H alos ulfuron- Met h y l H uman H eal th Ri sk Assessment 

### DP No. D42 I 8 1 9

UNITED S TATES ENVIRONMENTAL PROTECTION AGENCY

WASH I NGTON, D.C. 20460

M E MORANDUM

DATE: Jun e 1 0, 2015 OFFICE OF CHE MI CAL SAFETY AND POLLUTION PREVENTION

SUBJEC T: Halo s ulfuron-Methyl. Hum a n He a lth Ri s k Assessment fo r a Propo se d Use o n P ome Fruit Crop Gro up I 1-1 0 a nd S mall Fruit Vine Climb in g Subgroup, Except Fuzzy Ki w ifruit

, Subgroup I 3-07 F.

P C Code: 128721 Deci s i o n No.: 493338 P e titi o n No.: 4E8297 DP B a r code: 0421819 Re g i s trati o n Nos.: 81880-18

, 81880

- 2 R eg ul ato r y Action : Sect i on 3 Registration Case No.: NA Ri s k Assessme n t T y p e: Sing l e Chemica l Aggregate TXR No.: NA CAS No.: 10 0784-20-1 40 CF R: § 180 .4 79 MRID No. : NA

FROM:

THROUGH:

TO: Kristin Rur y, 

### MPH; Biolo g i st

# \6**~** Whang Phang

, Senjor To x i co l og i st 

### t Ri sk Assessment Branch 3 /

Wi lli am T. D r ew, Chem i s t

### ~ Risk Assessme nt Branch 2 H ealth Effects Divi s ion (7509P)

C hristin e Oli n ge r , Branch

## Ch**p~/(** '/}

. . Ri sk Assessme nt Branch 3

### ?.~ 

# / {___:..-

H ea lth Effects Division (7509P

S idn ey Jackson and Barb a r a Ma d den Minor Use & E m e r ge nc y R es p o n se Branch R eg i s t rat i o n Di v i s ion ( 7505P )

The R eg i s trati o n Di visio n (RD) r eq ue s t ed th e H ea lth Effects Division ( H E D) eva luat e the proposed ne w us es of h a l os ulfw·on-meth y l r eq u es t e d by the Interr eg i ona l R esea rch Project 4 ( IR4). Si n ce the la s t ri s k assess m e nt, the toxi c it y e nd poin t s and points of d e parture (PODs) h ave been r e

- eva luated ; th e r efore the res id entia l scenarios fo r in c lu s i on in th e aggrega t e ri sk

assess ment ha ve c han ged. The dietary exposure assess m e n t has been updated to r e flect the
propose d new u ses of halosulfuron -m et h y l

, and the aggregate risk assess m e nt ha s been u p d ated
to include the proposed new uses and t h e upd a t ed res i den t ial scenarios.

P age I of 40Halosulfuron-Methyl Human Health Risk Assessment DP No. 0421819

1.0 Exec utiv e Su mm ary

.. . ... . .. .. .. .. . ....... . ... .. .. .. .. .. .. .. ... . ... . ... . ... . .. .. .. . .. .. . .................... .. . .. .. .. . .. . .. .. . 4 2.0 HED Recommendations

.......................................................... . ...... .. . .. . ... . .. .. . .................... 6 2.1 Tolerance Consideration s

..................................... .. . .. .. .. .. .. . ... . .. . ... ...................... .. . .. .. .. . . 6 2.1.1 Enforcement Analytica l Method/Mu ltire s idue Methods

......................... .. .. .. . .. .. .. . . 6 2.1.2 Recommended To l erances

..................... . ............. .. .. . ... . .. .. . ... . .. .. . ... . .. . ................ .. . ..... 7 2.1.3 Int ernational Harmonization

................ . .. .. .. .. .. .. . ... . ... . ... . .. . ... . .. ................... .. . .. .. .. . .. . .. 8 2.2 Labe l Recommendations

. .. .. .. . ... .. .. .. .. ...................................... . .. .. . ... . .. . ... . . .................... . 8 2.2 .1 Recommendations from Re s idue Review s

...... .. . ... . ... . .. . ... . ... . .. .. .. . . .......... . .. .. . ...... . .. . .. 8 3.0 Introduction

.. .. .. . .. . ... . .. . ... . .. .. .. .. .. .. .. .. .. .. .. ....................... .. . ... . .. . ... . .. .. .. . .. ................ .. . .. . ... . .. . .. 8 3.1 Chemica l Identity

..... . .. .. .. .. .. . ... .. . ... . ... .. .. .. .. .. ... . .. ..................... .. .. . .. .. . .. .. .. . .. .. .. ................ . 8 3.2 P h ysica l /Chemica l C har acterist ic s

. ... .. ......................... ... . .. . ... . .. . ... . .. .. . ................ .. . .. .. .. 9 3.3 Pesticide Use Pattern

. . ............................ ... . ... . ... . .. .. ... . .. .............................. .. . ... . .. . .. .. . .... . 9 3.4 Anticipated Ex p osure Pathway s

. .... . ... . ... . ... .. .. .. .. . ... ....................... .. . .. .. .. . .. .. .. . .. .. . ....... 10 3.5 Cons id eratio n of Env ironm enta l Justice

...................... . ..... .. . ... . .. . .. .. .. ........ . .......... .. . .. 10 4.0 Hazard Characterization and Dose-Respon s e Assessment

. .. .. .. ...................... .. . ... . .. . ... 1 1 4.1 Tox icolo gy Studies Availab l e for Anal ys i s

. .. .. .. .. .. ... . .. . .................... .. . .. .. .. . .. .. .. . .. .. . ..... 11 4.2 Absorption, Distribution, Metabolism a nd Elimination

.. .. . ... . .. . .. ................... .. .. .. . .. . 12 4 .2.1 D e rmal absorpt ion

.. .. .. . ... . ... . ... . ... . ... . ... . ... . ... .. .. . ... .. .. . .. ... . . .. ................ .. .. .. . .. . ... . .. . .. ..... 12 4.3 S ummary of Toxico lo gica l E ffects

. .. .. .. .. ... . .. ............................. . .. .. .. .. . .. . ... . . ................ 12 4.4 Safety Factor for Infants and Children (FQPA Safety F actor)

.. .................. .. . ... . .. . . 13 4.4 .1 Completeness of the Toxicology Database

. .. .. .. .. .. . ... . ... . .. . .. .. . ................. . .. .. . .. . ... . .. . . 13 4.4.2 Ev idenc e of Neurotoxicity

. ... .. .. . ... .. .. .. .. .. ... . ... . ...... ...... . .................... .. . ... . .. . ... . .. . .. . .. .. . 13 4

. 4.3 Ev id ence of Sens iti v i ty/S u scept ibility in the De ve loping or Yo un g Animal..

...... 13 4.4.4 Residual Uncertainty in the Expos ur e Database

.. .. .. .. . ... . ....................... . .. .. . .. .. .. . .. 13 4.5 Toxicity Endpoint and Point of Departure (POD) Selections

.... .. .. .. . .. . ... . .. . ...... . ... . . . 14 5.0 Diet ary Exposure and Risk Assessment

...... . ........ . .. .. .. .. . .. .. .. . .. .. .. . .. .. .. . .. . ... . .. .. . .. . ............ 15 5.1 Residu es of Conce rn Summary and Rationale

. . ... . .. .. .. . ... . .. .. .. .. . .......................... .. . .. . 1 5 5.2 Food Residue Profi l e

.. .. .. .. .. ... . . ... ..... ... ..................................... .. . .. . ... . .. . ... . .. . ...... . ... . . ..... 16 5

. 3 Water Residu e Profi l e

............. .. .. .. .. ... .. .. .. .. ...... .. .. .. .. .. . ... . .. .. .. . ... . .. . ...... . .. ...................... 16 5.4 Dietary Risk Assessment

. .. .. .. .. .. .. .. .. ... . ... . ... . ... .. .. .. .. .. .. . ... . .. .. .. .. .. . . ....................... .. .. . .. .. . 17 5.4.1 Description of Residue Data Use d in Dietary Assessment

......... . .. .. . .. .. .. . .. .. . .. .. . .. .. 17 5.4.2 Percent Crop Treated U se d in Dietary Assessment

...... . ... . .. . ... . .. . ... . .. . .. .. .. . .. ......... 1 7 5.4.3 Acute Dietary Risk A ss e ss ment

. .. . ... .. ... . ... . ... . ... . .. .. ... ............................................... 17 5.4.4 Chronic Dietary Risk Assessment..

