Docket Number: EPA-HQ-OPP-2009-0637 www.regulations.gov



## Deltamethrin Final Work Plan Registration Review September 20103 DELTAMETHRIN FINAL WORK PLAN

Introduction :

This is the Environmental Protection Agency’s (EPA’s) Final Work Plan for the registration review of deltameth rin. This work plan includ es the expected registration review timeline. The work plan also addre sses public comments received concerning the Preliminary Work Plan in the Summary Document , which was posted in the deltamethrin registration review docke t (EPA-HQ-OPP-2009-0637), and any other comments concerning the ini tial docket postings. The Summary Document provided information on what EPA knows about the pest icide and what additional risk analyses and data or information the Agency believes are needed to make a registration review

decision.

The Agency is implementing the registration re view program pursuant to Section 3(g) of the Federal Insecticide, Fungicide, and Rode nticide Act (FIFRA), and will review each registered pesticide every 15 years to determ ine whether it continues to meet the FIFRA standard for registration. Ch anges in science, public polic y, and pesticide use practices will occur over time. The registration review program is intended to make sure that, as the ability to assess risk e volves and as policies and pract ices change, all registered pesticides continue to meet the statutory standard. Th e public phase of registration review begins when the initial docket is opened for each case. Information on this program is provided at: http://www.epa.gov/oppsrr d1/registration_review/

.

Deltamethrin is a pyrethroid registered for use on cotton, sorghum, artichokes, pears and a variety of vegetable, fruit, and tree nut cr ops for the control of a broad spectrum of pests including mites, ants, weevils, and beetles. It is also registered for use in residential and industrial applications for the control of cockroaches, pests of stored commodities,

and other nuisance or destructiv e insects. A deltamethrin pet collar is registered for the

control of fleas and ticks. Deltamethrin wa s first registered in the U.S. in 1994, and products containing deltamethrin were firs t marketed in the United States in 1997.

Deltamethrin is also a metabolite of the pyr ethroid pesticide tralomethrin, so that deltamethrin may occur as a result of the a pplications of tralomethrin. Since the deltamethrin PWP was issued, the tralomethrin registrant has reque sted to voluntarily

cancel all uses of tralomethrin. More info rmation on tralomethrin can be accessed via www.regulations.gov under Docket ID OPP-2010-0116.

Comments Received on Preliminary Work Plan :

Multiple comments were received during the 60-day public comment period on the Preliminary Work Plan

. These comments are summarized in this document and changes to the work plan set out in the Preliminary Work Plan are explained. In the Preliminary
Work Plan , EPA also solicited comments on three specific topics: environmental justice, water body impairment, and trade irritants. No comments or information were received during the comment period concerning envir onmental justice or trade irritants.4 Comments were received from three comment ers regarding water body impairment. As a result of comments additional data are require d for deltamethrin and are described below. For further discussion on these comments please see the Summary of Comments and Agency Responses section below.

Anticipated Risk Assessment and Data Needs:

The Agency expects to require data needed to update and revise the ecological risk assessment for deltamethrin (including an e ndangered species risk assessment) and the

human health risk assessment.

Ecological risk

The most recent assessment for deltamethrin was conducted in 2007, prompted by a proposal for a new tolerance for flax. The 2007 assessment references a 2002 assessment, and the 2002 assessment in turn references a 1994 assessment:

 “EFED Section 3 Registration of Deltamethrin for use on Flax and Results from the Submission of a 6(a)2 Adverse E ffects Daphnid Study,” USEPA, September 27, 2007.

 “Tolerance Petition for Uses of Deltame thrin (PC Code 097805) on Field Corn, Sorghum, Soybeans, Sunflowers, Bulb Ve getables, Cucurbit Vegetables, Leafy Vegetables, Fruiting Vegetables, Carro ts, Potatoes, Radishes, Artichokes, Cauliflower, Broccoli, Cabbage, Mustar d Greens, Tree Nuts, Stone Fruits, and Pome Fruits (DP Barcode D262498) In cremental Ecological Effects Risk Assessment Due to the New Uses,” USEPA, August 6, 2002.

