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. Executive Summary

EFED typically completes a preliminary pr oblem formulation for the ecological risk, environmental fate, and endangered species a ssessments to be conducted as part of the Registration Review of the insecticide/miticide chlorfenapyr. In the case of chlorfenapyr, all uses occur indoors, underground (termiticid e), or involve small quantities (crack and crevice treatment) and are not expected to result in si gnificant ecological exposure because greenhouse/indoor and underground uses have limited opportunity for outdoor residues, drift, runoff, and wildlife exposure

. The preliminary problem formulation identified two risk concerns that could result in outdoor environmental exposure. First, was a concern regarding label language (EPA Reg. No. 000241-00374) for fruiting vegetables grown in a greenhouse that stated “Compost any discarded plant material that has been tr eated,” EFED concluded in the preliminary problem formulation that exposure was po ssible and an ecological risk assessment needed to be performed. Subsequently, the re gistrant has modified this label to prohibit composting of chlorfenapyr-treated materi al. Therefore, EFED no longer considers composting to be a viable exposure route for chlorfenapyr to ecological receptors.

A second concern of EFED’s in the preliminary problem formulation dealt with

c hlorfenapyr being applied to soil underlying a concrete sl ab prior to the slab being poured (during construction) (EPA Reg. N o. 000241-00392). In the event that a major rain event occurs afte r treatment and prior to pouring of the concrete slab, there is a potential for exposure to chlorfenapyr in adjacent areas via runoff from the use site. EFED concluded that such exposure is possi ble because the label does not specify that the amount of time between application of ch lorfenapyr 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 su ch language should appear on the label. However, at this time, EFED does not believe this exposure route is sufficient in and of itself to warrant the collection of additional fate and effects data or the development of an ecological risk assessment.

2. Current Chlorfenapyr Uses

The currently registered crop/sites, use groups , and registration numb ers for chlorfenapyr are listed in Table 1 . These uses are taken from the LUIS report (dated: July 23, 2009) prepared by the Biological a nd Economic Analysis Division (BEAD) of the U.S. EPA Office of Pesticide Programs.

Table 1. Complete List of Chlorfenap yr Uses by Registration Number. Crop/Site Use Group Reg.No

Commercial Storages/Warehouses Premises Indoor Non-Food 000241-00392 007969-00285 MS02002300

Commercial/Institutional/Indus trial Premises/Equip. (Indoor) Indoor Non-Food 000241-00392 007969-00285 MS02002300Page 3 of 17 Table 1. Complete List of Chlorfenap yr Uses by Registration Number. Crop/Site Use Group Reg.No Dairies/Cheese Processing Plant Equipment (Food Contact) Indoor Food 000241-00392 007969-00285 MS02002300

Eating Establishments Indoor Food 000241-00392 007969-00285 MS02002300

Egg Packing Plants (Commercial) Indoor Food 000241-00392 007969-00285 MS02002300 Eggplant Greenhouse Food Crop 000241-00374

Feed Mills/Feed Processing Plants Indoor Food 000241-00392 007969-00285 MS02002300 Food Processing Plant Equipment (Food Contact) Indoor Food 000241-00392 MS02002300 Food Processing Plant Premises (Nonfood Contact) Indoor Food 007969-00285 Food Stores/Markets/Supermarkets Premises Indoor Food 000241-00392 MS02002300 Food/Grocery/Marketing/Storage/Distribution Facility Premise Indoor Food 000241-00392 007969-00285 MS02002300 Fruiting Vegetables Greenhouse Food Crop 000241-00374 Greenhouses-In Use Greenhouse Food Crop 000241-00374 Groundcherry (Strawberry Tomato/Tomatill o) Greenhouse Food Crop 000241-00374 Hospitals/Medical Institutions Premises (Human/Veterinary) Indoor Medical 000241-00392 007969-00285 MS02002300

Household/Domestic Dwellings Indoor Residential 000241-00392 007969-00285 MS02002300

Household/Domestic Dwellings Indoor Premises Indoor Residential 000241-00392 007969-00285 MS02002300

Household/Domestic Dwellings Outdoor Premises Outdoor Residential 000241-00392 007969-00285 MS02002300