....................... .. ...... . .. .. .. .. . .. . ... . .. . ... . .. . .. .. .. . .. .. . ... 18 5.4 .5 Cancer Dietary Ri s k Assessment..

... . ... . ... . ... . ... .. .. .. .. . .. .. .. ................................. .. . .. .. . 18 5.4.6 S umm ary Table

........................................... . ... . ....... . .. .. .. .. . .. .. .. . .. .. .. . ... . .. . .. .. .. . ... . .. . ..... 18 6.0 Re s idential (Non -Oc cupational) Exposure/Risk C hara cterization

............................. 18 6.1 Residential Risk Estimates for Use in Aggregate Assessment

.. . . .. .. .. . ...... . .. .. .. .. . ....... 19 6.2 Residential Bystander Post-application Inhalation E xposure

. ........................... . .. . . 1 9 6.3 Spray Drift

........................................................................................................... . .. .. . .. . 19 7.0 Aggregate Exposure/Risk Characterization

. ... . ... .. .. . ... . ... . ... . .. .. . .. .. .. . .. .. .. .. . .. .. . ... . . .. ........ 20 7.1 Acute Aggregate Risk

.......... .. .. .. . ... .. .. .. .. .. ... . .. ... .. . .. .. ... . .. .. .. .. .. . .. .. .. .. . ... . .. . ...................... 20 7.2 Short-Term Aggregate Ri sk

.................................................................... .. . .. . ... . .. . .. . .. . . 20 7.3 Intermediate-Term Aggregate Risk

.. .. .. ... . ... . ... . ...... .. .. . ... . ... . .. . ...... .. . .. .. .................... . . 21

Page 2 of 40

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 3 of 40 7.4 Chronic Aggregate Risk

................................ ................................ .............................. 21 7.5 Cancer Aggregate Risk

................................ ................................ ................................ 21 8.0 Cumulative Exposure/Risk Characterization

................................ ............................... 21 9.0 Occupational Exposure/Risk Characterization

................................ ............................ 22 9.1 Short

- /Intermediate

- Term Handler Risk

................................ ................................ ... 22 9.2 Short

- /Intermediate

- Term Post

- Application Risk

................................ .................... 25 9.2.1 Dermal Post

- Application Risk

................................ ................................ ................. 25 9.2.2 Inhalation Post

- Application Risk

................................ ................................ ............ 25 10.0 References

................................ ................................ ................................ ......................... 26 Appendix A. Toxicology Profile and Executive Summaries

................................ .................. 27 A.1 Toxicology Data Requirements

................................ ................................ ................... 27 A.2 Toxicity Profiles

................................ ................................ ................................ ............ 28 Append ix B: Sulfonylureas: comparative physical chemical properties and percent dermal absorption

................................ ................................ ................................ ................................ .... 32 Appendix C. Physical/Chemical Pro perties

................................ ................................ ............. 36 Appendix D. International Residue Limit

................................ ................................ ............... 37 Appendix E. Review of Human Research

................................ ................................ ................ 38 Appendix F. TTR and DFR Waiver Summary

................................ ................................ ....... 39

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 4 of 40 1 .0 Executive Summary

Halosulfuron

- methyl is a sulfonylurea herbicide used for the pre

- and post

- emergence control of annual broadleaf weeds and nutsedges in selected crops, as well as in residential turf grass and ornamentals. Halosulfuron

- methyl has been proposed for use on pome fruit crop group 11

- 10 and small fruit vine climbing subgroup, except fuzzy kiwifruit, subgroup 13

- 07F.

Proposed Use Profile The proposed use sites will be added to two formulated end

- use product labels (Sandea ® 

### Herbicide, EPA Reg. No. 81880

- 18 an d GWN

- 3061 ® 

### Herbicide, EPA Reg. No. 81880

- 2). Both end

- use products are dry flowable (DF) formulations containing 75% halosulfuron

- methyl by weight. The proposed maximum single application rates are as follows: 2 fl oz/A (0.094 lb ai/A) for pome fruit cr op group 11

- 10, and 1 fl oz/A (0.047 lb ai/A) for small fruit vine climbing subgroup, except fuzzy kiwifruit, subgroup 13

- 07F. Both products may be applied via groundboom, aerial, and handheld equipment; however, application with airblast and chemigation equipment is prohibited. Both labels list a restricted entry interval (REI) of 12 hours and require occupational handlers to wear long sleeves, long pants, shoes, and socks.

Exposure Profile Exposure to halosulfuron

- methyl can occur from dietary (food and drinking water), residential, and occupational exposure sources. Based on all of the proposed application rates and label information, only short

- and intermediate

- term dermal and inhalation exposures are expected for occupational handlers and post

- a pplication workers. Based on the existing residential uses of halosulfuron

- methyl on turf and ornamentals, only short

- term dermal and inhalation exposures are expected for residential handlers. Short

- term residential post

- application exposure is expected for adults and children. For the proposed uses of halosulfuron

- methyl, there is also potential for acute and chronic exposure through food and drinking water.

Toxicity/Hazard Characterization With repeated dosing, the available data did not demonstr ate a consistent target organ or tissue in any of the test animals; however, reduced body weights were seen in rats and dogs. Although there is qualitative susceptibility seen in the prenatal developmental toxicity study in rats and in rabbits, concern is low because a clear N o O bserved A dverse E ffect L evel (NOAEL) for these effects was established in each of the studies. Halosulfuron

- methyl did not produce any effects on reproductive parameters in the two

- generation reproduction study in rats. No neurot oxic effects were observed in the acute or subchronic neurotoxicity studies up to 2000 mg/kg or 760 mg/kg/day, respectively. An endpoint attributable to a single dose appropriate for the general US population was not found in the halosulfuron

- methyl toxic ity database ; however

, an endpoint attributable to a single dose that is appropriate for dietary risk assessment for females 13

- 14 years old was selected

. T he subchronic dermal study in rats has been reevaluated; no adverse effects were seen at doses up to the limit dose (1000 mg/kg/day ) and no dermal hazard was identified throughout the halosulfuron

- methyl toxicity database; therefore, a dermal point of departure (POD) was not selected . The incidental oral, and acute (females 13

- 49 years old only) and c hronic dietary points of departure ( PODs ) remain unchanged since the previous risk assessment. The acute dietary (females 13

- 49) POD is based on increased number of resorptions (total and per dam) and increased post

- implantation loss seen in the rabbit de velopmental

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 5 of 40 toxicity study at the Lowest Observed Adverse Effect Level (LOAEL) of 150 mg/kg/day. The short

- term incidental oral and inhalation POD is based on decreased food consumption and food efficiency (maternal toxicity) seen in the rabbit developmen tal toxicity study at the LOAEL of 150 mg/kg/day (NOAEL = 50 mg/kg/day). The chronic dietary POD is based on decreased body weight in females seen in the chronic dog toxicity study at the LOAEL of 40 mg/kg/day (NOAEL = 10 mg/kg/day). The Food Quality Pro tection Act (FQPA) Safety Factor (SF) has been reduced to 1X for all exposure durations and routes. Halosulfuron

- methyl is classified as “not likely to be carcinogenic to humans” and has low acute toxicity (Toxicity Category III

- IV) via the oral, dermal, and inhalation routes of exposure. It is not a dermal sensitizer.

