Docket Number: EPA-HQ-OPP-2010-0384 

www.regulations.gov

Amended Bifenthrin Final Work Plan for

Registration Review 

June 2011 

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AMENDED FINAL WORK PLAN FOR BIFENTHRIN 

Introduction: 

This is the Environmental Protection Agency’s (EPA or the Agency) Amended Final Work Plan for the 

registration review of bifenthrin. This document amends the December 2010 Bifenthrin Final Work 

Plan (FWP) to include additional human health effects toxicological data requirements and to remove 

several other data requirements previously included in the data gaps table. Unless otherwise stated in 

this amendment, all other elements of the Agency’s 2010 Bifenthrin Final Work Plan remain unchanged.

 

Changes to the Human Health Effects Data Needs: 

The Bifenthrin Human Health Assessment Scoping Document in Support of Registration Review

was completed on May 25, 2010 (D371583). The data needs as listed in the scoping document 

were subsequently amended by the memo Toxicology Data Needs Update: Bifenthrin Human 

Health Assessment Scoping Document in Support of Registration Review, dated May 17, 2011 

(D389066). The May 2010 scoping document listed specific toxicological data needs. However, 

upon further evaluation of the bifenthrin database, the Agency has determined that two additional 

toxicology studies (GLNs 870.1300, acute inhalation and 870.3250, 90-day dermal) are also 

needed for use in conducting a complete risk assessment for bifenthrin during registration 

review. The 90-day dermal study will be used to evaluate dermal exposure of an intermediate 

duration. The acute inhalation study will be used to define the acute toxicity category for this 

exposure route and to determine the appropriate warning signal word on product labels. 

To summarize, the following data requirements are being added for bifenthrin: 

• 870.1300 Acute Inhalation Study 

• 870.3250 90-day Dermal Study 

All other toxicological and residue chemistry data requirements remain as listed in the May 2010 

Bifenthrin Scoping Document and December 2010 FWP. 

Changes to the Ecological Data Needs:

Acute sediment toxicity tests (GLNs 850.1735 and 850.1740) were erroneously listed as data 

requirements in the “Summary of Data Gaps – Bifenthrin” table in the December 2010 Bifenthrin FWP. 

The “Summary of Comments and Agency Responses” section of the FWP explained that these two 

acute studies are no longer required because of the persistent half-life of bifenthrin. Although this 

change was explained in the text of the FWP, the data gaps summary table was not similarly updated. 

The requirements for chronic sediment toxicity tests for bifenthrin were included as data gaps in the 

December 2010 FWP and are still required, but the acute sediment toxicity studies are not required. The 

table listing the data gaps for bifenthrin has been corrected below. 

To summarize, the following ecological data requirements are being removed from the list of 

data requirements for bifenthrin: 

• 850.1735 Whole sediment: acute freshwater invertebrates 

• 850.1740 Whole sediment: acute marine invertebrates 
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All other environmental fate and ecological effects data requirements remain as listed in the 

December 2010 Bifenthrin FWP. 

Changes to Other Data Needs:

Recently, the Agency decided to no longer require GLN 830.7050, UV/Visible light absorption 

during registration review. This data was helpful during product reregistration, as it pertains to 

the structural analysis of the active ingredient. However, it is not necessary for the registration 

review process because it does not concern human health or environmental effects.

Note on the European Review of Bifenthrin

In May 2011, the European Food Safety Authority (EFSA) published the document “Conclusion 

on the peer review of the pesticide risk assessment of the active substance bifenthrin” in the 

EFSA Journal1

. Although the findings in the peer review document do not change the planned 

ecological or human health risk assessments, data requirements, or schedule for EPA’s 

registration review of bifenthrin, there are a number of studies referenced in the EFSA 

assessment that EPA has not had the opportunity to review. For example, there are some studies 

referenced in the EFSA document for which EPA has no data (i.e., honeybee tunnel and field 

studies) or studies that appear to indicate endpoints more sensitive than those relied on by EPA 

(i.e., chronic mouse study). 

EPA requests that any data generated for the European review process, which have not been 

previously submitted to EPA, be submitted to the Agency for review and consideration, as 

appropriate, during the registration review of bifenthrin. Further, if the data includes information 

on adverse effects of their products, these data are required to be submitted to EPA in accordance 

with Section 6(a)(2) of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). 

