2 I NTRODUCTION

This is the Environm ental Protection Agency’s (EPA or the Agency ) Final Work Plan (FWP) for the registration review of hydramethylnon . This work plan addresses public comments received concerning the Preliminary Work Plan (PWP) , which was posted in the hydramethylnon registration review docket (EPA

- HQ

- OPP

- 2012

- 0869 ). Hydramethylnon is a slow

- acting stomach toxicant insecticide registere d for use against ants

, cockroaches , crickets, earwigs, silverfish, and termites

. Hydramethylnon products are primarily used to control ants in non

- crop lands such as lawns, turf, and non

- bearing nursery stock. Hydramethylnon is also registered for the c ontrol of household ant species and cockroaches in nonfood use areas in and around domestic dwellings and commercial establishments. In addition to those uses, hydramethylnon is registered for use on grasses, rangelands, and in pineapple orchards.

The Ag ency 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 s tandard 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 regist ered pesticides continue to meet the statutory standard. The public phase of registration review begins when the initial docket is opened for each case. Informatio n on this program is provided on the Agency’s website

. 1

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 anticipated data needs

, expected risk assessments, or the estimated timeline identified in the PWP

, and a

summ ary of the Agency’s response s to th o se comments

. This section is followed by registration review planned data needs, risk assessments expected to be conducted , and the projected registration review timeline for hydramethylnon

. Lastly, there is a discussi on of next steps.

UPDATES SINCE THE PWP WAS ISSUED

The Agency has updated the planned data needs and ecological risk assessments since the PWP as a result of comments received during the public comment period. After reviewing the

comments

, the Ecologica l Fate and Effects Division has decided to incorporate an urban runoff scenario into the ecological risk assessment as requested

. These comments resulted in the addition of a Whole sediment : acute freshwater invertebrate ( Hyalella azteca ) study (GDLN 850.1735) to

, and the deletion of a Terrestrial Plant Toxicity, vegetative vigor study (GDLN 850.4150) from the list of anticipated data needs . Available information indicate s that a freshwater amphipod ( Hyalella azteca ) may be substantially more s ensitive to hydramethylnon than the commonly tested midge larvae and that hydramethylnon may partition into the sediment

. T herefore

, the Agency feels the need to include GDLN 850.1735 to capture the more sensitive

taxa . The Agency also determined that a vegetative vigor study is no longer needed for hydramethylnon

, as foliar exposure to terrestrial plants from the currently registered formulations (i.e., gel baits, bait stations and granular applications) is expected to be limited. For more

1 http://www.epa.gov/oppsrrd1/registration_review/3 information on this change please see Response to Public Comments on Hydramethylnon Registration Review Problem Formulation

.

SUMMARY OF COMMENTS AND AGENCY RESPONSES

During the 60

- day public comment period on the Hydramethylnon Preliminary Work Plan

, which opened on December 14, 2012 and closed on February 14, 2013 , the Agency received 7 public comment s. Comments were submitted by the technical registrant BASF Corporation, the California Stormwater Quality Association (CASQA), San Francisco Bay Regional Water Quality Control Board (SFB RWQCB), Dole Food Company, Glenn Taniguchi (a private pineapple grower), the Pineapple Growers’ As sociation of Hawaii, and FIFRA Endangered Species Task Force ( FESTF ) . The comments address the timeline described in the PWP, as well

as the planned ecological assessments and data requirements. In the PWP, EPA also solicited comments on the specific top ics of environmental justice, water quality concerns , and trade irritants; comment s were received regarding water quality concerns only.

This section does not capture every comment made about the PWP nor all of the Agency’s

responses. Summarized below ar e public comments that resulted in changes to the anticipated registration review data needs, risk assessments, or timeline, or are of a broader regulatory

nature. Public comments and EPA responses in their entirety are located in the docket, EPA

HQ

- OPP

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- 0869 . Summarized public comments and Agency responses related to the anticipated ecological risk assessment or data needs are in Response to Public Comments on Hydramethylnon Registration Review Problem Formulation

. There were no comments received

reg arding the anticipated human health risk assessment or data needs

.
Comments submitted by CASQA and SFB RWQCB in EPA

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- OPP

- 2012

- 0869

- (0014 and 0015)

.