 “Ecological Effects Branch Review of Deltamethrin,” USEPA, January 17, 1994.

The Agency has not conducted a risk asse ssment that supports a complete endangered species determination for deltamethrin. Th e ecological risk assessment planned during registration review will allow the Agency to determine whether deltamethrin’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 Agency

will consult with the U.S. Fish and Wildlife Service and/or National Marine Fisheries Service (the Services ), as appropriate.

The Agency anticipates requiring the followi ng data in order to conduct a complete ecological risk assessment, including an enda ngered species assessment, for deltamethrin:

• Guideline # 835.4300 Aerobic Aquatic Metabolism

• Guideline # 835.4400 Anaerobic Aquatic Metabolism

• Guideline #s 835.6100 & 6200 Environmental Chemistry Methods and Independent Laboratory Validations for Soil, Water and Sediment

• Guideline # 850.2100 Passerine Acute Avian Oral

• Guideline # 850.1400 Fish Early Life Stage (saltwater)5 • Guideline # 850.1500 Fish Life Cycle (saltwater)

• Guideline # 850.1350 Aquatic Inverteb rate Life-Cycle (saltwater)

• Guideline # 850.1790 Whole sediment, chro nic invertebrates freshwater and

marine

• Guideline # 850.4150 & 4250 Vegetative vigor and Seedling emergence, Tier I/

Tier II

• Guideline # 850.4400 Aquatic Vascular Plant Growth- Lemna spp. Tiers I/II

• Guideline # 850.5400 Algal toxicity test

, Tier I/II

• Non-guideline Aquatic Invert ebrate Acute Toxicity ( Hyalella azteca )

The following data would be used to in form removal percentages by waste water treatment, which is an input to the Exposure and Fate Asse ssment Screening Tool’s (EFAST) down-the-drain module. The Office of Pesticide Program s will continue to confer with the Office of Water with the goa l of refining our down-the-drain assessment for registration review. These studies should be conducted on deltamethrin.

o POTW Effluent Monitoring;

o POTW Treatability Study.

Please refer to the document “Environmenta l Fate and Ecological Risk Assessment Problem Formulation in Support of Regist ration Review for Deltamethrin, March 23, 2010,” for a more detailed discussion of an ticipated ecological risk assessment data

needs.

Human Health Risk

The most recent assessment for deltamethrin was conducted in 2009, prompted by a proposal for a new tolerance for flax. The assessment is documented in:

 “Tier I Estimated Drinking Water Concentr ations of Deltamethrin for the Use in

the Human Health Risk Assessment: IR-4 Tolerance Petition for the Use of Deltamethrin on Flax,” USEPA, April 24, 2007.

 “ Deltamethrin--Response to Tolerance Peti tion for Use on Flax,” USEPA, August 13, 2009.

Additional analyses are discussed in:

 “Deltamethrin--Human Health Assessm ent Scoping Document in Support of Registration Review,” USEPA, February 17, 2010.

This latter document includes an aggregate ri sk assessment that inco rporates residential uses not covered by the 2009 assessment, and documents some aggregate risk estimates of concern. The Agency believes that a re fined assessment utilizing additional data and new assessment methodologies may reduce so me of these risk estimates relative to conservative, default data and methodologies. For some residential uses with very low6 MOEs, refinement of the risk assessment is not likely to reduce risk estimates below levels of concern, and the Agency is curren tly working with affected registrants to mitigate the risks.

• The existing residue chemistry database for deltamethrin is adequate for risk
assessment purposes.

• The Agency is investigating the need for additional experimentation, regarding the pharmacokinetics of pyrethroids and the potential for increased susceptibility of young organisms. The Agency will revisit its decision on the need for an FQPA or other database uncertainty/safety factors following receipt of the toxicity data the Agency expects to require, a nd following a final determination of the potential for increased susceptibility of infants and children to pyrethroid pesticides based on the resu lts of all available data.

