1) assess the potential 

risks posed by drift and volatilization for children in places where they live and play, 2) 

accelerate the assessment of these potential risks, and 3) adopt uniform buffers for pesticides of 

special con,cern in the interim while the risk assessments are being conducted. 

EPA shares. the concerns expressed by the petitioners, and agrees that the risks from drift and 

volatilization must be accounted for, for both children and adults, and that action must be taken 

to mitigate any such risks. The Agency believes that the registration review program already in 

place is a timely, efficient, and effective way to assess and take action on these risks, and does 

not believe that imposing requirements for uniform, interim buffers is scientifically supportable 

or defensib.le. Thus the Agency grants in part and denies in part the petitioners' requests. 

We thank you for your interest and for your role in advancing awareness of the risks that 

pesticide drift and volatilization can pose to children. We hope that you will review and provide 

constructive comments on the newly published assessment methodologies for addressing those 

tisks. Should you desire fmther information on the Agency's approach to assessing drift and 

volatilization, please contact Jill Bloom of my staff, at bloom.jill@epa.!WV or (703) 308- 8019, 

and she will do her best to assist you. 

Enclosures: 

List of addressees 

Agency Response to "Pesticides in the Air - Kids at Risk: Petition to EPA to Protect Children 

from Pesticide Drift (2009)" 

2 
cc: 

Ms. Virginia Ruiz 

Director of Occupational and Environmental Health 

Farmworker Justice 

1126 16th Street, N.W., Suite 270 

Washington, DC 20036 

vruiz@ farn1workerjusttce.org 

Ms. Patti Goldman 

Ms. Janette K. Brimmer 

Earth justice 

705 Second A venue, Suite 203 

Seattle, WA 98104 

j brimmcr@ earth justice .org 

pgoldman @earthjustice.org 

3 
Addressees: 

Erik Nicholson 

National Vi1ce President 

United Farm Workers 

PO Box 8337 

Tacoma, WA 98418 

enicholson @ufw .org 

Paul Towers 

Organizing & Media Director 

Pesticide Action Network of North America 

1611 Telegraph Avenue, Suite 1200 

Oakland, CA 94612 

plower!'>@ _panna.org 

Barbara Gottlieb 

Program Director 

Physicians for Social Responsibility 

llll-14th Street, N.W., Suite 700 

Washingtom, D.C. 20009 

bgottl ieb@ psr.org 

Ariana Kelly 

Campaign Director 

MomsRising.org 

Family Environmental Health 

(no mailing address available 

ari:ma @momsri..,ini!.org 

Ramon Ramirez 

President 

Pineros y Campesinos Unidos del Noroeste 

300 Young St. 

Woodburn, OR 97071-4818 

ramonrarnii ez@ pcun.org 

Baldemar Velasquez 

President 

Farm Labor Organizing Committee 

3352 Plainview Dr. 

Toledo, OHl 43615 

bve lasq @floc. com 

Anne Katten 

California Rural Legal Assistance 

Foundation 

2210 K Street Suite 201 

Sacramento, CA 95816 

akatten @crlaf.org 

Michael Leong 

Vice President Corp. and Legal Affairs 

Sea Mar Community Health Center 

1040 S. Henderson Street 

Seattle, W A 98108 

mikeleong@seamarchc.org 

4 
A~en~y Response to 

"Pesticides in the Air- Kids at Risk: 

Petition to EPA to Pr·otcct {'hildrrn from Pesticide Drift (20U9l'' 

Table of l on tent~ 

I. Execu1tive Summary ............................................................................................................................ 2 

II. Background ........................................................................................................................................ 3 

A. Petition History and Major Claims by Petitioners ..................................................................... 3 

B. Lawsuit ...................................................................................................................................... 4 

Ill. Statutory and Regulatory Background/Framework .......................................................................... 4 

A. The Federal Insecticide, Fungic ide, and Rodenticide Acl... ...................................................... 4 

B. The Federal Food, Drug, and Cosmetic Act.. ............................................................................ 5 

C. Executive Orders Cited in Petition ............................................................................................ 7 

i. 1994 Environmental Justice Executive Order ........................................................................... 7 

ii. I 997 Children's Health Executive Order .................................................................................. 8 

IV. EPA's Pesticide Regulatory Programs ............................................................................................. 8 

A. EPA's Review of Pesticide Registration Applications ............................................................. 9 

B. Tolerance Setting .................................................................................................................... I 0 

1. Process overview ..................................................................................................................... IO 

11. The Tole rance Petition and Required Documentation ............................................................ II 

iii. How the Proposed Tolerance Action is Assessed ................................................................... I I 

C. Pesticide Re-evaluation Processes .......................................................................................... 12 

1. Reregistration .......................................................................................................................... 12 

11 . Registration Review ................................................................................................................ 13 

111. Regulatory Responses to Unacceptable Risks ......................................................................... 16 

V. How Pesticide Risks Are Assessed ................................................................................................. 17 

A. Hazard identification ................................................................................................................ I 8 

B. Dose-response ......................................................................................................................... 19 

C. Exposure .................................................................................................................................. 20 

D. Risk characterization ............................................................................................................... 20 

E. Children and pesticides ........................................................................................................... 2 1 

VI. Nomenclature Associated with Pestic ide Drift and Volatilization ................................................. 22 

VII. Assessing and Manag ing Risks from Spray Drift.. ....................................................................... 23 

A. Estimating Spray Drift and Potential Exposures to Bystanders .............................................. 23 

B. Assessment of Risk to Bystanders from Spray Drift ............................................................... 24 

C. How EPA Mitigates Potential Risks Associated with Spray Dri:ft .......................................... 26 

Vill. Assessing and Managing the Risks Due to Pesticide Volatilization ............................................ 27 

A. Quantifying Volatilization For Conventional Pesticides ......................................................... 28 

B. Estimation of Risks Associated with Pesticide Volatilization ................................................ 30 

C. How EPA Mitigates Potential Risks Associated with Volatilization ...................................... 3 1 

IX. Responses to Requests Made by Petitioners .................................................... .............................. 32 

A. EPA Will Evaluate the Risks to Children Associated with Spray Drift and Volatilization 

Exposures ................................................................................................................................................ 32 

B. Expediting Assessments of Spray Drift and Volatilization Outside of the Registration Review 

Schedule is not Necessary ....................................................................................................................... 34 

C. Immediate Adoption of Generic, Interim No-Spray Buffers Around Homes, Schools, Daycare 

Centers, and Parks to Protect Children from Drift Is Not Appropriate ................................................... 36 

X. Conc lusion ....................................................................................................................................... 38 

APPENDIX .......................................................................................................................................... 40 

1 
I. Executive Summar~· 

This document presents EPA's response to a petition that asked the agency to: I) evaluate the 

risks to chddren exposed to pesticides through drift and volatilization, 2) establish a separate 

process or modify its pesticide re-evaluation process to expedite assessment and management of 

these risks. and 3) for certain types of pesticides, require the adoption of ''one size fits all'' buffer 

zones between treated areas and places where children congregate. EPA grants in part and denies 

in part this petition. 

EPA ag;rees with Petitioners that individuals includjng children may be exposed to pesticides 

through drift and/or volatilization; that these exposures can occur in places where children live, 

go to schoetl, play, or are otherwise present; and that, apart from occupational activities, children 

(depending on certain factors, including age) may experience higher levels of pesticide exposure 

relative to their size than do adults. Furthennore, the Agency agrees with the petitioners that it 

should conduct pesticide-specific assessments of the risks that include drift and volatilization 

exposures, as appropriate, and that if warranted, the Agency will take action to mitigate those 

risks. The s.teps the Agency has been taking to address these exposures are discussed later in this 

document. 

Petitio111ers define the term drift to include "any airborne movement of pesticides away from a 

target site during and/or after application, including the airborne movement of pesticide droplets, 

pesticide powders, volati lized vapor-phase pesticides, and pesticide contaminated soil particles." 

In Sections VI through VIli of this response, EPA defines drift and volatilization as they relate to 

our risk assessments. The definitions differ mainly because the Agency draws a distinction 

between th1~ off-site movement of spray droplets or pesticide patticles during and shortly after 

the applica1tion process ("pesticide drift") and the movement of pesticide active ingredients as a 

vapor or gas that can occur for longer time after application is completed ("volatilization"). Both 

processes describe movement of pesticides through the air. The type of pesticide drift on which 

this response focuses is "spray" drift, the off-site movement of aerosols originating with 

pesticides applied as liquids, because spray drift is more likely to occur than the drift of 

pesticides in solid form, and when it does, it generally poses greater risk. EPA's efforts to assess 

and manage pesticide drift consequently are concentrated on spray drift. 

EPA denies the Petitioners' request that EPA use a process outside of the ongoing pesticide 

re-evaluation process, as currently scheduled, to assess and manage spray drift and volatilization 

risks. The Petitioners suggest that the Agency should use alternative approaches that reprioritize 

pesticides for registration review or speed up risk assessments. The Agency believes that such 

adjustments to the registration review process are not needed and do not represent an efficient 

use of limited Agency resources.

1 

1 If spec ific and significant concerns arise about an individual pesticide not in registration review at 

the time, the: Agency can utilize other processes as appropriate to assess and mitigate risks (as needed). 

These processes are described later in this document and are not intended to replace the systematic and 

regular actions that constitute registration review. See IV.C.iii, which discusses regulatory options for 

cases in which the Agency has determined that a registered pesticide no longer satisfies the statutory 

standard. 
EPA also denies the petition as it relates to Petitioners' request that EPA immediately adopt 

interim prohibitions on the use of certain pesticides that they allege are toxic and may be prone 

to drift or volatilization, near homes, schools, parks, and daycare centers or wherever children 

congregate. EPA instead believes that case-by-case, chemical-specific risk assessment is a sound, 

science-based approach, consistent with the Agency's mandate, that yields a more realistic 

representation of actual risks and facilitates the identification of what, if any, mitigation 

measures ()potentially including no-spray buffers) are needed to protect potentially exposed 

indi victuals. 

The response to the petition is organized in the following manner. After this executive 

summary, EPA follows with two sections (II and III) that discuss background on the petition, the 

pending lawsuit brought by the Petitioners, and the statutory and regulatory framework as it 

relates to EPA's implementation of its pestic ide programs. The next two sections of the response 

(IV and V) outline the Agency's pesticide regulatory programs and how EPA assesses and 

manages the risks associated with pesticide use. The following sections (VI through VIII) revisit 

the Agency's terminology for describing the off-site movement of pesticides through the air via 

spray drift and volatilization and explain how the risks of each are assessed and managed. The 

next sectio111 (IX) contains EPA's response to the Petitioners' request for three changes to the 

Agency's c:urrent practices. The last section (X) provides EPA's conclusion. 

II. Back~roond 

A. Pelltiun Hh.tor; 1d Major Claim' by Petmonep. 

In October 2009, a group of health and environmental organi zations2 ("Petitioners") jointly 

filed a petition entitled, ''Pesticides in the Air- Kids at Risk: Petition to EPA to Protect Children 

Erom Pestic:ide Drift (''Petition"). The Petition alleged that EPA has failed to address children'!\ 

exposures to and potential risks from pesticide drift and volatilization. More specifically the 

Petitioners ask EPA to: 

1. fu lly and expeditiously evaluate the exposure of children to pesticide drift or vapors that 

originate from agricultural applications and travel to areas where children congregate, such as 

homes, parks, schools, and daycare centers. Funhermore, the Petitioners ask that the Agency act 

to ensure that children are protected from aggregate pesticide exposures, including exposures to 

drift: 

2. impilcment an accelerated schedule (relative to the schedule for registration review) for 

completing drift asses ments and modifying registrations that prioritizes assessments based on 

the suspcct,ed degree of risk posed by the pesticide drift and volatilization; and 

2 Thc organizations include Pesticide Action Network North America (PANNA), United Farm 

Workers, Pitneros Y Campesinos Unidos Del Noroeste, Moms Rising, Sea Mar Community Health 

Center, California Rural Legal Assistance Foundation, Farm Labor Organizing Committee, and 

Physician for Social Responsibility. 

3 
3. immediately adopt interim prohibitions on the use of tox ic drift-prone pesticides such as 

organophosphates and n-methyl carbamates and certain other pesticides that arc used near 

homes, schools, parks, and daycare centers or wherever ch ildren congregate.3 

On November 4, 2009, EPA issued a Federal Register Notice requesting public comment on 

the assertions and requests made in the October 2009 petition. The comment period for tbe 

petition closed on January 4, 2010. EPA has reviewed the comments received:' 

B. Lawsuil 

On July 24,2013, the Petitioners filed a writ of mandamus lawsuit against EPA alleging that 

EPA had unreasonably delayed responding to their 2009 Petition. EPA and the Petitioners agreed 

to stay the case. ln EPA's unopposed motion lo stay the case, the Agency promised to issue a 

final response to the Petition by March 31,20 14.5 This response fulfills that promise. 

III. Statut•ory and Regulutury Background/Framen ork 

EPA regulates pesticides under the Federal Insecticide, Fungicide, and Rodenticide Act 

("FIFRA"), 7 U.S.C. §§ 136-136y, and the Federal Food, Drug, and Cosmetic Act ("FFDCA''), 

21 U.S.C. §346a. FIFRA sets forth a federal licensing scheme for the sale, distribution and use of 

pesticides; FFDCA establishes the mechanism and standards by which EPA must set tolerances 

(allowable levels) for pesticide residues in food. As a general matter, under FTFRA section 3, 

before a pesticide can be distributed or sold in the United States, it must be registered. 

Petitioners" administrative petition implicates both statutes. 

The principal purpose of FIFRA is to regulate the sale, distribution and use of pesticides 

(through registrations) whil e protecting human health and the environment from umeasonable 

adverse effects associated with pesticides. See generally FIFRA section 3. Under FIFRA, EPA 

register a ]pesticide only after conducting a scientific review of the risks, and when appropriate, 

benefits of that pesticide to determine whether the use of the pesticide causes "unreasonable 

adverse effects" to human health or the environment.6 Registration and registration review 

decisions under section 3, reregistration decisions under section 4, and cancell ation decisions 

under section 6 are governed by the same statutory standard, which generally is referred to as 

"risk-benefit" balancing, i.e., a pesticide must not pose "any unreasonable risk to man or tbe 

3 The pe titioners believe these interim measures also should apply to "all other pesticides that are ( I) 

registered for application by ground sprayers, broadcast equipment, and/or aerial equipment; and (2) 

suspected of causing acute poisonings, cancer, endocrine disruption, developmental effects, and/or 

reproductive effects. 

4 The Pe tition docket is found at http://www.regulations.2ov/#!dockLLDetaii:D=EPA-HO-OPP-2009-

0825. 

