2 composting of chlorfenapyr-treated material. Therefore, EFED no longer considers composting to be a viable exposure route for ch lorfenapyr to ecological receptors.

A second concern of EFED’s in the preliminary problem formulation dealt with c hlorfenapyr being applied to soil underlying a concre te slab prior to the slab be ing poured (during construction) (EPA Reg. No. 000241-00392). In the event that a ma jor rain event occurs after treatment and prior to pouring of the concrete sl ab, there is a potential for exposur e to chlorfenapyr in adjacent

areas via runoff from the use site. EFED concl uded that such exposure is possible because the label does not specify that th e amount of time between applic ation of chlorfenapyr and the pouring of the concrete slab be minimized. As of the time of this document, the label language

has not been modified. EFED continues to believe that such language should appear on the label.

However, at this time, EFED does not believe th is exposure route is sufficient to warrant the

collection of additional fate and effects data or the development of an eco logical risk assessment.

BASF Comment:

The currently registered uses for chlorfenapyr in the United States, being primarily indoor, are not expected to result in signi ficant exposure to endangered speci es. Therefore, an endangered species assessment is not needed at this time. (Page 4).

EFED Response:

Because the composting language has been modified on label EPA Reg. No. 000241-00374, EFED concurs that an endangered species assessment is not needed at this time as part of this Registration Review.

BASF Comment:

Following discussions with the chemical review manager, BASF agreed to remove composting directions from chlorfenapyr labels and subseque ntly submitted revised labeling to the EPA OPP Registration Division on August 10, 2010 to remove the composting directions from the current label (Page 4).

EFED Response:

EFED has received a copy of the revised labe l restricting the composting of treated plant

material. EFED will revise the Problem Formulat ion in light of the restriction on composting.

BASF Comment:

The currently registered uses for chlorfenapyr in the United States, being primarily indoor, are not expected to result in signi ficant exposure to endangered speci es. Therefore, an endangered species assessment should not be needed (Page 5).3 EFED Response:

EFED agrees that an endangered species assessment is not needed at this time as part of the chlorfenapyr Registration Review because chlorfenapyr is primarily registered for indoor, underground, or crack and crevice uses, which woul d not be expected to result in significant exposure to endangered species.

BASF Comment:

Per 40CFR 158.630, sediment testing is only required if the product is expected to enter the environment in significant concen trations, either by runoff or er osion, because of its expected use or mobility pattern. Based on its current uses in the United States and its mobility pattern, chlorfenapyr would not be expected to enter th e environment in significan t concentrations (Page

5).

EFED Response:

Chlorfenapyr is primarily used indoors, underground or as a crack and crevice treatment and is not expected to enter the environm ent in significant concentration; therefore, sediment testing is not required at this time for this Registration Review.

BASF Comment:

Per 40CFR 158.630 acute toxicity es tuarine and marine organism acute toxicity data is not required for indoor uses. Based on its current uses (primarily i ndoor and/or structural) in the United States and its mobility pattern, chlorf enapyr would not be expected to enter the environment in significant concentrations (Page 5).

EFED Response:

Chlorfenapyr is primarily used indoors, underground or as a crack and crevice treatment and is not expected to enter aquatic environments in significant concentration; therefore, an acute toxicity estuarine and marine study is not required for this Registration Review.

BASF Comment:

Per 40CFR 158.630 Fish early-l ife stage (freshwater) data is not required for indoor use. Based on its current uses (primarily i ndoor and/or structural) in the United States and its mobility pattern, chlorfenapyr would not be expected to enter th e environment in significant concentrations (Page 5).4 EFED Response:

Chlorfenapyr is primarily used indoors, underground or as a crack and crevice treatment and is not expected to enter aquatic environments in si gnificant concentration; therefore, a freshwater early-life stage study is not requir ed for this Registration Review.

BASF Comment:

BASF has previously submitted multiple soil methods (MRID 43492850). In response to this summary document BASF submitted multiple additio nal methods for both soil and water to EPA on August 4, 2010 (Page 5).

EFED Response:

Based on the new label use restric tion on the composting of treated plant material the Agency is no longer requesting the Registrant submit soil and water methods.

BASF Comment:

Following discussions with the chemical review manager, BASF agreed to remove composting directions from chlorfenapyr labels and subseque ntly submitted revised labeling to the EPA OPP Registration Division on August 10, 2010 to remove the composting directions from the current label. Therefore, a study evaluating chlorfenapyr degradation in compost should not be needed (Page 5).

EFED Response:

The label use restriction prohibi ting the composting treated plant material removes the need to evaluate chlorfenapyr de gradation in compost.

BASF Comment

In EFED’s Preliminary Problem Formulation (PF) for Ecological Risk, E nvironmental Fate, and Endangered Species Assessments for Chlorfen apyr (PC Code 129093; DP Barcode 373109), the following potential exposure pathways from chlorfenapyr-treated compost was outlined.5 Figure 1. Potential exposure pathways from chlorfenapyr-treated compost (EFED doc. May 11, 2010, pg. 7).