• Aside from the potential outcome of the research described above, the toxicology database for deltamethrin is essentially complete, with the exception of the immunotoxicity data. The Agency exp ects to require an immunotoxicity study (Guideline # 870.7800).

• The Agency anticipates conducting a new di etary risk assessment in registration review to incorporate upda ted drinking water estimates, information on dietaryconsumption, and usage information. In order to better understand postapplication residential ex posure, the Agency expect s to require data on the transfer of deltamethrin residues from pe ts wearing deltamethrin flea collars to humans. The Agency anticipates devel oping a refined aggregate assessment for combined exposures from food, drinking water, and residential exposures.

• The Agency anticipates conducting a ne w occupational risk assessment in registration review, which would utili ze any new and relevant toxicological endpoints, exposure data, policies, an d incident data as appropriate.

• Deltamethrin is an animal and environm ental metabolite of another pyrethroid insecticide, tralomethrin. In recent assessments, the human toxicology endpoint

selected for tralomethrin was derived from the same study as that used in assessing the risks associated with de ltamethrin use, and the dietary risk

assessment for deltamethrin accounted for tralomethrin use. Since the deltamethrin PWP was issued, the tralom ethrin registrant has requested to voluntarily cancel all uses of tralomet hrin. Depending on the outcome of the voluntary cancellation process the Agency ma y or may not include tralomethrin in any risk assessments. More informa tion on tralomethrin can be accessed via www.regulations.gov under Docket ID OPP-2010-0116.

• In 1997, tolerances for tralomethrin and deltamethrin were reassessed in response to a general policy change in which time limitations for tolerances were deleted. For this FQPA reassessment, exposures associated with the use of both7 tralomethrin and deltamethrin were comb ined. The basis for this approach was that tralomethrin is rapidly metabolized by animals to deltamethrin (as a result of debromination) and the toxicology profiles of deltamethrin and tralomethrin are virtually identical. Since the tralomet hrin registrant is pursuing voluntary cancellation of tralomethrin, future tolera nce expressions and dietary assessments for deltamethrin may be modified to account for this change.

• Deltamethrin is a member of the pyrethroid class of insecticides. This class also includes permethrin, cypermethrin, cyfl uthrin, tau-fluvalin ate, bifenthrin, fenpropathrin, and lambda-cyhalothrin, am ong others. EPA developed a draft science policy document on the proposed common mechanism of toxicity for naturally-occurring pyrethri ns and synthetic pyrethroi ds (Draft Science Policy Paper: Common Mechanism Grouping for the Pyrethrins and Synthetic Pyrethroid Pesticides, May 19, 2009, available in the docket at http://www.regulations.gov/search/R egs/home.html#documentDetail?R=0900006
4809a62df ). The FIFRA Scientific Adviso ry Panel (SAP) su pported the draft science policy (Minutes from the SAP m eeting on the Evaluation of the Common Mechanism of Action of the Pyrethroid Pesticides, September 9, 2009, available

in the docket at http://www.regulations.gov/search/R egs/home.html#documentDetail?R=0900006

480a1f8d7 ). EPA will finalize the policy document on the pyrethroid common mechanism of toxicity ta king into account the reco mmendations of the SAP. Pesticides with a common mechanism of toxicity are subject to cumulative risk assessment under the FQPA. Research is on-going by EPA’s Office of Research and Development (ORD) to make improvements to the Stochastic Human Exposure and Dose Simulation (SHEDS) probabilistic exposure model, which are important for the cumulative risk assessment. EPA ORD is also developing physiologically-based pharmacokinetic models for several pyrethroids. The status of both of these research modeling effort s will be reviewed by the FIFRA SAP in July, 2010. For information regarding EPA’ s efforts to evaluate the risk from pyrethroids, see http://www.epa.gov/oppsrrd1/reevaluation/pyrethroidspyrethrins.html

.

