Page 1 of 4 

### UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF CHEMICAL SAFETY
AND POLLUTION PREVENTION



### DATE: 02

- 18

- 2015

SUBJECT: 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 DP Barcode : D 425697

Decision No.: 496921 Registration No.: NA

Petition No.: NA Regulatory Action: Reg Review Risk Assessment Type: Occupational/Residential Exposure Assessment Case No.: 7419

TXR No.: NA CAS No.: 122453

- 73

- 0

MRID No.: NA 40 CFR: §180.513



### FROM: Kelly M. Lowe , Environmental Scientist

Health Effects Division (HED)/Risk Assessment Branch (RAB) 1 (7509P)

THRU : Charl

es Smith III, Branch Chief HED/RAB 1 (7509P)

TO : Margaret Hathaway

Kevin Costello, Branch Chief

Pesticide Re

- evaluation Division (PRD; 7508P)

INTRODUCTION In 2014, HED conducted a preliminary risk assessment (PRA) of registered uses for chlorfenapyr as part of Registration Review 1 

### . In this assessment, DFR data were required i n accordance with

40 CFR Part 158

, since the calculated occupational dermal post

- application margins of exposure ( MOEs ) were less than two ti mes the level of concern ( LOC ; i.e., < 200) based on default values for the fraction of application rate available for transfer after a foliar application

.

In response to this data requirement, the Registrant, BASF, submitted a study, “ Determination of dislodgeable foliar residues in azaleas and chrysanthemums treated with Alert 2SC .” This study

1 Perron, M et al., 2014. Chlorfenapyr

– Preliminary Human Health Risk Assessment for Registration Review.

D416560.Page 2 of 4



### was reviewed by HED and found to be acceptable for use in risk assessment 2



### . The occupational
post

- application assessment for chlorfenapyr has been updated in t his 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, D416560 , Table 9.2.2.1) and the supporting occupational and residential exposure assessment (Memo, L. Venkateshwara, 18

- Jun

- 14, D417598, Table 6.2.2.2).

Summary of DFR study Determination of Dislodgeable Foliar Residues in Azaleas and Chrysanthemums Treated with

ALERT® 2SC (

MRID 49503201; HED Review: Memo, K. Lowe, xx

- xxx

- 2015, D423652).

This study was designed to determine the dissipation of DFRs of the active ingredient (ai) chlorfenapyr from treated azalea and chrysanthemum foliage. The test product, ALERT® 2SC (CL 303630 2SC)

, was a 21.4% ai chlorfenapyr solubl e concentrate formulation. The field phase of the 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 of 0.64 lb ai/A, using a

retreatment interval (RTI) of 5 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

.

Chlorfe napyr DFRs from azalea foliage averaged 0.516 μg/cm 2 

### immediately after the first application, 0.833 μg/cm 2 

### immediately after the second application, and 0.842 μg/cm 2 

### immediately after the third application. Average residues reached a maximum of 1.00 μg/cm 2 

### at
12 hours after the 3 rd 

### application , and declined only slightly to 0.751 μg/cm 2 

### by 14 days after the

3 rd 

### application.

Chlorfenapyr dislodgeable foliar residues from chrysanthemum foliage averaged 0.101 μg/cm 2 

### immediately after the first application, 0.159 μg/cm 2 

### immediately after the second application,
and 0.0908 μg/cm 2 

### immediately after the third application. Average residues remained relatively steady through the last sampling interval. The maximum average residue of 0.164 μg/cm 2



### occurred at 7 days after the 3 rd 

### 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 of this study and the results are considered acceptable for risk assessment purposes. Since residues remained relatively stable throughout the sampling period, HED would recomme nd that the highest residue value identified during the study period be used in the occupational post

- application assessment for chlorfenapyr.

