Docket Number EPA-HQ-OPP-2011-0907 www.regulations.gov



## Tetramethrin Final Work Plan Registration Review

May 20123 

### FINAL WORK PLAN – TETRAMETHRIN

Introduction :

This is the Environmental Protection Agency’s (EPA or the Agency) Final Work Plan (FWP) for the registration review of tetramethrin. The FWP includes the expected registration review

timeline. The FWP also addresses any public comments received on the Preliminary Work Plan (PWP) in the Summary Document, which was posted in the tetram ethrin registration review docket (EPA-HQ-OPP-2011-0907). The Summary Document, dated December 15, 2011, provided information on what EPA knows about the pesticide and what additional risk analyses and data or information the Agency believes are needed to make a regist ration review decision.

The Agency’s implementation of the registrati on review program requi res review of each registered pesticide every 15 years to determin e whether it continues to meet the Federal Insecticide, Fungicide, and Rode nticide Act (FIFRA) standard for registration. Changes in science, public policy, and pestic ide use practices occur over time. The registration review program is intended to make sure that, as the ab ility to assess risk evolves and as policies and practices change, all registered pesticides contin ue to meet that statutory standard. The public phase of registration review begins when the ini tial docket is opened for e ach case. Information on this program is provided on the Agency’s website 1

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Tetramethrin is a broad-spectrum, first-generation s ynthetic pyrethroid insect icide. It is a rapid knockdown agent registered for use against flying a nd crawling insects, such as wasps, hornets, roaches, ants, fleas, and mosquitoes. There are no registered food or agricultural uses of tetramethrin. It is used primarily in residen tial, commercial, institutional, and industrial areas and can be used both indoors, including app lications to pets, a nd outdoors. Although tetramethrin products are not classified as restri cted use pesticides, some tetramethrin end-use products are labeled for use by pe st control operators only. Pr oducts containing tetramethrin were first registered in 1968. The Reregistration Eligibility D ecision (RED) for Tetramethrin was completed in June 2008 and revised in Ap ril 2010. The cumulative risk assessment for the pyrethroids and pyrethrin s was published on November 9, 2011 and is available in public docket EPA-HQ-OPP-2011-0746.

Updates Since the Summary Document was Issued :

There are no updates for tetramethrin since the Summary Document was issued and the initial registration review docket opened.

Summary of Comments and Agency Responses :

The Agency did not receive any comments on the tetramethrin PWP during the 60-day public comment period, which began on December 21, 2011 and ended on February 21, 2012. EPA also solicited comments on the specific topics of environmental justic e, water body impairment, and trade irritants, but no comments or information were received on those issues.

1 http://www.epa.gov/oppsrrd1/registration_review/4 Risk Assessment and Data Needs :

The Agency will require data to conduct a comprehensive ecological risk assessment, including an endangered species assessment, for all uses of tetramethrin. For human health, EPA will conduct revised residential and occupational risk assessments during regi stration review. If toxicological endpoints or points of departure are revised, they will be considered in the new assessment, as well as any changes to the sta ndard operating procedures or default exposure assumptions. Below is a summary of the issu es relevant to the registration review of

tetramethrin.

Ecological Risk:

 The most recent comprehensive ecological risk assessment for tetramethrin was completed in February 2008 in support of the tetramethrin RED.

 An updated comprehensive ecological risk assessment of all registered uses of tetramethrin will be conducted during registration review. The new assessment will incorporate the most up-to-date modeli ng methodologies, updated toxicological endpoints, and data submitted under the registration review data call-in.

 Tetramethrin uses relevant to the ecological ri sk assessment are limited to spot treatments ( e.g ., spraying a wasp hive), space treatments ( e.g ., spraying of an aerosol can in a storage room or other enclosed space), and or namental applications against crawling and flying insects ( e.g ., spraying hedges). EPA’s standa rd risk assessment methodology is not applicable for these kinds of uses because standard expected environmental concentrations (EECs) cannot be directly calculated (without majo r assumptions) using the Agency’s typical tools due to a number of factors, including non-standard use rates ( e.g ., 1-2 second burst, lbs a.i./ft 3 ) and estimations of the magnit ude of use in a given area ( e.g ., a neighborhood or campsite) at a given time. For the tetramethrin risk assessment, the Agency will use the required ecological data and an estimate of exposure, taking into consideration the specific uses of tetramethrin, to assess th e potential for ecological risk

associated with its use.