--5 In re: Pesticide Action Network North America, et al. v. EPA, No. 13-72616 (91h Circuit) 

4 
envirorunent, taking into account the economic, social, and environmental costs and benefits of 

the use of any pesticide." FIFRA §§ 3(c)(5) & 2(bb); 7 U.S.C. §§ l36a(c)(5) & l36(bb). If this 

standard is not satisfied, EPA may not register the pesticide and existing pesticides are subject to 

modification or cancellation. See FIFRA §§ 3(c)(5) & 6(b); 7 U.S.C. §§ 136a(c)(5), & 136d(b). 

In order to properly evaluate pesticide applications, FIFRA and its implementing regulations 

generally rcequire applicants for registration to submit or cite to a significant body of toxicity and 

exposure data for the pesticides for which they are seeking registration. See 7 U.S.C. § 

l36a(c)(2)('A) (directing EPA to publish guidelines for submissions by applicants); 40 C.F.R. §§ 

158.1 et seq.l6l.20 et seq. (setting forth information to be provided by applicants). 

While EPA must consider a broad range of factors in determining whether a pesticide meets 

this standard, the balancing of the various risks and benefits of the pesticide, and consideration of 

inherent po,Jicy questions, is left largely to the discretion of EPA: ''[W]ithin broad limits, the 

[Ajdrninistrator has latitude not merely to find facts, but also to set policy in the public interest. 

Like most regulatory statutes, ... FTFRA confers broad discretion on the [Administrator]." 

Wellford v. Ruckelshaus, 439 F.2d 598, 601 (D.C. Cir. 1971); See also Envtl. De.f Fund v. EPA, 

465 P.2d 528, 538 (D.C. Cir. 1972) (FIFRA empowers EPA to "take account of benefits or their 

absence as affecting imminency of hazard"). 

As part of the process of EPA's approval of a pesticide registration, the agency must review 

and ultimately approve proposed labeling and directions for use for each pesticide. See FIFRA § 

3(c)(5)(B). The approved pesticide label sets f01th the lawful conditions of use for a pesticide, 

i.e., those mandated by EPA in order to ensure that the pesticide will not cause umeasonable 

adverse effects to human health or the environment. See /d. § 3(d). Indeed, it is a violation of 

FIFRA for any person to use a pesticide in a manner inconsistent with the EPA-approved 

labeling. St?e lei. § 12(a)(2)(G). 

B. fiJL' federal Food. Drug. and Ct)\Jllelic A~l 

ln 1996, the Food Quality Protection Act ("FQPA") was enacted, amending FFDCA and 

FIFRA to require all pesticides the use of which results in residues on food to meet new dietary 

risk standa1rds. The FQPA amended the FIFRA risk-benefit standard ("any unreasonable risk to 

man or the envirorunent") to add another element to the definition of that term: "a human dietary 

risk from residues that result from a use of a pesticide in or on any food inconsistent with the 

standard under lFFDCA section 408]." See FIFRA § 2(bb); FFDCA § 408(b)(l). In other words, 

the registration of a pesticide is contingent upon its meeting the food safety standard established 

under FFDCA section 408, if use of the pesticide results in residues on food. Section 408 also 

was amended by FQPA to add protections for infants and children and to establish the estrogenic 

substances screening program. 

7 Public Law 104- I 70, I 10 Stat. 1489 (1996). 

5 
Sectio111 408 of the FFDCA authorizes EPA to establish by regulation ''tolerances" setting the 

maximum permissible levels of pesticide residues in foods. 8 FFDCA §§ 30l(a), 408(a). 

Tolerance setting is discussed in more detail in Section IV .B. 

EPA may only promulgate a pesticide tolerance, if the tolerance is "safe." FFDCA § 

408(b)(2)(A)(i). "Safe'' is defined by the FFDCA section 408 to mean that "there is a reasonable 

certainty that no harm will result from aggregate exposure to the pesticide chemical residue, 

including all anticipated dietary exposures and all other exposures for which there is reliable 

informatiOJ}." /d. § 408(b)(2)(A)(ii) [emphasis added]. Section 408's reasonable certainty of no 

harm standard is a risk-only standard, which generally does not allow consideration ofbenefits.9 

Congress also amended the FFDCA to require that EPA re-assess, using the new safety standard, 

the existing tolerances and exemptions for all pesticide chemical residues that were in effect on 

August 3, Jl996. ld. § 408(q)(l). Congress directed EPA to complete the reassessments by 

August 3, 2006. 

Congress instructed EPA, when applying the new safety standard, to assess, among other 

things, the risks of pesticide chemicals based on available information conceming the special 

susceptibililty of infants and children to pesticide chemical residues. FFDCA § 408(b)(2)(C). To 

ensure that there is a reasonable certainty that no harm will result to infants and children from 

aggregate exposure to pesticide chemical residues, Congress mandated that EPA apply an 

additional ten-fold margin of safety (known as the FQPA safety factor) in setting tolerances 

unless reliable data show that a different margin of safety will be safe for infants and children. 

/d. The addlitional ten-fold margin of safety can be reduced or removed based on such a finding. 

The FQP A amendments to the FFDCA also directed EPA to consider "aggregate exposure" 

in its decisilon-making. EPA has intetpreted "aggregate exposure" to refer to the combined 

exposures-to a single chemical across muJtiple routes (oral, dermal, inhalation) and across 

multiple pathways (food, drinking water, residential). As amended by FQP A, section 

408(b)(2)(ii) of FFDCA requires the Agency to make a finding for each tolerance or tolerance 

exemption "that there is a reasonable certainty that no harm will result from aggregate exposure 

to the pestkide chemical residue, including all anticipated dietary exposures and all other 

exposures for which there is reliable infOimation"{emphasis added]. Section 408(b)(2)(C)(ii)(O 

of FFDCA states that the Agency must find "there is a reasonable certainty that no harm wiJI 

result to infants and children from aggregate exposure to the pesticide chemical residues." 

Finally, section 408(b)(2)(D)(vi) directs the Agency, when making tolerance decisions, to 

consider ''aggregate exposure levels .. . to the pesticide chemical residue .. .including dietary 

exposure and exposure from other non-occupational sources." 

EPA reaffirms its consistent interpretation of FFDCA section 408 as requiring consideration 

of all exposures to pesticide residues and other related substances other than those exposures 

8 Without such a tolerance or an exemption from the requirement of a tolerance, a food conta·ining a 

pesticide residue is "adulterated" under section 402 of the FFDCA and may not be legally moved in 

interstate commerce. 

<> Benefits may only be considered under section 408 in one very narrow circumstance not applicable 

in this case. 

6 
occurring 1111 the occupational setting. 10 Relevant exposures include pesticide residues in food and 

water and •exposures to pesticides around the home or in public from sources other than food and 

water. 

It is important to note that Congress has expressly provided that any issue that can be raised 

through th•e FFDCA review process can only be reviewed through that process.

11 Accordingly, to 

the extent a petition to revoke tolerances and cancel registrations raises issues relevant to the 

establishment or revocation of tolerances, EPA's response to those issues may be challenged 

only through the administrative and judicial review procedures provided in section 408 of the 

FFDCA and are not reviewable under FIFRA or any other provision of law. 

EPA includes the following general discussion on two Executive Orders mentioned by 

Petitioners as support to their claims. 12 

1. Executive Order 12898: Federal Actions to Address Environmenta l Justice in 

Minority Populations and Low-Income Populations 

On February 11, 1994, President Clinton issued Executive Order 12898 on Federal Actions 

to Address Environmental Justice in Minority Populations and Low-Income Populations. 13 This 

Order focUises federal attention on the environmental and human health conditions of minority 

and low-income communities and calls on agencies to make achieving environmental justice 

("EJ") part: of their mission. Since the issuance of that Executive Order, EPA has been actively 

working to ensure that EJ issues are considered in its decision-making processes. In September 

2011, EPA issued its Plan EJ 2014 strategy. 14 The strategy is the Agency's roadmap for 

advancing environmental justice. Based on this strategy, the Agency seeks to: 

• Protect: the environment and health in overburdened communities. 

10 See Jmidacloprid; Order Denying Objections to Issuance of Tolerance 69 Federal Register 30042, 

30073 (May 26, 2004). 11 FFDCA § 408(h)(5); NRDC v. Johnson, 461 F.3d 164, 176 (2d Cir. 2006). 12 These. Executive Orders do not create an independent right of action against the United States. 13 http:/ /www2.epa.gov/la w..,-regulationsh;ummary-executi ve-order-12898-federal-net ions-addressenvironmemal-justtce 

14See http://www.epa.gov/compliancdej/plan-ej/for more information. The plan is not a rule or 

regulation. It is a strategy to help integrate environmental justice into EPA's day-to-day activities. Plan EJ 

2014 has three major sections: Cross-Agency Focus Areas, Tools Development Areas, and Program 

Initiatives. Within these areas, EPA plans to more effectively protect human health and the environment 

for overburdened populations by developing and implementing guidance on incorporating environmental 

justice into EPA's rulemaking process. EPA also plans to enable overburdened communities to have full 

and meaningful access to the permitting process and to develop permits that address environmental justice 

issues to the greatest extent practicable under existing environmental laws. Under the two statutes at issue 

here, FIFRA and the FFDCA, EPA has already begun to incorporate these considerations into its 

licensing program. 

7 
• Empower communities to take action to improve their health and environment. 

• Establis h partnerships with local, state, tribal, and federal governments and organizations to 

achieve healthy and sustainable communities.15 

EPA is committed to addressing risks to population groups with unique exposure pathways, 

such as children, farm and migrant workers, urban poor populations, rural or isolated 

populations, and Native Americans and Alaskan Nattves [emphasis added]. 16 EPA's Office of 

Pesticide Programs has developed an internal training program for staff that provides an 

overview of environmental justice issues to be considered in risk assessment. Guidance 

materials and the templates for risk assessment documents direct risk assessors to address 

environmental justice concerns specifically as a basic element of pesticide risk assessment and 

the Agency risk management decision-making process includes consideration of any such 

concerns identified for the subject pesticide. 

11. Execu6ve Order 13045: Protection of Children from Environmental Health Risks 

and Safety Risks 

On April 2 1, 1997. President Clinton signed Executive Order 13045 on the Protection of 

Children from Environmental Health Risks and Safety Risks. 17 This Executive Order requires all 

federal agencies to assign a high priority to addressing health and safety risks to children, 

coordinate research priorities on children's health, and ensure that their standards take into 

account sp<::cial risks to children. While not directly cited in the Petition, it should also be noted 

that on October 20, 1995, EPA adopted the Policy on Evaluating Health Risks to Children 

(predating the Executive Order). This policy requires the EPA to consider the risks to infants 

and children consistently and explicitly as part of risk assessments generated during its decision 

making process, including the setting of standards to protect public health and the environment. 18 

rn response to Executive Order 13045, EPA established the Office of Children's Health 

Protection r(''OCHP") in May 1997. The focus of this office is to make the protection of 

children's health a fundamenta l goal of public health and environmental protection in the United 

States. The Agency's Office of Pesticide Programs and OCHP are committed to ensuring that the 

Agency's risk assessments for pesticides are protective of children's health. 19 

IV. EPA •s es ti ci ~ e~u atory Programo., 

15 Petitioners claim that EPA's pesticide assessments do not adequately address environmental justice 

issues as directed by the 1994 EJ Executive Order (Exec. Order No. 12,898, 59 Fed. Reg. 7,629 (Feb. II , 

1994)). EPA disagrees. EPA's commitment to EJ issues is clear from its recent pronouncements on these 

is ues. 

16 http://:t![?h .aphapublications.org/doi/full/ I 0.2105/ AJ PH.20 11.30011 1 

17 http://yoscmite.epa.gov/ochp/ochpweb.nsf/content/whatwe executiv.htm 

18 http://yo:-.emite.epa.gov/ochp/ochpweb.m.f/contenUpolicv-evaJ risb children.htm 19 hUp:/1 ~ao.go\/product!-./GAO- J 3-254 

8 
The folllowing sections discuss how EPA implements its statutory obligations under FIFRA 

and the FFDCA. 

A. EPA·~ R~v1ew nf Pl!-.ttuue Rcg ~lmt on App_li_t:a· _ iL'~n:-______________ . 

EPA provides an application kit20 to assist in preparation of an application to register a 

pesticide. The applicant is responsible for submitting or citing all of the information and data 

that are required to support the registration, including proposed product labeling, and scientific 

data that meet the data requirements related to the specific product the applicant intends to 

register. In addition, the applicant provides a Confidential Statement of Formula that details the 

composition of the pesticide product, i.e., 1) all active ingredients, 2) all inert ingredients, 3) all 

impurities of toxicological significance associated with the active ingredient, and 4) all 

impurities found to be present at a level equal to or greater than 0.1 percent by weight of the 

technical g;rade active ingredient.21 

The applicant will also provide EPA with draft labeling. FIFRA section 2(p )(1) defines 

"label" as '·'the written, printed or graphic material on, or attached to, the pesticide or device or 

any of its containers or wrappers." The term "labeling" is defined as "all labels and all other 

written, priinted, or graphic matter -

(A) accompanying the pesticide or device at any time; or 

(B) to which reference is made on the label or in literature accompanying the pesticide or 

device." See FIFRA § 2(p)(2) 

Labeling includes detailed information such as the ingredients statement, warnings and 

precautionary statements, and directions for use. It is unlawful to sell or distribute a pesticide if 

any claims made for it differ from claims made on labeling required for registration. See FIFRA 

§ 12(a)(l)(B). Therefore, advertising claims for a pesticide product must not contradict claims 

made in the product's labeling. Labeling requirements are codified in 40 CFR Part 156. EPA has 

developed a Label Review Manuat22 

as guidance to its staff on reviewing labels. 

Applicants are responsible for citing or generating all data to meet data requirements. The 

purpose of these data requirements is to demonstrate that the product will not cause unreasonable 

adverse effects on the environment. [n general, these data are used to evaluate whether a 

pe ticide has the potential to cause adverse effects on humans, non-target wildlife, and plants, as 

well as possible contamination of surface water or groundwater from leaching, run-off, and spray 

drift. For pesticides that will need a tolerance or tolerance exemption to demonstrate a reasonable 

certainty of no harm, additional data are needed. 

Requirements may include, as app1icable, data on: 

• spr:ay drift, 

• residue chemistry, 

20 http://www.cp:u .?ov/pesticides/registrationkttl 

21 http://www gpo. go y~/pkg/CFR-20 I 1-LiLle40-vol24/pdf/CFR-20 ll-tltle40-voi2..J.-sec 158-

320.pdf 

22 http:/l\\ ww .epa. !!ov/oppfcad l/labeltn!!/lnnl 

9 
• environmental fate, 

• toxicology, 

• applicator exposures 

• reentry protection, 

• wildlife and aquatic organisms, 

• plant protection, 

• nontarget insects, 

• product perfonnance, and 

• product chemistry. 

