Page 2 of 27

A. PHYSICIANS COMMITTEE FOR RESPONSIBLE MEDICINE (PCRM)

COMMENTS :

1. PCRM Comment:

“The Summary Document indicates that the Agency may request testing for avian acute oral toxicity. We strongly support the use of the newly revised OECD Test Guideline 223 for the acute avian oral toxicity test...”

EFED Response :

To da te the OECD has adopted the TG 223 guideline and has issued a validation report. At this time EFED is actively evaluating the results of the OECD validation report to determine if the TG 223 effects endpoints and dose/response information adequately addre ss the purposes of the avian acute oral data requirement as described in 40 CFR Part 158. Until the Agency‟s evaluation of that validation report is completed, EFED will not classify avian toxicity studies performed using the TG 223 protocol and the studi es cannot be used to fulfill current data requirements.

2

. PCRM Comment:

“In response to past comments on the avian acute oral toxicity test... „EPA is not likely to accept studies conducted under the OECD guideline unless additional study validation is conducted for passerine species (from EFED Response to Comments on Preliminary Work Plan for Sodium Acifluorfen )‟... If the Agency is interested in collecting all data in consideration of the use of the 223 then it should not state that it will not accept i nformation gathered according to this protocol.”

EFED Response :

EFED will consider all data submitted regarding the potential toxicity of pesticides. In reading through the previous Agency response, we understand how the sentence „EPA is not likely to accept studies conducted under the OECD guideline...” could be misunderstood. To clarify what was meant, the Agency will not be able to classify studies conducted using TG223 and passerines as „acceptable‟ (and, thus, fulfilling guideline requirements) unti l it is verified that the OECD TG 223 using passerines adequately addresses the purposes of the passerine acute oral data requirement as described in 40 CFR Part 158.

2

. PCRM Comment:

“... (T)he EFED document was not in the docket despite the final work plan stating it should be; this is also true for Hymexazol... Can this be checked so that we may access these documents?”Page 3 of 27

EFED Response :

EFED was able to access the EFED Registration Review Problem Formulation for Cyfluthrin

and Beta

- cyfluthrin in the public docket (Document ID: EPA

- HQ

- OPP

- 2010

- 0684

- 0004) (Docket ID: EPA

- HQ

- OPP

- 2010

- 0684).

B

. C ALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD

– CENTRAL

VALLEY REGION (C RWQCB

- CVR) COMMENTS :

1. CRWQCB

- CVR Comment:

“ ...(T)he current Clean Water Act Section 303(d) list for California... has 3 listings for pyrethroids in the Central Valley Region... The 2010 303(d) list contains an additional 10 streams in the Central Valley which are exceeding water quality standards due to levels of pyrethroids in sediments.”

EFED Response :

EFED will include relevant information on 303(d) listings in the final environmental risk assessment. The preliminary EFED problem formulation for cy fluthrin and β

- cyfluthrin reflects the current list of 303(d) impaired water bodies. The list with the 10 additional bodies of water identified as impaired due to pyrethroids has not been finalized, and, therefore, was not included in the problem formulat ion.

2

. CRWQCB

- CVR Comment:

“While these pyrethroid

- impaired streams are all in the Sacramento Area, there is no indication that pyrethroid concentrations are different in other urban areas in California. A statewide investigation by Holmes et al . (2 008) showed pyrethroids present at toxic levels in benthic sediments... throughout California. ”

EFED Response :

This study was included in the „Open Literature Information‟ appendix (Appendix C) in EFED‟s preliminary problem formulation for cyfluthrin and β

- cyfluthrin. Information from the study will be considered when conducting the environmental risk assessment for the cyfluthrins.

3

. CRWQCB

- CVR Comment:

“A recently published study of sources of pyrethroid pesticides to the Delta (Weston and Lydy, 2010) examined pyrethroids in urban runoff, municipal wastewater treatment plants and agricultural drains discharging to the Delta. Nearly all urban runoff samp les were toxic to Hyalella azteca due to pyrethroids, particularly bifenthrin and cyfluthrin. ”Page 4 of 27

EFED Response :

The article by Weston and Lydy (Weston and Lydy, 2010) was included in EFED‟s preliminary problem f ormulation and considered in making deci sions on data requirements for cyfluthrin and β

- cyfluthrin

.

4

. CRWQCB

- CVR Comment:

In response to th e impairments identified in West on and Lydy (2010), “... as required by the Clean Water Act, the Central Valley Water Board will soon be developing TMDLs to address cyfluthrin and other pyrethroids of concern... The Central Valley Water Board, and the dischargers we regulate, must direct considerable resources to our ongoing efforts to address the water quality impairments associated with current

- use pestici des that impact water quality such as diazinon, chlorpyrifos, and now pyrethroids... In many ways, pollution prevention through effective regulation of pesticide use would be much more efficient and effective than the regulatory options available to water co ntrol agencies implementing the Clean Water Act.”

EFED Response :

EFED defers a specific response to this comment to OPP‟s Pesticide Re

- evaluation Division (PRD) since it relates directly to risk management, labeling, and product registrations

.

5

. CRW QCB

- CVR Comment:

“As part of our TMDL development efforts, the Central Valley Water Board recently funded researchers as UC Davis to develop ambient water quality criteria for cyfluthrin. The resulting
final criteria document... which is attached... should be useful to USEPA in this registration
review.”

EFED Response :

The Agency appreciates the submission of this document and will consider it in the risk assessment conducted for cyfluthrin and β

- cyfluthrin as part of the Registration Review process.