 Certain tetramethrin labels are unclear with respect to application parameters like the size of the treated area, the extent of a treated “spot,” retreat ment intervals, or maximum annual application rates. In the absen ce of clear label information, EPA must approximate these parameters in order to conduct a quantitative assessment for tetramethrin. The Agency encourages clear a nd consistent label langu age for the sake of all stakeholders and encourages registrants to review tetramethrin product labels for clarity.

 A risk assessment that supports a complete endangered species determination has not

been conducted for tetramethrin. The eco logical risk assessment planned during registration review will allow the Agency to determine whether tetramethrin’s use has “no effect” or “may affect” federally liste d threatened or endangered species (listed species) or their designated critical habita ts. When an assessment concludes that a pesticide’s use “may affect” a listed species or its designated critical habitat, the Agency5 will consult with the U.S. Fish and Wildlife Service and/or National Marine Fisheries Service (the Services ), as appropriate.

 On January 19, 2011, the Center for Biologi cal Diversity and the Pesticide Action

Network North America filed a lawsuit in th e United States District Court for the Northern District of California, against EP A for allegedly failing to undergo consultation with the Services regarding the effects of over 350 pesticides, incl uding tetramethrin, on over 200 endangered and threatened species throughout the United States (Center for Biological Diversity, et al. v. EPA, et al., No. C 11-00293 (N.D.Cal.).

 Data gaps exist in the ecological database for tetramethrin. EPA will require the following studies for use in conducting a comp lete ecological risk assessment, including an endangered species assessment, for th e registration review of tetramethrin.

835.6100 – Terrestrial field dissipation study 2
835.6200 – Aquatic field dissipation study 2
850.1025 – Acute toxicity estuar ine and marine organism s (oyster shell growth) 850.1035 – Acute toxicity es tuarine and marine organisms (mysid) 850.1075 – Acute toxicity estuarine and marine organisms (fish) 850.1075 – Freshwater fish toxicity (using TEP) 850.2100 – Avian oral toxicity (passerine species) 850.4100 – Terrestrial plant toxicity, seedling emergence, Tier II 850.4150 – Terrestrial plant toxic ity, vegetative vigor, Tier II Non-guideline – Aquatic invertebrate acute toxicity testing using Hyalella azteca (using TGAI and TEP) 3

 Studies conducted with freshwat er invertebrates and fish will be required using a typical end-use product (TEP) containing tetramethrin and the synergist piperonyl butoxide in addition to a TEP containing tetramethrin a nd the synergist MGK-264. Tetramethrin is

co-formulated with either or both synergists in numerous products. Because available information indicates that greater toxicity enhancement can occur at higher synergist-toactive ingredient ratios, sele ction of the TEPs for these data requirements would include those with the highest synergis t-to-active ingredient ratio that are registered for outdoor

uses.

 Please refer to the December 5, 2011 document Registration Review – Preliminary Problem Formulation for the Ecological Risk Assessment for Tetramethrin in the registration review docket (EPA-HQ-OPP-2011-0907-0003) for a detailed discussion of the upcoming risk assessment and data needs.

2 See footnote 7 of 40 CFR 150.1300. EPA will require only the environmental chemistry analytical methods and

independent laboratory validation (ILV) portions of this guideline for soil and water, rather than the full field dissipation study.

3 The Summary Document erroneously listed this data requirement as Guideline 850.1020.6 Human Health Risk:

 The most recent comprehensive human health risk assessment for tetramethrin was conducted in June 2008 in support of the tetramethrin RED. The occupational and residential exposure assessments were revised in 2009 and 2010.