Dietary Exposure (Food and Drinking Water) and Risk Estimates Unrefined acute (females 13

- 49 years old) and chronic dietary exposure assessments were conducted for the currently registe red and proposed new uses of halosulfuron

- methyl

. There were no appropriate toxicological effects attributable to a single exposure (dose) for the general population or any other population subgroups except females 13

- 49 years old; therefore, a dietary ex posure assessment was not conducted for these population subgroups. T he acute (females 13

- 49 years old) and chronic dietary assessments included tolerance

- level residues for all commodities and assumed 100% crop treated (CT) for all crops

. For both the a cute and chronic assessments, the modeled surface water estimated drinking water concentration (EDWC) from the currently registered rice application scenario was the highest EDWC for all proposed/registered crops and was incorporated directly into the diet ary assessment s

. The results of the acute dietary analysis for food and drinking water indicate that acute dietary exposure and risk estimate s do not exceed the Agency’s level of concern ( LOC = < 100% of the

a cute population adjust dose (a PAD ) ) for females 13

- 49 years old

. The unrefined acute dietary exposure estimate at the 95 th 

### percentile is <1% of the aPAD

. The unrefined chronic dietary (food and drinking water) exposure to halosulfuron

- methyl is below the LOC (<100% of the chronic population a djusted dose (cPAD)) for the general U.S. population and all population subgroups. The chronic dietary exposure and risk estimates are 2.1% of the cPAD for the general U.S. population and 5.7% of the cPAD for children 1

- 2 years old, the most highly expose d population subgroup.

Aggregate Exposure and Risk Estimates There is potential short

- term exposure to halosulfuron

- methyl via dietary (which is considered background exposure) and residential (which is considered primary) exposure pathways for adults an d children . The most conservative scenario was chosen for each population (e.g., mixing/loading/applying ( M/L/A ) via handheld equipment to turf for adults and hand

- to mouth exposure to treated turf for children 1 to < 2 years old). For adults and childre n 1 to < 2 years old, the short

- term aggregate risk estimates are not of concern; the margins of exposure (MOEs) are 2 5 ,000 and 1,800, respectively.

Occupational Exposure and Risk Estimates There are no occupational handler risk estimates of concern for the proposed uses of halosulfuron

- methyl at baseline ( without personal protective equipment; PPE). The LOC for occupational handler risk from inhalation exposures is a MOE < 100. For the proposed uses of

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 6 of 40 halosulfuron

- methyl, the short

- term occupation al handler inhalation MOEs ranged from 14,000 to 50,000,000 and the intermediate

- term occupational handler inhalation MOEs ranged from 2,700 to 9,900,000 at baseline PPE (no respirator)

.

Because no dermal hazard was identified, dermal occupational handler and post

- application assessments were not required.

Based on the Agency's current practices, a quantitative non

- cancer occupational post

- application inhalation exposure assessment was not performed for halosulfuron

- methyl at this time. If new policies or procedures are put into place, the Agency may revisit the need for a quantitative occupational post

- application inhalation exposure assessment for halosulfuron

- methyl

. Review of Human Research This risk assessment relies in part on data from studies in which adult human subjects were intentionally exposed to a pesticide or other chemical. These data, which include Pesticide Handlers Exposure Database Version 1.1 (PHED 1.1); the Agricultural Handler Exposure Task Force (AHET F) database; the Residential Standard Operating Procedures ( SOPs ; Lawns & Turf), and other registrant

- submitted exposure monitoring studies (MRID 44339801), are (1) subject to ethics review pursuant to 40 CFR 26, (2) have received that review, and (3) are compliant with applicable ethics requirements. For certain studies, the ethics review may have included review by the Human Studies Review Board. Descriptions of data sources, as well as guidance on their use, can be found at the Agency website 1



### .

Envi ronmental Justice Potential areas of environmental justice concerns, to the extent possible, were considered in this human health risk assessment, in accordance with U.S. Executive Order 12898, "Federal Actions to Address Environmental Justice in Minority Populations and Low

- Income Populations," http://www.eh.doe.gov/oepa/guidance/justice/eo12898.pdf ).

2.0 HED Recommendations

HED has examined the hazard and exposure database s for halosulfuron

- methyl

. Pending submission of revised Section s B and F (to correct the commodity definition f or subgroup 13

- 07F ) and submission of analytical reference standards , there are no issues that would preclude the establishment of the recommended to lerances . The recommended tolerances are listed in Table 2.2.2, below , the need for analytical reference standards is mentioned in Section 2.1.1, and the tolerance recommendations are listed in Section 2.1.2

.

2. 1 Tolerance Considerations

2.1 .1 Enforce ment Analytical Method /Multiresidue Methods

1 http://www.epa.gov/pesticides/ science/handler

- exposure

- data.html and http://www.epa.gov/pesticides/science/post

- app

- exposure

- data.html

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 7 of 40 Adequate analytical methods utilizing gas chromatography (GC ) thermionic

- specific detection (TSD, nitrogen specific) are available for the enforcement of tolerances for residues of halosulfuron

- methyl in plants (Method RES

- 109

- 97

- 4), and a GC/ECD for residues of halosulfuron

- methyl and its 3

- CSA metabolites in livestock commodities (Method RES

- 046

- 93). The plant method determines halosulfuron

- methyl as its rearrangement ester (RRE), and the livestock method converts residues of halosulfuron

- methyl and metabolites containing the 3

- CSA moiety to 3

- CSA for determination. For confirmation, the RRE can be determined by GC/MS with monitoring at m/z 327. BEAD/ ACB conducted s uccessful petition method validation s (PMV s ) for both methods (G.J . Herndon; D 250584; 10/ 28 / 19 98).

The analytical reference standards for parent halosulfuron

- methyl (having expired on 24 October 2013) and metabolite 3

- CSA (having expired on 17 February 2006) are currently unavailable in EPA’s National Pesticide Standards Repository (NPSR ). RD should notify the registrant regarding this lack of reference standards , and direct the registrant to provide n ew reference standards

, or updated certificates of analysis (COAs) , as soon as possible.

Data concerning the recovery of halosulfuron

- methyl and 3

- CSA using the Food and Drug Administration (FDA) multiresidue method protocols ( PAM Volume I ) were previousl y reviewed by HED. H alosulfuron

- methyl and 3

- CSA w ere not adequately recovered by any of these procedures. The data were forwarded to FDA for evaluation

, and updating of PAM Volume I

.

2. 1

. 2 Recommended Tolerances

T he Organi s ation for Economic Co

- operation and Development ( OECD ) tolerance calculation procedure w as not used for the submitted pear and grape field trial results. T he tolerances were set at the limit of quantification ( LOQ ) because all of the resi d ue values obtained were non

detect a ble (< limit of detection; LOD)

.

The submitted pear and grape field trial data are adequate, and support the establishment of permanent tolerances in pome fruit group 11

- 10 and small vine climbing fruit except fuzzy kiwifruit subgroup 13

- 07F at 0.05 ppm.

Upon establishment of the recommended tolerance in pome fruit group 11

- 10, the existing tolerance in apple should be removed (40 CFR §180.479[a][2]).

The proposed use on small vine climbing fruit except fuzzy kiwifruit subgroup 13

- 07F is for regiona l registration, east of the Rocky Mountains only (40 CFR §180.479[c]).

The incorrect entry

, succulent shelled pea and bean subgroup 6
, should be removed from 40 CFR §180.479[a][2]

. The correct entry, succulent shelled pea and bean subgroup 6B, is listed immediately beneath the incorrect entry.

TABLE 2. 1 .2 Tolerance Summary for Halosulfuron

- methyl (40 CFR §180.479 ). Propose d or Existing * Commodity Proposed or Existing * Tolerance (ppm) Recommended

Tolerance (ppm) Correct Commodity Definition ; Comments 40 CFR §180.479(a)(2)

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 8 of 40 TABLE 2. 1 .2 Tolerance Summary for Halosulfuron

- methyl (40 CFR §180.479 ). Propose d or Existing * Commodity Proposed or Existing * Tolerance (ppm) Recommended

Tolerance (ppm) Correct Commodity Definition ; Comments

Fruit, pome, group 1 1

- 10 0.05 0.05 Based on data supporting the existing tolerance in ap ple, and field trial data

on pear submitted by IR

- 4. Apple* 0.0 5* Remove Cover ed by the tolerance to be established in pome fruit group 11

- 10

. 40 CFR §180.479 (c)

Small fruit vine climbing subgroup, except fuzzy kiwifruit, subgroup l 3

- 07F 0.05 0.05 Fruit, small, vine climbing, except fuzzy kiwifruit, subgroup 13

- 07F

. Based on field trial data on grape (the representative commodity for the subgroup) submitted by IR

- 4. * A tolerance is currently established at the listed level in the corresponding commodity.