C

. CALIFORNIA STORMWATER QUALITY ASSOCIATION (CASQA) COMMENTS :

1. CASQA Comment:

CASQA appreciates “... EPA‟s consideration of non

- agricultural sources and exposure pathways in the proposed updated ecological risk assessments for cyfluthrin and beta

- cyfluthrin. However, EPA‟s proposed approach should more explicitly account for urban sources of these pesticides, including specifically outdoor applications to both landscaped and impervious surfaces. ”

EFED Response :Page 5 of 27

EFED is currently further exploring methods to assess urban and residential uses on a national basis. EFED will consider comments regarding the need to include models that consider transport of runoff from impervious surfaces and stormwater drainage systems while it develops

these methodologies. At the present time, EFED considers the use of the impervious scenario (a Pesticide Root Zone Model (PRZM) modeling scenario) as the most suitable available modeling approach for impervious runoff and has used this approach for some assess ments completed for Endangered Species in California. The PRZM impervious scenario may be used in the tier 2 coupled aquatic models PRZM/Exposure Analysis Modeling System (EXAMS) along with a residential or other suitable scenario such as rights

- of

- way (R OW) to obtain Estimated Environmental Concentrations ( EECs ) . The conceptual model for the residential scenario integrates simultaneous modeling of the individual use scenario with an impervious scenario. This approach assumes that no watershed is complet ely covered by either the 1⁄4 acre lot (the basis for the residential scenario) or undeveloped land (the basis for the ROW scenario) for residential and ROW use patterns; therefore, differential amounts of runoff will occur within the watershed. The impervi ous scenario was developed to represent the paved areas within a watershed not including roads, parking lots, sidewalks, and buildings outside the 1⁄4 acre lot (the 1⁄4 acre lot scenario accounts for impervious surfaces such as buildings within the represented area). By modeling a separate scenario for impervious surfaces, it is also possible to estimate that amount of exposure that could occur when the pesticide is oversprayed onto this surface. Using two scenarios in tandem requires post

- processing of the m odeled output in order to derive a weighted EEC that represents the contribution of both the pervious ( i.e. , residential and ROW scenarios) and the impervious surfaces. Exposure from both scenarios can also be weighted and aggregated. The daily time seri es from each model run from the times series file (NAME_TS.out) generated from the PRZM graphical user interface (PE5.pl) residential and impervious surface scenarios are combined using Microsoft EXCEL. The time series data are weighted based on percentag e of impervious surface, the percentage of the pervious surface treated, and an adjusted time series is created. Rolling averages for the relevant durations of exposure ( e.g. , 21 day and 60 day averages) are calculated, and the relevant one

- in

- ten year EE C is generated from these distributions.

The Agency intends to use available non

- agricultural use and usage data, such as the Kline database, the California Department of Pesticide Regulation‟s (CDPR) Pesticide Use Reporting Data and Pest Control Operator ‟s usage survey, and the Residential Joint Venture Task Force homeowner survey data (2003), to make certain reasonable assumptions regarding various applications and information related to urban/residential use. Due to the limited data available,

exposure to the environment and uncertainties will be characterized. Detailed information on

non

- agricultural use and usage of pyrethroid products, specifically cyfluthrin and β

- cyfluthrin

, would be useful in order to reduce those uncertainties for the final envi ronmental risk assessment for cyfluthrin and β

- cyfluthrin

.

2. CASQA Comment:

“Water quality impacts must be prevented through use restrictions.”Page 6 of 27

EFED Response :

EFED defers a specific response to this comment to OPP‟s PRD since it relates directly to risk management, labeling, and product registrations

.

3

. CASQA Comment:

“The conceptual models must explicitly include urban sources.”

EFED Response :

A revised conceptual model that includes urban sources (specifically impervious surfaces) will be included in the risk assessment conducted for cyfluthrin and β

- cyfluthrin as part of the Registration Review process.

4

. CASQA Comment:

“Modeling of non

- agricultural sources must use an urban runoff model.”

EFED Response :

See the response to C.1. above.

5

. CASQA Comment:

“Most cyfluthrin use in California is urban...” and is applied by professional applicators.

EFED Response :

The use/usage information will be considered in the risk assessment conducted for cyfluthrin and β

- cyfluthrin as part of the Registration Review process, especially as it relates to the urban/residential portion of the risk assessment.

6

. CASQA Comment:

“The risk assessment must consider cumulative impacts.”

EFED Response :

EFED is continuing to explore ways in which cumulative effects could be accounted for in our ecological risk assessments

.

7

. CASQA Comment:

“The registration process must effectively prevent water quality impacts.”Page 7 of 27

EFED Response :

EFED defers a specific response to this comment to OPP‟s PRD since it relates directly to risk management, labeling, and product registrations

.

8

. CASQA Comment:

The risk assessment should “...(e)valuate exposures in both water column and sediments.”

EFED Response :

As stated in the preliminary problem formulation, sediment and water column exposures will be evaluated as part of the risk assessments conducted for cyfluthrin and β

- cyfluthrin

.

9

. CASQA Comment:

“The NPDES monitoring data... are submitted to the State o f California through the NPDES permitting system. We recommend that EPA contact the California State Water Resources Control Board for this data. We also recommend that EPA contact the California Department of Pesticide Regulation (DPR) for related infor mation... We suggest that it is incumbent upon EPA to take a more active role in identifying and acquiring pertinent monitoring data.”

EFED Response :

All readily available or submitted monitoring data will be considered in the environmental risk

assessmen t.

D

. CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD

– SAN FRANCISCO BAY REGION (CRWQCB

- SFBR) COMMENTS :

1. CRWQCB

- SFBR Comment:

“Pesticides that are applied per label instructions often pollute urban streams, largely because the pesticides runoff impervious surfaces during rain or irrigation events. In the long run, we request that the U.S. EPA develop tests and thresholds for was hoff of pesticides from impervious
surfaces...”

EFED Response :

As discussed in response C.1. above, EFED is currently developing methodologies to examine runoff from impervious surfaces on a national basis. EFED will consider these comments as

these meth ods are developed.

2

. CRWQCB

- SFBR Comment:

“The Work Plan‟s problem formulation does not recognize cyfluthrin transport via urban runoff
to surface waters of the United States.”Page 8 of 27

EFED Response :

Please see the response to C.1. above.

3

. CRWQCB

- SFBR Comment:

“Based on available monitoring data..., we can readily conclude that urban runoff contains cyfluthrin that has been washed away from treated surfaces during rain events and cleaning operations, and by irrigation overflows. The risk hypothesis and conceptual model do not recognize cyfluthrin applications to impervious surfaces.”