Data requirements in support of applications for registration of a pesticide product are 

specified in 40 CFR Part 158Y 

EPA's review of the application includes the assessment of the risks to human health and the 

environment that may be posed by the pesticide?4 

B. Toleran~r Setting 

1. Proces~ overview 

A tolerance is the maximum allowable concentration of a pesticide on a particular food item. 

The tolerance is the residue level that triggers enforcement actions. That is, if residues are found 

above that level, the commodity will be subject to seizure by the government. EPA must 

consider a number of factors when it establishes, modifies, leaves in effect, or revokes a 

tolerance for a pesticide chemical residue. FFDCA § 408(b)(2)(D). The process for the 

establishment, modification, or revocation of tolerances, is described directly below. 

A tolerance action may be initiated by EPA of its own accord25 or in response to an 

administrative petition. /d. § 408(d)(l), (e)(l). "Any person may fil e with lEPA] a petition 

proposing t he issuance of a regulation . .. establishing, modifying, or revoking a tolerance for a 

pesticide chemical residue in or o:n a food." /d. § 408( d)( 1 )(A). If EPA determines that an 

administrative petition meets the statutory and regulatory requirements governing petition 

contents, EPA publishes a notice of the administrative petition's fi ling. !d. § 408(d)(3). (The 

Agency will also publish a notice when the action is Agency-initiated.) 

After the publication of the notice, EPA must give "due consideration" to the petition and 

chen: i) issue a final regulation establishing, modifying, or revoking a tolerance; ii) issue a 

proposed regulation under the separate provisions of the FFDCA § 408(e), and thereafter issue a 

23 Data requirements are described at http://www.gpp.gov/fdsys/pkg/CFR-20 ll-llll1!40-

vol24/pdf/CFR-20 II-Litle40-vol24-part 158.pdf; links to guide lines for the conduct of required studies are 

located at tp www.e pa.go /pes ides/ cc/g ideli i.!s .h m 14 For flllrther details on the pesticide registration see 

hltp ://epa.l!o /pes ki es/f cts ee eg tr ti on. htm . 25 When, for example, the tolerance action follows a cancellation action. 

10 
final regulation after additional public notice and comment; or iii) issue an order denying the 

petition. FFDCA § 408(d)(4)(A). See NRDC v. Johnson, 461 F.3d atl73-74. 

After EPA issues a regulation or order establishing, modifying, or revoking a tolerance for a 

pesticide chemical residue on food, any person may file objections with EPA and request an 

evidentiary hearing on those objections. FFDCA § 408(g)(2). After consideration of any such 

objections, EPA must issue a final order separately stating the action taken on each objection and 

whether any hearing is appropriate. ld. § 408(g)(2)(C). Then the Agency can conclude its 

deliberations and grant, modify, or deny the tolerance, as appropriate. 

ii. The Tolerance Petition and Required Docwnentation 

As discussed above, a determination on the proposed tolerance relies on the risk-only 

standard from FFDCA section 408. EPA must ensure that the use associated with the tolerance 

will not pose unreasonable risks to human health. Except in ce11ain instances,26 a tolerance 

petition request is usually accompanied by an application for registration, an application to 

amend the registration of a cutTently registered product, or an experimental use permit for the 

uses proposed in the petition. As risk assessments are a component of the standards for 

evaluating both tolerance proposals and registration actions, EPA determines whether any 

meaningful risks exist for the proposed uses, based on an evaluation of the applicant's petition 

for a toleratnce. The Agency bases its tolerance decision on the aggregate exposures and risks 

associated with the pesticide and the use to which the petition applies. Aggregate exposure is the 

combined 'exposures to a single chemical across multiple routes (oral, dermal, inhalation) and 

across multiple pathways (food, drinking water, residential).27 

iii. How the Proposed Tolerance Action is Assessed 

The risks of concern that are considered in the setting of tolerances are the human health 

risks from aggregate exposures, which are the sum of exposures from each relevant pathway--

food, drinking water, and/or residential. The assessment of human health risks is described in 

more detail in Section V. Aggregate risks are calculated based on varying durations of exposure. 

When no r,esidentiaJ uses exist, aggregate risks are based on exposure contributions from food 

and drinking water for the acute and chronic durations. For residential-use pesticides, residential 

exposures are combined with food and drinking water exposures for each applicable duration of 

exposure. As discussed above, a determination on the proposed tolerance will be based on the 

risk-only standard from FFDCA section 408. 

26 A request for an import tolerance generally would not require an accompanying application for 

registration. 

27 Residential exposures include exposures associated with homes, home lawns, yards, gardens, 

apartments and grounds around apartment buildings, schools, schoolyards, daycare facilities, 

playgrounds, athletic fields, and parks and other public spaces. 

11 
In 1997, EPA issued "HED SOP 97.2 Interim Guidance for Conducting Aggregate Exposure 

and Risk Assessments (11/26/97)."28 The Agency continued to work on more sophisticated 

methods for estimating aggregate exposures to pesticides, and in 2001, released "General 

Principles for Performing Aggregate Exposure and Risk Assessments,"29 to augment the 

guidance dlocument. 

The aggregate risk assessment process relies on available data, assumptions designed to be 

protective of public health, standard analytical methods and Agency SOPs to estimate exposures 

to a pesticide for each potential pathway and route of exposure. EPA combines these separate 

exposure estimates to calculate potential aggregate exposure and risk; aggregate exposures 

estimated im this way reflect upper-bound or high-end of exposures for each route/pathway. The 

most highly exposed &rroup, which generally also has the highest associated risk, is used as the 

basis for d1ecision-making purposes. Aggregate risk assessments conducted in this manner 

typically can be refined by the use of additional exposure data and data specifically designed to 

address the uncertainties within an individual aggregate analysis, as well as more soph isticated 

analysis techniques. 

The assumption implicit in this approach is that individuals can encoumter the high-end 

exposures from the different pathways all at one time. In actuality, co-occurrence of high-end 

food, drinking water. and residential exposure scenarios is very unlikely. Thus, in using this 

approach, EPA is confident that aggregate exposure estimates will overstate, sometimes 

significantly, the amount of a pesticide to which people actually are exposed. The primary 

advantage to relying on these highly conservative assessments is that they require relatively 

fewer data and analytical resources and less time to conduct. In addition, an aggregate risk 

assessment of this type may be enough to indicate that a particular pesticide use satisfies the 

appropriate regulatory standards. 

1. Reregistration 

FIFRA requires the periodic re-evaluation of cunently registered pesticides. In 1988, 

Congress amended FlFRA section 4 to include a specific process for the "reregistration" of 

pesticides containing active ingredients first registered before November I, 1984. Pub. L. 100-

532, title I, § 102(a), 102 Stat. 2655, 2683(1988). To make a Reregistration Eligibility Decision 

(RED), 30 EPA reviewed all the studies that were submitted by the pesticide registrants for a 

28 U.S. Environmental Protection Agency. 1997e. Memorandum from Margaret Stasikowski, Health 

Effects Division to Health Effects Division Staff. "HED SOP 97.2 Interim Guidance for Conducting 

Aggregate Exposure and Risk Assessments (J 1/26/97);" November 26, I 997. Office of Pesticide 

Programs, Office of Prevention, Pesticides, and Toxic Substances, Washington, D.C. Available upon 

requesL 

29 Imp:/ /www .epa.go\/~~tic ide~trac/..,cleoce/al!1!regate .pdf 

30 In particular cases, the Agency issued a variation on the RED, i.e., a Tolerance Reassessment 

Decision, or, for individual active ingredients identified as belonging to a group of pesticides with a 

common mechanism of action, an Interim Reregistration Decision may have been issued before the RED. 

12 
pesticide active ingredient, as well a.;; other relevant information, developed the appropriate risk 

assessments, and decided whether or not the pesticide active ingredient satisfied the risk-benefit 

standard of FIFRA section 3(c)(5). After determining eligibility of the active ingredient, EPA 

determined whether to reregister products containing the active ingredient?' See FlFRA § 

4(g)(2)(B) .. In conjunction with most REDs, the Agency "called-in" active ingredient- or 

product-specific data considered necessary to reduce uncettainty in the RED risk assessments. 

Reregistration wa an open and transparent process. Before finalizing its decision on the 

eligibiHty for reregistration of a pesticide, EPA made the supporting risk assessments available 

for public comment, although it was not required to do so. Comments were solicited particularly 

on the factual basis of the risk assessments and also on options for mitjgating the risks posed by 

the subject pesticide. These comments were considered in the Agency's decision-making. 

Most of the pesticides specifically named in the Petition went through the reregistration 

process. Information on the reregistration status and links to the reregistration dockets for any 

pesticide can be accessed via the Agency's Chemsearch database.

32 And, as explained more fully 

below, they have also been scheduled for review early in the current re-evaluation process, 

known as Registration Review. See FlFRA § 3(g). 

ii. Registration Review 

Once the reregistration decisions for all the subject active ingredients were completed, the 

Agency began the next re-evaluation process under FIFRA, which requires EPA to regularly 

review pesticides to ensure that they continue to satisfy the statutory standard for registration. 

The ongoing re-evaluation process is called registration review. Section 3(g) of FIFRA requires 

EPA to complete its initial registration review cycle by October 1, 2022, for all pesticides 

registered Jprior to October 1, 2007, and by 15 years after the date of initial registration for 

pesticides registered after that date. /d.33 Following the initial review of the pesticide, EPA must 

conduct subsequent reviews of each registered pesticide every 15 years thereafter. 

The registration review program34 makes sure that, as the ability to assess risk evolves and as 

policies and practices change, all registered pestjcides continue to meet the statutory standard of 

no unreasonable adverse effects. Through registration review, the Agency is ensuring that 

registered jpesticides do not cause unreasonable risks to human health or the environment when 

used as directed on product labeling. Changes in science, public policy, and pesticide use 

practices will occur over time, and the cyclical nature of registration review wi!J enable the 

31 While the Agency has completed its starutory requirement to make eligibility determinations on the 

subject active ingredients, product reregistration is still ongoing for some reregistration cases. 

32 llp://iaspub.epa.gov/npc>./Qe~1ic deslf?p=chemicab,earc : I ; search by active ingredient name, PC 

Code, or CAS number. 33 See also 40 CFR Pan 155 for the implementing regulations. An overview of rhe process is found at 

hllp:l/\\ '"" .cpa.gov/oppsrrd l/reg1strntion review/highlight'\ htm. 

~ Unlike earlier re-evaluation programs, registration review operates continuously, and provides for 

the review of all registered pesticides. 

13 
Agency to consider updated information every time a pesticide comes up for registration 

review. 35 

In conducting the registration review program, EPA generally is reviewing pesticides in 

chronological order according to their baseline dates;

36 that is, older cases are being reviewed 

fir t. In addition, many pesticides that received priority sc ed n~ for reregisn·ation have been 

scheduled early in registration review. Thus, food-use chemicals that were identified as or 

suspected of having risk concerns at the outset of reregistration generally are scheduled early in 

the registration review process. Additionally, within this structure, EPA plans to review certain 

related pesticides at the same time, particularly pesticides in the same family, with the same 

general structure and mode of action. 

In reregistration, EPA gained experience and benefited from efficiencies in the concurrent 

review of pesticides in families like the organophosphates (OPs). N-methyl carbamates (NMCs), 

triazines, and chloroacetaniJides. The rodenticides and soil fumigants were also reviewed 

concurrently. EPA s to continue the practice of grouping related pesticides during 

registration review. 8 Potential efficiencies from this practice include: 

• Technical and regulatory issues may be resolved more easily looking across an entire 

chemical class or group; 

• Resources can be optimized within EPA, among stakeholders, and within other federal 

agencies; and 

• ln developing decisions, a "level playing field" among chemicals in the group may be 

assmed so that EPA's actions do not inadvertently cause increased risks. 

EPA completed cumulative risk assessments and reregistration risk management decisions 

for the OP pesticides in August 2006 and the NMC pesticides in September 2007. In recent 

years, EPA and stakeholders have invested significant resources in gaining a betler 

understanding of these classes of pesticides. The registration review of the OPs began in 2008, 

and the N-methyl carbamate review began in 2010. The Petitioners are requesting expedited 

reviews for both classes of chemicals. These classes of pesticides were among the first 

pesticides to enter the registration review program, so the assessment of risks associated with 

their use (including risks to children, and risks from spray drift), and the management of those 

risks. should be accomplished early in the current registration review cycle, and in subsequent 

cycles as well. Volatilization will also be addressed based on the results of the screening analysis 

and the subsequent availability of pertinent data, should they be required for individual 

pesticides. The scheduling of these classes of pesticides in registration review reflects an 

tmderstanding of the importance of addressing the toxicity, dietary and aggregate risks, and the 

JS The Agency uses the best, most recent information in any risk assessment, but the cyclical nature of 

registration review assures that assessments for any one pesticide will be updated at least every 15 years. 36 The baseline date is the date when a RED was completed, or for a pesticide not subject to 

rere~ istratio , the date when the pesticide was first registered. 7 Pestic ides used on food crops were given high priority because they have potential to affect the 

population 21t-large via dietary exposure. 38 The overview at http://\'-'WW.epa.gov/orm.rrd 1/regJ!-.Lratton rev1e\~ /h1ghli~hts.htm provides links to 

information on the pesticide family groupings. 

14 
volume of use for these pesticides. See Appendix to this response for the registration review 

schedules for the OPs and NMCs. 

EPA initiates a registration review by establishing a docket for a pesticide registration review 

case and opening the docket for public review and comment. The Agency publishes a Federal 

Register notice that announces the availability of a Preliminary Work Plan (PWP) and provides a 

comment period of at least 60 days. Anyone may submit data or information in response. EPA 

will consider information received during the comment period in conducting a pesticide's 

registration review. The PWP: 

• explains what EPA knows about the pesticide from previous risk assessments including 

hazard and exposure infonnation related to children. when available, and application of 

uncertainty factors including the FQPA safety factor; 

• tentatively identifies what kind of risk assessments are needed; 

• tentatively identifies what data will be needed to conduct the assessments; 

• addresses the uncertainties in the database that will impact the risk assessments 

(paJrticularly missing or unclear use parameters); 

• provides basic use and usage information and other background information on the 

pesticide; and 

• provides a proposed schedule that lays out milestones up until the registration review 

decision is made. 

Information from registration review dockets that have opened is readily accessible via 

Chemical Search on a chemical-by-chemical basis. 

Registration review, as set forth in the regulations, is a transparent process in which 

stakeholde1rs of all types are invited to provide relevant data and comments. At the beginning of 

registration review, the public is asked to comment on the PWP and its supporting documents; by 

soliciting these comments, EPA aims to gather additional information that can enhance 

registration review planning and decision-making. Other registration review documents also are 

subject to aL public comment period, such as when the preliminary risk assessments are posted to 

the docket later in the process. Similar approaches to public notification and comment were used 

during reregistration and can be used in decision-making about new active ingredients. 