### The currently established tolerance expression s for halosulfuron

- methyl are adequate, and include both coverage and compliance statements for enforcement purposes.

2. 1

. 3 International Harmonization

Codex has not established maximum residue levels ( MRLs ) for halosulfuron

- methyl in either group 11

- 10 or subgroup 13

- 07F . Canada’s PMRA has an existing MRL in apple at 0.05 mg/kg, which is harmonized with the existing tolerance

. There are no Canadian MRLs on crop subgroup 13

- 07F or any other members of the pome fruit group 11

- 10

.

2. 2 Label Recommendations

2. 2 .1 Recommendations from Residue Reviews

The labels should stipulate that the minimum PHI is 14 days for group 11

- 10 and subgroup 13

- 07F , as stated in Section B of the petition volume, and as reflected in the pear and grape field trial studies. The labels should stipulate that the minimum RTI for pome fruit is 45 days, as stated in Section B of the petition volume.

3.0 In troduction

Ha losulfuron

- methyl is a selective herbicide belonging to the sulfonylurea group of herbicides, which inhibits the action of acetolactate synthase ( ALS ) , a specific plant enzyme not found in mammals . Halosulfuron

- methyl is used for the pre

- and post

- emergen ce control of annual broadleaf weeds and nutsedges on various agricultural crops, as well as in residential turf grass and ornamentals

. Halosulfuron

- methyl has been proposed for use on pome fruit group 11

- 10 and small vine climbing fruit except fuzzy kiwi fruit subgroup 13

- 07F by IR

- 4.

3.1 Chemical Identity

The chemical structure and nomenclature of h alosulfuron

- methyl are listed in Table 3 .1

.

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 9 of 40 TABLE 3 .1 Test Compound Nomenclature

. Chemical structure

Common name h alosulfuron

- methyl Company experimental name s MON 12000, NC

- 319 Molecular formula C 13 H 15 ClN 6 O 7 S Molecular weight 434.8 amu IUPAC name m ethyl 3

- chloro

- 5

- (4,6

- dimethoxypyrimidin

- 2

- ylcarbamoylsulfamoyl)

- 1

- methylpyrazole

- 4

- carboxylate CAS name m ethyl 3

- chloro

- 5

- [[[[(4,6

- dimethoxy

- 2

- pyrimidinyl)amino]carbonyl]amino] sulfonyl]

- 1

- methyl

- 1 H

- pyrazole

- 4

- carboxylate CAS registry number 100784

- 20

- 1 End

- use product s (EP s ) 75% DF formulation ( Sandea Herbicide ; EPA Registration #81880

- 18) and 75% DF formulation ( GWN

- 3061 Herbicide ; EPA Registration #81880

- 2)

. Chemical structure of 3

- chlorosulfonamide acid (3

- CSA)

3

- c hloro

- 1

- methyl

- 5

- sulfamoyl

- 1 H

- pyrazole

- 4

- carboxylic acid



### 3.2 Physical/Chemical Characteristics

Halosulfuron

- methyl is a solid under ambient conditions and has a low volatility. The compound has a relatively low solubility in organic solvents. It is slightly soluble in water, and this solubility increases with increasing pH. Its octanol/water partition coefficient su ggests that accumulation of halosulfuron

- methyl in fatty tissues is unlikely. The physical/chemical properties of halosulfuron

- methyl are listed in Appendix C.

3.3 Pesticide Use Pattern

A summary of the proposed uses of halosulfuron

- methyl is provided in Table 3.3.

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 10 of 40 Table 3.3 . Summary of Directions for Use of Halosulfuron

- Methyl

.
Applic. Timing, Type, and Equip. Formulation

[EPA Reg. No.] Max.

Applic. Rate (lb ai/A) Max. No.

Applic. per Season Max.

Seasonal Applic. Rate (lb ai/A) RTI

(days) Use Direc tions and

Limitations

Pome Fruit Group 11

- 10

Groundboom 1

, Aerial, Handheld Dry Flowable

[81880

- 18 and 81880

- 2] 0.094 2 2 0.094 “Later in Season” 3 May be re

- treated once

later in the season. Do not apply to nursery stock. Pre

- emergence and post

emergence applications. For best results, apply to bare ground. Small Fruit Vine Climbing Subgroup, Except Fuzzy Kiwifruit, Subgroup 13

- 07F

Groundboom 1

, Aerial, Handheld Dry Flowable

[81880

- 18 and 81880

- 2] 0.047 2 0.094 45 Pre

- and post

- emergen ce directed application. Contact with grape vines should be avoided. Use of

a s hieldboom is recommended. Do not contact crop foliage. Do not apply to nursery stock. 1. Not to include chemigation or airblast applications

. 2. May apply 2 applications, but not at the maximum single application rate. 3. See Section 2.0 for recommended label language (RTI

- 45 days).



### 3.4 Anticipated Exposure Pathways

Humans may be exposed to halosulfuron

- methyl in food and drinking water since halosulfuron

methyl may be applied directly to growing crops and application may result in halosulfuron

methyl reaching surface and ground sources of drinking water. In resident ial settings, residential handlers may be exposed while handling halosulfuron

- methyl, and adults and children may be exposed when contacting turf treated with halosulfuron

- methyl. In an occupational setting, applicators may be exposed while handling the p esticide prior to application as well as during application. There is also a potential for post

- application exposure for workers re

- entering treated fields.

Dietary and aggregate r isk assessments have been completed for the existing uses of halosulfuro n

- methyl. This risk assessment considers all of the aforementioned exposure pathways based on the proposed new uses of halosulfuron

- methyl, but also considers existing uses of halosulfuron

- methyl, particularly in the dietary and residential exposure asses sments.

3.5 Consideration of Environmental Justice

Potential areas of environmental justice concerns, to the extent possible, were considered in this human health risk assessment, in accordance with U.S. Executive Order 12898, "Federal Actions
to Address Environmental Justice in Minority Populations and Low

- Income Populations," ( http://www.epa.gov/environmentaljustice/resources/policy/exec_order_12898.pdf ). As a part of every pesticide risk assessment, OPP considers a large variety of consumer sub groups according

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 11 of 40 to well

- established procedures. In line with OPP policy, HED estimates risks to population subgroups from pesticide exposures that are based on patterns of that subgroup’s food and water consumption, and activities in and around the home that involve pesticide use in a residential setting. Extensive data on food consumption patterns are compiled by the U.S. Department of Agriculture’s National Health and Nutrition Examination Survey, What We Eat in America, (NHANES/WWEIA) and are used in pesticide risk assessments for all registered food uses of a pesticide. These data are analyzed and categorized by subgroups based on age and ethnic group. Additionally, OPP is able to assess dietary exposure to smaller, specialized subgroups and
exposur e assessments are performed when conditions or circumstances warrant. Whenever appropriate, non

- dietary exposures based on home use of pesticide products and associated risks for adult applicators and for toddlers, youths, and adults entering or playing o n treated areas post

- application are evaluated. Spray drift can also potentially result in post

- application exposure and it is also being considered whenever appropriate. Further considerations are also currently in development as OPP has committed resou rces and expertise to the development of specialized software and models that consider exposure to other types of possible bystander
exposure s and farm workers as well as lifestyle and traditional dietary patterns among specific subgroups.

4.0 Hazard Char acterization and Dose

- Response Assessment

Halosulfuron

- methyl is a member of the sulfonylurea class of herbicides. It inhibits acetolactate synthase ( ALS )

, an enzyme found in plants and micro

- organisms that catalyzes the first step in the synthesis of th e branched

- chain amino acids such as valine, leucine, and isoleucine. ALS is also found in mammals, but its function and mode of action are unknown

.