EFED Response :

Please see the responses to C.1. and C.3. above.

4

. CRWQCB

- SFBR Comment:

“We request that EPA examine both professional and non

- professional cyfluthrin urban use... at a level of detail sufficient to determine which use patterns need modification or cancelation to end aquatic toxicity.”

EFED Response :

Please see the response to C.1. above.

5

. CRWQCB

- SFBR Comment:

“The modeling approaches described are inappropriate for urban runoff and urban watersheds because they do not account for the most important factors in urban runoff pollutant transport

– impervious surfaces and storm drainage system design.”

EFED Response :

Please see the response to C.1

. above.

6

. CRWQCB

- SFBR Comment:

“To facilitate Work Plan improvements to assess surface water risks associated with urban cyfluthrin use, we have attached two detailed conceptual models linking urban pyrethroid application locations to receiving waters .”

EFED Response :

The Agency appreciates the submission of these documents and will consider them in the risk assessment conducted for cyfluthrin and β

- cyfluthrin as part of the Registration Review process.Page 9 of 27

7

. CRWQCB

- SFBR Comment:

“Cumulative risks with other pyrethroids must be evaluated.”

EFED Response :

Please see the response to C.6. above.

8

. CRWQCB

- SFBR Comment:

“All data necessary for a scientifically sound environmental risk assessment should be requested/reviewed...” including data for sensitive saltwater species ( Americamysis bahia ), chronic sediment toxicity data for salt water species found in the Western U.S., aquatic toxicity data to account for potential increased toxicity in cold water, and data needed for urban exposure

assessmen ts.

“This list should be reviewed in light of available data from the open scientific literature and from studies required by California Department of Pesticide Regulation (DPR), as some of the needed data may already be available or be forthcoming.”

E FED Response :

Acceptable toxicity data using A. bahia are available for cyfluthrin and will be used in the cyfluthrin risk assessment. EFED currently recommends the use of the estuarine/marine amphipod, Letptocheirus plumulosus , for assessing chronic toxicity of pesticides in sediments because of its long history of development with EPA and by other Agencies (U.S. Army Corps of Engineers). Currently, L. plumulosus is the only estuarine/marine test species for which

chronic sedi ment toxicity testing has been validated for use in the Agency 1 . Although L. plumulosus is distributed along the east coast of the United States, available literature indicates it has similar sensitivity as E. estuarius

, H. azteca and Ampelisca abdita. 2 Furthermore, the Agency will consider results from other test species provided they are scientifically defensible and appropriate for use in the Agency‟s forthcoming risk assessment.

1 USEPA/USACE. 2001. Method for Assessing the Chronic Toxicity of Marine and Estuarine Sediment

- associated

Contami nants with the Amphipod Leptocheirus plumulosus . First Edition. EPA EPA 600/R

- 01/020. March 2001

2 DeWitt, T.H., B.L. McGee, R. Alden, H. Phelps, and A. Pinkney. 1992. A multi

- species, multi

- lab comparison of the toxicity of a Chesapeake Bay sediment. Presented at the Thirteenth Annual Meeting of the Society for Environmental Toxicology and Chemistry, Cincinnati, OH, November 8

- 12.

McGee, B.L., C.E. Schlekat, and E. Reinharz. 1993. Assessing sublethal levels of sediment contamination with the

estuarine amphipod, Leptocheirus plumulosus

. Environ Toxicol. Chem. 12:577

- 588.

SAIC. 1993a. Draft data report on comparative sensitivity of four amphipod species to sediment associated

contaminants. Submitted to USEPA. EPA contract No. 68

- CO

- 0044. Prepared by Sci ence Applications International Corporation, Narragansett, RI. 15 pp.Page 10 of 27

EFED acknowledges the documented negative correlation of the toxicity of pyrethroids with temperature ( e.g. , Weston et al. 2009 and Hardwood et al. 2009). 3 EFED will consider available and submitted literature on the temperature effects on pyrethroid toxicity as part of its forthcoming risk assessment. EFED will take into account this factor in its characterization of risk ( e.g. , potentially as part of a sensitivity analysis).

EFED will consider all submitted studies and available open literature information while conducting its environmental risk assessment.

9

. CRWQCB

- SFBR Comment:

“Cyfluthrin in POTW effluent can be transferred to biosolids. The Work Plan should evaluate potential impacts from the use of pesticides to biosolids land application in cases where down

the

- drain assessments indicate that pesticides would partition to biosolids. ”

EFED Response :

Discharge of cyfluthrin and/or β

- cyfluthrin into the environment via effluent will be considered to the best degree possible in the risk assessment. The Agency is actively evaluating the extent

to which ec ological risk from cyfluthrin and β

- cyfluthrin via land application of biosolids should be addressed in its forthcoming environmental fate and ecological risk assessment, and by extension, any additional data that may be required. As part of this evaluati on, OPP is working closely with the Office of Water which regulates land application of biosolids under the Clean

Water Act.

10

. CRWQCB

- SFBR Comment:

“Please plan to obtain data submitted to the DPR under its pyrethroid reevaluation effort...”

EFED Response :

EFED will consider all submitted studies and available open literature information while conducting its environmental risk assessment.

11

. CRWQCB

- SFBR Comment:

“We appreciate U.S. EPA‟s recognition of monitoring information in the open lite rature. We
have included a list of additional relevant references as an attachment.”

3 Weston, D.P., J. You, A.D. Harwood and M.J. Lydy. 2009. Whole Sediment Toxicity Identification Evaluation Tools for Pyrethroid Insecticides: III. Temperature Manipulation. Environ. Tox. & Chem ., Vol. 28, No. 1, pp. 173

– 180, 2009

Hardwood, A.D., J. You and M.J. Lydy. 2009. Temperature as a Toxicity Identification Evaluation Tool for Pyrethroid Insecticides: Toxicokinetic Confirmation. Environ Toxicol & Chem 28 (5) pp. 1051

- 1058, 2 009Page 11 of 27

EFED Response :

EFED appreciates the list of references provided by the commenter. These references will be

considered for the environmental risk assessment conducted for cyfluthrin and β

- cyfluthrin

.