1. Comment: Hydramethylnon can be applied via broadcast application as a loose granular formulation. Impervious surfaces runoff through urban transport pathways should be included in the conceptual model and risk analysis

.

Response: The Agency concurs with the comments that the risk assessment should include impervious surface modeling for urban areas a nd appreciates the fact sheet submission of impervious surface coefficients. At the time of the Registration Review Risk Assessment, the Agency will revise the risk hypothesis and conceptual models to include relevant routes of exposure to hydramethylnon, including granular application on impervious surfaces. Detailed information on non

- agricultural use and usage of hydramethylnon would be useful for re fin ing the Registration Review Ecological Risk Assessment for hydramethylnon.

2. Comment: Additional s ediment toxicity study using Hyalell a azteca , is needed to quantify the environmental effects of hydramethylnon on aquatic invertebrates in sediments.

Response: The Agency has determined that submission of data on the sediment toxicity of hydramethylnon to Hyalella azteca is necessary

, in addition to the existing Chironomus dilutus sediment toxicity data

, as it is generally a more sensitive freshwater macroinvertebrate than Chironomus dilutus . The following study will be included in the4 Registration Review DCI: Guideline 850.1735

– Whole sediment: acute freshwater invertebrates ( Hyalella azteca )

.

3. Comment: CASQA mentioned that an effective registration review process would prevent pesticide

- related aquatic toxicity in waters and sediments of surface waters receiving urban runoff discharges. It is essential then that pesticide regulatory processes adequately consider potential water quality impacts, so that such impacts are prevented before they result in Clean Water Act ( CWA ) Section 303(d) impaired waters listings.

Response: The Agency acknowledges the comments. At the time of the Registration Review Ecol ogical Risk Assessment, all relevant CWA Section 303(d) impaired waters listings will be considered. The Agency’s goal is to ensure that its registration review decisions are protective of water resources and do not result in an additional burden for stat es under the CWA.

4. Comment: CASQA and SFB RWQCB a sks to modify the proposed registration review timeline to reflect a reasonable period for public review of the draft risk assessment, as the proposed 30

- day public comment period is inadequate for review o f these highly technical documents.

Response: As mentioned in the projected registration review timeline

, regulations generally require the Agency to provide a public comment period of at least 30 calendar days for draft risk assessments. For conventiona l pesticides, the Agency plans to provide a 60 calendar day public comment period generally for draft risk assessments.

Comments submitted by BASF Corporation (BASF) in EPA

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- 2012

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- 0012

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5. Comment: BASF states that t he terrestrial plant toxicity vegetative vigor study (EPA Guideline 850.4150) is only conditionally required based on the use pattern (40 CFR 158.660). Vegeta tive vigor studies are not require d for contained pesticide treatment such as bait boxes and pher omone traps and are generally not required for granular formulations. Since there is no direct crop spray application use registered for hydramethylnon (registered only as gel baits, bait stations, and granular end use products )

, t he risk for direct plant exposure is limited. BASF believes the vegetative vigor study should be removed from the
FWP.

Response: The Agency thanks BASF’s clarification that hydramethylnon is not labeled for direct crop spray application. The vegetative vigor study requirement (Guideline 850.4150) is no longer included in the list of data needs based on the registered use pattern of gel baits, bait stations and granular applications that will result in limited exposure to terrestrial plants through the foliar route

. The Agency also thanks BASF for acknowledging EPA’s request in the PWP by providing additional use/usage information on hydramethylnon, this information will be considered in the registration review risk assessments.5 Comments submitted by The Pineapple Growers Ass ociation of Hawaii , Glenn Taniguchi , and Dole Food Company in EPA

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- ( 0011, 0010 , and 0009)

.

12

. Comment: The Pineapple Growers Association of Hawaii, Glen Taniguchi

, and Dole Food Company state that hydramethylnon has been used in pineapple cultivation for more than 30

years , and stress the importance of the hydramethylnon (Amdro) product to the Hawaiian pineapple industry

. Amdro is applied to their pineapple fields on a n as

- needed basis

, up to 3 times per year pa rticularly where there is a known history of ant problems. Approximately 750 acres are treated annually. They also provided the Agency with additional Hawaii use information and stress the safety of the product.