 The Food Quality Protection Act (FQPA) require s the Agency to consider the cumulative risks of chemicals sharing a common mechanism of toxicity. Tetramethrin is a member of the pyrethroid/pyrethri ns common mechanism group ( http://www.regulations.gov ; EPA-HQ-OPP-2008-0489). The members of this gr oup share the ability to interact with voltage-gated sodium channels ultimately lead ing to neurotoxicity. The cumulative risk assessment for the pyrethroids/pyrethrins was published on November 9, 2011 and is

available at http://www.regulations.gov ; EPA-HQ-OPP-2011-0746. No cumulative risks of concern were identified, a llowing the Agency to consid er new uses for pyrethroid active ingredients. For information regardi ng EPA’s efforts to evaluate the risk of exposure to pyrethroids, refe r to the Agency’s website 4

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 A dietary (food) exposure assessment is not needed during registration review because there are currently no registered food or feed uses for tetram ethrin. Dietary exposure is not expected based on registered uses.

 A drinking water dietary assessment for te tramethrin will not be conducted during registration review given the limited extent of potential exposure s based on currently registered use sites and the environmental fa te properties of tetramethrin that limit its mobility.

 Revised residential and occupational expos ure assessments will be conducted during registration review to reflect current st andard operating procedures and revised toxicological endpoints.

 During registration review, EPA will consid er data submitted in response to the 2010 RED data call-in (DCI) (GDCI-069003-28621) and will revise toxicological endpoints as needed. See the “Summary of Data Gaps ” table for further details regarding the previously-issued DCI. No additional human health data will be required in the registration review DCI.

 Please refer to the December 13, 2011 document Tetramethrin: Human Health Risk Scoping Document in Support of Registration Review in the registration review docket (EPA-HQ-OPP-2011-0907-0005) for a detailed discussion of upcoming risk assessments

and data needs.

Endocrine Disruptor Screening Program :

As required by FIFRA and FFDCA, EPA reviews num erous studies to asse ss potential adverse outcomes from exposure to chemicals. Collectiv ely, these studies includ e acute, subchronic and

4 http://www.epa.gov/oppsrrd1/reevaluation/pyrethroids-pyrethrins.html7 chronic toxicity, including asse ssments of carcinogenicity, ne urotoxicity, developmental, reproductive, and general or systemic toxicity. These studies include endpoints which may be susceptible to endocrine influe nce, including effects on endocri ne target organ histopathology, organ weights, estrus cyclicity, sexual maturatio n, fertility, pregnancy rates, reproductive loss, and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and chronic studies that assess gr owth, developmental and reprod uctive effects in different taxonomic groups. As part of its reregistration decision for tetramethrin, EPA reviewed these data and selected the most sensitive endpoints fo r relevant risk assessment scenarios from the existing hazard database. However, as requi red by FFDCA section 408(p ), tetramethrin is subject to the endocrine screeni ng part of the Endocrine Disrup tor Screening Program (EDSP).

EPA has developed the EDSP to determine whet her certain substances (including pesticide active and other ingredients) may have an effect in humans or wildlife similar to an effect produced by a “naturally occurring estrogen, or ot her such endocrine effect s as the Administrator may designate.” The EDSP employs a two-tiered approach to making th e statutorily required

determinations. Tier 1 consists of a battery of 11 scr eening assays to identify the potential of a chemical substance to interact with the estrog en, androgen, or thyroid (E, A, or T) hormonal systems. Chemicals that go th rough Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal systems will proceed to the next stag e of the EDSP where EPA will determine which, if any, of th e Tier 2 tests are necessary base d on the available data. Tier 2 testing is designed to identify a ny adverse endocrine-related eff ects caused by the substance, and establish a dose-response relationship between the dose and the E, A, or T effect.