12

. CRWQCB

- SFBR Comment:

“ We do not have separate 303(d) listings for cyfluthrin; rather our 303(d) listings are for all pyrethroids. Thus, 303(d) listings are not a perfect indicator of the ex tent of surface water problems associated with cyfluthrin... Because their toxicity is additive, 303(d) listings are being made for „pyrethroids‟ as a group rather than for individual pyrethroids.. .”

EFED Response :

EFED will include relevant information o n 303(d) listings in the final environmental risk

assessment.

E

. TRI

- TAC (TT) COMMENTS :

1. TT Comment:

“Tri

- TAC supports EPA‟s decision to conduct a down

- the

- drain assessment for cyfluthrin. Tri

TAC also supports the decision by the Offices of Pesticide Programs and Water to work together

to refine the down

- the

- drain assessments for registration review. F inally, Tri

- TAC supports EPA‟s decision to request monitoring data and additional aquatic toxicity data from publicly

owned treatment works (POTWs).”

EFED Response :

No response needed.

2

. TT Comment:

“ This cover letter provides the comments we shared with the bifenthrin docket and requests that the workplan for cyfluthrin be modified to address the same issues. ”

EFED Response :

T he comments from Tri

- TAC and the EFED responses for the bifenthrin problem formulation

are available in the registration r eview docket at www.regulations.gov ( Docket ID: EPA

- HQ

OPP

- 2010

- 0384) . The EFED responses to the Tri

- TAC comments on bifenthrin also apply for cyfluthrin and β

- cyfluthrin

.Page 12 of 27

F

. BAYER CROPSCIENCE (BCS) COMMENTS :

1. BCS Comment:

“The agency has drafted a very thorough conceptual model and broad risk hypotheses, which Bayer believes can be more narrowly focused to better correspond to the compounds properties

and uses. Sufficient information already exists to f ocus the ERA on arthropods, especially those residing in the aquatic environment. ”

EFED Response :

Through registration review, EPA is reviewing each registered pesticide every 15 years to determine whether it still meets the FIFRA standard for registrat ion. In addition, EPA intends to meet its responsibility u nd er the Endangered Species Act in the registration review program. T o ensure that the use of cyfluthrin and β

- cyfluthrin will not adversely impact non

- listed and/or listed species

, a risk assessm ent involving all of the major taxonomic groups normally assessed by EFED will be conducted.

2

. BCS Comment:

“Bayer CropScience proposes to conduct an ecological risk assessment for the cyfluthrins taking into account the established mitigations listed on product labels, in particular vegetative buffer

zones and no

- spray zones. We strongly recommend that the agency also accounts for these existing mitigations in its own risk assessment.”

EFED Response :

Currently EFED has methods to address the potent ial impacts of vegetative buffers and no

- spray zones on potential exposures to non

- target organisms from spray drift. There are currently no approved methods in EFED to address the impacts of buffer strips on runoff. EFED is continuously working on impro ving its risk assessment methods, including how to best address the impact of vegetative buffer strips on the estimated exposures to non

- target organisms. CropLife has evaluated models that incorporate vegetative buffer strip efficiencies and effects on

r unoff. CropLife‟s evaluation will be considered when methods to evaluate the potential for vegetative buffers to reduce runoff are developed. EFED will incorporate

, to the best of its

abilities based on the available information and approved methodologie s, the application restrictions that appear on approved labels at the time of the risk assessment into the exposure

assessments for th e cyfluthrins

.

3

. BCS Comment:

“Also, any risk assessment should include consideration of all studies available, even when they are discounted for legitimate reasons. The transparency that explicit inclusion of all studies allows is helpful in supporting weight of evidence approaches along with building confidence in
the assessment.”Page 13 of 27

EFED Response :

It is EFED‟s policy to consider all available submitted data and open literature studies relevant to the chemical(s) being assessed in our risk assessments. It is also EFED‟s policy to exclude information from studies that have been classified as „invalid‟ ( i.e., not scient ifically valid). It is

unclear how the inclusion of studies that have been reviewed and found to be invalid would be

“... helpful in supporting weight of evidence approaches along with building confidence in the

assessment.”

4

. BCS Comment:

“We plan to submit a risk assessment to the agency at the end of the time period assigned for generation of data according to the agency‟s data call

- in request.”

EFED Response :

EFED will consider all submitted data in the risk assessment conducted for cyfluthrin a nd β

cyfluthrin

.

5

. BCS Comment:

“ We specifically ask the agency to consider in their evaluation of the cyfluthrins information previously submitted by the Pyrethroid Working Group. For example, in 1997 PWG performed an ecological risk assessment for pyrethroid use on cotton (Holmes et al ., 1997; Maund et al

., 1997; Ritter et al ., 1997; Travis, 1997). While the assessment was performed using cypermethrin as a representative pyrethroid , it is very much relevant to the cyfluthrins and the other pyrethroids (Dobbs and Maund, 2000). ”

EFED Response :

EFED will consider these studies when conducting the risk assessment for cyfluthrin and β

cyfluthrin

.

6

. BCS Comment:

“ Bayer CropScience concurs with the agency that the degradates of cyfluthrin, resulting from cleavage of the ester bond are significantly less toxic than the parent compound and therefore are not stressors of concern for the ecological risk assessment. Additional ecotoxicity studies with the degradates, which confirm their lower toxicity, will be submitted by Bayer CropScience. ”

EFED Response :

EFED would appreciate (and will consider) additional toxicity data on the cyfluthrin and β

cyfluthrin degradates to help confirm the assumption that degradates are less toxic to non

- target organisms than the parent(s). Such data would help reduce uncertainties associated with degradates in the risk assessment conducted for these chemicals.Page 14 of 27

7

. BCS Comme nt:

Bayer CropScience noted several errors in the pesticide use/usage tables provided in the problem

formulation.

