DATE: SUBJECT: UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460

03-10-2015 OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION

Chlorfenapyr. Addendum to Registration Review Preliminary Risk Assessment to Update Occupational Post-application Assessment based on Submitted Dislodgeable Foliar Residue (DFR) Data
PC Code: 129093 Decision No.: 496921 Petition No.: NA DP Barcode: D425697 Registration No.: NA Regulatory Action: Reg Review Case No.: 7419 Risk Assessment'Type: Occupational/Residential Exposure Assessment TXRNo.:NA MRIDNo.:NA CAS No.: 122453-73-0 40 CFR: §180.513 FROM: Kelly M. Lowe, Environmental**Scientist ~~~;;.co:;;;,,,.**  Health Effects Division (HED)/Risk Assessment Branch (RAB) 1 (7509P) Charles Smith III, Branch Chief 

# c_ C 

# ')S;PHEDIRAB 1 (7509P) THRU:
TO: Margaret Hathaway Kevin Costello, Branch Chief Pesticide Re-evaluation Division (PRD; 7508P)

INTRODUCTION In 2014, HED conducted a preliminary risk assessment (PRA) ofregistered uses for chlorfenapyr as part ofRegistration Review1• Inthis assessment, DFRdatawere required in accordance with 40 CFR Part 158, since the calculated occupational dermal post-application margins ofexposure (MOEs) were less thantwo times the level ofconcern (LOC; i.e.,< 200) based on default values for the fraction ofapplicationrate available for transfer after a foliar application. In response to this data requirement, the Registrant, BASF, submitted a study, "Determination of dislodgeablefoliar residues in azaleas andchrysanthemums treatedwithAlert2SC." This study

1 Perron, Met al., 2014. Chlorfenapyr- Preliminary Human Health Risk Assessment for Registration Review. D416560. Page 1 of4was reviewed by HEO and found to be acceptable for use in risk assessment2• The occupational post-application assessment for chlorfenapyr has beenupdated in this addendum using the submitted chemical-specific data and a summary is provided below
. These risk estimates supersede those provided in the PRA (Memo, M. Perron et al, 22-May-2014, 0416560, Table 9.2
.2.1) and the supporting occupational and residential exposure assessment (Memo, L. Venkateshwara, l8-Jun-14, 0417598, Table 6.2.2.2). Summary ofOFR study Determination of Dislodgeable Foliar Residues inAzaleas andChrysanthemums Treatedwith ALERT®2SC (MRID 49503201; HED Review: Memo, K. Lowe, xx-xxx-2015, D423652). This study was designed to determine the dissipation ofOFRs ofthe active ingredient (ai) chlorfenapyr from treated azalea and chrysanthemum foliage. The test product, ALERT® 2SC (CL 303630 2SC), was a 21.4% ai chlorfenapyr soluble concentrate formulation. The field phase ofthe study was conducted in greenhouses located at Plant Sciences Inc., in Watsonville, California (NAFTA Region 10) during September of 1998. Three foliar broadcast applications were made to potted azalea and chrysanthemum plants at a target rate of0.64 lb ai/A, using a retreatment interval (RTI) of5 days. Actual rates ranged from 0.63 to 0.64 lbs ai/A. The foliar broadcast spray applications were made using a backpack sprayer with a handheld boom. Chlorfenapyr OFRs from azalea foliage averaged 0.516 μg/cm2 immediately after the first application, 0.833 μg/cm2 immediately after the second application, and 0.842 μg/cm2 immediately after the third application. Average residues reached a maximum of 1.00 μg/cm2 at 12 hours afterthe 3rd application, and declined only slightly to 0.751 μg/cm2 by 14 days after the 3rd application. Chlorfenapyr dislodgeable foliar residues from chrysanthemum foliage averaged 0.101 μg/cm2 immediately after the first application, 0.159 μg/cm2 immediately after the second application, and 0.0908 μg/cm2 immediately after the third application. Average residues remained relatively steady through the last sampling interval. The maximum average residue of0.164 μg/cm2 occurred at 7 days after the 3rd application. Chlorfenapyr residues dislodged from the azalea and chrysanthemum foliage remained relatively stable over the 14-day sampling period after the last application. Therefore, a regression analysis was not performed. No major issues were identified during review ofthis study and the results are considered acceptable for risk assessment purposes. Since residues remained relatively stable throughout the sampling period, HEO would recommend that the highest residue value identified during the study periodbe used in the occupational post-application assessment for chlorfenapyr.