 

 

1 European Food Safety Authority; Conclusion on the peer review of the pesticide risk assessment of the active 

substance bifenthrin. EFSA Journal 2011;9(5):2159. [101 pp.]. doi:10.2903/j.efsa.2011.2159. Available online: 

www.efsa.europa.eu/efsajournal.htm 
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Amended Summary of Data Gaps for Bifenthrin: 

The table below summarizes all registration review data needs for bifenthrin. For more information on 

these data needs please refer to the following documents: Bifenthrin Final Work Plan, December 2010; 

Bifenthrin Human Health Assessment Scoping Document in Support of Registration Review, May 25, 

2010 (D371583); Toxicology Data Needs Update: Bifenthrin Human Health Assessment Scoping 

Document in Support of Registration Review, May 17, 2011 (D389066); Revised EFED Registration 

Review Problem Formulation for Bifenthrin, December 22, 2010 (D384352). These documents are 

located in the bifenthrin docket (EPA-HQ-OPP-2010-0384). 

Guideline 

Number Data Requirement Test 

Material

Estimated 

Timeframe

835.1230 Mobility Adsorption/Desorption TGAI 12

835.2120 Hydrolysis TGAI 12

835.2240 Photodegradation in Water TGAI 12

835.4100 Aerobic Soil Metabolism TGAI 24

835.4200 Anaerobic Soil Metabolism TGAI 24

835.4300 Aerobic Aquatic Metabolism TGAI 24

835.4400 Anaerobic Aquatic Metabolism TGAI 24

835.6100 (7)2 Environmental Chemistry Methods (ECM) and Independent 

Laboratory Validation (ILV)– soil TGAI 24

835.6200 (7)2 ECM and ILV – water and sediment TGAI 24

850.1010 Acute Toxicity Freshwater Invertebrates (Hyalella azteca) TGAI 12

850.1035 Acute Toxicity Estuarine/Marine Organisms – Mysid TEP 12

850.1350 Aquatic Invertebrate Life Cycle (saltwater) TGAI 12

850.1400 Fish Early Life Stage (estuarine / marine) TGAI 12

850.1500 Fish Life Cycle3 TGAI 24

850.2100 Avian Oral Toxicity (passerine species) TGAI 12

850.4100 Seedling Emergence (Tier II4) TEP 12

850.4150 Vegetative Vigor (Tier II4) TEP 12 

850.4400 Aquatic Plant Growth (aquatic plant toxicity) (Tier II4) TGAI 12

850.5400 Aquatic Plant Growth (algal toxicity) (Tier II4) TGAI 12 

 

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 40 CFR Part 158 Guideline Study 835.6100 and 835.6200 Footnote 7 states “Environmental chemistry methods 

used to generate data associated with this study must include results of a successful confirmatory method trial by an 

independent laboratory. Test standards and procedures for independent laboratory validation are available as 

addenda to the guideline for this test requirement.” 

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 If the registrant chooses to conduct this study on an estuarine / marine fish, then the additional requirement for the 

fish early life stage study (Guideline 850.1400) could be satisfied with this one study. 

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 A Tier II study is required. A Tier I plant study may be conducted in lieu of a Tier II study with the understanding 

that any adverse effects observed by the Tier I study would necessitate conduct and submission of a Tier II study as 

well. 
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Guideline 

Number Data Requirement Test 

Material

Estimated 

Timeframe

Non-GDLN Whole sediment: chronic invertebrates, freshwater and 

marine5 TGAI 12

Non-GDLN POTW Treatability Study TGAI 12

Non-GDLN Leachability from Treated Wood6 TEP 24

860.1340 Residue Analytical Method (revised version of method P2763) TGAI 24

860.1500

Magnitude of Residue in Crop Plants [herb subgroup 19A, 

artichoke, caneberry subgroup 13-07A, hops, cotton gin 

byproducts, and grapes].

TGAI 24

870.1300 Acute Inhalation Study TGAI 8

870.3250 90-Day Dermal Study TGAI 24

870.3465 90-Day Inhalation Study TGAI 24

870.7800 Immunotoxicity Study TGAI 12

 

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 Tests on Hyalella azteca, Chironomus dilutus, and Leptocheirus plumulosus are expected to be required. 6

 Data are currently in Agency review. When available, EPA will provide the registrant with a Data Evaluation 

Record documenting its review and classification of the data. Should the Agency determine these data to be 

unacceptable, the leachability from treated wood data requirement will remain outstanding, and new data will be 

required.