EFED Response :

EFED appreciates these comments and will consider them when conducting the risk assessment for cyfluthrin and β

- cyfluthrin

. The risk assessment will be based on all approved labels (at the time of the risk assessment) for cyfluthrin and β

- cyfluthrin

. If the potential errors identified by BCS are relevant to the use/use patterns for cyfluthrin and β

- cyfluthrin at the time the risk

assessment is conducted , corrections to the use/usage data will be made, if applicable.

8

. BCS Comment:

“Bayer CropScience agrees with the agency that the potential for ecological risks associated with interactions of cyfluthrin and the synerg ist PBO are small. Products containing the synergist are only registered as indoor aerosol sprays. Coincident exposure of cyfluthrin and PBO in the environment is extremely unlikely following indoor use of cyfluthrin products.”

EFED Response:

EFED will confirm with OPP‟s Registration Division that the only cyfluthrin products that contain PBO are products registered for indoor use only and that cyfluthrin products are not

tank

- mixed with PBO when used outdoors . If it is confirmed that no cyfluthrin prod ucts with outdoor uses are registered at the time of the risk assessment and that PBO is not mixed with cyfluthrin products used outdoors , it will be considered in the exposure assessment.

9

. BCS Comment:

“The PWG has commissioned extensive studies of the urban waterways and Bayer CropScience

asks that EFED consider the work of Hall et al. (2008a,b) in their assessment.”

EFED Response:

EFED will consider all submitted data in the risk assessment conducted for cyfluthrin and β

cyfluthrin

.

10

. BCS Comment:

“The agency states that the cyfluthrins exhibit a potential for bioaccumulation in fish in the above mentioned documents. In reality, following a drift event, the cyfluthrins rapidly migrate from the water column to sediment (as described above) and there is only a short exposure period in which uptake to fish can occur. For this reason, the standard fish bioaccumulation testing protocol (at least 4 weeks of constant exposure in tanks without sediment) is a conservativePage 15 of 27

model for understanding th e bioaccumulation potential of these compounds. The available

information also demonstrate that during the elimination phase (14 days post

- exposure) the cyfluthrins were rapidly eliminated from fish tissues (Carlisle & Roney, 1984). The cyfluthrins

show no potential to bioaccumulate in fish.”

EFED Response:

The problem formulation indicated a potential for bioaccumulation of cyfluthrin , based on its physicochemical properties ( e.g. , a very high K OW ). Cyfluthrin has some of the characteristics

observed in chemicals that bioaccumulate. The potential for bioaccumulation will be examined using the K OW (based) Aquatic Bio

- Accumulation Model (KABAM v.1.0), with adjustments for

biotransformation rates (as indicated in the Section 7.2 of the problem formulation). The bioconcentration in fish study indicated a relatively low BCFs of 854x in whole fish (if compared to its high log K OW of 5.97 ), with moderately moderate depuration (~50% between ≤3). Note that biotransformation rates can vary widely for different species and taxa. 4

11

. BCS Comment:

“EPA acknowledges that the review of open literature provided in Appendix C is, at this stage, a cursory evaluation, and Bayer urges that agency to do a more thorough evaluation. The current review gives an incomplete picture of current pyrethroid research

... Bayer CropScience recommends a more complete evaluation of the open literature that includes an assessment of the quality of the research as part of an overall weight of evidence approach.”

EFED Response:

All s ubmitted studies and studies identified in the open literature using ECOTOX are reviewed for acceptability criteria. Those studies determined to be scientifically valid and usable for risk assessment purposes will be included in the risk assessment. A ddi tionally, a bibliography containing all of the open literature studies (even those that do not pass acceptability criteria) will be provided in the risk assessment as an appendix

.

12. BCS Comment:

Guideline #835.1230 Mobility Adsorption/Desorption

“Bayer CropScience agrees that a full adsorption/desorption study would provide valuable data to reduce uncertainty concerning the extent of adsorption with concentration as described by the

Freundlich exponent .”

EFED Response :

No response needed.

4 DiGiulio, R. T., Benson, W. H., Sanders, B. M., & VanVeld, P. A. 2003. Biochemical Mechanisms: Metabolism, Adaptation, and Toxicity. In G. M. Rand (Ed.), Fundamentals of Aquatic Toxicology (pp. 523

- 560). New York: Taylor & Francis.Page 16 of 27

13. BCS Comment:

Guideline #835.4100 Aerobic Soil Metabolism

“Bayer CropScience is submitting the study report “Aerobic Soil Metabolism of β

- Cyflutrhin

phenoxy

- 1,2,3,4,5,6

- 14C6 (cyclopropanecarboxylic acid, 3

- (2,2

- dichloroethenyl)

- 2,2

- diemthyl

- , cyano(4

- fluoro

- 3

- phenoxyphenyl)methylester) in Sandy Loam from Fresno, California (Bayer Report M

- 079875

- 01

- 1) which was conducted at the request of the California Department of Pesticide Regulation (CDPR). This study will satisfy one of the β

- cyfluthrin requirements.

Bayer CropScience agrees to submit an aerobic soil metabolism study in two soils with cyfluthrin and at least one of which cyclopropyl

– labels, following issuance of the data call

- in.

Bayer CropScience intends to submit a new study with β

- cyfluthrin on f our soils (two European soils and two US soils) with either fluorophenyl

- or cyclopropyl

- labels (at least one with cyclcoprorpyl

- label), following issuance of the data call

- in. ”

EFED Response:

EFED will review these studies when they are received and will use all scientifically valid data

in the risk assessment.

14. BCS Comment :

Guideline #835.4200 Anaerobic Soil Metabolism

“ EPA has requested an anaerobic soil metabolism study conducted with cyfluthrin on one soil for the evaluation of transformation pathways and three additional soils for rates of transformation

determination.