• During registration review, the tolerance expression for deltamethrin in 40 CFR §

180.435 will be reviewed to ensure that it appropriately covers the metabolites and degradates of deltamethrin and that it specifies the residues to be measured for each commodity. Any proposed revisions would be to the chemical description rather than the individual tolerance levels.

The Agency anticipates needing the followi ng data in order to conduct a complete

human health risk assessment for deltamethrin:

• Guideline # 870.7800 Immunotoxicity

• Special Study, Pet Collar Residue Transfer8 Please refer to the document “Deltamethrin

. Human Health Assessment Scoping Document in Support of Registration Review ,” February 17, 2010 for a more detailed

discussion of human health risk estimates a nd anticipated human health risk assessment

data needs.

Other Data Needs

• Guideline # 830.7050 UV/Visible Light Absorp tion – this study is a new data requirement under 40 CFR part 158 (Produc t Chemistry Data Requirements) for registration of a pesticid e (food and non-food uses). The Agency anticipates requiring this study to obtain basi c information a bout the compound’s identity/composition and the wavelengths at which the compound may be susceptible to photochemical degradation.

Endocrine Disruptor Screening Program

As required under FFDCA section 408(p), EP A has developed the Endocrine Disruptor Screening Program (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 other such endocrine effects as the Administrator may designate.” The EDSP employs a two-tiered approach to making the statutorily required determinations. Tier 1 cons ists of a battery of 11 screening assays to identify the potential of a chemical substan ce to interact with th e estrogen, androgen, or thyroid (E, A, or T) hormona l systems. Chemicals that go through Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA will determine which, if any, of the Tier 2 tests are necessary based on the available data. Ti er 2 testing is designed to identify any adverse endocrine related effects caused by th e substance, and esta blish a quantitative relationship between the dose a nd the E, A, or T effect.

Between October 2009 and February 2010, EPA issu ed test orders/data call-ins for the first group of 67 chemicals, which contains 58 pesticide active ingredients and 9 inert ingredients. This list of chemicals was selected based on the potential for human exposure through pathways such as food and wa ter, residential activity, and certain postapplication agricultural s cenarios. This list should not be construed as a list of known or likely endocrine disruptors.

Deltamethrin is not among the group of 58 pestic ide active ingredients on the initial list

to be screened under the EDSP. Under FFDCA sec. 408(p) the Agency must screen all pesticide chemicals. Accordingly, EPA antic ipates issuing future EDSP orders/data callins for all Registration Review cases, includ ing those for which EPA has already opened a Registration Review docket for a pesticide active ingredient.

For further information on the status of the ED SP, the policies and procedures, the list of 67 chemicals, the test guidelines and the Tier 1 screening battery, please visit our website: http://www.epa.gov/endo/.9 Timeline :

EPA has created the following estimated ti meline for completion of the registration

review for deltamethrin.

Projected Deltamethrin Regi stration Review Timeline

Activities Estimated Date Opening the docket Open Docket and Public Comment Period 2010 – March Close Public Comment 2010 – May Case Development Final Work Plan 2010 – August Issue DCI 2011 – April - June Data Submission 2013 – April - June Open Public Comment Period for Preliminary Risk Assessments 2014 – Oct. – Dec.

Close Public Comment Period 2015 – Jan. - March Registration Review Decision Open Public Comment Period for Proposed Registration Review

Decision 2015 – April - June

Close Public Comment Period 2015 – July – Sept. Final Registration Review Deci sion and Begin Post-Decision Follow-up 2016

Total (years)* 6
* An assessment of the potential cumulative risk from th e pyrethroid class of insecticides may impact this

time estimate.

Summary of Comments and Agency Responses :

The deltamethrin registration review doc ket was open for a 60-day comment period beginning on March 31, 2010. During the co mment period, multiple comments were received. Some of the comments received prompted changes in the work plan. Comments received regarding data requirements and comments received that necessitated changes to the deltamethrin work pl an are addressed below. Please see Deltamethrin. Response to Comments on the Human Health Assessment Scoping Document, dated August 12, 2010, and Preliminary Workplan and Response to Comments on the Registration Review – Environmental Fate and Ecological Risk Assessment Problem Formulation in Support of Registration Revi ew for Deltamethrion (PC Code 097805; DP Barcode D379665, dated August 18, 2010, located in docket number EPA-HQ-OPP2009-0637, for EPA’s responses to other comments received.