Meat Processing Plant Premises (Nonfood Contact) Indoor Non-Food 000241-00392 007969-00285 MS02002300 Nonagricultural Outdoor Buildings/Structures Terrestrial Non-Food Crop* 000241-00392 MS02002300 Ornamental and/or Shade Trees Greenhouse Non-Food Crop 000241-00374 Ornamental Herbaceous Plants Greenhouse Non-Food Crop 000241-00374 Ornamental Non-flowering Plants Greenhouse Non-Food Crop 000241-00374 Ornamental Woody Shrubs And Vines Greenhouse Non-Food Crop 000241-00374 Pepino (Melon Pear) Greenhouse Food Crop 000241-00374 Pepper Greenhouse Food Crop 000241-00374

Pets (Unspecified) Indoor Non-Food 000241-00392 007969-00285 MS02002300Page 4 of 17 Table 1. Complete List of Chlorfenap yr Uses by Registration Number. Crop/Site Use Group Reg.No

Poultry Processing Plant Premises (Nonfood Contact) Indoor Food 000241-00392 007969-00285 MS02002300

Sewage Systems Aquatic Non-Food Industrial 000241-00392 007969-00285 MS02002300 Tomatillo Greenhouse Food Crop 000241-00374 Tomato Greenhouse Food Crop 000241-00374

Zoos Indoor Non-Food 000241-00392 007969-00285 MS02002300 * The Use Group designation, Terrestrial Non-Food Crop, is confusing because it refers to use on building and structures below concrete slabs, within the soil around foundations, and in and around cracks and crevices. It is probably meant to in dicate “some terrestrial application that is not to a food crop.” However, a literal interpretation would be “application to some crop other than food.”

The majority of these uses occurs in enclos ed indoor environments; and therefore, are assumed by EFED to have no complete exposur e pathways to ecologi cal receptors and, therefore, pose no risk to these recepto rs. However, several of the uses in Table 1 merit further explanation because these use group names may appear to result in outdoor exposures to ecological receptors:

• Household/Domestic Dwellings Outdoor Premises (Outdoor Residential) and Nonagricultural Outdoor Buildings/Structures (Terrestrial Non-Food Crop) – refers to uses that form a zone or ba rrier in the soil su rrounding a building or structure (under concrete slab floorin g and adjacent to basement walls) during construction and crack and cr evice treatments that are used on existing buildings and structures. Pre-construction uses of chlorfenapyr result in the pesticide sequestered by soils under th e floor of, or adjacent to the basement walls of, a building. Post-construction and crack and crevice treatments are limited to a 9.4 x 10 -5 lbs ai per 2 sq. feet every four week s. Therefore, assuming 4 sides of a building are treated with side s 10’ high by 100’ long (4000 ft 2 ) would result in a maximum treatment of 0.18 lbs ai to the building. However, EFED believes such applications would be unlikely to crea te a significant exposure pathway to ecological receptors because: most stru cturally sound buildings have far fewer cracks and crevices than the maximum a pplication rate allows; much of the applied pesticide would be retained inside the crevice or crack; and much of the pesticide that was dislodged from its applic ation site would be retained in any soil and/or landscaping at the ba se of the treated wall.

• Sewage Systems (Aquatic Non-Food Industrial) – is a crack and crevice treatment that is used in cracks in the concrete slab flooring around floor drains. The intent is not to discharge the chemi cal to the sewer system but, rather, to prevent ground-dwelling insects from en tering a building through cracks in the flooring around the drain. The label specifies that the drain must lead to a sewage system (and thus presumably, would be gr eatly diluted if some of the pesticide went down the drain) to prevent the use of the chemical arou nd drains that mayPage 5 of 17 discharge immediately outside of the build ing (where relatively little dilution might occur).

• Zoos (Indoor Non-Food) – is also a crack and crevice use that is used on buildings enclosing zoo animals.

3. Chlorfenapyr Persistence Chlorfenapyr and its degradates have been show n to be highly persis tent. Chlorfenapyr's persistence is typified by a laboratory aer obic soil metabolism half -life of 1.4 years and its observed comparable field dissipa tion "half-life" of 1.3 years (MRID 44452621, 43492850). Chlorfenapyr is essentially stable to laboratory hydrolys is and anaerobic soil metabolism. Chlorfenapyr also has an organic carbon partition coefficient (K oc ) of 11,500 L/kg and thus binds to organic particulat es and is generally immobile in soil. Sediment would be its principl e latent reservoir in aquatic systems where it would remain available for extended periods.