Response: The Agency acknowledges the comments on the critical importance of this chemical to the pineapple industry and appreciates the clarification on the use pattern and techniques. EPA would also like to thank The Pineapple Growers Association of Hawaii for it s suggested risk mitigation measures; these will be taken into consideration during registration review.

PLANNED DATA NEEDS

Table 1 below summarizes the planned data needs for hydramethylnon based on the Registration Review: Preliminary Problem Formulati on for Environmental Fate, Ecological Risk, Endangered Species, and Drinking Water Exposure Assessments for Hydramethylnon

, Hydramethylnon. Human Health Assessment Scoping Document i n Support of Registration Review, and Response to Public Comments on Hydra methylnon Registration Review Problem Formulation

. The table has been updated since the PWP to reflect public comments which resulted in changes to the data needs

.

Table 1: Planned D ata Needs for the Hydramethylnon Registration Review

Guideline
Number 2 Study Title 2 Test Material Estimated Timeframe (Months from receipt of DCI)

835.2240 Aquatic photodegradation TGAI 12
835.4300 Aerobic Aquatic Metabolism TGAI 24
835.4400 Anaerobic Aquatic Metabolism TGAI 24

850.1025 Acute toxicity estuarine and marine organisms (oyster shell growth) TGAI 12

850.1300 Freshwater invertebrate life cycle 3 TGAI 12

2 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 A vailability” 77 FR 38282, June 27, 2012. http://www.regulations.gov/#!documentDetail;D=EPA

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3 The planned DCI will specify that testing with eith er a freshwater invertebrate or an estuarine/marine invertebrate (for a species with a valid acute toxicity test) is to be performed. The resulting acute to chronic ratio (ACR) will then be applied to the other invertebrates.6 Table 1: Planned D ata Needs for the Hydramethylnon Registration Review

Guideline
Number 2 Study Title 2 Test Material Estimated Timeframe (Months from receipt of DCI)

850.1 350 Saltwater invertebrate life cycle 3 TGAI 12

850.1400 Fish early

- life stage toxicity test (freshwater and estuarine/marine) 4 TGAI 12

850.1735 Whole sediment: acute freshwater invertebrates ( Hyalella azteca ) TGAI 12

850.2100 Avian oral toxicity (passerine species) TGAI 12
850.4100 Seedling emergence and seedling growth TEP 12
850.4400 Aquatic plant toxicity test using Lemna spp TGAI 12
850.4500 Algal toxicity TGAI 12
850.4550 Cyanobacteria toxicity TGAI 12

850.6100 Environmental Chemistry Methods and Associated Independent Laboratory Validation for soil and

water TGAI 12

870.7800 Immunotoxicity 5 TGAI 12 TGAI = technical grade active ingredient; TEP = typical end

- use product ; Degr. = degradate

RISK ASSESSMENTS FOR REGISTRATION REVIEW

During registration review, t he Agency will conduct a comprehensive ecological risk assessment, including an endangered species assessment, for all uses of hydramethylnon

. For human health,
EPA will not conduct a revised dietary, residential

, and occupational risk assessment s during registration review though a drinking water assessment from surface water sources only will be conducted

. If toxicological endpoints or points of departure are revised based on the data that are required for registration review

, they will be considered in the new assessment s , as well as any changes to the st andard operating p rocedures or default exposure assumptions

.

Table 2 below summarizes the planned registration review risk assessments based on the EFED Problem Formulation and HED Scoping Document and has been updated since the PWP to reflect public comments which resulted in changes to the planned risk assessments. These changes to the planned risk assessments include d the addition of an urban runoff scenario to

4 The planned DCI will specif y that testing with either a freshwater fish or an estuarine/marine fish (for a species with a valid acute toxicity test) is to be performed. The resulting acute to chronic ratio (ACR) will then be applied to the other fish.