4.1 Toxicology S tudies A vailable for A nalysis

The halosulfuron

- methyl toxicity database is considered adequate for risk assessment; a ll of the required toxicity studies are available to support the propose d uses (Appendix A). At this time the requirement for subchronic inhalation toxicity and the immunotoxicity studies are waived ( D. Smegal, TXR 0054045, 02/22/2012 ; & K. Rury, TXR 0056723

, 08/06/2013). The available studies include:

 a 28

- day and a 90

- day oral toxicity in rats,

 90

- day oral toxicity in dogs,

 21

- day dermal toxicity in rats,

 1

- year oral toxicity in dogs,

 combined/carcinogenicity in rats,

 carcinogenicity study in mice,

 carcinogenicity study in mice,

 developmental toxicity studies in rats and rabbits,

 2

- generation reproduction in rats,

 acute and subchronic neurotoxicity studies,

 metabolism studies, and

 a battery of genotoxicity studies.

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 12 of 40 4.2 Absorption, Distribution, Metabolism and Elimination

With oral administration, halosulfuron

- methyl was absorbed rapidly but not c omplete ly from the gastrointestinal tract. In the rat metabolism study, the absorbed halosulfuron

- methyl was eliminated in t he urine and feces within 72 hours, and a pproximately 90% of the administered dose was eliminated within 48 hours. Negligible levels of radioactivity were found in most tissues with the exception of the blood, in which measurable levels were detected at 7 days post dosing (earliest reported examination time). Desmethyl NC

- 319 and the 5

- hydroxy derivatives were found in urine and feces, respectively; and these two derivatives were considered to be major metabolites. The absorption, elimination, and metabo lism showed no sex dependence.

4.2.1 Dermal absorption

A dermal penetration study is not available for halosulfuron

- methyl. However, in

- vivo dermal absorption data indicate that many sulfonylureas have relatively low dermal absorption values (ranging from 1

- 4.7% for concentrate and 1.7

- 21% for dilu te formulation s in rats)

. Based on the physical chemical properties and structural analysis, de rmal absorption for halosulfuron

- methyl is expected to be within the range of dermal absorption values shown in Appendix B (1

- 21% in

vivo dermal absorption in rats)

. The expected low dermal absorption for halosulfuron

- methyl was also supported by the resu lts of a 21

- day dermal toxicity study, where no toxicity was observed up to the limit dose (1000 mg/kg/day).

4.3 Summary of Toxicological Effects

With repeated dosing, the available data did not demonstrate a target organ or tissue in any of the
test an imals. Reduction in body weight was seen in the 90

- day and 1

- year oral toxicity studies in dogs. Reduced body weights were also seen in rat studies at higher dose levels than those seen in dogs. A n effect on the hematological parameters was detected in the dog studies, but the magnitude of changes was slight and the effect was considered to be marginal. Thus, the slight hematological changes were not considered to be adverse.

In the prenatal developmental toxicity study in rats, increases in resorption s, soft tissue (dilation of the lateral ventricles) and skeletal variations, and decreases in body weights were seen in the fetuses compared to clinical signs and decreases in body weights and food consumption in the maternal animals at a similar dose leve l. In the rabbit developmental toxicity study, increases in resorptions and post

- implantation losses and decreases in mean litter size were observed in the presence of decreases in body weight and food consumption in maternal animals. The fetal effects s een in developmental toxicity studies in rats and rabbit s represented a qualitative increase in susceptibility. However, a clear NOAEL for these effects was established in both rat and rabbit developmental toxicity studies. N o quantitative susceptibility was found in studies following pre

- and/or post

- natal exposures. Halosulfuron

- methyl did not produce any effects on reproductive parameters in the two

- generation reproduction study in rats. No neurotoxic effects were observed in the acute or subchronic n eurotoxicity studies up to 2000 mg/kg or 760 mg/kg/day, respectively

. In addition, no adverse effect was found in a 21

- day dermal toxicity study at doses up to the limit dose (1000 mg/kg/day).

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 13 of 40 Halosulfuron

- methyl is negative for mutagenicity in a batter y of genotoxicity studies. It is classified as “not likely to be carcinogenic to humans” based on lack of evidence for carcinogenicity in mice and rats following long

- term dietary administration.

Halosulfuron

- methyl has low acute toxicity (Toxicity Cat egory III

- IV) by oral, dermal, and inhalation routes of exposure. It is not a dermal sensitizer , but it produced transient eye irritation which was cleared within 24 hours

.

4.4 Safety F actor for Infants and Children (FQPA Safety Factor)

The FQPA safet y factor has been reduced to 1x for the reasons detailed below (Sections 4.4.1

- 4.4.4).

4.4.1 Completeness o f the Toxicology Database

The toxicology database for halosulfuron

- methyl is complete with the requirements for inhalation and immunotoxicity studies being waived at this time. Consequently, HED believes the existing data are sufficient for toxicity endpoint selection for exposure/risk assessment scenarios and for evaluation of the requirements under the FQPA

.

4.4.2 Evidence of N eurotoxicity

There was no neurotoxicity found in the halosulfuron

- methyl toxicity database . No adverse neurobehavioral signs were observed at doses approaching the limit dose in any of the subchronic or chronic studies in rats or mice

. No neurotoxic effects were observed in acute or subchronic neurotoxicity studies in which animals were dosed at systemically t oxic dose levels

. A developmental neurotoxicity study is not required.

4.4.3 Evidence o f Sensitivity/Su sceptibility in the Dev eloping o r Young Animal

There was no quantitative evidence of increased susceptibility following pre

- and/or post

- natal exposure. However, the qualitative susceptibility observed in the developmental toxicity studies in rats and rabbits was of low concer n because (1) in both studies, there were clear NOAELs/ LOAELs for developmental and maternal toxicities; (2) the developmental effects were seen in the presence of maternal toxicity; and (3) the effects were only seen at the high dose levels. In rats, th e developmental effects were seen at a dose (750 mg/kg/day) which was approaching the limit

- dose (1000 m g /kg/day). Furthermore, the PODs for risk assessment are protective of the effects which occur at high doses.

4.4.4 Residual Uncertainty in the Exposure Datab ase
There are no residual uncertainties in the exposure database. Since the dietary and non

- dietary exposure estimates were based on several conservative assumptions, HED does not believe that the exposure estimates are underestimated. The dietary assessment s conducted with the Dietary Exposure Evaluation Model software with the Food Commodity Intake Database (DEEM

- FCID)

were conservative and utilized tolerance

- level residues for all crops, default processing factors

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 14 of 40 for all commodities , an d assumed that 100% of the proposed and registered crops were treated with halosulfuron

- methyl . The dietary exposure analys e s also assumed that all drinking water will contain halosulfuron

- methyl at the highest EDWC levels modeled by the Environmental Fat e and Effects Division ( EFED ) for ground water or surface water. Therefore, the dietary analysis does not underestimate risk from exposure to halosulfuron

- methyl. Similarly, HED does not believe that the occupational and residential exposure s are underestimated because they are also based on conservative assumptions

, including maximum application rates, baseline PPE

, and standard values for unit exposures and acreage treated/amount handled

.

4.5 Toxicity Endpoint and Point of D eparture (POD) S elections

There is one change to the pr ior toxicity endpoint and point of departure selections for halosulfuron

- methyl ( Hazard Identification and Assessment Review Committee ( HIARC ) report, 08/23/2002; Attachment B). The rationales for endpoint selection as presented in the 2002 HIARC report on halosulfuron

- methyl are considered applicable for the current consideration with the exception of the dermal toxicity endpoint. The previous toxicity endpoint for dermal exposure assessments was based on the resul ts of a 21

- day dermal toxicity study, where the no observed effect level (NOEL) and lowest observed effect level (LOEL) were established at 100 and 1000 mg/kg/day, respectively. The LOEL was based on “total body weight gains in males”. However, following a reevaluation of this study according to the current evaluation standard

, there was only 4% reduction in absolute body weight in the affected 1000 mg/kg/day males. This reduction was not considered to be adverse and no other adverse effect was reported in this study. No LOAEL could be established, and the NOAEL was 1000 mg/kg/day. Based on this

re

- evaluation, halosulfuron

- methyl did not cause adverse effects at the limit dose (1000 mg/kg/day), and no toxicity endpoint could be established for dermal ex posure scenario. In addition, no quantitative susceptibility was found in studies following pre

- and/or post

- natal exposures. Hence, no dermal exposure assessment was necessary.