This document makes final the work plan for the deltamethrin registration review

process.10 Comments by Tri-TAC/East Bay Municipa l Utility District and County Sanitation Districts of Los Angeles County [EPA-HQ-OPP-2009-0637-0013 and EPA-HQ-OPP2009-0637-0018] (Note: These comments are substantially similar are thus addressed together)

Comment 1: The submitters stated that the deltamethrin work plan does not identify indoor uses as a possible rout e of aquatic exposure and woul d like it to reflect impacts on urban water quality from sewer discharge fr om the indoor uses of deltamethrin. They

indicate that some of the indoor uses of de ltamethrin include surface treatment (aerosols, foggers or sprays), treatment of carpets and of animal kennels and pet sleeping quarters, pet collars, and sewer treatments could resu lt in indoor discharges into sewer systems

when treated surfaces are washed with wate r which is disposed of down-the-drain. Contaminated disposal water may arise from treated surfaces washed with water; carpet cleaning water; rinse water from mops, rags or brushes used to clean treated surfaces; or pet bathe rinse waters. Pesticide discharged in water via these rout es (down-the-drain) may reach publically owned treatment works (POTWs), and subsequently be discharged

into the environment in effluent and/ or in biosolids from POTWs. Submitters stated that EPA should evaluate potential impacts from deltamethrin in both POTW effluents and biosolids (which may be subsequently applied to land) as part of the risk assessment. Stress was placed on the fact that adsorption to biosolids and volat ilization/ stripping are “cross-media transfer” processes as opposed to “removal mechanisms.” They indicate that the potential impacts of such processes should be addressed in the ecological risk

assessment. Submitters also cited a st udy which found that pyrethroids are not completely removed or degraded during wast ewater treatment and are present in final

POTW effluent.

Response 1 : The Agency agrees that indoor uses can result in discharg es of deltamethrin residues into sewer systems and will be included in the assessment as a possible route of exposure to the environment. Assumptions will be used to quantify the potential loading to drainage systems. Discharge of deltamethri n into the environment via effluent will be considered to the best degree possible in th e assessment. However, deltamethrin in biosolids is not anticipated to be assessed dur ing registration review. At this time, the Agency does not have a methodology to assess the exposure resulting from application of biosolids to land. The Agency has begun disc ussions with other EPA Offices to explore methodology to make quantitative estimates of exposures due to biosolids applied to land. EPA recognizes the potential exposure fr om down-the-drain sour ces of pyrethroids, and will continue to investigate ways of more accurately reflecting these sources in fate and ecological exposure assessments.

Comment 2: Tri-TAC and the Districts recommende d that additional data should be requested to inform the risk assessment. They supported the data call-in for aquatic toxicity data and recommended that the Agen cy imposed stringent conditions on issuing waivers and withhold registra tion decisions until required toxicity data are submitted.

Response 2: The Agency has requested chronic toxici ty data for estuarine/marine fish and invertebrates. Furthermore, chronic whol e sediment toxicity da ta are necessary to11 establish the effects assessment of pyrethro ids such as deltamethrin towards benthic communities. Besides the data required in the preliminary problem formulation, the Agency will also call for an acute (96-hour) Hyallela azteca water column toxicity study

to better characterize the acute route of exposure for the most sensitive aquatic invertebrate species. More information rega rding EPA’s future request for this study is

included in this document after the “Nex t Steps” section of the document.

The Agency will use the E-FAST down-the-drain model or a more refined version of the

model for assessment of wastewater effluent exposure. However, modifications to the model are currently being discussed. EP A will utilize all the data available in determining the potential for deltamethri n to reach ecological receptors through

wastewater effluent. To th at end, the Agency is request ing that any existing or ongoing pyrethroid POTW effluent monitoring data be submitted.