EPA may also. as needed, consult with registrants, the U.S. Department of Agriculture. and 

other stakelholders to resolve any uncertainties about how the product is used, particularly if use 

parameters are not clear from product labeling, or if the registrant may have data not already 

submitted to the Agency that could inform the process. For example, some labels are not 

specific about retreatment intervals or seasonal maximum application rates. Without actual use 

parameters, the Agency is forced to make conservative assumptions that can result in overly 

conservative risk assessment results. The Agency may solicit such information in a "Focus 

Meeting." These meetings can be held whenever in the registration process they might be 

helpful. To ensure transparency. materials associated with Focus Meetings are available in the 

pesticide-specific registration review dockets. If a focus meeting is held prior to the docket 

15 
opening, these materials are posted to separate docket. 39 Once the docket opens, a copy of the 

focus meeting notes will be posted to the case-specific docket. 

After the close of the initial comment period, EPA revises its work plan as needed based on 

public input and any additional information that has become available in the interim. The Final 

Work Plan is then posted to the docket, and EPA prepares to call-in any data needed for the risk 

assessments. Once the registrants submit the required data, work on the risk assessments begins. 

As noted above, EPA makes the draft risk assessments available for public review and comment, 

and subsequent to review of public comments, the Agency posts the revised assessments. If the 

revised assessments indicate that there are risks of concern, EPA may invite the public to submit 

suggestions for mitigating those risks. These suggestions are used in the development of a 

proposed negistration review decision. 

EPA will announce the availability of a proposed registration review decision on the docket 

and will provide a public comment period of at least 60 days. The process culminates with a final 

registration review decision- EPA's determination on whether the pesticide in question meets or 

does not meet the standards for registration. The final registration review decision discusses any 

changes tha t are needed to the pesticide's registration or labels to address the risks of concern. If 

a registrant fails to take action to implement these changes, EPA may take appropriate action 

under FIFRA. 

To meet its statutory obligations for registration review, EPA is opening 70 or more dockets 

armually continuing through 2017, and almost all of the pesticides registered at the start of the 

program will have dockets opened by 2017. The Agency is directed to complete the first round 

of registration reviews by October 1, 2022; during that time the Agency will complete the 

registration reviews of at least 744 pesticide cases comprising I ,165 active ingredients. 

Pesticides 1registered after 2007 will be folded in each year.

40 

iii. Regulatory Responses to Unacceptable Risks 

If EPA determines that a pesticide product does not meet the statutory standard, the Agency 

may take "appropriate regulatory action.'' Such regulatory actions can include, but are not 

limited to, restricting pesticide uses or canceling the pesticide's registration. See FlFRA §§ 3(d) 

& 6(b ). If EPA chooses to cancel a pesticide registration, EPA must first issue a Notice of Intent 

to Cancel and hold a formal administrative hearing, if one is requested by a person adversely 

affected by the notice. See FfFRA § 6(b ). 

If the Agency determines that an "imminent hazard" exists from the use of a pesticide 

(including a pesticide that was not eligible for reregistration), EPA may commence proceedings 

39 Gene1ral information about focus meetings is at 

http.//www .epa.gov/oppsn·d 1/reeistrat•on revJew/focus-meetings.html; the docket itself is at 

http.//www. regulations.l!ov/#!docketDeta il ,D=EP A-HQ-OPP-20 12-0778. 40 The status of all completed and ongoing registration reviews can be found at 

hllp://v. W\\ .cp .!mv/opp~rrd I /re!!JS.lration rev1ew/ree re\1 ie,., !>laiU'i.hlm. 

16 
to suspend the registration of a pesticide during the time needed to complete cancellation 

proceeding;s. See FIFRA § 6(c). Section 2(1) of FIFRA defines imminent hazard as: 

laJ situation which exists when the continued use of a pesticide during the time required 

for cancellation proceeding would be likely to result in unreasonable adverse effects on the 

environmen! or will involve unreasonable hazard to the survival of a species declared 

endangered or threatened by the Secretary pursuant to the Endangered Species Act. ... 

If the EPA determines that an emergency exists such that the imminent hazard wiJI occur 

during the period necessary to complete normal suspension proceedings, the EPA may issue an 

immediately-effective emergency suspension order in advance of completing suspension 

proceeding,s. !d.§ 6(c)(3). 

Courts addressing the suspension provisions have held that an imminent hazard exists if there 

is "a substantial likelihood that serious harm will be experienced during the year or two required 

in any realms tic projection of the administrative process." Love v. Thomas, 858 F.2d 1347, 1350 

(9l11 Cir. 1988) (quoting Environmental Defense Fund v. EPA, 465 F.2d 528, 540 (D.C. Cir. 1972). 

In the case of an emergency suspension, one court has found by analogy that suspension is 

appropriate if there is a "substantial likelihood that serious harm will be experienced during the 

three or four months required in any realistic projection of the administrative suspension 

process." Dow v. Blum, 469 F.Supp. 892, 90 l (E. D. Mich. 1979). Thus, courts interpreting the 

FIFRA us pension standard have made clear that an imminent hazard finding requires a greater 

degree of I ikelihood, immediacy, and severity of harm than is otherwise required to take a 

cancellation action under FIFRA. And in evaluating the nature and extent of inf01mation before 

EPA, the courts have instructed the Agency to consider ( 1) the seriousness of the threatened 

hru.m, (2) tlhe immediacy of the threatened harm, (3) the probability that the threatened harm will 

occur, and ( 4) the benefits to the public of the continued use of the pesticide !d. at 902. 

EPA's review and re-evaluation processes for pesticides have been developed to account for 

advancements in science so that risks can be identified and managed before a pesticide is 

registered and at regular intervals thereafter. Through these processes, the Agency can anticipate 

and correct problems with the use of pesticides as time goes on, and, ideally, reduce the chances 

that a pesticide would pose risks of an immediacy and magnitude like those associated with an 

imminent harm finding. 

V. How Pesticide Risks .\reAssessed 

The type of assessment pertinent to this Petition is the human health risk assessment41 

(ecological risk assessments are not discussed in the Petition). EPA uses a science-based risk 

assessment. approach. Risk is a function of both the hazard associated with a pesticide and how 

much exposure occurs to that pesticide. Hazard is the innate ability of a pesticide or other 

stressor to cause an adverse effect (its toxicity). At EPA, hazards are typically identified from 

the results of testing on several animal species and typically the most sensitive effect is used as 

·II See hllp://www.epa gov/oe~ttcJde<Jnboutlovcr viev .. rbk ns~C!>S.htm 

17 
the basis for risk assessment. Exposure is the amount or concentration of a stressor with which 

an affected. individual or group interacts. Risk is a function of both hazard and exposure and 

represents the likelihood that an individual or group will be adversely affected by that stressor. 

Both hazard and exposure can differ according to a person's age, thus EPA uses age-appropriate 

behaviors t:o determine exposures and also looks at any special sensitivity to pesticides 

associated with the age of the exposed parties. EPA uses the National Research Council's fourstep process42 for its human health risk assessments. The four steps include: 1) hazard 

identification, 2) dose-response assessment, 3) exposure assessment, and 4) risk characterization. 

Each of these steps is summarized below. 

It is important to note that risk assessment and risk management are separate activities. Risk 

management relates to the ways in which the risks characterized in the assessment may be 

reduced or eliminated. Risk management measures can include tolerance revocation or the 

cancellation of registrations, termination of some uses of a pesticide, changes to a pesticide's use 

parameters, and risk reduction training for people who are occupationally exposed, such as 

pesticide applicators. 

The first step in the risk assessment is to identify potential health effects that may occur from 

different types of pest1cide exposure. EPA considers the full spectrum of a pesticide's potential 

health effects. 

Typically, a pesticide active ingredient is subjected to many toxicity studies, and the data 

from these studies (if determined to be acceptable) are used in risk assessment. Requirements for 

the relevant data are typically imposed on the pesticide applicant or registrant, and the studies are 

typically conducted by independent laboratories, with strict standards for data surety.43 The data 

are evaluated for acceptability by EPA scientists. The toxicity studies primarily are performed on 

laboratory animals or in vitro, although some of the required studies are conducted in the field. 

The Agency will also review human toxicity studies, with qualifications, as discussed below, but 

does not re:quire them. EPA evaluat~s pesticides for a wide range of potential toxic effects 

including eye and skin irritation, neurological effects, cancer, and birth defects. ln addition to 

reviewing the required studies, EPA also consults the public literature or other sources of 

supporting information. 

The required tests are used in the assessment of potential health effects in infants, children, 

and adults. They are conducted for exposures of different durations, as appropriate to represent 

the durations of exposure anticipated for various lifestages and behaviors. Exposures may be of 

single day or longer durations, up to and including durations sparming a lifetime. Additionally, 

EPA considers the route by which these exposures may occur-orally, e.g., through the diet or 

via childre"n's mouthing behaviors; through the skin; or by inhalation. 

42 The National Research Council produces reports for the National Academy of Sciences. The 

process is explained at llup://~ jU! v/ris assessmentJh allh rh.l- htm . 43 Required laboratory practices for studies used to support pesticide registration are detailed at 

http://wW\\ . gpo.~rov/fdsv~/pl,. !!/CFR-?0 J titl O-vo xmi CFR-:?. 0 I l -tll le40-vol:?.4-panl60.xml 

18 
To address risks to infants, children, and adults, EPA typically requires animal testing at 

mttltiple life stages, including during gestation and shortly after. The effects that are observed in 

this type of testing are fetal development (including birth defects) and reproductive success. The 

results of these studies are particularly applicable to the assessment of risks to the fetus and 

young children and, when compared to studies with adult animals, provide a basis for evaluating 

the relative sensitivity of the young to adults. 

In order to develop a risk assessment that is protective of human health, the Agency will 

select the '''most sensitive" endpoints and the corresponding point of departure (POD) from 

among these different studies for the relevant populations, taking into account the durations and 

routes of exposure. The endpoint can be described as the toxic effect itself. The POD is 

typically the dose level below the lowest dose at which the adverse effect is manifested. 

As an example, consider an endpoint that was selected from a shorter-term animal study in 

which the :animals were exposed via the dermal route, for a pesticide that is registered for use on 

lawns. In nhis example, the POD based on this endpoint would be used to estimate 1isks to adults 

and to children aged 1 to 2 years old. Children in this age group typically are the most highly 

exposed relative to children of all ages for pesticide residues on turf by weight and because of 

their behavior on lawns, as they are exposed to residues through contact with their skin when 

they play i:n their yards or in parks and playgrounds, and are also exposed orally, predominantly 

via hand-to-mouth behaviors. 

As noted previously, the Agency also will consider relevant data from sources other than 

required studies, including data from prospective and retrospective epidemiologic studies, 

incident reports,44 

and studies in which human subjects have been exposed intentionally to a 

pesticide (although the latter must undergo an specialized review to ensure that the Agency does 

not rely on data from studies that violate established ethical standards).

45 EPA uses its draft 

"Frarnewotrk for Incorporating Human Epidemiologic & Incident Data in Risk Assessments" 

when considering those types of data.46 

The second step in the risk assessment process is to consider the dose levels at which adverse 

effects were observed in test animals and to extrapolate those dose levels to an equivalent dose in 

humans. For animal studies, the uncertainty around the extrapolation from test animals to 

humans and the variability of sensitivity in the human population are accounted for by 

uncertainty factors. The default factors assume there could be up to a ten-fold difference 

between animals and humans and up to a ten-fold difference between the average person and the 

most sensi1tive people in the population. That is, humans generally are assumed to be 10 times 

more sensitive than animals, and the most sensitive individuals generally are assumed to be 10 

times more sensitive than that. These uncertainty factors create a margin of safety for protecting 

44 For e:xample, per analysis of pesticide acute illnesses based on 1998-2006 NIOSH SENSOR data, 

see http:/l<:litp03.meh~>-Ilih.gov/anicle/in fo'k 3Ado,r/c 2Ft 0. 1289% 2Fehp.l 00284.3, referenced in the 

Petition. 

45 http://www .cpa.gov/oppfead 1/iwidance/human-tel>L.hLm 

46

hnp://www .regulatlon~.go,J#!documcnt.DeLaii:D=EP A-HQ-OPP-2009-0851-(XJO-l 

19 
people who may be exposed to the pesticides. The FFDCA requires EPA to use an extra 10-fold 

safety factor to protect infants and children from effects of the pesticide, unless reliable data 

show that a different (larger or smaller) factor would protect the safety of infants and children.47 

The third step in the risk assessment process is to address how long, and at what level people 

are exposed to a pesticide, a critical consideration when selecting endpoints and also for 

calculating. risks. For spray drift, exposures are assessed for contact with previously 

contaminated surfaces such as lawns adjacent to treatment areas. More specifically, the Agency 

assesses exposures from dermal contact (e.g., children playing on lawns) and also non-dietary 

ingestion from mouthing behaviors of young children. Adults also are expected to have 

exposures from dermal contact. For volatilization exposure, the primary exposures result from 

inhalation since exposure is to the gas or vapor form of a pesticide. 

In general, pesticide residues deposited on surfaces (such as grass or the leaves of treated 

crop plants.) remain available for exposure to people entering treated area'i, or areas in which 

spray drift residues have settJed, for more than a single day, so subchronic studies are used to 

derive endjpoints and PODs. Single day (acute toxicity) studies also may be considered in order 

to evaluate risks on the day of applicatjon (when the greatest exposures are likely). Impacts on 

fetuses due to the exposure of pregnant women are included in the risk assessments when 

information on reproductive and developmental toxicities is available. If information on 

reproductive and developmental toxicities is not available, an uncertainty factor may be used to 

account fo1r the possibility of the special sensitivity of children not apparent from available data. 

More details are provided in Sections VIT and VIII below on how exposures to spray drift 

and volatilization are determined. 

D. Risk \.'h,trncteruauon 

The last step in the risk assessment process is to combine the hazard and exposure 

assessments to describe the overall risk from a pesticide. Risk characterization explains the 

assumptions used in assessing exposure as well as the uncertainties

48 that are built into the doseresponse assessment, and whether or not the assumptions and uncertainties used are likely to 

overstate or understate potential risks. The strength of the overall database is considered, and 

broad conclusions are made. 

In summary, the risks to human health from a pesticide depend on both the toxicity of the 

pesticide and the likelihood of people coming into contact with it. At least some exposure and 

some toxicity are required to result in a risk. For example, if the pesticide is very toxic, but no 

people are exposed, there is no risk. Likewise, if there is ample exposure but the chemical is nontoxic, there: is no risk. 

47 EPA may modify these uncertainty factors on a case-by-case basis when supported by chemicalspecific behavior. 

48 These are uncertainties not covered by FQPA or other uncertainty factors, e.g. deriving from an 

incomplete database. 