For the general population acute dietary toxicity endpoint, the available da ta did not demonstrate an adverse effect attributable to a single dose. Although the acute neurotoxicity study summarized in Appendix A showed a death occurred in this study, the death was not considered to be treatment related and occurred at 2 000 mg/kg/ day (limit dose for acute neurotoxicity study) where no compound related effect was found. Hence, this study was not used for selecting a POD for risk assessment.

The PODs and toxicity endpoints selected for various exposure scenarios applicable to this risk assessment are summarized in Table 4.5.1.

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 15 of 40 Table 4. 5 .1 Summary of Toxicological Doses and Endpoints for Halosulfuron

- methyl for Use in Dietary,

Occupational and Non

- Occupational Human Health Risk Assessments Exposure/ Scenario Point of

Departure Uncertainty/

FQPA Safety Factors RfD, PAD,

L OC for Risk Assessment Study and Toxicological Effects

Acute Dietary (Females 13

- 49 years of age) NOAEL=

50 mg/kg/day UF A = 10x

UF H = 10x FQPA SF= 1x Acute RfD = 0.5

mg/kg/day

aPAD =0.5 mg/kg/day Developmental Toxicity

– Rabbit

LOAEL = 150 mg/kg/day based on increased number of resorptions (total and per dam and increased post

- implantation loss (developmental toxicity). Acute Dietary (General Population) No adverse effect attributable to a single dose was identified; therefore, no dose/endpoint was

selected for this exposure scenario.

Chronic Dietary (All Populations) NOAEL=

10 mg/kg/day UF A = 10x

UF H = 10x FQPA SF= 1x Chronic RfD =

0.1 mg/kg/day cPAD = 0.1 mg/kg/day Chronic Toxicity

– Dog

LOAEL = 40 mg/kg/day based on decreased body weight in females.

Incidental Oral Short

Term (1

- 30 days) NOAEL=

50 mg/kg/day UF A = 10x

UF H = 10x FQPA SF= 1x Residential LOC

for MOE = 100 Developmental Toxicity

- Rabbit

LOAEL = 150 mg/kg/day based on decreased food consumption and food efficiency (maternal toxicity). Dermal Short

Term (1

- 30 days) Intermediate

Term (1

- 6 months) + A 21

- day dermal toxicity tested up to the limit dose (1000 mg/kg/day) demonstrated no adverse

effects. No dermal toxicity endpoint could be established.

Inhalation Short

- Term (1

- 30 days) NOAEL =

50 mg/kg/day UF A = 10x

UF H = 10x FQPA SF= 1x Residential and

Occupational LOC for MOE = 100 Developmental Toxicity

- Rabbit

LOAEL = 150 mg/kg/day based on decreased food consumption and food efficiency (maternal toxicity). Cancer (oral, dermal, inhalation) Classification: "not likely to be carcinogenic to huma ns" by the oral route, based on no evidence

of carcinogenicity from studies in rats and mice.

Toxicity via the inhalation route is presumed to be equivalent to oral toxicity. NOAEL = no observed adverse effect level. LOAEL = lowest observed adverse effect level. UF = uncertainty factor. UF A = extrapolation from animal to human (inter

species). UF H = potential variation in sensitivity among members of the human population (intra

- species). FQPA SF = FQPA Safety Factor. PAD = population adjusted do se (a = acute, c = chronic). RfD = reference dose. MOE = margin of exposure. LOC = level of concern. N/A = not applicable



### 5.0 Dietary Exposure and Risk Assessment

5.1 Residues of Concern Summary and Rationale

HED has concluded that t he residue of concern for tolerance enforcement and risk assessment in target plants and rotational plants is halosulfuron

- methyl (G. J. Herndon, No DP # , 09/16/1993 and 05/21/1996).

HED previously concluded that the residue of concern in ruminants is halosulfuron

- me thyl. However, because the approved enforcement method for livestock commodities quantifies the parent compound and metabolites containing the 3

- CSA moiety by converting residues to 3

-

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 16 of 40 CSA, tolerances for residues of parent and its metabolites in livestock commodities are determined as 3

- CSA, expressed in halosulfuron

- methyl equivalents.

The residue of concern in drinking water is halosulfuron

- methyl.

Table 5.1. S ummary of Halosulfuron

- methyl Metabolites and Degradates to be included in the Risk Asse ssment and Tolerance Expression

.

Matrix Residues Included in Risk Assessment Residues Included in Tolerance Expression

Plants Primary Crop Halosulfuron

- methyl Halosulfuron

- methyl

Rotational Crop Halosulfuron

- methyl Halosulfuron

- methyl

Livestock Ruminant Halosulfuron

- methyl* Halosulfuron

- methyl, 3

- CSA

Poultry Halosulfuron

- methyl* Halosulfuron

- methyl, 3

- CSA Drinking Water Halosulfuron

- methyl Not Applicable *Residues are determined as 3

- CSA

, and expressed in halosulfuron

- methyl equivalents.



### 5 .2 Food Residue Profile

The data submitted in support of the requested uses (PP# 4E8297 )

, along with previously reviewed data, are adequate for risk and tolerance assessment. Maximum residues of halosulfuron

- methyl are expected to occur at very low levels ( <0.05 ppm , the LOQ ) from the

new uses on group 11

- 10 and subgroup 13

- 07F proposed in the current petition. The established livestock tolerances are adequate to cover the proposed and registered uses.

H alosulfuron

- methyl residues generally tend to decline or remain stable with increasing PHI, and do not increase to any significant degree. Following foliar applications, halosulfuron

- methyl is present primarily as surface residues; translocation does not appear to be extens ive. In general, halosulfuron

- methyl residues do not tend to concentrate in processed fractions, other than via dehydration or from surface residues.

Residues of halosulfuron

- methyl are not expected to accumulate above the LOQ in rotational
crops. HED previously concluded that rotational crop tolerances and restrictions are not required for halosulfuron

- methyl

.

No significant livestock feedstuff s are associated with the proposed new use s on group 11

- 10 and subgroup 13

- 07F . Feed items associated wit h the existing use on apple were addressed previously, in conjunction with registration of the use on that commodity

.

5.3 Water Residue Profile

Tier I surface and ground water EDWCs were evaluated for the proposed new uses of halosulfuron

- methyl and to incorporate updated models employed by EFED, including the Pesticide Root Zone Model

- Ground Water (PRZM

- GW) ( M. Barrett, D421820, 04/15/2015). However, the highest EDWCs continue to be from the existing use on rice

. The Tier I EDWCs for halosulfuron

- m ethyl are based on a maximum annual application rate of 0.125 lb ai/A for rice. The two screening models, the Food Quality Protection Act (FQPA) Index Resevoir Screening Tool ( FIRST ) and Screening Concentrations in Ground Water ( SCI

- GROW ) , were

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 17 of 40 used for estimatin g EDWCs of halosulfuron

- methyl. Estimates for halosulfuron

- methyl in surface water based on the FIRST model for rice are 59.2 ppb for both acute and chronic concentrations.

Table 5.3 summarizes the results

.

Table 5.3 . Summary of Estimated Surface Water and Groundwater Concentrations for Halosulfuron

- methyl.

Duration Surface Water Conc., ppb a Groundwater Conc., ppb b

Acute 59.2 0.065 Chronic (non

- cancer) 59.2 0.065

a From the FIRST model.

b From the SCI

- GROW model.


### The drinking water models and their descriptions are available at the EPA internet site: http://www.epa.gov/oppefed1/models/water/

.