5 Recently, OPP published the findings of its retrospective analysis of immunotoxicity studies submitted to the Agency, concluding that none of the studies included in the analysis resulted in a Point of Departure (POD) that is lower than the PODs selected from other availab le guidelin e toxicology studies ( http://www.epa.gov/pesticides/regulating/immunotoxicity

- retro

- analysis.pdf )

. EPA will consider requests for waivers for this study, particularly in light of the retrospective analysis. A weight

- of

- evidence rationale will be considered relative to the chemical’s toxicological profile, primary target organ system(s) and mode of toxic action, and any immuno

- related data available from structurally

- r elated compounds.7 reflect the Agency’s concurrence with CASQA and SFB RWQCB’s comments as se en on page 3 ( comment 1).

Table 2: Planned Risk Assessments for the Hydramethylnon Registration Review

Type of Risk Assessment Conduct ? Notes

Eco logical and Environmental Fate Comprehensive ecological (species to be assessed include terrestrial and aquatic organisms ), including endangered species Y Regarding degradates of concern: The Agency has concluded that t he stressor of concern is the parent hydramethylnon

. Two known major degradates 6

will not be assessed further because of the low toxi city based on the ECOSAR analysis. However, several unidentified degradates from photolysis and anaerobic degradation studies will be assumed as the parent hydramethylnon unless they are properly identified.
Incidents Will check for updates For a discussion of reported ecological incidents for hydramethylnon , see page 16 of the Problem Formulation.
Human Health Dietary
Food N It is unlikely that a new assessment will be needed, unless the planned drinking water assessment determines significant estimated residues in drinking water from surface water

sources. Drinking water Y The Agency plans to conduct an assessment of drinking water from surface water sources only, since hydramethylnon appears to have a low potential for groundwater contamination. Occupational Handlers (mixers, loaders, applicators) N Absent any new toxicity or exposure data, changes to the standard operating procedures, or default exposure assumptions, the Agency plans to rely on previous assessments where there was no risk estima tes of concern associated with hydramethylnon handler or post

- application occupational exposure. Post

- application N

Residential
Handlers N There is very low potential for dermal and inhalation exposures to residential handlers due to the properties of the gel formulation and bait

station packaging

. Post

- application N

6 1,5

- bis(alpha, alpha, alpha

- trifluoro

- p

- tolyl)

- 1,4

- pentadien

- 3

- one ( CL98,724, 28%) and 4H

- pyrimido [2

- 1

- c]as

triazio

- 4

- one1,6,7,8

- tetrahydro

- 7,7

- dimethyl

- 3

- [p

- (trifluoromethyl)

- styryl] (CL247,176, 25.2% and 30.5%)8 Other Aggregate N E valuates the combined risk from dietary and residential exposures. Based on current estimated risk levels

, a new quantitative aggregate risk assessment is not likely to be necessary.
Cumulative N/A Hydramethylnon has not been identified as a member of a common mechanism group.
Tolerances Y The tolerance expression for hydramethylnon will be reviewed during registration review to ensure that it appropriately covers the metabolites and degradates of hydramethylnon and that it specifies the residues to be measured for each commodity.

Incidents Will check for updates For a discussion of reported human incidents for hydramethylnon, see page 10 of the Scoping Document and Hydramethylnon: Review of Human Incidents

.

TIMELINE

EPA has created the following estimated timeline for the completion of the hydramethylnon registration review in Table 3 below

. The projected timeline has been modified to indicate that the Agency plans to provide a 60 day public comment period generally for conventional pesticide draft risk assessments

.

Table 3: Registration Review for Hydramethylnon

– Projec ted Registration Review Timeline Activities Estimated Date Opening the D ocket Open Docket and 60

- day Public Comment Period Dec 2013

– Completed
Close Public Comment Feb 2013

– Completed Case Development
Final Work Plan May

– Completed
Issue DCI Jan.

– March

– 2014
Data Submission Jan.

– March

– 2016
6 0

- day Public Comment Period for Draft Risk Assessments 7 July

– Sept.

– 2017 Registration Review Decision
60

- day Public Comment Period for Proposed Registration Review
D ecision Jan.

– March

– 2018

Registration Review D ecision and Begin P ost

- D ecision F ollow

- up 2018 Total ( years ) 6

7 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 pu blic comment period generally for draft risk assessments.9 NEXT STEPS

As noted previously, the Agency plans to require several environmental fate, ecological effects, and human health studies for hydramethylnon through a D ata C all

- I n Notice , expected to be issued early 2014

.