20 
E. Ch ilclrcn and p~-..tkldc-. 

--~-----------------------------------------------------

EPA has developed methods for estimating pesticide exposures to children through the diet 

and via non-dietary sources such as residential exposures. These methods rely on the best 

available scientific sources, such as EPA's "Exposure Factor's Handbook ... 49 Dietary exposures 

are based on consumption data for children, and residential exposures are based on methods 

outlined in the ''Standard Operating Procedures (or SOPs) for Residential Exposure 

Assessme111t."50 The SOPs address exposures for various lifestages, and allow for the 

identification of the most highly exposed lifestage. The SOPs, including the concept of lifestage, 

have been discussed extensively by the FIFRA Scientific Advisory Panel (SAP).51 The 2012 

revision of the SOPs reflect the input of the SAP.52 

Young children may have unique exposures that adults do not have because of age-specific 

behaviors, for example, picking things up from the ground and mouthing them, or putting their 

hands (pott ntially contaminated with pesticide residues) in their mouths. They may also come 

into contact with pesticides when crawling or at play on treated or contaminated surfaces. 

Children up to adolescence have a higher surface to weight ratio than adults, so they may also be 

proportionately more highly exposed via the dermal route. Children can also be more highly 

exposed via the dietary route because they consume more food and water in proportion to body 

size than adults, and the types of food they eat a lot of tend to contain more pesticide residues. 

Available data pertinent to children's health risks are evaluated along with data on adults and 

the most sensitive, appropriate POD is defined (e.g., NOAEL or no observed adverse effect 

level) for 1rhe most sensitive critical effect(s) based on consideration of all health effects. By 

doing this, protection of the health of children will be considered along with that of other 

potentially sensitive populations. In most cases, it is appropriate to evaluate the potential hazard 

to children separately from the assessment for the general population or other population 

subgroups. 

The apjproach used by EPA to account for pesticide exposures in children is consistent with 

EPA's general risk assessment methods53 and follows the Agency's age grouping guidance. 5

4 

The approach is also consistent with recommendations from the National Academy of Science 

49 http://cfpub.epa.l!ov/ncea/rislJrecordi spl ny.c f m?deid=236252. 50 http./ www.epn.gov/pesticJde~/!\cicncc/rc-.ide ial-exposure-sop ml 51 The SAP is a federal advisory committee consisting of independent, external scientific experts that 

advises the Agency's Office of Pesticide Programs (OPP) on technical issues. 

51 The SAP meeting report is at http://www .~:pa gov/sc poly/sap/mcc.>ting,s/2009/1 00609meetmg.lnml. 53 EPA' s risk assessment methods can be fo und at ttp://w~w.cpa gov/risk/guidan e.htm : An 

overview of EPA's approach to assessing and managing these risks is provided in the 20 I 0 report 

"Protecting Children's Health," found at tt p://www.epa.~rov/pes icides/health/protecting-children.pdL 54 An overview of EPA's approach to assessing and managing these risks is provided in the 2010 

report "Protecting Children's Health," found at http://www .epa.gov/pesticides/health/protectingchiiJrt:n.pdf.: the 2005 paper "Guidance on Selecting Age Groups for Monitoring and Assessing 

Childhood Exposures to Environmental Contaminants, at 

http://www .epa.gov/raflpublkauonslpdfs/AGEGROUPS.PDF, advises risk assessors on selecting 

appropriate age ranges for use in implementing the Agency's initiatives on pr 

21 
1993 report, "Pesticides in the Diets of Infants and Children,"55 cited extensively by the 

Petitioners. EPA has adopted many of the recommendations from that report into its current risk 

assessment' procedures. 

\!1. omcndature Associ:Jtcd '~ith Spra~ Drift and Volatilization 

EPA w;es an informative nomenclature that allows for a clear delineation between the 

possible forms and/or sources of pesticide movement through the air and away from treated 

fields. This approach provides for a means of avoiding confusion when describing the unique 

processes and factors that can contribute to pesticide movement. Whether or not pesticide drift 

occurs duri,ng or after application is an important factor, as is whether or not pesticides are 

applied in )l iquid form or as solid material. 

As indicated previously, for this response, the Agency focuses on "spray" drift, the off-site 

movement of aerosols originating with pesticides applied as liquids, rather than dust drift, 

because spray drift is more likely to occur and generally poses greater risk. Also as noted 

previously,, the Petitioners do not appear to differentiate between drift and volatilization. 

Although there are similarities in the mode of transport (through the air) associated with 

volatilization and spray drift, EPA assesses spray drift and volatilization separately, for several 

reasons: 

• They a1re two distinctly different processes. Spray drift is dependent on how applications are 

made and on the form in which the pesticide is applied, while volatilization is driven by the 

physical and chemical characteristics of the pesticide active ingredient (especially its vapor 

pressure). 

• Spray drift occurs at the time of application and shortly thereafter, for as long as droplets 

remain aloft. Volatilization, on the other hand, can occur during the application process and 

also over longer periods of time depending upon the physical and chemical characteristics of 

the pesticide and how it was applied. 

• The route of exposure that the Agency assesses for volatilization is inhalation. The Agency's 

assessment of spray drift focuses on dermal exposures and exposures from non-dietary oral 

ingestion (predommantly from hand-to-mouth behaviors in young children). Inhalation 

exposures are not included in the Agency's spray drift assessments for the following reasons: 

• Most, but not all, of the droplets in spray drift are too large to be respirable. 

• For agricultural pesticides, the Worker Protection Standard (WPS) prohibits the 

application of a pesticide such that it contacts, either directly or through drift, any 

worker or other person. 5

6 This WPS prohibition mitigates the potential for bystander 

exposure to active drift, but not the residues of drift that are deposited on surfaces to 

which bystanders may be exposed. 

The Ag:ency at present lacks an assessment methodology for drift inhalation exposures. 

• The wa.ys that the risk from volatilization and spray drift can be mitigated are different. 

55 hllp.//w\H\ .nap.edulopcnbook..php?record •d=2126&page= I. 56 hUp://www.epa.gov/pcsucade~health/IA orJ...er.htm 

22 
The opterating definitions of "spray drift" and "volatilization" are discussed in detail in 

Sections VII and VIII, respectively. 

VU. As~e.c;..., in~ot und ~1ana in g Risk>i from pnl~ Drift 

EPA has been working with a broad range of public and private stakeholders to address 

concerns related to spray drift and the potential for adverse effects related to drift exposure. 5

7 

EPA's goall is to assess, and if necessary, to mitigate spray drift via a science-based approach 

relying on ,case-specific information. 

Spray drift is influenced primarily by environmental conditions (such as wind speed) and 

application parameters (such as formulation type, application method, application rate, 

droplet/particle size, application release height). Some degree of pesticide drift is an inevitable 

result of ne:arly all types of pesticide application. Even under the best of circumstances, a minute 

amount of pesticide can move out of the treatment area for a short distance. When the amount of 

drift is such that it poses risks of concern, the Agency will take action to mitigate those risks. 5

8 

Quantifying the potential risks of spray drift is a complex process that involves predicting the 

amount of drift associated with various types of application equipment, estimating potential 

exposures, and considering the potential health effects from such exposures. Managing the risks 

associated with spray drift can be complex as well and there are a variety of potential approaches 

that can be used, as discussed more thoroughly below. 

A. E~lllllltll mg Spray Dril t u11d PutentrJI Exposure~ to By~laml~:r:-. ~\J 

-------------------------- Since the early 1980's, EPA has been working to better understand spray drift. Information 

key to this effort was developed by a group of pesticide registrants working collaboratively to 

create a database that addressed spray drift data requirements under 40 CFR 158.440.60 This 

group is rc1ferred to as the Spray Drift Task Force (SDTF).

61 Since its formation in 1990, the 

SDTF has generated standardized data on spray drift levels associated with a variety of 

application methods under varying field and meteorological conditions. The database was 

reviewed by EPA internally, through external peer review workshops, and by the SAP.

62 Using 

the database, the SDTF began working with EPA's Office of Research and Development and the 

USDA's Agricultural Research Service and Forest Service in 2000 to develop and validate a 

57 The Pesticide Program Committee (PPDC) is a federa l advisory committee that includes 

representatives from a broad variety of stakeholders interested in pesticide regulation. See 

http://www.cpa.l!ov/oppfead 1/cb/ppdc/.The PPDC's Spray Drift Workgroup has provided valuable input 

on the Agency's approach to assessing and mitigating spray drift. Membership of the Workgroup includes 

environ men tal advocacy groups, grower associations, registrants, and state officials. See 

http://www. epa.gov/oppfenu I /cb/ppdc/spraydri ftlmembers.htm. 

SR hllp://www .e pa go /pe~ ic ide~/fact he l!I pra ydrifLhlm. 59 For PIJrposes of this response, bystanders are defined as people who, live, play, or work in areas at 

proximity to pesticide-treated areas. 

60 See bllp://www.epa.gov/ocspp/pubs/frslpubli<.:atiom,ffest Guideline!>/sen es840.lllm 

61 The Task Force's website is at http://www.agdrift.com/ 

62 See hl.lp:/1\\ ww .epa.go\/scipoly/ ... ap/meetlngs/1997/decembe r/spravdrift.htm. 

23 
model for predicting the magnitude of off-target movement of pesticides via spray drift, called 

the "AgDrift'' model. 

The Ag;Drift model was developed to assess spray drift under a variety of different conditions 

for aerial, ground, and orchard air-blast applications. Input features provide the capability to alter 

over 30 parameters related to the aerial application method including types and numbers of 

nozzles, weather cond1tions, and terrain features. AgDRIFT also can provide empirically based 

predictions for ground and airblast applications made under various conditions, and can 

accommodate differences in use patterns that relate to crop-specific pest management needs. In 

addition, users can run the AgD1ift model to estimate the amount of spray drift at specified 

distances from the application site. 

Spray dlrift associated with aerial application has been evaluated extensively by the U.S. 

Army and the USDA Forest Service, so the drift database is more extensive for aerial 

applications compared to ground applications. For orchard airblast and groundboom sprayer 

estimates, AgDrift is more limited; unlike estimates for aerial applications, there is no 

mechanistic option for these ground applications. Rather, an empirkal approach based on the 

available d.ata is used, and users are more limited in the number of factors that can be considered 

(e.g., orchard canopy type for airblast sprayers). Even so, AgDrift is a powerful tool for 

quantifying spray drift for these application methods. 

For aerial applications, EPA uses AgDrift to predict conservative estimates of the amount of 

spray drift given the conditions specified on pesticide labels (when such conditions are not 

specified Oin the proposed label, the Agency uses conservative assumptions). AgDRIFT has 

more limited capabilities to reflect label specifications for ground applications. AgDrift can be 

used to estimate the risk reduction attributable to buffer zones of specified widths (essentially by 

estimating the differences in the amount of spray drift at different distances from the application 

site). In addition to its use in assessing bystander risks, AgDrift can be used in environmental 

assessments to estimate the potential spray drift exposures to non-target animals and plants. It 

also is used to estimate the potential contribution of spray drift to pesticide residues in drinking 

water. 

Results from the use of AgDrift represent a range of possible outcomes that are reflective of 

cultural practices tied to how the target crop are produced and the nature of the pesticide being 

applied. For example, a contact insecticide application to dense-canopy field crops may be most 

efficacious when the spray is composed of finer aerosols, while a systemic herbicide applied to a 

field crop c:anopy of lesser density, where complete spray coverage is not needed to achieve the 

desired degree of efficacy, can contain droplets of a larger size (as an aside, larger size or coarse 

droplets tend to drift less, all other factors being equal). 

EPA acknowledges that there is some potential for drift exposures to occur indoors, but 

believes that the amount of drift entering enclosed structures is very small relative to the amount 

present out-of-doors. The Agency's efforts to understand the human health dsks posed by drift 

are focused! on outdoor exposures. 

B. As l: ... .,llletlt ofR1 ... 1. to B}'tander:-. from Sp1:.1_ Dntl ---------- ~---------------------------------

24 
EPA has been working to refine and standardize the way it assesses the risks to bystanders 

from spray drift. On December 5, 2013, EPA presented its approach to assessing spray drift to 

the PPDC. EPA made this new methodology for assessing spray drift available for public 

comment on January 29, 2014. The announcement and directions on how to submit comments 

on the proposal can be accessed on the public docket.63 EPA will continue to conduct spray drift 

risk assessments under its current process while it reviews and analyzes comments received 

during the public comment period, which originally was scheduled to end on March 31, 2014, 

but is being extended by 30 days. After reviewing public comments, EPA plans to finalize its 

methodology and consider it in cases that warrant spray drift risk assessment. 

The methodology for assessing spray drift exposures is based in part on the methodology for 

assessing r'esidential exposures to pesticides on turf, as explained be1ow,64 coupled with 

estimates of the amount of spray drift reaching the area in question, which are derived as 

described in Section A., above. EPA has developed methods for estimating risks for residential 

scenarios in which people may be exposed through their use of a pesticide or because they live, 

work, or play in places where pesticide use occurs. As noted previously, EPA uses its SOPs for 

residential exposure assessment as the basis for estimating exposures in these situations. These 

SOPs have undergone extensive external peer review by the SAP.65 SOPs exist for a wide range 

of possible exposure scenarios. 

The Agency assesses bystander risks from spray drift based on the residential turf scenario, 

in which people (including children) are exposed to pesticide residues on lawns.66 If an 

agricultura.l pesticide is also registered for use on residential turf, EPA has determined that an 

additional drift assessment is not necessary beyond that of the residential turf. For an agricultural 

pesticide nQt also registered for use on turf, the Agency can use the screening methodology that 

is included in the new drift methodology, and may be able to conclude, qualitatively, that drift 

does not pose risks of concern for bystanders, so a quantitative assessment is not needed. When 

a quantitati ve assessment is needed, the methodology calls for the use of the AgDrift model to 

estimate the amount of pesticide residue available on turf for the exposures of adult and child 

bystanders. The estimated amount of residue and the exposure factors for adults' and childrens' 

time and activities on lawns are used to calculate exposures through the skin and from the 

mouthing behaviors (predominantly hand-to-mouth) of children of appropriate developmental 

age. These exposures are compared to the appropriate endpoint and POD, as discussed in V.B. 

"Hazard Identification" above. 

The development of the SOPs for evaluating lawn pesticides considered a number of factors 

related to how residues should be quantified, the appropriate behavioral considerations for adults 

63 http://\\ ww.regulatton .. I!O\/#!dockecDetaii;D=EPA-HQ-OPP-20 I J-06 76 

64 ht ://www.e a.gov/pe~tt ic.l e..Jsc ce/res icl nti -expo re ~o hlml 

bS http://www.epa.goy/sctpoly/sap/tools/atozindex/residentexp.htm and 

hnp://www .1epa.gov/sc ipoly/sap/meetings/2009/ 1 00609meeting.html 

66 See particularly the Lawns/Turf SOP at hl //www.e a.gov/pe~ li ides/scie cdres tdcn

expo:-.ure-..,op.html. The SOP identifies default values for exposure parameters e.g., time that a child 

spends on the lawn, how often children will put their hands in their mouths, etc. These values have been 

selected so that exposure estimates overall will be conservative. 