Comment 3: The submitters commented on the costs of toxicity bioassays required by NPDES permits, the costs of chemicals monitoring and other related costs, the costs of removing a toxicant and the costs rela ted to maintain or upgrade POTWs.

Response 3: The Office of Pesticide Programs does not have jurisdiction over the cost of these procedures.

Comments by the California Stormwater Quality Association (CASQA) [EPA-HQ-OPP2009-0637-14]

Comment 1: CASQA requests to include an assessm ent of the outdoor urban uses of deltamethrin by expanding the conceptual mode l and the analysis plan of the problem formulation. The modeling approach for th e urban uses should include uses such as broadcast applications on impervious surfaces around buildings.

Response 1: The above mentioned exposure pathway will be included in planned ecological risk assessment for deltamethrin.

Comment 2: CASQA requests that both water column and sediment exposures be evaluated by EPA.

Response 2: The Agency routinely uses the tie r 2 coupled aquatic models PRZM/ EXAMS to develop EECs to be used with the toxicity tests to calcu late risks quotients in the water column and in the pore water (of th e sediment phase). As indicated above (in response to comment from Tri-TA C and the Districs), at this time, the EPA is requiring chronic whole sediment toxicity testing for all the synthetic pyre throids undergoing reevaluation. Furthermore, acute water colu mn testing on the aquatic invertebrate Hyalella

azteca is also being required, as this organism is known to be particularly sensitive to pyrethroids.12 Comments by Bayer Crop Scien ce (BCS) [EPA-HQ-OPP-2009-0637-0016]

Comment 1: BCS has indicated that the assessmen t of tralomethrin as a source of deltamethrin will not be required because they intend to cancel all uses of tralomethrin.

Response 1: During registration review, if tralomet hrin tolerances have been canceled and there is no longer a need to include residues resulting fro m the use of tralomethrin in any assessments, these residues will not be included. However, if for some reason the Agency believes that tralomethrin still need s to be accounted for in an assessment, for example, if tralomethrin is still in the channe ls of trade, then the Agency will continue to
account for tralomethrin in the assessment.

Comment 2: BCS submitted comments on each of the studies proposed to be required in the deltamethrin registration review data call-in. A summary of their comments, and EPA’s responses, is included below.

Summary of BCS Comments on Proposed De ltamethrin Data Requirements and EPA Response Guideline Number BCS Comment EPA Response

835.4300 Aerobic Aquatic Metabolism An aerobic aquatic metabolism study is being

conducted and will be

submitted. Acknowledged

835.4400 Anaerobic Aquatic Metabolism BCS intends to conduct this study. Acknowledged

835.6100, 835.6200

Environmental Chemistry Methods and Independent Laboratory Validations for soil, water, and sediment BCS is submitting two Analytical Methods for soil, water and sediment, and agrees to submit the corresponding Independent Laboratory Validations.
BCS indicates that the analysis of some of the degradates is not necessary due to their low toxicity compared to the parent compound. EPA will evaluate the submitted information for their suitability. It is the responsibility of the registrant to submit information to support their asse rtion that the degradates of deltamethrin are of low toxicity.

850.2100 Passerine Avian Oral Toxicity BCS states that there is
sufficient data available to characterize the toxicity of
deltamethrin to birds and that the avian acute risk picture for deltamethrin is unlikely to change by the submission of this study because thechemical is relatively nontoxic to birds. In 2007, the Agency updated its data requirements in 40 CFR Part
158 to include an acute oral toxicity study for passerine species. As stated in the problem formulation, passerines are
smaller and have faster
metabolisms than waterfowl and upland game bird species traditionally used in avian toxicity13 tests which could impact their sensitivity to chemicals. Therefore the toxicity of deltamethrin is an uncertainty at this time. Registrants should submit any information available to address this uncertainty. 850.1400, 850.1500 Fish Early Life Stage/Fish Life Cycle (Estuarine/Marine) BCS believes that the existing data on toxicity to
fish is sufficient. BCS indicates that at most, only
one of the studies should be required. They suggest to conduct only the early life stage study. A chronic toxicity test is still required, but due to similarity in endpoints for the freshwater fish early life stage and full life cycle studies, an early life stage study for estuarine/marine fish may be adequate.

