Docket Number EPA-HQ-OPP-2014-0780 

www.regulations.gov 

Ethoxyquin Final Work Plan 

Registration Review: Initial Docket 

Case Number 3 

Approved by: 

Date: 

June 2015 

,~ Richard P. Keigwin, Jr. 

Director 

Pesticide Re-evaluation Division 
These and other supporting documents for the ethoxyquin registration review case may be found 

in the docket EPA-HQ-OPP-2014-0780 at http://www.regulations. gov. 

INTRODUCTION 

This is the Environmental Protection Agency's (EPA or the Agency) Final Work Plan (FWP) for 

the registration review of ethoxyquin. This work plan addresses public comments received 

concerning the Preliminary Work Plan (PWP), which were posted in the ethoxyquin registration 

review docket (docket number EPA-HQ-OPP-20 14-0780). Ethoxyquin (1 ,2-dihydro-6-ethoxy2,2,4-trimethylquinoline) is an antioxidant registered for use as a deterrent of scald (browning) in 

pears. Ethoxyquin is applied through post-harvest indoor application via a drench/in-line spray 

treatment, thermal fogging, and/or impregnated wraps. All applications are made to pears in 

storage and prior to packing. There are no registered residential uses of ethoxyquin. 

The Agency is implementing the registration review program pursuant to Section 3(g) of the 

Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), and will review each registered 

pesticide every 15 years to determine whether it continues to meet the FIFRA standard for 

registration. Changes in science, public policy, and pesticide use practices occur over time. The 

registration review program is intended to make sure that, as the ability to assess risk evolves and 

as policies and practices change, all registered pesticides continue to meet the statutory standard. 

The public phase of registration review begins when the initial docket is opened for each case. 

Information on this program is provided on the Agency's website. 

The FWP begins with any updates since the PWP was issued. Next is a summary of substantive 

comments received during the public comment period for the PWP concerning planned data 

needs, expected risk assessments, or the estimated timeline identified in the PWP, and a 

summary of the Agency's responses to those comments. This section is followed by registration 

review planned data needs, risk assessments expected to be conducted, and the projected 

registration review timeline for ethoxyquin. Lastly, there is a discussion of next steps. 

UPDATES SINCE THE PWP WAS ISSUED 

There are no updates on the ethoxyquin registration review case since issuance of the PWP. 

SUMMARY OF COMMENTS AND AGENCY RESPONSES 

During the 60-day public comment period on the Ethoxyquin Preliminary Work Plan, which 

opened on December 17, 2014 and closed on February 17, 2015, the Agency received two public 

comments. Comments were submitted by the Northwest Horticultural Council (NHC) and the 

Physicians Committee for Responsible Medicine (PCRM). In the PWP, EPA also solicited 

comments on the specific topic of environmental justice but no comments or information were 

received on those issues. 

Summarized below are the public comments. The full comments in their entirety are located in 

the docket, EPA-HQ-OPP-2014-0780. 

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Comment submitted by NHC in EPA-HQ-OPP-2014-0780-0007. 

1. Comment: NHC commented on behalf of the Pear Bureau Northwest, representing pear 

growers, packers and shippers in the states of Oregon and Washington. The comment provided 

information on the use of ethoxyquin in pear packinghouses. NHC included a general waste 

water permit and an example of the NPDES waste discharge permit issued to pear packers. They 

noted waste discharge permits issued to other pear packers are similar or identical to the one 

provided. 

Response: The agency thanks NHC for its comments. While the provided permits clarified 

questions for the agency, it did not negate the need for the requested risk assessments. The 

agency will keep its risk assessments requirements as is for the registrant 

Comment submitted by PCRM in EPA-HQ-OPP-2014-0780-0008. 

1. Comment: PCRM agreed with EPA's request for a dermal penetration study. They suggested 

the use of the in vitro method for this study. 

Response: The Agency thanks PCRM for its comment. Currently, HED policy does not accept 

the in vitro dermal penetration data by itself as a substitute for the in vivo dermal penetration 

data. PCRM is referred to the EPA guidelines in conducting an in vivo dermal penetration study. 

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PLANNED DATA NEEDS 

Table 1 below summarizes the planned data needs for ethoxyquin based on the Registration 

Review: Preliminary Problem Formulation for Environmental Fate, Ecological Risk, 

Endangered Species, and Human Health Drinking Water Exposure Assessments for Ethoxyquin 

and Ethoxyquin. Human Health Assessment Scoping Document to Support Registration Review. 

The planned data needs have not changed from what was included in the PWP. 

Table 1: Planned Data Needs for the Ethoxyquin Registration Review 

Estimated 

Guideline Study Title1 

Timeframe 

Number1 Test Material (Months from 

receipt of DCI) 

835 .1230 Leaching and adsorption/desorption TGAI 12 

835 .1240 

835 .2120 Hydrolysis TGAI 12 

835.2240 Photodegradation in water TGAI 12 

835.4300 Aerobic aquatic metabolism TGAI 24 

850.1300 Aquatic invertebrate life cycle (freshwater) TGAI 12 

850.1400 Fish early-life stage (freshwater) TGAI 12 

850.4400 Aquatic plant growth (aquatic vascular plant TEP 12 

toxicity), tier II 

850.4500 Aquatic plant growth (non-vascular aquatic plant TEP 12 

toxicity), tier II 

870.3465 90-day inhalation (rat)2 TGAI 24 

870.7600 Dermal penetration TEP 24 

TGAI = techntcal grade active mgredient; TEP = typical end-use product; 

RISK ASSESSMENTS FOR REGISTRATION REVIEW 

Table 2 below summarizes the planned registration review risk assessments based on the EFED 

Problem Formulation and HED Scoping Document. The planned assessments have not changed 

from what was included in the PWP. 