25 
and children, development of appropriate exposure metrics, how exposures should be combined, 

and what age groups should be considered as the basis for risk management. EPA considers 

adults involved in heavy yardwork and children ages 1 to 2 (based on both body weight and play 

behavior) as the two groups most highly exposed to turf-applied pesticides. EPA has 

extensively considered children of varying ages in order to ascertain which lifestage (referred to 

as index Iifestage in the SOPs) has the highest relative exposure given behaviors that occur at 

various stages of development. Children between 1 and 2 years old routinely and very active) y 

engage in outdoor play, and they exhibit mouthing behaviors (predominantly hand-to-mouth) 

which contribute to the overall exposure levels. 

EPA relics on a number of assumptions when using the SOPs in the calculation of risks from 

spray drift. Risks are based on residue levels present on the day of application when they are at 

their highest levels because they have not had a chance to dissipate. Risks are also estimated 

based on a standardized lawn width of 50 feet. The standardized lawn was derived from U.S. 

Census information for single- and multi-unit dwellings-it is the mean lot width for multi-unit 

housing and also is a reasonable representation for single-unit housing with smaller lots. A lowend lot size is used because the concentration of spray drift residues is assumed to be inversely 

correlated to lot size due to lhe effects of residue dilution in larger lot sizes.67 Use of "day of 

application" residues and the standardized lawn size contribute to a data-infonned conservative 

estimate of risk. 

C. il<m EPA Mitigate' Potential Risk' A"'l..lCi::tted \vith Spr:ty Dnft 

Unacce:ptable risks associated with spray drift can be mitigated in a number of ways, 

including changes to application parameters, use of drift reduction technologies,68 changes to 

formulations, and no-spray buffer zones, either in combination or by themselves.

69 While the 

use of buff,er zones is one of the key issues raised by the petitioners, other measures also can be 

used to manage potential risks associated with spray drift. Changes to application parameters 

and pesticide labels that may mitigate drift risks include reduced application rates; prohibition of 

certain application methods; soil-incorporation of pesticides at the time of application; and 

prescriptiv~~. product-specific labeling that requires a pat1icular spray quality (i.e., droplet sizes) 

or climatic conditions. The Agency may also undertake cancellation of specific uses, in those 

rare cases where spray drift causes unreasonable risks that cannot otherwise be mitigated. 

There is a significant level of effort within the agricultural engineering community to 

develop both drift reduction technologies and best management practices to reduce spray drift. 

Useful drift reduction technologies include different forms of spray nozzles and other 

sophisticated application equipment (e.g., sensors for canopy identification that turn off nozzles 

67 More information on the standardized lawn is found in the proposed methodology at 

http://www.rcgulattons.gov/#!JockelDeta•I;D=EPA-HQ-OPP-20 13-0676. 68 http;//'www .epa.gov/etop/etc at psdt.html and http://www.t:pa.gov/etop/ctc <H proppsdt.html . An 

instructive presentation on the Drift Reduction Technology Program is located at 

http://www .cpa. gov/oppfead 1/cb/ppdc/20 /m:~y ~sJOn-7 -drift-ri!UliCliOn.pdf 

6

Q When appropriate, EPA considers the potential consequences of mitigation measures in light of the 

impact on p1roducers and on the potential for undesirable risk trade-offs. 

26 
at ends of rows), and the use of adjuvants.70 EPA, working with academia and industry, has 

developed a program to rate drift reduction technologies, and plans to identify on its website 

tested technologies and the risk reduction potential attributable to them.71 Other potential means 

of reducing exposures to spray drift are already commonly accepted,72 for example, the 

adj ustment of release height in ground applications. Some formulation types are less prone to 

drift than others; for example, switching to a dry (soil-incorporated) formulation from one that is 

applied as :a liquid may reduce drift potential. A series of possible drift reduction measures are 

already included in the proposed EPA method for calculating risks from spray drift as a sta1ting 

point for considering mitigation options should they be required. This element of the method 

will facilitate consistency in the Agency's decision-making process for managing spray drift 

risks. 

The Agency has used the proposed assessment approach to support pesticide drift risk 

mitigation in past decision-making. The Agency completed its Preliminary Human Health Risk 

Assessment for chlo~yrifos (an orgar10phosphate pesticide) under the registration review 

process in July 201 1. 3 That assessment identified risk concerns for bystanders from exposure to 

spray drift from agricultural applications of chlorpyrifos and provided estimates of the potential 

risk reductiions associated with various drift mitigation options. 

In the Spray Drift Mitigation Decision for Chlorpyrifos (J ul y 2012),74 EPA annOtmced an 

agreement with the chlorpyrifos registrants for implementing use restrictions intended to reduce 

spray drift risks to bystanders. In accordance with the agreement, risk mitigation was 

accomplished through amendments to chlorpyrifos product labels, which were put in place by the 

end of the same year. Mitigation measures were: buffer zones for groundboom, airblast, and 

aerial applications of chlorpyrifos around sites such as homes, sidewalks, and recreational areas; 

and a reduced application rate for aerial applications of chlorpyrifos (from 6 to 2 pounds active 

ingredient tper acre). 

VIII. A~sto;, ing and Mana~ing the Risks I>u~ tn Pestiddc Volatilization 

Pesticide volatHization can be defined as the change of a pesticide in solid or liquid form to a 

gas or vapor after application has occurred.75 Volatilized pesticides can move off-site resulting 

in the potential for exposure outside the treatment area. The volatilization process is complex 

and depends on many factors that include the innate physical and chemical properties of the 

pesticide, tihe innate characteristics of the site where it is applied, and the atmospheric conditions 

at the time of application. Other factors that impact volatilization, particularly those associated 

with application parameters, directions for use, and best management practices are under the 

70 An adjuvant is broadly defined as any non-pesticide material added to a pesticide product or 

pesticide spray mixture to enhance the pesticide's performance and/or the physical properties of the spray 

mixture. 71 htl p://www .epa. !!ov/pcstic illrs/f act1>ht.!ets/spra ydrift.htm#othc r 

72 For eMmple, http://pe~ticidcs ewardship.org/drift!Pages/defauiLaspx provides a general overview 

of existing t·echnologies. 73 See hup://www.regulations.gov/#!documemDetaiLD=EPA-HQ-OPP-2008-0850-001 5. 74

See hltp.//www.regulatiom •. gov/# !documcntDetai l:D=EPA-HO-OPP-2008-0850-0 I OJ 

75 See hup://www .epa.gov/oppOOOO 1/about/intheworks/volattlizatiOn.htm 

27 
control of the user and can be manipulated to reduce off-site movement.76 For example, soil 

incorporation of the pesticide, compaction of the soil, and (particularly in the case of fumigant 

pesticides) tarping and tenting can reduce volatilization from soil- applied pesticides. The use of 

certain adjuvants may reduce volatilization from pesticides applied to foliage. 

Fumigamt pesticides are highly volatile.

77 Once applied, they will change into a gaseous form 

that works by filling the application space or by permeating the soil to kill a wide array of pests. 

Efficacy is achieved by ensuring that the appropriate air concentration is maintained for the 

necessary time in order to control the pest of concern. 78 Practices that are used to reduce 

exposure to (while also improving the efficacy of) fumigant applications include the use of tarps, 

field condinions management (e.g., soil moisture levels), and the use of specialized application 

implements (e.g., specially designed shanks for closing up and compacting the soil disturbances 

to retain th1e fumigant in soil). 

Conventional pesticides (pesticides other than fumigants) tend to be much less volatile than 

fumigants because of differences in their physical-chemical properties, although some 

conventional pesticides volatilize under some circumstances. Conventional pesticides also are 

designed to achieve efficacy via different mechanisms so volatility is not a key required 

characteris1tic. When conventional pesticides do volatilize in the field, they too can move outside 

of the treatment area . 

. Qu:mtrfymg \'lllrnilu:JLion for Ctli1Vl'lltH.""~Hal Pc~til:idc!o. 

EPA has developed a good understanding of the volatilization of fumigant pesticides, as 

noted above and discussed by the SAP,79 including an understanding of how use site conditions 

can impact volatilization. The volatilization of conventional pesticides has not been studied to 

the same eKtent. A number of entities are now focusing on the volatilization of conventional 

pesticides. Research to enhance our understanding of the volatilization of conventional 

pesticides could include work on the impact of a crop canopy or leaf type on the volatilization 

process. Air monitoring data are also important in efforts to characterize how much of a pesticide 

will volatihze and travel out of the treatment area. 

The approach used in the past fumigant risk assessments and EPA's proposed approach for 

conducting volatilization exposure assessments for conventional pesticides consider both single 

application events and the contamination of ambient air within a local community, region, or the 

76 As in controlling drift, practices that limit the off-site movement of volatilized pesticides can 

improve Lhe effi cacy of an application by keeping more pesticide where it is needed to control the target 

pests. 

77 Background and status of the Agency's re-evaluation of the fumigants is found at 

h ttpJ /www .I.!D"· gov/pest1c ides/rcregistrat ion/so1l fumigan ts/soi 1-fum -reg-bac "-gmd. html 

78 The interaction of concentration and time to achieve efficacy is commonly referred to as the 

required comcentration x time schedule (CxT). 79 Supporting documents and the final report from the December 1-4, 2009 SAP meeting on 

··scientific Issues Associated with Field Volatilization of Conventional Pesricides are located in the 

docket at http.//wW\\ .1-eeulaLions. gov/#1docketDctaii:D:EPA-HO-OPP-2009-0687. 

28 
airshed (the air supply for a defined geographical region) from multiple applications within the 

same area. 

Potential impacts associated with individual application events can be managed more directly 

through pesticide labels than potential exposures to ambient air. Also, more information can be 

collected to quantify the volatilization associated with a single pesticide application event than 

the concenltrations expected in ambient air. "Flux" is the term used to describe how much 

volatilization (or emission) of a pesticide can occur across a given area for specific period of 

time. Field data can be collected for empirical use in risk assessment and also as the basis for 

empirically based dispersion modeling. There are a number of recognized flux methods in the 

peer-reviewed literatme.80 Along with air concentration measurements each method requires 

that detailed meteorological data be collected and that the conditions of the application are also 

well- documented. 

A large number of flux studies have been completed for fumigants, so their behavior under 

various field conditions is relatively well understood. Flux data have been also generated for a 

limited number of conventional pesticides including chlorpyrifos,

81 but in general, they are not 

available for conventional pesticides. This lack of flux data for conventional pesticides was a 

primary focus of the 2009 SAP review. EPA presented a number of options for predicting tlux 

in lieu of data which would allow EPA to screen conventional pesticides for potential risk 

concerns. Building on advice from the SAP,82 the Agency developed a screening methodology 

using a preferred approach known as the Woodrow equation.83 

EPA has recently announced the availability of this screening metbodology84 and is soliciting 

public inputt on the new methodology and the proposed approach for assessing volatilization for 

conventional pesticides. EPA will finalize the approach after considering public comment. 

Along with distinct application events, EPA also considers potential exposures to ambient air 

that may represent those within a community, region, or widespread airshed depending upon 

where, when, and how such monitoring data were collected. Such data have been used 

empirically and EPA characterizes such data to the extent possible given available resources. 

The 2009 EPA SAP analysis provides an example of how an air monitoring result could be 

characterized by risk assessors based on use infmmation and knowledge of the application site 

relative to where monitors are placed. To date, EPA has not attempted a modeling approach for 

80 Relevant citations can be found in the bibliography to "Scientific Issues Associated with Field 

Volatilization of Conventional Pesticides Presented Jointly to the FIFRA Scientific Advisory Panel, 

USEPA, 2009" at http://www .regulation;).gov/#!tlocumentDettJ il :D-EPA-HQ-OPP-200Y-0687 -0006. 

They include: USEPA, 2008; Majewski and Capel, 1995; Lenoir et al., 1999; Majewski and Baston, 

2002; McConnell et al., 1998; Zamora et al., 2003; Glotfelty eta/., I 990; Schomburg eta/. , 1991. 

81 The pre liminary volatilization evaluation for chlorpyrifos is found at 

http://www.regulation!-..gQv/#!documentDetati:D=EPA-HQ-OPP-2008-0850-0 I 14; supporting documents 

posted in the same docket discuss the modeling of flux rates. 

82 The fimal report of the SAP is found at http;//www.regulations.gov/#!documcnLDemti.D=EPA-110-

0PP-2009-0687-0037. 83 See Woodrow eta/., 1997 and 2001. Citations found at 

http://v. '' w.rei!ulations gov/#!documentDetail:D=EPA-HQ-OPP-::!009-0687-0006. 84 http://www .rcgulaLtOfl'>.gov/#!dockelDetaii;D=EP A-110-0PP-2014-0:219 

29 
predicting :ambient exposures to pesticides for these types of circumstances, but plans on 

exploring such approaches in the future. 

Air monitoring data for conventional pesticides are limited and the quality is generally 

Jacking compared to current protocols. The data that do exist mostly come from California; data 

collection under authority of California's Toxic Air Contaminant statute85 began in the mid1980s and tContinues in the present time. The Washington Department of Health has collected air 

monitoring data with a focus on organophosphates involved in agricultural production.86 

PANNA (one of the Petitioners) has also collected air monitoring data for a number of pesticides 

in various locations throughout the United States.

87 The Agency does consider these "Drift 

Catcher" d:ata for risk characterization, despite certain limitations, and has concluded that the data 

thus far are; not suggestive of concentrations of pesticides in the air that pose significant risks to 

human health. Other sources of air monitoring data are found in the scientific literature. 

At this time, EPA has conducted at least one volatilization assessment for a conventional 

pesticide using the fumigant methodology approach.

88 Volatilization risk assessments for the 

fumigants and conventional pesticides consider distinct, individual pesticide applications as well 

as ambient air contamination from multiple applications of the same pesticide in the same 

general area. While single application event risk estimates are based on modeled values, ambient 

air analyses are based on empirical values; for ambient risk estimation the most representative 

exposure statistic is selected and compared to the appropriate toxicological value. Additionally, 

risk assessments for both ambient air and single application events are informed by incident 

information. Looking for commonalities in the incident information and the predictive risk 

estimates is a critical consideration for regulatory decision-making. 