According to the anaerobic soil metabolism stu dy guideline (#835.4200), the test system will be flooded and changed to anaerobic condition from aerobic condition at 30 days after treatment (or

one half

- life, whichever comes first). Bayer CropScience has conducted aerobic metabolism

studies in two soi ls with cyfluthrin and one soil with β

- cyfluthrin . The distribution of cyfluthrin,

CO 2 , and bound residues was 60

- 69%, 6

- 17%, and 14

- 17%, respectively, at day 28 after treatment, accounting for 89

- 94% of the applied material (Wagner et al., 1983). The di stribution of β

- cyfluthrin, CO 2 , and bound residues was 66%, 15%, and 14% respectively, at day 30 after treatment, accounting for 95% of the applied material (Aga, 2002). Only one metabolite (PFB

acid) was detected at 10% in one soil at day 28, no other m etabolites were detected greater than

5% at 28

- 30 days. Thus, at the point of converting the anaerobic soil test system from aerobic to anaerobic conditions by flooding the systems, the primary residue in the soil will be parent cyfluthrin (or β

- cyfluthri n). Therefore, at that point the test system will be similar to the anaerobic aquatic test system, since in an aquatic system cyfluthrin will partition rapidly into the soil/sediment. Bayer CropScience believes the anaerobic aquatic metabolism study is a n appropriate substitution for the anaerobic soil study (see anaerobic aquatic discussion below). ”Page 17 of 27

EFED Response:

Anaerobic metabolism studies are requested in both soil and in aquatic systems because degradation rates and pathways can differ in these t wo environments. Therefore, both studies are

needed.

15. BCS Comment:

Guideline #835.4300 Aerobic Aquatic Metabolism

“Bayer CropScience agrees to submit an aerobic aquatic metabolism study following issuance of

the data call

- in.”

EFED Response:

No response needed.

16. BCS Comment:

Guideline # 835.4400 Anaerobic Aquatic Metabolism

“Bayer CropScience agrees to submit an anaerobic metabolism study following issuance of the

data call

- in.”

EFED Response:

No response needed.

17. BCS Comment:

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

“Bayer CropScience agrees to submit modern mass

- spectrometry methods for cyfluthrin in water, sediment, and soil. Bayer CropScience al so agrees to conduct ILV on these methods. The methods will separate the four enantiomeric pairs of isomers, I, II, III, and IV. The quantitation of cyfluthrin will be based on the sum of all isomers, and the quantitation of β

- cyfluthrin will be

based on the sum of isomers II and IV. The methods are not intended for data collection in field dissipation studies, thus the inclusion of metabolites (FPB

- acid, FPB

- ald, and DCVA) is not necessary du e to their low toxicity compared to parent.”

EFED Response:

At this time, FPB

- acid ( 4

- fluoro

- 3

- phenoxybenzoic acid ), FPB

- ald ( 4

- fluoro

- 3

- phenoxybenzaldehyde ), and DCVA ( 3

- (2,2

- dichlorovinyl)

- 2,2

- dimethyl

- cyclopropanecarboxylicPage 18 of 27

acid ) are not considered residues of toxicological concern; therefore, environmental ch emistry

methods do not need to include these residues for identification.

18. BCS Comment:

“Regarding multi

- residue methods, the Pyrethroid Workin g Group (PWG) has submitted a multi residue method (Robinson, 2007) and ILV (Reed, 2006) for pyrethroids in se diment (bifenthrin, cypermethrin, cyfluthrin, deltamethrin, esfenvalerate, fenpropathrin, γ

- cyhalothrin and permethrin). This method does not distinguish the isomers of the individual pyrethroids.”

EFED Response:

The multi

- residue method will be a valuable tool for monitoring pyrethroids in sediments. The

method will be reviewed a nd made available to the public , as appropriate

.

19. BCS Comment:

“EPA has requested a study to be conducted according to the American Wood Preservers

Association Standard M ethod of Determining the Leachability of Wood Preservatives (E11

- 06).

Bayer CropScience does not understand the justification for this study since we are not aware of any cyfluthrin and β

- cyfluthrin products registered for use as wood preservative treatme nts.”

EFED Response:

Applications to protect wood from wood

- infesting pests are allowed on some labels such as EPA registration number s 432

- 1363, 432

- 1377, 432

- 1483, 11556

- 124, and 11556

- 145. Therefore,

EFED still recommends a study conducted according to the American Wood Preservers Association Standard Method of Determining the Leachability of Wood Preservatives (E11

- 06) be requested

. The method should be amended so that cyfluthrin is applied as specified on labels instead of impregnated int o the wood. In the absence of data, EFED would assume that 100% of cyfluthrin applied to wood surfaces is available for washoff.

20. BCS Comment:

POTW Effluent Monitoring and Treatabilit y Study

“Bayer CropScience is actively involved with the PWG in respon ding to the re

- evaluation of pyrethroids by the California Department of Pesticide Regulation (CDPR). A key component of the response is to better characterize the risk associated with the detection of pyrethroids in the sediment of urban creeks. The PWG will provide updates of effluent monitoring and will

conduct the tre atability study according to a protocol agreed between EPA and PWG.”

EFED Response:

No response needed.Page 19 of 27

21. BCS Comment:

Guideline # 850.2100 Passerine Avian Oral (Cyfluthrin)

“ While Bayer CropScience believes overall that the existing studies are sufficient to characterize the toxicity of the cyfluthrins to birds, we recognize that this study is mandatory and will conduct the study as requested. It is unlikely that conducting the passerine study will change the risk assessment for the cyfluthrins. ”

EFED Response:

No response needed.

22

. BCS Comment:

Guideline # 850.2300 Avian Reproduction Study (Mallard duck only) (Cyfluthrin)

“In addition to the two cyfluthrin mallard reproduction studies (Carlisle, 1984 and Beavers, 1986) that the agency has in their possession, Bayer has identified an additional mallard reproduction study (Beavers et al ., 1990) which will be submitted to meet this data request. It must be noted that Bayer disagrees with the agencies finding of a lack of a NOAEL based on the studies currently in the agencies possession. The three cyfluthrin mallard re production consistently support a NOAEL of 250 ppm.”