2 Lowe, Kelly. 2015. Chlorfenapyr : Review of “ Determination of Dislodgeable Foliar Residues in Azaleas and Chrysanthemums Treated with ALERT® 2SC

. ” D423652.Page 3 of 4

Summary of DFR Values for Treated Chrysanthemums and Azaleas in a Greenhouse with Chlorfenapyr ; MRID# 49503201

. Greenhouse Chrysanthemums Greenhouse

Azaleas
Study Target Rate (lb ai/A) 0.64

Spray Volume (GPA) 198

- 201

Measured Average Day 0 Residue ( μg/cm 2 ) [measured “as soon as sprays dried”] 1 st application: 0.101

2 nd application: 0.159

3 rd application: 0.0908 1 st application: 0.516

2 nd application: 0.833

3 rd application: 0.842

Highest Measured Value (μg/cm 2 ) 0.164

(7 days after 3 rd application) 1.00 (12 hours after 3 rd application)



### Proposed use of DFR data:

 Use the azalea DFR data to estimate post

- application exposure for g reenhouse
ornamentals/non

- bearing p lants and g reenhouse vegetables using the highest measured
value

.

 Use the chrysanthemum DFR data to estimate post

- application exposure for f loriculture

c rop s (cut flowers) using the highest measured value

.

Crop DFR Data Site Proposed use of
DFR Data Characterization

Greenhouse Ornamental, Non

bearing Plants

Greenhouse vegetables Azaleas Greenhouse Highest measured
value  DFR data collected in greenhou se.

 Study crop matches ornamental plant crop group.

 Highest residues dislodged from azalea foliage; considered protective for greenhouse vegetables.

Floriculture Crop (cut flowers) Chrysanthemum Greenhouse Highest measured
value  DFR data collected in greenhouse.

 Study crop matches cut flower

crop group.



### Updat ed Occupational Post

- application Assessment:

The updated short

- and intermediate

- term occupational post

- application exposure scenarios associated with the registered uses of chlorfenapyr are summarized in the table below

. All scenarios resulted in MOEs greater than the LOC of 100 (ranging from 880 to 28,000 ) on day 0 (12 hours after application) ; and, therefore, are not of concern to HED.

Occupational Post

- application Non

- Cancer Exposure and Risk Estimates for Chlorfenapyr.

Crop/Site Activities Transfer Coefficient (cm 2 /hr) DFR 1 Dermal Dose (mg/kg/day) 2 MOE 3

Short and Intermediate

- Term

Floriculture Crop (cut flowers) Container Moving, Pinching,

Hand Pruning, Hand Weeding, Scouting, Transplanting, 230 0.05 0.00018 28,000

Irrigation (hand set) 1,900 0.0015 3,400Page 4 of 4

Occupational Post

- application Non

- Cancer Exposure and Risk Estimates for Chlorfenapyr.

Crop/Site Activities Transfer Coefficient (cm 2 /hr) DFR 1 Dermal Dose (mg/kg/day) 2 MOE 3

Short and Intermediate

- Term

Hand Harvesting 4,800 0.0037 1,300

Greenhouse Vegetables Transplanting, Irrigation (hand watering) 230

0.31 0.001 4,600

Hand harvesting, Pinching, Pollination, Hand Pruning, Scouting, Turing, Tying/training, Hand Weeding, Propagating, Hand Pruning, Scouting 1200 0.006 880

Greenhouse Ornamental, Non

bearing Plant Hand harvesting, Hand Pruning,

Scouting, Container Moving, Hand Weeding, Transplanting, Pinching, Tying/Training, Grafting, Propagating 230 0.001 4,600

1. DFR = chemical

- specific data from MRID 49503201.

a. For floriculture crops, DFR data for chrysanthemums was used. Highest measured 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. For greenhouse vegetables and ornamental/non

- bearing plants, DFR data for azaleas was used. Highest measur ed 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/cm 2 ) × Transfer Coefficient × 0.001 mg/μg × 8 hrs/day × dermal absorption ( 13 %)]  BW ( 69 kg).
3. MOE = POD (5 mg/kg/day) / Daily Dermal Dose.