2 Lowe, Kelly. 2015. Chlorfenapyr: Review of"Determination ofDislodgeable FoliarResidues in A:zaleas and Chrysanthemums Treated with ALERT® 2SC." 0423652. Page2of4Summary ofDFRValues for Treated Chrysanthemums and Azaleas in a Greenhouse with Chlorfenapyr; MRID# 49503201. Greenhouse Greenhouse Chrysanthemums Azaleas Study Target Rate (lb ai/A) 0.64 Spray Volume (GPA) 198

- 201 Measured Average Day 0 Residue (μg/cm2) pt application: 0.101 ptapplication: 0.516 2nd application: 0.159 2nd application: 0.833 [measured "as soon as sprays dried"] 3rd application: 0.0908 3rd application: 0.842 Highest Measured Value (μg/cm2) 0.164 1.00 (7 days after 3rd application) (12 hours after 3rd application) Proposed use ofDFRdata: • Use the azalea DFR datato estimate post-application exposure for greenhouse ornamentals/non-bearing plants and greenhouse vegetables using the highest measured value. • Use the chrysanthemum DFRdatato estimate post-application exposure for floriculture crops (cut flowers) using the highest measured value. Crop DFRData Site Proposed use of Characterization DFRData 

### • DFR data collected in greenhouse
. Greenhouse 

### • Study crop matches ornamental Ornamental, Non- Highest measured plant crop group.

bearing Plants Azaleas Greenhouse value 

### • Highest residues dislodged from azalea foliage; considered Greenhouse vegetables protective for greenhouse vegetables. Floriculture Crop (cut Highest measured 

### • DFR data collected in greenhouse
. flowers) Chrysanthemum Greenhouse value 

### • Study crop matches cut flower crop j;(l"Oup. Updated Occupational Post-applicationAssessment: The updated short- and intermediate-term occupational post-application exposure scenarios associated withthe registered uses ofchlorfenapyr are summarized in the table below. All scenarios resulted inMOEs greaterthanthe LOC of 100 (ranging from 880 to 28,000) on day 0 (12 hours after application); and, therefore, are not ofconcernto HED. Occupational Post-application Non-Cancer Exposure and Risk Estimates for Chlorfenapyr. Crop/Site Activities Transfer Coefficient DFR1 Dermal Dose MOE3 (cm2!hr) (mglkg/day)2 Short and Intermediate-Term Container Moving, Pinching, Floriculture Crop Hand Pruning, Hand Weeding, 230 0.00018 28,000

(cut flowers) Scouting, Transplanting, 0.05 Irrigation (hand set) 1,900 0.0015 3,400 Page 3 of4Occupational Post-application Non-Cancer Exposure and Risk Estimates for Chlorfenapyr. Crop/Site Activities Transfer Coefficient DFR1 Dermal Dose MOE3 (cm2 /hr) (mg/kg/day)2 Short and Intermediate-Term Hand Harvesting 4,800 0.0037 1,300 Transplanting, Irrigation (hand 230 0.001 4,600 watering) Greenhouse Hand harvesting, Pinching, Vegetables Pollination, Hand Pruning, Scouting, Turing, Tying/training, 1200 0.006 880

Hand Weeding, Propagating, 0.31

Hand Pruning, Scouting Hand harvesting, Hand Pruning, Greenhouse Scouting, ContainerMoving, Ornamental, Non- Hand Weeding, Transplanting, 230 0.001 4,600

bearing Plant Pinching, Tying/Training, Grafting, Propagating 1
. DFR= chem1cal-spec1fic datafrom MRID49503201. a. For floriculture crops, DFR datafor chrysanthemums was used
. Highestmeasured value= 0.164 ug/cm2 adjusted for difference in application rates between the study (0.64 lb ai/A) and the registered labels (0
.2 lb ai/A). b
. Forgreenhouse vegetables and ornamental/non-bearingplants, DFR data for azaleas was used. Highestmeasured value= 1
.00 ug/cm2 adjusted for difference in application rates between the study (0
.64 lb aiA) and the registered labels (0
.2 lb ai/A)
. 2
. Daily Dermal Dose= [DFR (μg/cm2) x Transfer Coefficient x 0
.001 mg/μg x 8 hrs/day x dermal absorption (13 %)] + BW (69 kg)
. 3
. MOE= POD (S mg/kg/day) I Daily Dermal Dose
.

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