The Agency's approach to assessing risks associated with single application events is multifaceted. It includes the use of information on how the pesticide is used; flux data, which are 

needed for use of the Woodrow equation89 (or, if flux data are not available, information on 

physical and chemical properties of the pesticide); and information on the toxicology of the 

pesticide from the inhalation route of administration (if inhalation toxicity data are not available, 

other toxiciity data may be used). An air dispersion model is used to estimate air concentrations 

85 http://www .cdpr.ca.gov/doc<./emon/pubs!Lacmenu.htm, and 

http://www. cdpr.ca.gov/doc~/emon/pubs/~c/tacstdys.htm 116 http:// w \\ w .doh. wa.gov/dtp/Pest/dnft htrn 

87 See lmp://www.panna.org/srience/drift; the Agency considers Drift Catcher data when available 

and uses them in risk characterization. Unfortunately, the raw data that EPA prefers are not always 

available and the timing intervals for air samples under the PANNA protocol tend not to permit 

association with particular applications of the pesticides detected. 88 Refer to the fumigant risk assessment documents for a detailed overview of the risk assessment 

process available: htlp://w\-\ w.eoa gov/pesticides/rerel!istration/soil fumigams/soil-fum-regbaLk~rnd.html#infomlatton 8 http://www.rel!ulauons.gov/#!documentDetail:D=EPA-HQ-OPP-2009-0687-0006 

30 
of volatilized pesticides sunounding treated fields.90 Model inputs incJude standard assumptions 

about field sizes and the surrounding tenain, and weather data for representative locations. 

Dispersion modeling is a two-step process. First, flux information is used to characterize how 

much applied pesticide will volatilize from a treatment area, and then the dispersion of the 

volatilized pesticide around the treatment area is characterized. Changing weather patterns over 

time are considered. The mathematical approach to compute how volatilized residues will 

dissipate is based on a construct known as a Gaussian plume.91 

EPA has data requirements for information needed to support regisu·ations of pesticides that 

may result in inhalation exposures.

92 Such data are strongly prefened for use in volatilization 

risk assessments, but if necessary oral toxicity data can be used. Issues related to the use of oral 

data for inhalation exposures were discussed by the SAP in 2009. 

As noted previously, EPA has recently released a screening methodology for characterizing 

the potential risks associated with volatilization of conventional pesticides. The Agency has used 

the methodology to conduct a screening level assessment of all currently-registered conventional 

pesticides, and found that onl y about 20 percent of conventional pesticides need to be evaluated 

further so that the Agency can better understand the potential risks associated with their 

volatilization and off-site movement. The results of this screening exercise will be released 

along with the methodology. The Agency may need additional information to perfonn more 

detailed assessments, such as data that are needed to model flux, inhalation toxicity data, and 

information on the pesticide's use parameters. Comments submitted by the public on the 

screening analysis and its conclusions will be considered as the Agency detennines how to 

proceed. Also as noted previously, the Agency has already conducted at least one volatilization 

risk assessment for a conventional pesticide, and it can be viewed on the public docket.93 

C. HO\ . ., EPA Mttig'-llC' PNcmiat Risk A-.sociatcd " ith Volaulization 

After clhemical risk assessments are completed, EPA must determine whether there are risks 

to be mitigated, and if so, how that should be accomplished. EPA has used this process to 

address ris]ks posed by the volatilization of a pesticide and its off-site movement. Options that 

can be effective include: buffer zones, reduced application rates, low volatility formulations or 

adjuvants, tarping and tenting of treated fields, and crop management practices. 

The fumigants assessment and mitigation measures provide a framework for considering 

how to manage potential volatility risks associated with conventional pesticides. For the 

fumigants, EPA required a suite of complementary mitigation measures to protect handlers, 

workers, and bystanders from risks resulting from exposure to the soil fumigant pesticides. The 

measures were designed to work together to address the full range of risks, but were focused on 

the risks of volatilization to people (workers and bystanders), and included restricted-use status, 

90 http://w\\: w ~pa.gov/!>c poly "ap/meel JH!~ 00-t/082404 mtg.htm and 

http.//WW\\ .exponentcom/pafum/. 

'lt Distribution based on the standard bell-shaped curve. 

92 See 40 CFR § 158.500. 

93 Chlorpyrifos: httn://www.regulation.,.gov/#!documentDeta ii;D=EPA-HQ-OPP-2008-0850-01 30 

31 
use site limitations, application rate reductions, and buffer zones with chemical-specific widths.94 

Other risk management measures implemented for the fumigants are not relevant to conventional 

pesticides, such as the use of tarps over treated fields, which is employed in conjunction with 

fumigant applications to reduce the off-gassing from soil applications. Risk mitigation measures 

differ among pesticides because the individual risk assessments were based on chemical-specific 

information. 

IX. Responst.-s tu Rc(.tu~sts Made b~ Petitioners 

EPA reads the petition to make three specific requests for programmatic changes: I ) that 

EPA evaluate the rish to children exposed to pesticide drift and volatilization for all pesticides, 

2) that EPA modify its pesticide re-evaluation process to expedite assessment of these risks, and 

3) that, for certain types of pesticides, the Agency require the adoption of generic buffer zones 

between treated areas and places where children could congregate.95 The Agency's responses to 

each of these elements follow. 

Although this petition addresses how EPA assesses risk under the FFDCA, it does not 

specifically request to cancel registrations or modify or revoke specific tolerances. The 

Petitioners also are requesting that EPA require interim buffers for all "drift-prone" pesticides 

during the time EPA makes the programmatic changes they have requested. Because the 

Petitioners are suggesting specific changes to use practices but not requesting cancellation of 

registrations, we also have interpreted the petition to request that EPA attempt to procure 

voluntary label amendments from the registrants. However if the registrants did not agree, 

Agency-initiated cancellation actions would likely be needed to achieve the requested relief. 

EPA Will E\.alu·ntt' the Risk' u1 Chilun.:n Ao.,,ou nted with Sp1a) Drift ~lml Vuhllili~<•tion 

Expo--me,. 

While it is true that EPA has not always assessed the risks to children from spray drift and 

volatilization, the need for consistent and refined methods have Jed to the development of 

appropriate methodologies for doing so. The development of these methods is described in 

detail in Sections VII and VIII of this response. 

The Pc;ritioners are requesting that pesticide drift and volatilization risk assessments be 

conducted for all pesticides. We agree. The first step in EPA's new spray drift assessment 

methodology is a screening process to facilitate the identification of conventional pesticides that 

could pose risks of concern to bystanders through spray drift. As previously noted, the Agency 

released th1e draft spray drift. assessment methodology earlier this year. Elements of the ''needs 

94 http:/lwwv. .epa. gov/pe:,IJC ide:,/rerel-! istrat ion/so i I fum1gants/i mplement1 PI! -new-safetymeusures. htm l#ri' k 

95 As noted earlier, the Agency considers residential exposures to include exposures associated with 

homes, home lawns, yards, gardens, apartments and grounds around apartment buildings. schools, 

schoolyards, daycare facilities. playgrounds, athletic fields, and parks and other public spaces. 

32 
screening" process arc detailed in materials posted to the docket on ''Consideration of Spray 

Drift in Pesticide Risk Assessment."96 The new volatilization methodology is designed to serve 

as a stand-alone screening methodology for any and all conventional pesticides. As noted above, 

the Agency has already used the volatilization melhodology to screen all currently-registered 

pesticides. The screening processes include consideration of factors such as methods of 

application and use patterns of the subject pesticide. Using the screening procedures for both 

spray drift .and volatilization, EPA considers the potential for exposure in a qualitative way. In 

the case of spray drift. pesticides for which the screen indicates there are potential risk concems 

will undergo a quantitative assessment. Thus, we grant the Petitioners' request to conduct spray 

drift and volatilization assessments for all pesticides, while noting that some of these assessments 

will not provide quantitative results. 

In the l:ast several years, EPA has conducted a number of spray drift and volatilization risk 

assessments, even while the proposed assesl';ment methodologies were being developed and 

refined. EPA conducted volatilization assessments for the fumigant pesticides during 

reregistration.97 ChloqJyrifos also recently underwent a s~ray drift evaluation,9

R while the 

recently released proposed drift assessment methodology 9 was still in development (see Section 

V II B). The preliminary human health 1isk assessment for chlorpyrifos wa completed in July 

2011 100 and attendant risk reduction measures for spray drift exposures were implemented in 

July 2012.

101 EPA also recently published a draft volatilization risk assessment for 

chlorpyrifos 102 

and is working to finalize the assessment even as work continues on the 

volatilization methodology. The methodologies set out tand~u di zed procedures so that the way 

spray drift and volatilization are assessed will be consistent between pesticides in general, but 

they are not substantively different from the approaches that were used to assess spray drift and 

volatilizatkm for pesticides in rhe recent past. 

Fmthcr evidence of EPA's commitment to reducing the risks to children exposed to 

pesticides is demonstrated by actions taken during pesticide reregistration process to terminate 

residential uses, as wa · done with many organophosphate insecticides. EPA now has betterdeveloped tools for determining when spray drift poses risks to bystanders, and is committed to 

taking action on risks tO bystanders, including children, during registration review. 

The Pe1titioners also are requesting that EPA include the drift and volatilization exposw·es of 

children in its aggregate assessments. Including spray drift and volatilization in EPA's aggregate 

risk assessments would involve the following steps. First, EPA would look at exposures from 

drift and volatilization under the new policies to determine whether any non-negligible exposure 

q

6 Process described aL http://www.rel!ulation..,.gov/#!documenlDeta il:D=EPA-HQ-OPP-20 13-0676-

0003. 

q

7 Based on the fi ndings from these assessments, EPA required the implementation of risk mitigation 

measures, including measures intended to protect bystanders. The risk mitigation measures are detaHed at 

http.//W\\ W .e a.'l.OV/pc~t iC ides/ rC I! tr ti j) f umigants/implementtng-new .tf y- ures.h ml . 

8 hnp://www.regulations.go\ /#!documentDetail;D=EPA-HQ-OPP-2008-0850-01 05 

99 http://w w. gulati ~. ov/#! oc um ntDetait EPA Q-OPP-20 I J-0676-000 I 

100 http://www .regulat ions.swv/# !documt:mDeta i I ;D=EPA-HQ-OPP-2008-0850-0025 

101 http://www.regul:luons.gov/#!documemDetaii;D- EPA-HQ-OPP-2008-0850-0 I 03 

102 hllp://ww w.r gu ~. gov/# !doc nLD taii EPA HQ-OPP-2008-0S5 -0 11 4 

33 
due to drift or volatilization could occur. If non-negligible exposure could occur, EPA would 

quantitatively assess that exposure under the new policies and then aggregate that exposure with 

other sources of exposure consistent with existing policies on aggregate exposure. However, 

aggregation of drift and volatilization exposure with other sources of exposure is not specifically 

addressed in existing aggregate exposure policies, and thus EPA's approach may need to be 

modified to account for the factors involved in drift and volatilization exposure. Finally, if initial 

aggregate exposure estimates using conservative methodologies indicate there could be a risk of 

concern, EPA would need to develop efficient approaches to refining those assessments. 

EPA fully agrees with the Petitioners that exposures to spray drift and volatilized pesticides 

should be considered in our risk assessments, and that the risks to children, with their unique 

biology and behaviors. must be considered separately from risks to adults. The Agency has 

developed rthe methodologies for assessing drift and volatilization and is committed to 

considering the comments of the public on them so that we may employ the best possible science 

in assessing these risks and taking action to mitigate risks as needed. 

B. E~pedtting \''L''ment' ,JJ Sprn) Dnfl .md Volatihzatton nuhitk (If I he Rcg1str.Jiit'n 

R~' iew Schedule j, nn N~Le ... ,ar) ------~---------------------------------------------

Petitioners state that EPA should accelerate its schedule for completing drift and 

volatilization risk assessments and prioritize pesticide reviews based on the suspected degree of 

risks posed. to children. Petitioners suggest that this acceleration should be accomplished through 

modifications to the registration review process or by utilizing other authorities. Petitioners 

believe thart registration review is too slow to be protective of drift and volatilization risks to 

children. 103 EPA's response to this request covers aspects of public health policy and the 

Agency's obligations under FIFRA and the FFDCA, and issues of efficiency. 

The Ag;ency is denying the Petitioners' reque. t to the extent that they ask EPA to perform 

bystander risk assessments of the chemicals highlighted in the Petition before considering other 

exposures and risks. The registration review program is an appropriate and risk-protective 

approach for evaluating and managing the risks associated with spray drift and volatilization 

(and other rtypes of risk as well). Utilizing a process outside of registration review to assess these 

risks to children separately from other types of risk would bypass and defer the comprehensive 

evaluations that allow the Agency to rely on the best and newest developments in science and to 

address the full complement of potential risks. The consideration of all potential risks at one 

time for a s.ingle active ingredient can lead to the adoption of a package of risk mitigation 

measmes that works for all the risks of concem, or at the very least. that do not work in 

opposition to each other. 

103 The lPetitioners also assert that because the registration revjew process is designed to update the 

reregistration risk assessments, and since the Agency did not address the risks to bystanders from drift 

and volatilization during reregistration, registration review will not include such assessments. In reality. 

the Agency updates risk assessments on the basis of available data and scientific developments1 so drift 

and volatilization will be included in registration review, even if they were not considered during 

reregistration. 

34 
To set the schedule for registration review, EPA relied primarily on the baseline date for each 

pesticide case (usually its RED date or the date the first product containing the active ingredient 

was registered). Additionally, some registration review cases were grouped for program 

efficiency. The OPs and NMCs were among those cases. 104 For the most part, food- use 

pesticides subject to reregistration were given priority scheduling in reregistration, and thus, they 

have the eadiest baseline dates. The OPs and NMCs, on which the Petitioners focus, have been 

scheduled at the front-end of registration review and many individual pesticides from those 

families are currently undergoing risk assessment. EPA believes that, insofar as the Petition 

requests EPA to give high priority to certain chemicals in its registration review program, the 

petition asks for an acllon that has already occurred. 

The OPs and NMCs account for more than 40 individual active ingredients. Alt of these 

pesticides have entered registration review (or were canceled prior to entering registration 

review).The preliminary risk assessments for I 2 of the pesticides in these two families are 

scheduled to be completed before October 2014.The schedule for OP and NMC registration 

reviews 105 is summarized in the Appendix to this response.

106 The Appendix also identifies the 

pesticides in these groups that were cancelled subsequent to tolerance reassessment or during the 

beginning stages of registration review. 

With respect to conducting separate bystander exposure assessments of individual pesticides. 

if the Agen1cy granted Petitioners' proposal. it would significantly reduce the efficiency of the 

overall registration review program. Separating tJ1e bystander drift risk assessment fm children 

from the ongoing comprehensive evaluations for these same chemicals would require Agency 

resources to be redirected to the evaluation of one type of potential risk. and management of the 

full complement of potential risks associated with a pesticide would be deferred. ln addition. the 

overall demand for resources and the time needed to assess firM spray drift and then all other 

potential risks for a given pesticide would be greater in total than the time and resources needed 

to conduct a comprehensive assessment of that pesticide, and thus would slow Agency action on 

risk management. Regisu·ation review, as currently planned, is the most efficient way to achieve 

the Petitioners' and EPA's common goal of protecting human health, including the health of 

children, and the environment. Adopting the approach proposed by the Petitioners also would 

significantly reduce EPA's ability to meet its statutory obligation to complete registration review 

by 2022 or the date tlult is I 5 years after the date on which the first pesticide containing a new 

active ingredient is registered. See FIFRA § 3(g)( I )(A)(iii). 