EFED Re sponse:

EFED looks forward to receiving the data and reviewing them for adequacy and suitability for

use in risk assessment.

23

. BCS Comment:

Guideline # 850.1025/1035 Oyster and Mysid Acute Toxicity (saltwater; cyfluthrin TEP only) (Cyfluthrin)

“Mollusks are one of the least sensitive taxa to pyrethroids, so additional testing is unlikely to influence the aquatic risk assessment. Two studies (Barrows, 1984 and Carr, 1986) examining the toxicity of cyfluthrin to the eastern oyster exist. The EC50 values reported by the authors were 5 and 3.42 μg/L; slightly different from the value of 2.69 μg/L cited by agency. Bayer requests clarification from the agency on this discrepancy. Also Table 7.2 (page 75) of EPA problem formulation does not accurately r eflect the existence of the two available oyster studies (MRID‟s: 00146118 and 00158783), although they are listed in the bibliography.”

EFED Response:

Based on the available data evaluation records (DERs) for these studies, the Barrows and Dillon (1984) oyster study (ACC. No.: 250816; MRID: 00146118) is classified as invalid and is notPage 20 of 27

acceptable for use in risk assessment. The results were based on a s tatic, rather than a flow

through system.

Based on the available DER for Carr (1986) (ACC. No.: 262443; MRID 00158783), the results from this study were found to be acceptable for use in risk assessment. The discrepancy between the study reported EC 50 value ( i.e ., 3.42 μg a.i./L) and the one reported in the problem

formulation ( i.e

., 2.69 μg a.i./L) is due to the fact that the analysis conducted by EFED (unlike what was done by the study author) did not use the pooled controls (the negative and solvent

controls combined ).

24

. BCS Comment:

Non

- Guideline Study: Aquatic Invertebrate Acute Toxicity ( Hyalella azteca ) (Cyfluthrin)

“Besides considering additional single species data on non

- standard test organisms , will the agency also consider more complex studies (e.g., mesocosoms and population modeling) that are useful in putting the results of single species studies into an ecological context? ”

“ Will the agency accept studies with closely related species (e. g., Gammurus spp. ) as meeting this data requirement? Bayer does have a study (Heimbach, 2000) conducted with a non

- USA

formulation for Gammurus pulex which Bayer will submit for review. If the existing data is deemed inadequate to meet the data requirement , Bayer will, upon confirmation that a robust test protocol is available, conduct the study as requested. ”

EFED Response:

EFED will consider all submitted data for use in the risk assessment conducted for cyfluthrin and β

- cyfluthrin . It is unlikely th at a mesocosm study would be adequate to fulfill the data requirement for an acute toxicity study with H. azteca . Additionally, unless it can be demonstrated that a related species is at least as sensitive to cyfluthrin as H. azteca , a study with a related species would likely not be adequate to fulfill this data requirement since H. az teca ha s been demonstrated to be substantially more sensitive to pyrethroids than Daphnia magna

. Furthermore, a study using a non

- USA formulation is not adequate for use in risk assessments conducted by the agency unless it can be demonstrated that the non

- USA formulation is representative of a formulation registered in the USA

.

25

. BCS Comment:

Non

- Guideline Study: Whole sediment: chronic invert ebrates freshwater and marine (Cyfluthrin)

“

... Bayer would like to work with the agency, industry and experts in the scientific community to ensure that the methods used are robust, reliable, and predictive.

With respect to existing marine 28

- day sedime nt study (MRID 46591506) with Leptocheirus plumulosus, reproduction was not included in the initial protocol because amphipod reproduction is not a robust endpoint. However, an analysis of reproduction was performed post studyPage 21 of 27

termination on preserved samples. Please see Giddings (2006) for a reporting and analysis of the available data. Bayer believes this existing study, conducted at EPA‟s request and with their guidance, should meet the data requirement for a marine chronic sediment study. “

EFED Response:

EFED is actively working with the PWG to develop an acceptable methodology for a whole sediment chronic toxicity invertebrate study that would provide results that are adequate for use

in risk assessment.

Regarding the Giddings (2006) s ummary ( MRID 46871501 ), the study author made the following conclusion:

“... (B)oth growth (dry weight at 28 d) and reproduction of L. plumulosus appeared to be subject to unknown sources of variability among and within studies. Until the cause(s) of

this variability have been identified and brought under control, results of the L. plumulosus tests must be interpreted with caution, and the reproduction data are considered unreliable” (p. 27).

Although, EFED will consider the information in this report in the risk assessment for the cyfluthrins, based on Giddings‟ (2006) own evaluation of the cyfluthrin study, it is unlikely that these data would be adequate to fulfill the data requirement for a marine chronic sediment study

.

26

. BCS Comment:

Guideline # 850.4100 and 850.4150 Vegetative vigor and Seedling emergence, Tier I/ Tier II (Cyfluthrin)

“The screening study (Lechelt

- Kunze, 2002a) addresses the potential effect of cyfluthrin to non

target plants and should fulfill the regulatory data requirement. ... Because cyfluthrin works in insects as a neural toxin, and unlike insects, plants do not have neural networks, it is highly unlikely that cyfluthrin would cause phytotoxicity. Cyfluthrin has been registered for use on a very wide range of plants for ma ny years and while Agency‟s review of the available incident data found three phytotox incidents, those incidents are much more likely to be due to other factors (e.g. herbicide contamination resulting from improperly cleaned spray tanks) rather than cyflu thrin... We request that considering the properties of cyfluthrin and its long history of safe use on a range of plants, that additional plant testing of cyfluthrin be waived.”