1 On June 27, 2012, EPA announced certain revisions in harmonized guideline series 850 - Ecological Effects Tests 

- including renumbering and other designations or changes for some guideline studies. See "Final Test 

Guidelines; OCSPP 850 Series; Notice of Availability" 77 FR 38282, June 27, 201 2. 

http://www .regulations.gov/#! documentDetail; D=EP A -HQ-OPPT -2009-0 154-0028 

2 A 28-day inhalation study is expected to be required in lieu of a full 90-day inhalation toxicity study. 

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Table 2: Planned Risk Assessments for the Ethoxyquin Registration Review 

Type of Risk Assessment Conduct? Notes 

Ecological and Environmental Fate 

Comprehensive ecological y The limited nature of the application of ethoxyquin 

(species to be assessed may preclude the possibility of ecological exposure. 

include terrestrial and aquatic However, until uncertainties regarding wastewater 

organisms), including disposal and vapor ventilation at pear treatment 

endangered species facilities are addressed, the Agency will presume the 

need to assess ecological exposure and risk during 

registration review (see page 2 of the Problem 

Formulation for additional information). 

Incidents Will check for There were no reported ecological incidents for 

updates ethoxyquin, see page 7 ofthe Problem Formulation 

for additional information. 

Human Health 'k"~ '~1' , ' ~ 

Dietary 

Food N The 2004 human health risk assessment did not 

identify dietary risks of concern (from food only). 

An updated dietary risk assessment may be conducted 

during registration review if there are changes to 

endpoints, points of departure, safety factors, and/or 

exposure estimates. 

Drinking water N The Agency anticipates evaluating the need for a 

drinking water assessment during registration review 

to incorporate any updates to the current use 

information. 

Occupational 

Handlers (mixers, loaders, y The most recent occupational assessment (2008) did 

app I i cators) not identify risks of concern. An updated 

Post-application y occupational handler and post-application assessment 

is anticipated during registration review to 

incorporate information from the anticipated dermal 

and inhalation toxicity studies. 

Residential 

Handlers N There are currently no registered residential uses for 

Post-application N ethoxyquin. A quantitative residential exposure 

assessment is not anticipated during registration 

review. The Agency anticipates evaluating the need 

for spray drift and volatilization risk assessment 

during registration review. 

·Other 

Aggregate N An aggregate assessment is not anticipated during 

registration review because ethoxyquin is not 

registered for residential use. 

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Cumulative N Ethoxyquin has not been identified as a member of a 

cumulative group that shares a common mechanism 

of toxicity, therefore, a cumulative risk assessment is 

not planned. 

Tolerances y EPA anticipates updating the US tolerance expression 

for ethoxyquin during registration review to reflect 

current policy. 

Incidents Will check for There were no reported human incidents for 

updates ethoxyquin. See page 8 of the Scoping Document 

and the Ethoxyquin: Tier I Review of Human 

Incidents for more information. 

Additional human health and ecological information is requested for this registration review 

case. Areas of particular interest to EPA are described below: 

• Although ethoxyquin is only applied indoor in pear storage and packing facilities, such 

facilities may be hosed down for cleaning purposes and may generate wastewater 

containing residues of ethoxyquin. Information on the cleaning process and disposal of 

wastewater at treatment facilities is requested. 

• Ethoxyquin is applied via thermal fogging, and exposure to non-target organisms via 

residues in vapor and/or aqueous solution may occur as a result of ventilation. 

Information on ventilation standards and practices at treatment facilities is requested. 

• Ecological incidents (non-target plant damage and avian, fish, reptilian, amphibian and 

mammalian mortalities) not already reported to the Agency. 

• Water quality monitoring data. 

• Human incidents not reported to the Agency. 

TIMELINE 

EPA has created the following estimated time line for the completion of the flonicamid 

registration review in Table 3 below. The projected timeline has not changed since the PWP. 

Table 3: Registration Review for Ethoxyquin- Projected Registration Review Timeline 

Activities Estimated Date 

Opening the Docket 

Open Docket and 60-day Public Comment Period 2014 - December 

Close Public Comment 2015 - February 

Case Development 

Final Work Plan 2015 - June 

Issue DCI 2015 July- Sept. 

Data Submission 2017 July- Sept. 

60-day Public Comment Period for Draft Risk 2019 Jan. -March 

Assessments 

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Table 3: Registration Review for Ethoxyquin- Projected Registration Review Timeline 

Activities Estimated Date 

Registration Review Decision 

60-day Public Comment Period for Proposed 2019 Oct. - Dec. 

Registration Review Decision3 

Registration Review Decision and Begin Post-Decision 2020 

Follow-up 

Total (years) 6 

NEXT STEPS 

As noted previously, the Agency plans to require several environmental fate, ecological effects, 

and human health studies for ethoxyquin through a Data Call-In Notice, expected to be issued by 

September 2015. 

3 The regulations governing Registration Review generally require the Agency to provide a public comment period 

of at least 30 calendar days for draft risk assessments; see 40 CFR Part 155 .53(c). For conventional pesticides, the 

Agency plans to provide a 60 calendar day public comment period generally for draft risk assessments. 

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