The same logic applies to the idea of assessing chemical-specific volatili7.ation risks 

separately from the comprehensive registration review assessment. Significamly. preliminary 

application of the volatilization scTeening methodology currently under development Led the 

Agency to conclude thlt only 20% or so of all pesticide active ingredients have characteristics 

that suggest that they potentially could pose any meaningful level of volatilization risk. Thus, 

including the volatilization risk assessment in the registration review process as a matter of 

liM Desc!fibed in a Federal Register Notice: http://www.gpo.gov/fdsyvpl..g!FR-2006- I 0-J l/html/E6-

16~83 .htm. 

105 http://w\\ \Lepa go,/re-.ticideslcumulative/ identifies the organophosphate and n-methyl carbamate 

pesticides by name. 106 The full schedule is at htLpJ www.epa.gov/opp~mJI/rl!gistration revi~w/schedule hun . 

35 
course will not appreciably affect the resources needed or timing for the vast majority of 

registration review decisions. 

Petitioners suggest that EPA could accelerate the reviews of drift risks for children by 

utilizing other authorities, such as rulemaking107 or the special review process. 108 Rulemaking is 

a long, resource-intensive process that can take many years to complete, and EPA believes its 

limited resources are better spent assessing and developing risk mitigation measures for 

pesticides individually than developing a regulation that could take many years to finalize. As an 

example, the Petitioners suggest that the WPS Rule is an appropriate model for implementing 

broad changes for a large number of pesticides at once. Although the WPS is an important and 

effective tool for reducing worker risk, it took approximately eight years to develop and 

promulgate the initial J 992 ntle and as many years to develop a set of proposed amendments to 

the 1992 rule. 109 · 

And while Special Review served its purpose in the past, individual Special Reviews 

typically took man y years to conclude and used Agency resources to address a narrow set of risk 

concerns at a time when there was no systematic re-evaluation process for pesticide registrations. 

Indeed, in 2009, the Agency announced that "[t]he pesticide program is moving toward closing 

out both the Special Review and the reregistration programs" in favor of new re-evaluations of 

previously registered pesticides to be conducted under registration review. 110 That is not to say 

that potential risk concerns that rise to the highest levels, including ·'emergency" or "imminent 

hazard'' status, must wait to be addressed in registration review- the processes for such 

situations include those described in Section IV of this response. 

Based on these considerations, for existing registrations, EPA has concluded that registration 

review, as currently planned, is the most appropriate, time]y, and efficient way to achieve the 

Petitioners' and EPA's common goal of protecting human health. including the health of 

children, and the environment. 

C 1mmedl3te Adl•ption l•l Jntenm No-Spray Huff~r:-- A.r0und Home'. Sdlltof,. D::tyl.u\• 

Center,. and Park:-. to Protect Chtldren (rom Drift Is Not Approp1 inte --------------------- Petitioners request that EPA impose interim no-spray buffers around locations where 

children congregate and that these measures should apply to OPs, NMCs, and all other pesticides 

that are: "(1) registered for application by ground sprayers, broadcast equipment, and/or aerial 

equipment; and (2) suspected of causing acute poisonings, cancer, endocrine disruption, 

107 Although Petitioners mention EPA's general rulemaking authority under FIFRA, EPA is not 

treating this petition as a specific request for rulemaking. Instead EPA understands Petitioners' statements 

being made .as actions that could be taken by EPA. The Agency's general rulemaking authority is 

provided at 7 U.S.C. § 136w(a)( 1 ). 

108 40 C.F.R. § 154.7 

109 The revisions to the WPS were just released for public comment on February 20, 20 14--

hup.//wwwxegula ion~ v/#!doc mentD ta.ii PA Q-OPP-20 1 J -0184-0002. 110 hnp://epa.eCiv/oppfead I /cb/c5.b page/updatec-./2009/namechane.e-prd.hunl 

36 
developmental effects, and/or reproductive effects." 111 Petitioners further state that. the interim 

buffers sho1dld be at least 60 feet in width for ground applications and 300 feet in width for aerial 

applications regardless of the pesticide being applied, and that these buffer requirements should 

remain in place at least until case-specific drift risk assessments can be undertaken. To 

accomplish this request, Petitioners further suggest that the Agency could use administrative 

procedures rather than chemical-specific risk assessment and management to effect the generic 

buffers i.e., rulemaking or a Pesticide Registration (PR) Notice. The Agency's response to this 

request covers the usefulness of the alternate approaches, the scientific basis for pesticide 

decision-making, and issues of efficiency. 

The Agency denies the Petitioners' request to impose a requirement for interim buffers of 

either 60 or 300 feet on these pesticides before EPA completes the registration reviews for these 

pesticides. EPA contends that drift and volatilization are not posing risks of concern for all 

pesticides, and that interim buffers, as suggested by the Petitioners, are not the most efficient or 

scientificallt appropriate way to mitigate such risks for any particular pesticide or group of 

pesticides. 

1 2 It is the Agency's practice to assess pesticide risks based on chemical-specific 

data. The Agency acknowledges that the OPs and NMCs are generally among the more acutely 

toxic pesticides, but risk is a function of both toxicity and exposure, so toxicity alone is not 

sufficient to characterize the risks these pesticides may cause to bystanders via drift or 

volatilization, or to determine if risk mitigation is needed. Additionally, the OPs and the NMCs 

were reevaluated both in reregistration and in the tolerance reassessment process and, at that time 

found to meet the applicable statutory safety standards. These pesticides will be reassessed again 

in the next 'few years under registration review. Because pesticides vary in environmental fate 

characteristics, and use sites and parameters, potential exposures also differ, not just between 

different active ingredients, but also between different uses of the same active ingredient. 

The pesticides other than the OPs and NMCs that the Petitioners believe warrant the use of 

60 and 300 foot buffers are a very large and diverse group. Without considering pesticidespecific data, it is impossible to know the risks posed by each. Again, the manner in which the 

Petition prQiposes to manage the drift and volatilization risks associated with these pesticides 

ignores the interaction of exposure and hazard. When these pesticides underwent reregistration, 

the Agency found that (with certain conditions) they met the statutory standards of FIFRA and 

FFDCA. ln order to make the same type of determinations when spray drift and volatilization 

exposures arc appropriately considered for each individual case, the Agency must satisfy the 

same standmds. 

111 While an exact count of pesticides that fit in this second category cannot be made, the effects listed 

are a large subset of the complete set of adverse effects the Agency takes into consideration. Furthermore, 

EPA notes that the Petition describes the referenced pesticides and groups of pesticides as "drift prone." 

The Agency rejects this notion. Because drift is influenced by factors other than the characteristics of the 

pesticide active ingredient, primarily the physical form of the product as applied, the application method, 

climate, and wind, no one active ingredient or pesticide family can be considered to be drift-prone. There 

are particular formulations and application methods that may make certain applications of a pesticide 

product prone to drift. Volatilization, on the other hand, is a direct function of the physical and chemical 

properties of an active ingredient, and the Agency is able to identify pesticides that tend to volatilize. 

112 EPA does not believe the Petitioners have presented adequate justification for interim, across-theboard buffers for all the pesticides they have identified as being of special concern. 

37 
Even if buffer restrictions may be appropriate to mitigate the risks to children from spray 

drift and volatilization for some pesticides, the EPA contends that the same buffer width will not 

be appropriate for each of them. Despite the Petitioners' request for across-the-board, interim 

buffers, the Petition itself makes the point that case-specific assessments have shown that buffers 

of varying widths are needed to mitigate risks associated with different pesticides. They cite 

examples of the different buffer widths that EPA determined were necessary for products contain 

different active ingredients- e.g., for the fumigants, widths ranging from 25 ft to one-half mile. 

EPA believes that the more scientifically defensible approach involves determining whether nospray buffers are necessary to protect children on a pesticide-by-pesticide basis. This is the 

approach the Agency has taken and intends to include in consideration of bystander exposure in 

future risk assessments. 

Finally, the Agency believes that the requests made by the Petitioners with regard to interim 

buffers would divert limited Agency resources from important risk assessment and risk 

management activities and would diminish the overall level of protection EPA is able to achieve 

in its pesticide re-evaluations. The alternate means that the Petitioners suggest to implement the 

buffer requirement are also resource-intensive, time-consuming, and not likely to result in the 

broad protections the Petitioners desire. The resource and time requirements of rulemaking are 

discussed above. 

The Petitioners suggest that EPA could use a Pesticide Registration (PR) Notice113 to inform 

registrants that label amendments are necessary to address drift and volatilization, and, that 

failure to make these changes could result in cancellation or the finding that their products are 

misbranded. Although EPA agrees that a PR Notice is a useful tool to communicate new 

policies to pesticide registrants, compliance with a PR Notice is voluntar y, and the Agency 

believes that registrants are not likely to implement changes that Jack a risk-based rationale. If 

EPA took action to require the amendment of pesticide registrations to mitigate spray drift via 

buffers of uniform width, pesticide applicants and registrants could challenge the validity and 

applicabili1ty of the science behind the Agency-prescribed regulatory actions. Additionally, the 

resources needed to pursue a cancellation proceeding are extensive, and in the absence pesticidespecific assessments, would not be an effective use of EPA's limited resources. 

X. CHndusion 

The Agency appreciates the concern the petitioners express for bystanders, particularly 

children, who may be harmed by exposure to spray drift and the off-site movement of volatilized 

pesticides. We share this concern. The Agency has assessed spray drift and volatilization for 

particular pesticides in the past and is now taking steps to formalize the assessment 

methodologies for future assessments. These methodologies include screening-level assessment 

processes far use in determining if there is a need to take a more in-depth look at any given 

pesticide. Thus, all pestic ides will be assessed either qualitatively or quantitatively. The Agency 

also believes that we are addressing pesticide risks on a schedule that gives the most potentially 

113 PR Notices are Lsued by EPA's Office of Pesticide Programs to inform pesticide registrants and 

orher interested persons about important policies, procedures and regulatory decisions. The Agency's PR 

Notice webjpage is at !.!Jtp://www.epa.gov/PR Notic~~ . 

38 
risky pesticides precedence. We will continue to use approved approaches to account for the 

differences between children and adults in their exposures and sensitivity to pesticides. 

The Agency believes that its cmTent program of registration review is the most 

comprehensive and effective way to assess and mitigate pesticide risks and to take advantage of 

new and emerging science. The Agency believes that looking at a particular pesticide and all the 

potential risks associated with its use in a comprehensive fashion provides the best opportunity to 

effectuate necessary protections for human health and the environment. Other means of 

managing the risks po ·ed by spray drift and volatilization as suggested by the Petitioners, such as 

conducting drift and volatilization-only assessments or re-ordering the pesticides in registration 

review, are either not needed, not likely to be successful, require more resources than are 

available, and/or take more time than registration review. 

While we understand the thinking behind the proposal to mandate generic, uniform buffer 

requirements on pesticides of particular concern, we do not agree that a "one size fits all" 

solution is appropriate or scientifically defensible. Without case-specific assessments and risk 

mitigation, we believe it is unlikely that registrants will voluntarily adopt generic buffers. 

Pesticide registrants are by law afforded specific rights and opportunities to oppose decisions by 

the Agency that affect their registrations. Because the evidence needed to support the 

cancellation or amendment of registrations within this context must be scientifically defensible 

and specific to the subject pesticide, we believe that Agency resources are better spent in 

registration review. 

39 
APPE:\Dl'\ 

Registration Review Timelines for Pesticide Families Specifically Cited in the Petition 

T a bl e 1 . , A n f acapa . t e d 0 r anop h h R osp ate e . astra f aon R ' evtew Mil estones 

11 4 

Draft Human 

Active Ingredient Docket Opening Health Risk Assessment Final Decision 

Acephate 3/18/09 2014 2015 

Azinpllos-melhyl All registrations cancelled 2012 

Bensulide 6/25/08 2015 2015 

Chlorelhox yfos 12/17/08 2014 2015 

Chlorpyrifos 3/18/09 July 6, 2011 2016 

Chlorpyrifos-meth yl 3/13/10 2015 2016 

Coumaphos 6/25/08 2014 2015 

Diazinon 6/25/08 2014 2016 

Dichlo:rvos 6/24/09 2015 2016 

Dicrotophos 6/25/08 2014 2015 

Dimethoate 3/18/09 2014 2015 

Disulfoton 3/18/09 All registrations subsequently cancelled 

Ethoprop 12/17/08 2014 2015 

Fenamiphos All registrations cancelled 2007 

Fenitmthion 3/18/09 2015 2015 

Fenthion All regisu·ations cancelled 2004 

Fosthiazate 6/24/09 2013 2014 

Malathion 6/24/09 2014 2016 

Methamidophos 12117/08 All registrations subsequently cancelled 

Methidathion 3/18/09 All registrations subsequently cancelled 

Methyl parathion 6/24/09 All registrations subsequently cancelled 

Naled 3/18/09 2015 2016 

Ox ydemeton-methyl 6/25/08 All registrations subsequently cancelled 

Phorate 3/18/09 2015 2015 

Phosmet 6/24/09 2015 2015 

Phostelbupirim 6/24/09 2016 2017 

Pirimiphos-methyl 3/18/09 2015 2016 

Profenofos 6/25/08 2015 2016 

Propetamphos 6/25/08 All registrations subsequent! y cancelled 

Phosalcone 2/19/08 All registrations cancelled effective 12/30/ 15 

Temephos 6/25/08 All registrations subsequently cancelied 

Terbu£os 6/25/08 2014 2015 

Tetrach.lorvinphos 6/25/08 2014 2015 

Tribufos 3/18/09 2015 2016 

Trichlorfon 3/18/09 2015 2016 

114 Dates in the future should be consjdered tentative. 

40 
T bl 2 A t' . t d N M th I C b t R . R . Mil a e 115 . n acapa e - e lYI ar ama es egastrabon evaew estones 

Draft Human 

Active Ingredient Docket Opening Health Risk Assessment Final Decision 

Aldicarb 6/20/12 2015 2017 

Carbaryl 9/22/10 2016 2018 

Carbofuran All registrations cancelled 2009 

Formetanate HCI 12/22/10 2016 2017 

Methiocarb 6/22/10 2015 2016 

Methomyl 9/22/10 2015 2016 

Oxamyl 9/22/10 Early 2015 2016 

Pirimicarb All registrations cancelled 2010 

Propox.ur 12/16/09 2014 2016 

Thiodicarb 12/16/09 2015 2016 

115 Dates in the future should be considered tentative. 

41