5.4 Dietary Risk Assessment

Acute and chronic aggregate dietary ( food and drinking water ) exposure and risk assessments were conducted using the DEEM

- FCID Version 3.16 . This software uses 2003

- 2008 food consumption data from the U.S. Department of Agriculture’s (USDA’s) National Health and Nutrition Examination Surve y, What We Eat in America (NHANES/WWEIA).

5.4.1 Description of Residue Data Used in Dietary Assessment

The acute and chronic assessments are unrefined assessments using proposed and established tolerance

- level residues and 100% CT for all commodities . Additionally, DEEM default processing factors were assumed except for where tolerances were established for processed commodities or when processing studies showed no concentration

. Based on processing studies, the default processing factors were reduc ed to 1 for tomato paste, tomato puree, potato flour, and potato granules/flakes.

5.4.2 Percent Crop Treated Used in Dietary Assessment

The acute and chronic dietary exposure assessments assumed that 100% of the proposed and registered crops were trea ted with halosulfuron

- methyl (100% CT).

5.4.3 Acute Dietary Risk Assessment

There was no indication of an adverse effect attributable to a single dose for the general U.S. population. However, an aRfD was established for females 13

- 49 years old, and an acute dietary exposure assessment was only conducted for that population subgroup . The unrefined acute dietary exposure estimate at the 95 th 

### percentile is <1% of the aPAD for females 13

- 49 years old.

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 18 of 40 5.4.4 Chronic Dietary Risk Assessment

The unrefined c hronic dietary (food and drinking water) exposure to halosulfuron

- methyl is below HED’s level of concern (<100% of the cPAD) for the general U.S. population and all population subgroups. The chronic dietary exposure estimates are 2 .1 % of the cPAD for the general U.S. population and 5.7 % of the cPAD for children 1

- 2 year s old, the most highly exposed population subgroup.

5.4.5 Cancer Dietary Risk Assessment

Halosulfuron

- methyl is classified as “not likely to be carcinogenic to humans”; therefore a

cancer dietary exposure assessment was not conducted.

5.4.6 Summary Table

Table 5. 4 .6 . Summary of Dietary (Food and Drinking Water) Exposure and Risk for Halosulfuron

- Methyl.

Population Subgroup Acute Dietary (95th Percentile) Chronic Dietary
Dietary Exposure (mg/kg/day) % aPAD* Dietary Exposure (mg/kg/day) % cPAD*

General U.S. Population

N/A N/A 0.002091 2.1 All Infants (<1 year old) 0.004987 5.0
Children 1

- 2 years old* 0.005740 5.7
Children 3

- 5 years old 0.004025 4.0
Children 6

- 12 years old 0.002488 2.5
Youth 13

- 19 years old 0.001597 1.6
Adults 20

- 49 years old 0.001817 1.8
Adults 50

- 99 years old 0.001767 1.8
Females 13

- 49 years old 0.004139 <1 0.001812 1.8 *The subpopulation(s) with the highest risk estimates

. The highest risk estimate is bolded.



### 6.0 Residential (Non

- Occupational) Exposure/Risk Characterization

There are no proposed residential uses at this time; however, there are existing residential turf uses that have been reassessed to reflect the removal of the dermal POD for halosulfuron

- methyl; therefore, the residential scenarios for aggregate risk assessment have changed.

Since the estimated children’s post

- application incidental oral exposure from halosulfuron

methyl applications to res idential turf using default TTR values for halosulfuron

- methyl is minimal in comparison to the level of concern (i.e., the calculated MOE is greater than 10 times higher than the level of concern, MOE = 24,000 compared to the LOC of 100)

, EPA is waiving the 40 CFR TTR data requirement. In this instance, it is unlikely that chemical

- specific TTR

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 19 of 40 data would be needed to further refine exposure assessments or would add appreciably to

our general understanding of the availability of turf tran sferable pesticide residues. See Appendix F for more details.

6. 1 Residential Risk Estimates for Use in Aggregate Assessment

Table 6 .1 reflects the residential risk estimates that are recommended for use in the aggregate assessment for halosulfuron

- m ethyl.

 The recommended residential exposure for use in the adult aggregate assessment reflects inhalation exposure from mixing/loading/applying halosulfuron

- methyl via backpack sprayer or manually pressurized handwand to turf.

 The recommended residential e xposure for use in the children 1 to <2 years old aggregate assessment reflects hand

- to

- mouth exposures from post

- application exposure to treated turf.

Table 6 .1. Recommendations for the Residential Exposures for the Halosulfuron

- Methyl Aggregate Assessment.

Lifestage Exposure Scenario Dose (mg/kg/day) 1 MOE 2

Inhalation Oral Inhalation Oral

Adult s M/L/A via Backpack Sprayer or

Manually

- Pressurized Handwand

to Turf 0.000215 N/A 230,000 N/A

Child ren (1 to <2 years old) Hand

- to

- Mouth Exposure to

Treated Turf N/A 0.00207 N/A 24,000

1 Dose = the highest dose for each applicable lifestage of all residential scenarios assessed

. 2 MOE = margin of exposure. T he se MOEs are associated with the highest residential doses

.



### 6. 2 Residential Bystander Post

- application Inhalation Exposure

Volatilization of pesticides may be a source of post

- application inhalation exposure to individuals nearby pesticide applications. The agency sought expert advice and input on issues related to v olatilization of pesticides from its Federal Insecticide, Fungicide, and Rodenticide Act Scientific Advisory Panel (SAP) in December 2009, and received the SAP’s final report on March 2, 2010 ( http://www.epa.gov/scipoly/SAP/meetings/2009/120109meeting.html ). The agency has evaluated the SAP report and has developed a Volatilization Screening Tool and a subsequent Volatilization Screening Analysis (http://www.regulations.gov/#!docketDetail;D=EPA

- HQ

- OPP

- 2014

- 0219). During Registration Review, the Agency wil l utilize this analysis to determine if data (i.e., flux studies, route

- specific inhalation toxicological studies) or further analysis is required for halosulfuron

- methyl

.
In addition to this screen, t he A gency has developed a preliminary bystander volati lization inhalation exposure assessment for halosulfuron

- methyl utilizing the currently available inhalation toxicity and air monitoring data.

6. 3 Spray Drift

Spray drift is a potential source of exposure to those nearby pesticide applications. This is particularly the case with aerial application, but, to a lesser extent, spray drift can also be a

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 20 of 40 potential source of exposure from the ground application method s (e.g., groundboom and airblast) employed for halosulfuron

- methyl. The agency has been working with the Spray Drift Task Force (a task force composed of various registrants which was developed as a result of a Data Call

- In issued by EPA), EPA Regional Of fices and State Lead Agencies for pesticide regulation and other parties to develop the best spray drift management practices (see the agency’s Spray Drift website for more information). 2 

### The A gency has also developed a policy on how to appropriately con sider spray drift as a potential source of exposure in risk assessments for pesticides. The potential for spray drift will be quantitatively evaluated for each pesticide during the Registration Review process which ensures that all uses for that pesticide will be considered concurrently. The approach is outlined in the revised (2012) Standard Operating Procedures For Residential Risk Assessment (SOPs)

- Residential Exposure Assessment Standard Operating Procedures Addenda 1: Consideration of Spray Drift. This document outlines the quantification of indirect non

- occupational exposure to drift.

7.0 Aggregate Exposure/Risk Characterization

HED must consider and aggregate (add) pesticide exposures and risks from three major sources: food, drinking water, and residential exposures. In an aggregate assessment, exposures from relevant sources are added together and compared to quantitative estimates of hazard (e.g. a NOAEL or PAD), or the risks themselves can be aggregated. When aggregating exposures and

r isks from various sources, HED considers both the route and duration of exposure. For halosulfuron

- methyl , potential exposures from food, drinking water and residential scenarios were aggregated.

This assessment has utilized the Residential SOPs implem ented in January of 2012 and the updated PODs for halosulfuron

- methyl ( i.e., the dermal POD was removed since the previous assessment) . HED confirms that there are no risk estimate s of concern resulting from the proposed or existing uses of halosulfuron

- m ethyl.