BASF has submitted a revised label for chlorf enapyr which removes composting as an acceptable practice. Therefore BASF has modified the PF reflecting the removal of compost

from the label. The modified PF can be found in Figure 2

.

Figure 2 . Revised potential exposure pathways from chlorfenapyr based on the modified label submitted by BASF.

EPA in its Preliminary Problem Formulation' ( PF) for Ecological Risk, Environmental Fate, and Endangered Species Assessments for Chlorf enapyr (PC Code 129093; DP Barcode 373109) document, the Agency requested a series of st udies to address concer ns in their PF. The requested studies are as follows:

1. Guideline 850.4100, 41500, 4400, 5400 - Aquatic a nd Terrestrial Plant Toxicity.

2. Guideline 850.1735 and 850.1740 - Whole sediment: fr eshwater and marine invertebrates. Chlorfenapyr applied to plants grown in greenhouse Edible portion harvested from plants (Health Effects

Division Assessment)6 3. Guideline 850.1075 - Fish Acute LC 50 RBT for degradate CL357806.

4. Guideline 850.1025 - Estuarine/Ma rine Acute Invertebrate LC 50 Oyster.

5. Guideline 850.1400 - Fish ELS study.

6. Special Study - Evaluation of chlorfenapyr in compost.

BASF has revised the PF based on our newly revise d label. Since the PF has been revised based on the new BASF label, we no longer see any basi s for the studies request ed. BASF provides the following rationale for the dismi ssal of the requested studies.

1. Guideline 850.4100, 4150, 4400, 5400 - Aquatic and terrest rial Plant Toxicity. Based on the 40 CFR code requirements found on Table 158.5 40, these studies are not required for greenhouse use.

2. Guideline 850.1735 and 850.1740 - Whole sediment: fr eshwater and marine invertebrates. Based on the 40 CFR code requirements f ound on Table 158.490, these studies are not required for greenhouse use.

3. Guideline 850.1075 - Fish Acute LC 50 RBT for degradate CL357806. Based on the 40 CFR code requirements found on Table 158.490, these studies are not required for greenhouse use.

4. Guideline 850.1025 - Estuarine/Ma rine Acute Invertebrate LC 50 Oyster. Based on the 40 CFR code requirements found on Table 158.490, these studies are not required for greenhouse use.

5. Guideline 850.1400 - Fish ELS study. Based on the 40 CFR code requirements found on Table

158.490, these studies are not required for greenhouse use.

6. Special Study - Evaluation of chlorfenapyr in co mpost. Since the revise d BASF label does not have a labeled compost use, we no longer see any basis for this request.

EFED Response:

Based on the revised label use restriction prohibiti ng the composting of treated plant material the Agency is no longer requesting th e studies listed immediately above.

PCRM Comment:

We also wish to comment on the fish test ing proposal "(850.1075) Acute Fish Toxicity Study" that the EPA submitted for Chlorfenapyr. We believe that the number of animals used can be reduced by following an acute threshold or "limit test" approach. This approach was first pioneered on the observation that fish are rarely more sensitive than algae and daphnia." The fish7 median lethal concentration (LC50) test is replaced with an acute threshold test in which fish testing would be performed at one concentratio n only (the lowest EC50 concentration obtained with previous algae and daphnia testing). A vers ion of this approach has been adopted by the OECD as a guidance document and they wi ll be publishing the final one shortly," While that approach will not satisfy the EPA's data needs, in previous co mments EFED scientists have illuminated a potential way forward that may help to reduce fish testing in some cases: The definitive LC50 test for a formulated product could be waived if a limit test [is] performed. This strategy is based on the predicted environmenta l exposure. The limit test dose is set not arbitrarily but is unique to each case and is set in order to ensure that pr edicted exposure will not reach the Agency's Level of Concern. If fewer than 50% of fish die at the calculated single-dose "limit," the full LC50 test would produce an LC50 result that is higher than the LOC, ensuring that the environmental exposures will not be acut ely harmful. If the limit test is unsuccessful--

that is, if more than 50% of fish die at that dose level, a full 96-hour LC50 test would be required.

Clearly, this approach is not ri ght for all chemicals, as following this approach for substances that are expected to be more acutely toxic than the LOC would in fact us e more animals. Existing information and QSAR models can help dete rmine whether this strategy would reduce the number of fish killed. We encourage the regi strant to determine whether this strategy is appropriate for this situation.

We also encourage the use of (Q)SAR data ei ther in place of, or addition to, the fish experimental data. When correctly applied, (Q)SARs can feasibly replace in vivo data in some instances; requesting (Q)SAR data in addition to in vivo data would increase Agency and registrant comfort and confidence with the us e and evaluation of data from such methods.

EFED Comment:

Based on the revised label use restriction prohibiti ng the composting of treated plant material the Agency is no longer requesting these studies.