850.1350 Aquatic

Invertebrate Life Cycle BCS agrees to submit a mysid chronic life cycle study. Acknowledged.

850.1790 Whole sediment; chronic

invertebrates

freshwater and

marine BCS indicates it would like to work with the Agency, industry, and scientific experts to ensure that methods to evaluate toxicity of sediments are robust, rliable, and predictive. Acknowledged. EPA welcomes input regarding evaluation ofpyrethroid toxicity to sedimentdwelling organisms.

850.4150, 850.4250 Vegetative Vigor and Seedling Emergence, Tier

I/Tier II BCS will submit a set ofrepresentative Tier 1 nontarget plant studies with deltamethrin. However, it is indicated that they were not conducted according to GLP. These studies may be used as supplemental information in the risk assessment, but do not fulfill the guideline requirement. Acknowledged. Once submitted,
the studies will be evaluated for
use in the final risk assessment.

850.4400 Aquatic

Vascular Plant

Growth – Lemna

spp. Tiers I/II BCS asserts that because deltamethrin is a pyrethroid and non-phytotoxic, a toxicity study with Lemna

spp. will not be expected to impact the overall risk

assessment. No studies have been submitted to
demonstrate the lack of phytotoxicity to aquatic vascular plants, there fore a study is required to address this uncertainty.

850.5400 Algal toxicity test, Tier I/II BCS indicates that two algal toxicity studies have already
been submitted to EPA. In EPA has received two algal studies from the registrant. Once
submitted the three additional14 addition three other studies
will be submitted. algal studies will be reviewed to
inform the deltamethrin risk

assessment.
870.7800 Immunotoxicity BCS acknowledges data deficiency and will respond accordingly to the DCI. During registration review, the Agency will evaluate any new immunotoxicity data submitted by BCS and will incorporate the
results into the overall hazard
characterization and risk

assessment. Special Study: Pet

Collar Residue

Transfer BCS provided information
received from a manufacturer of a pet collar product concerning the mode
of action of the flea collar and the quantity of
deltamethrin released. EPA appreciates the additional information provided. In its comment, BCS mentions a study
in which the extent of
deltamethrin release over time
was confirmed. EPA would like for this study and any other pertinent information be submitted in response to this data requirement.

830.7050 UV/Visible Light Absorption BCS did not comment on this proposed study. None

Comments by Physicians Committee for Re sponsible Medicine (PCRM) [EPA-HQ-OPP2009-0637-0015]

Comment: PCRM would like EPA to use Or ganisation for Economic Co-operation and Development (OECD) guideline for acute avia n oral toxicity, whic h is on the verge of adoption by OECD.

Response: The Agency requires a toxicity te st be conducted to estimate the acute oral

LD 50 of deltamethrin to a passerine species. PCRM recommends that the new OECD test guideline be used for this test because it uses considerably fewer animals than the traditional LD50 test described by Test Guideline 850.2100. The new OECD test guideline for measuring avian acute oral toxicity with a sequential dosing procedure is Test Guideline (TG) 223. Current policy within the Office of Pesticide Programs regarding the acceptance of avian acute e ffects studies conducted using the TG 223 protocol states the following:

Until the OECD TG 223 validation process is completed and the guideline has been approved by OECD, studies that utilize this guideline should not be classified; pending results of the va lidation, they may then be classified as ‘acceptable,’ assuming that they m eet all other guideline requirements.