EFED Response:

The Agency received this study [ Lechelt

- Kunze , C. (2002): Cyfluthrin EC 050: Post

- emergence screening for herbicidal activity. Bayer AG, Monheim, Germany. M

- 056722

- 01

- 2; MRID 48350619] on January 11, 2011; it is still being processed and is not currently available to EFED for review

. Therefore, we are

not a ble to address whether or not this study can be used to fulfill this data requirement at this time

. When the study becomes available, EFED will review the study to determine if it can be used to fulfill this data requirement.Page 22 of 27

In addressing this comment, it was determined that a search of OPP‟s Aggregate Incident

Database was not included in EFED‟s cyfluthrin problem formulation. Therefore a search of the Aggregate Incident Database was conducted on January 4, 2011, for cyfluthrin in order to ga ther more information regarding potential plant incidents associated with the use of the chemical. There are currently 132 “minor” plant incidents listed in the Aggregate Incident Database for cyfluthrin that date from 1999 to 2004 (see APPENDIX A ). Sinc e detailed information is not
available for the aggregate incidents, it is current EFED policy to assume that these incidents are the result of registered uses unless information is provided that indicates otherwise. Therefore,

EFED do es not recommend wai ving the terrestrial plant toxicity data requirement for cyfluthrin

at this time.

27

. BCS Comment:

Guideline # 850.4400 Aquatic Vascular Plant Growth

- Lemna spp. Tiers I/II (Cyfluthrin)

“ Because the cyfluthrin is a pyrethroid and non

- phytotoxic, no study has been requested by any regulatory authority in the past, and to our knowledge no such study currently exists. Conduct of a study with cyfluthrin is not expected to impact the overall risk assessment. ”

EFED Response:

Due to the terrestrial plant incidents associated with cyfluthrin and a lack of phytotoxicity data for the chemical, there is uncertainty regarding the potential impacts of cyfluthrin on non

- target plants (including aquatic plants). Therefore, EFED still recommends that these data b e requested.

28

. BCS Comment:

Guideline # 850.1400 or 850.1300/850.1350 Fish Early Life Stage or Invertebrate Life Cycle (β

cyfluthrin)

“ Bayer CropScience understands the agency‟s interest in a Mysidopsis bahia life

- cycle study and

will conduct it as r equested. ”

EFED Response:

No response needed.

29

. BCS Comment:

Guideline # 850.4100 or 850.4150 Seedling emergence or Vegetative vigor (β

- cyfluthrin)

“ The screening study (Lechelt

- Kunze 2002b), addresses the potential effect of β

- cyfluthrin to

non

- target plants and fulfills the regulatory data requirement... We request that considering the properties of β

- cyfluthrin and its history of safe use on a range of plants that additional plant

tes ting of β

- cyfluthrin be waived. If, after consid ering the available information , the Agency decid(es) additional plant testing is necessary, we propose that the agency rely on a study withPage 23 of 27

cyfluthrin and hold additional testing with β

- cyfluthrin in reserv e. It is highly unlikely that additional toxicity te sting with plants will generate data that will result in significant impact s to the ecological risk assessment or use pattern.”

EFED Response:

The Agency received this study [ Lechelt

- Kunze , C. (2002): Β

- cyfluthrin EC 025: Post

- emergence screening for herbicidal activity. Bayer AG, Monheim, Germany. M

- 055590

- 02

- 2; MRID 48350620] on January 11, 2011; it is still being processed and is not currently available to EFED for

review. Therefore, we are not able to address whether or not this study can be used to fulfill this data requirement at this time. When the study becomes available, EFED will review the study to determine if it can be used to fulfill this data requirement.

The re are two plant incidents listed for β

- cyfluthrin in the Aggregate Incident Database (see

APPENDIX A ). Since detailed information is not available for the aggregate incidents, it is current EFED policy to assume that these incidents are the result of reg istered uses unless information is provided that indicates otherwise. These incidents along with those plant

incidents reported from the EIIS database for cyfluthrin and β

- cyfluthrin (not all of which can be

attributed to other chemicals) and those report ed for cyfluthrin in the Aggregate Incident Database, indicate a potential risk to plants from the use of these chemicals.

As described in the data request justification table from the problem formulation for cyfluthrin

and β

- cyfluthrin (see p. 110 of t he document) and per current EFED policy, terrestrial plant data

for β

- cyfluthrin are only required for the most sensitive monocot and dicot species (as identified from the cyfluthrin plant studies). EFED still recommends that these data be requested.

30

. BCS Comment:

Guideline # 850.4400 Aquatic Vascular Plant Growth

- Lemna gibba (β

- cyfluthrin)

“Because the β

- cyfluthrin is a pyrethroid and non

- phytotoxic, no study has been requested by any regulatory authority in the past, and to our knowledge no such study currently exists. Conduct of a study with β

- cyfluthrin is not expected to impact the overa ll risk assessment.

If, after considering the available information, the Agency deciding additional plant testing is necessary, we propose that the agency rely on a study with cyfluthrin and hold additional testing with β

- cyfluthrin in reserve.”

EFED Re sponse:

Due to the terrestrial plant incidents associated with β

- cyfluthrin and a lack of phytotoxicity data for the chemical, there is uncertainty regarding the potential impacts of β

- cyfluthrin on non

target plants (including aquatic plants). Therefor e, EFED still recommends that these data be requested for both cyfluthrin and β

- cyfluthrin , per current EFED policy

.Page 24 of 2 7

References:

Holmes, R.W., B.S. Anderson, J.W. Hunt, D.B. Crane, A. Mekebri and V. Connor. 2008. Statewide Investigation of the Role of Pyrethroid Pesticides in Sediment Toxicity in California‟s Urban Waterways.

Environ. Sci. Technol. 2008

, 42, 7003

– 7009.

Weston, D.P. and M.J. Lydy. 2010. Urban and Agricultural Sources of Pyrethroid Insecticides to the

Sacramento

- San Joaquin Delta of California. Environ. Sci. Technol. 2010
, 44, 1833

– 1840.

USEPA, 2010. Response to Public Comments on the EFED Registration Review Problem Formulation for Bifenthrin (PC Code No. 128825; DP Barcode D382626). Office of Pesticide Programs, United States Environmental Protection Agency, Washington, DC. December 22, 2010.Page 25 of 27

APPENDIX A: Incidents Reported in the Aggregate Incident Database for Cyfluthrin and β

- cyfluthrinPage 26 of 27Page 27 of 27