Because of the persistence of parent and relatively short study durations, only small amounts of structurally similar metabolites or degradates were identified in soil in the field and lab studies. However, AC 312,094 has been detected at 10% to 16% of parent in the radiolabeled North Carolina study (MRID 44452623). This metabolite has intermediate mobility characteristics (median K oc around 2200). Coupled with its persistence, this means that it has high potential for runoff into surface water with comparable amounts in solution and eroding so il if chlorfenapyr is used in outdoor environments.

In general, transformation products appear to approximate or exceed the persistence of the parent. Structurally similar metabo lites or degradates (AC 312,094, AC 303,267, AC 303,268, AC 322,118, AC 322,250, AC 325,195, some of which exhibit ecotoxicity) were identified in soil in field and/or lab studies. Concentrat ions of these, when detected were typically a few percent each or less of the applied chlorfenapyr.

4. Chlorfenapyr Toxicity Available toxicity data are summarized below and are further discussed in Appendix A

. These data were obtained from previous a ssessments (DP Barcode: 241963). In general, chlorfenapyr has demonstrated high acute toxi city to terrestrial and aquatic organisms, and has demonstrated chroni c toxicity at concentrati ons in the low μg/L range.

Chlorfenapyr is very highly toxic to birds on an acute basis. The LD 50 values for redwinged blackbird ( Agelaius phoneiceus ), mallard ( Anas platyrhynchus ), and bobwhite quail ( Colinus virginianus ) are 2.2, 8.3, and 34 mg/kg, respectively (MRIDs 43887004, 42770227, and 42770228). It is also very highly t oxic to waterfowl and passerine species and highly toxic to upland gamebirds on an acute dietary basis (MRID 42770229, 42770230, and 44452613). Chlorfenapyr has also re sulted in reproductive and growth effects to birds at low concentrations of 1.5 mg/kg-diet. The mallard duck NOAEC value of 0.5 mg/kg-diet, which is based on reduced body weight, serves as the chronic toxicity endpoint for avian long-term exposur e risk calculations (MRID 434928-13).Page 6 of 17 Chlrofenapyr has been shown to be less toxi c to mammals compared with birds. Acute LD 50 values in mammals range from appr oximately 45 mg/kg-bw to 1152 mg/kg-bw (MRIDs 43492828, 42770201, 42770207). A 2-generation mammalian study (MRID 43492836) produced a NOAEC value of 60 mg/kg-diet (5 mg/kg-bw).

Chlorfenapyr is highly toxic to honey bees ( Apis mellifera ) on an acute contact exposure basis with a corresponding LD 50 value of 0.12 μg/bee.

In aquatic organisms, acute LC 50 values for chlorfenapyr range from 7 μg/L to 12 μg/L in freshwater fish (MRIDs 42770231 and 42807801), 60 μg/L in saltwater fish (MRID 43492816), 6 μg/L to 18 μg/L in freshw ater invertebrates (MRIDs 42770232, 43887009), 2 μg/L in saltwater invertebrates (MRI D 43492818), and 0.2 mg/kg to 20 mg/kg sediment in benthic organisms (MRIDs 44452619, 44560002). Therefore, on an acute exposure basis, chlorfenapyr is very highly toxic to freshwater a nd estuarine/marine fish and invertebrates. Chronic NOAEC values ra nge from 0.2 μg/L in estuarine/marine inverterbrates (MRID 43492821) to 4 μg/L (fre shwater fish and invertebrates; MRIDs 43492819 and 43492822). Additional information from the 1998 EFED assessment is presented in Appendix A

.

Conclusion

EFED does not intend to conduct an ecological risk assessment as the majority of chlorfenapyr uses are in enclosed environm ents; and therefore, are assumed by EFED to not have complete exposure pathways to eco logical receptors and, therefore, pose no risk to ecological receptors.

References USEPA. August 31, 1998. Chlorfenapyr (PIRATE TM , ALERT TM , AC 303,630) Insecticide-Miticide Environmental Fate and Ecological Effects Assessment and Characterization for a Section 3 fo r Use on Cotton. DP Barcode: D241963, D240108, D243556, D245813, D246459, D246093, D246661. 140pp.Page 7 of 17 Appendix A. Guideline Toxicity Data as Presented in Previo us Assessments (DP 241963)Page 8 of 17Page 9 of 17Page 10 of 17Page 11 of 17Page 12 of 17Page 13 of 17Page 14 of 17Page 15 of 17Page 16 of 17Page 17 of 17