To date the OECD has adopted the TG 223 gui deline and has issued a validation report. At this time EFED is actively evaluating th e results of the OECD validation report to15 determine if the TG 223 effects endpoints and dose/response information adequately address the purposes of the avian acute oral da ta requirement as described in 40 CFR Part 158. Until the Agency’s evaluation of that va lidation report is completed, EFED will not classify avian toxicity studies performed us ing the TG223 protocol and the studies cannot be used to fulfill data requirements. Therefor e, we cannot say at this time whether or not avian toxicity studies done under TG 223 will be acceptable to meet our data requirements.

Validation work conducted on TG 223 test guide line to date has been limited to studies with the upland game birds (e.g., northern bobw hite). Because no work has been done to date to validate this guideline for passerine species, it is doubtful that we would accept studies done under this guideline for fulfilling requirements for passerine acute toxicity

data unless additional validation work with passerines is done.

Next Steps :

o The Agency plans to issue a DCI in mid 2011, requiring the deltamethrin studies needed to complete the human health, ecological, and endangered species risk

assessments.

Additional Data :

o Comments were received regarding water body impairment. As a result of these comments, additional data not previously identified in the deltamethrin preliminary work plan are required and are described below.

Guideline Number: Non-guideline Study Title: Aquatic Invertebrate Acute Toxicity ( Hyalella ) Rationale for Requiring the Data

Available information in the Agency ECOTOX database indicates that the freshwater amphipod, Hyalella azteca , is substantially more sensitive to pyrethroids than Daphnia

magna , the commonly tested freshwater invertebra te. Information on th e acute toxicity of

deltamethrin to H. azteca was not identified in this probl em formulation. Therefore, in order to ensure that risk to sensitive aqua tic invertebrates are a ppropriately quantified, additional acute toxicity testing of H. azteca is needed (water column exposure, not sediment-spiked)

.

Practical Utility of the Data

How will the data be used? The freshwater acute toxicity study with Hyalella would allow the Agency to analyze acutely toxic effects to one of th e most sensitive species of fres hwater aquatic invertebrates.

The effects data would be used to determin e the likelihood that acute risks can potentially impact aquatic communities, either by direct effects on invertebrates or by indirect effects by reducing the food source for their predators (e .g., fish). By refining the assessment, the Agency would be able to determine whether the mitigation imposed as part of the registration review process was appropriate due to toxicity co ncerns with deltamethrin.16 How could the data impact the Agency’s future decision-making? If future risk assessments are performed w ithout these data, the Agency would have to account for the potential increased sensitivity of Hyalella to deltamethrin using other means which may include using an extrapolation fact or based on sensitivity differences with other pyrethroids. Since this extrap olation factor would involve uncertainty, it is likely that a conservative factor would be applied. This may impinge on the Agency’s flexibility in coming into compliance with the Endangered Species Act and could result in use restrictions for deltamethrin which are unnecessarily severe.

Guideline Number: N/A Study Title: POTW Effluent Monitoring and POTW Treatability Study Rationale for Requiring the Data POTW Effluent Monitoring – Request any existing or ongoing POTW effluent monitoring data for the pyrethroids be submitted to the Agency.

POTW Treatability Study – In addition, the Agency is anticip ating requiring a bench scale study of waste water treatment. A pilot treatability stud y is required to better parameterize E-FAST for assessment of the “down-the-drain” exposure rout e. The pilot treatability study will characterize concentrations of deltamethrin in effluent, concentr ations of deltamethrin in biosolids, and resulting removal efficiency in publically owned treatment works (POTWs) based on known concentrations of

deltamethrin in influent. Practical Utility of the Data

How will the data be used? These data would be used to inform removal percen tages by waste water treatment, which is an input to the Exposure and Fate Assessment Screeni ng Tool’s (E-FAST) “down-the-drain” module.

How could the data impact the Agency’s future decision-making? Without these data, the Agency will have to make assumptions regarding the level of removal of deltamethrin ( e.g. , results of modeling from the EPIWEB v.4.0 may be used). These assumptions are likely to be crude and conservative. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with th e Endangered Species Act, and could result in use restrictions for deltamethrin which may otherwi se be avoided, or which are unnecessarily severe.