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between October 2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 chemicals, which contains 58 pest icide active ingredients and 9 inert ingredients. Tetramethrin is not among the group of 58 pesticide active ingred ients on the initial list to be screened under the EDSP. Accordingly, as part of registrati on review, EPA will issue future EDSP orders/data call-ins, requiring the submission of EDSP scr eening assays for tetramethrin. For further information on the status of the EDSP, the polic ies and procedures, the list of 67 chemicals, future lists, the test guidelines and the Tier 1 screening battery, pl ease visit our website: http://www.epa.gov/endo/

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Timeline :

EPA has created the following estimated timeline for the completion of tetramethrin’s registration review.

Registration Review for Tetramethrin – Projected Registration Review Timeline

Activities Estimated Date Opening the Docket Open Docket and Public Comment Period Dec. 2011 - Completed

Close Public Comment Feb. 2012 - Completed Case Development

Final Work Plan May 2012 - Completed

Issue DCI 2013 – Jan. – March8 Registration Review for Tetramethrin – Projected Registration Review Timeline

Activities Estimated Date

Data Submission 2014 – Jan. – March Open Public Comment Period for Draft Risk Assessments 2015 – July – Sept.

Close Public Comment Period 2015 – Oct. – Dec. Registration Review Decision Open Public Comment Period for Proposed Registration Review

Decision 2016 – Jan. – March

Close Public Comment Period 2016 – April – June Registration Review Decision and Begin Post-Decision Follow-up 2016 Total (years) 5 5

Next Steps :

As noted previously, the Agency plans to requ ire several environmenta l fate and ecological effects studies through a DCI, expected to be i ssued in early 2013. In addition, the Agency will review toxicity data submitted as required by the 2010 DCI. This new information will be used to conduct complete risk assessments for all registered uses of tetramethrin.

5 Any changes in the cumulative risk from the pyrethroid class of insecticides may impact this time estimate.9 

### SUMMARY OF DATA GAPS – TETRAMETHRIN

The table below summarizes the data needs for tetramethrin listed in Registration Review – Preliminary Problem Formula tion for the Ecological Risk Assessment for Tetramethrin , dated December 5, 2011; Tetramethrin: Human Health Risk Scoping Document in Support of Registration Review, dated December 13, 2011; and outstanding data previously required through EPA’s DCI process.

Guideline

Number Data Needs Test Material Estimated

Timeframe

(Months from receipt of DCI)

835.6100 Terrestrial field dissipation study 6 TGAI 12

835.6200 Aquatic field dissipation study 6 TGAI 12

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

850.1035 Acute toxicity estuarine and marine organisms (mysid) TGAI 12

850.1075 Acute toxicity estuarine and marine organisms (fish) TGAI 12

850.1075 Freshwater fish toxicity TEP 12
850.2100 Avian oral toxicity (passerine species) TGAI 12

850.4100 Terrestrial plant toxicity, seedling emergence, Tier

II 7 TEP 12

850.4150 Terrestrial plant toxicity, vegetative vigor, Tier II 7 TEP 12

Nonguideline Aquatic invertebrate acute toxicity using Hyalella

azteca 8 TGAI & TEP 12

The studies below were previously required thro ugh a generic DCI (GDCI-069003-28621), issued in June 2010 and are still outstanding. The studies are listed for reference although they will NOT be included in the registration review DCI.

870.3700 Prenatal developmental toxicity TGAI due 6/2012

870.6200 Acute and subchronic neurotoxi city battery TGAI due 6/2012
870.6300 Developmental neurotoxicity 9 TGAI due 6/2014

6 See footnote 7 of 40 CFR 150.1300. EPA will require only the environmental chemistry analytical methods and

ILV portions of this guideline for soil and water, rather than the full field dissipation study.

7 The registration review DCI will provide that a Tier I plant study may be conducted in lieu of a Tier II study with

the understanding that any adverse effects observed by th e Tier I study would necessitate conduct and submission of a Tier II study as well.

8 The Summary Document erroneously listed this data requirement as Guideline 850.1020.

9 The June 2010 DCI included the statem ent, “EPA has determined that, as an alternative to the generation and

submission of a new DNT study, pyrethroid registrants may instead choose to cite the six previously submitted DNT studies for pyrethroid pesticides.”