7.1 Acute Aggregate Risk

The aggregate acute risk estimates include exposure to residues of halosulfuron

- methyl in food and water, and do not include dermal, inhalation

, or incidental oral exposure. There were no appropriate toxicological effects attributable to a single exposure (dose) for the general population or any other population subgroups except fema les 13

- 49 years old; therefore, an aggregate exposure assessment was not conducted for these population subgroups. The acute risk esti mate for the females 13

- 49 years old , resulting from aggregate exposure to halosulfuron

methyl in food and drinking water

, is below the Agency’s LOC and is <1% of the aPAD

. There was no indication of an adverse effect attributable to a single dose for the general U.S. population.

7.2 Short

- Term Aggregate Risk

2 Available: http://www.epa.gov/opp00001/factsheets/spraydrift.htm

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 21 of 40 There is potential short

- term exposure to halosulfuron

- methyl via dietary (which is considered background exposure) and residential (which is considered primary) exposure pathways. The
most conservat ive scenario was chosen for each population (e.g., hand

- to mouth exposure to treated turf for children 1 to < 2 years old and M/L/A via handheld equipment to t urf for adults). For adults and children 1 to < 2 years old, the short

- term aggregate risk estim ates are not of concern; the MOEs are 22,000 and 1,800, respectively. For a description of the residential exposure scenarios considered in the aggregate risk assessment, see K. Rury, D425728, 05/ 25 /2015 and N. Tsaur, D396460, 06/12/2012.

Table 7.2 Short

- Term Aggregate Risk Calculations

.

Population Short

- or Intermediate

- Term Scenario

NOAEL mg/kg/day LOC 1 Average Food and Water Exposure mg/kg/day Residential

Exposure mg/kg/day 2 Tota l

Exposure mg/kg/day 3 Aggregate MOE

(food, water, and residential) 4

Adult s 5 50 100 0. 001817 0.000215 0. 002032 25,000 Child ren 1 to < 2 years old 0.00574 0.00207 0.02854 1,800

1 LOC = 100, 10X UF A , 10X UF H , FQPA SF = 1X.

2 Residential Exposure Scenarios = Table 6.1

. 3 Total Exposure = Avg Food & Water Exposure + Residential Exposure)

4 Agg regate MOE = Incidental Oral NOAEL 50 mg/kg/day ÷ Total Exposure )
5 Adult subpopulation selected from the dietary exposure assessment is Adults 20

- 49 from the chronic dietary exposure assessment, which is the mo st protective adult subpopulation.



### 7.3 Intermediate

- Term Aggregate Risk

Intermediate

- term residential exposure is not expected for halosulfuron

- methyl due to the intermittent application by homeowners. Therefore, the intermediate

- term aggregate risk would be equivalent to the chronic dietary exposure estimate

.

7.4 Chronic Aggregate Risk

Chronic exposure is not expected for the adult residential (dermal and inhalation) exposure pathway. Therefore, the chronic aggregate risk would be equivalent to the chronic dietary exposure estimate. Refer to Section 5.4. 4 for the chronic dietary (food and drinking water) exposure assessment.

7.5 Cancer Aggregate Risk

Halosulfuron

- methyl is considered “not likely to be carcinogenic to humans;” therefore, an aggregate cancer risk assessment has not been conducted.

8.0 C umulative Exposure/Risk Characterization

Unlike other pesticides for which EPA has followed a cumulative risk approach base d on a common mechanism of toxicity, EPA has not made a common mechanism of toxicity finding as

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 22 of 40 to halosulfuron

- methyl and any other substances and halosulfuron

- methyl does not appear to produce a toxic metabolite produced by other substances. For the purposes of this tolerance action, therefore, EPA has not assumed that halosulfuron

- methyl has a common mechanism of toxicity with other substances. For information regarding EPA’s efforts to determine which chemicals have a common mechanism of to xicity and to evaluate the cumulative effects of such chemicals, see the policy statements released by EPA’s Office of Pesticide Programs concerning common mechanism determinations and procedures for cumulating effects from substances found to have a commo n mechanism on EPA’s website at http://www.epa.gov/pesticides/cumulative/.

9.0 Occupational Exposure/Risk Characterization

This document presents an assessment of the proposed uses of halosulfuron

- methyl on p ome f ruit crop g roup 11

- 10 and s mall f ruit v ine c l imbing s ubgroup, e xcept f uzzy k iwifruit, s ubgroup 13

- 07F. Based on application rate and label information, only short

- and intermediate

- term exposure is expected for occupational handlers and post

- application workers. Chronic exposure is not expected for the proposed use pattern.

9.1 Short

- /Intermediate

- Term Handler Risk

There are no occupational handler risk estimates of concern for the proposed uses of halosulfuron

- methyl at baseline (no personal protective equipment; PPE). The LOC for occupational handler risk is a margin of exposure (MOE) < 100. At baseline PPE (no respirator), the short

- term occupational handler MOEs ranged from 14,000 to 50,000,000 and the intermediate

- term occupational handler MOEs ranged from 2,700 to 9,900,000 for the propos ed uses of halosulfuron

- methyl. See Tables 9.1.1 and 9.1.2 for details.

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 23 of 40 1 Based on the “Occupational Pesticide Handler Unit Exposure Surrogate Reference Table”; Level of mitigation: Baseline or Eng. Controls (enclosed cockpits for aerial applications)

. 2 Based on registered or proposed label s (Reg. No s

. 81880

- 18 and 81880

- 2 ). 3 Exposure Science Advisory Council Policy #9.1. 4 Inhalation Dose = Inhalation Unit Exposure ( μ g/lb ai) × Conversion Factor (0.001 mg/ μ g) × Application Rate (lb ai/acre or gal) × Area Treated or Amount Handled Daily (A or gal/day) ÷ BW ( 80 kg). 5 Inhalation MOE = Inhalation NOAEL ( 50 mg/kg/day) ÷ Inhalation Dose (mg/kg/day). Table 9 .1.1. Occupational Handler Short

- Term Exposure and Risk Estimates for Halosulfuron

- Methyl

.

Exposure Scenario Crop or Target LOC Inhalation Unit Exposure ( μ g/lb ai) 1 Maximum

Application Rate 2 Area Treated or

Amount Handled Daily 3 Inhalation

Baseline Dose (mg/kg/day) 4 MOE 5

Mixer/Loader

Mixing/Loading for Aerial Application Pome Fruit

100 8.96 0.094 lb ai/A
350 acres 0.00369 14,000

Small Fruit Vine Climbing 0.047 lb ai/A 0.00184 27,000

Mixing/Loading for Groundboom Application Pome Fruit
8.96 0.094 lb ai/A
40 acres 0.000421 120,000
Small Fruit Vine Climbing 0.047 lb ai/A 0.00021 240,000

Applicator

Applying Sprays via Aerial Equipment Pome Fruit

100 0.0049 (engineering control

- enclosed cockpit) 0.094 lb ai/A
350 acres 0.00000201 25,000,000
Small Fruit Vine Climbing 0.047 lb ai/A 0.00000101 50,000,000

Applying Sprays via Groundboom Equipment Pome Fruit
0.34 0.094 lb ai/A
40 acres 0.0000160 3,100,000
Small Fruit Vine Climbing 0.047 lb ai/A 0.00000799 6,300,000

Flagger

Flagging for Aerial Applications Pome Fruit
100 0.35 0.094 lb ai/A
350 acres 0.000144 350,000
Small Fruit Vine Climbing 0.047 lb ai/A 0.0000720 690,000

Mixer/Loader/Applicator
Mixing/Loading/Applying via Backpack Sprayer (Soil Directed) Pome Fruit

100 2.58 0.0063 lb ai/gal 40 gallons 0.00000806 6,200,000

Small Fruit Vine Climbing 0.0031 lb ai/gal 0.00000040 13,000,000

Mixing/Loading/Applying via Mechanically Pressurized Handgun (Soil Directed) Pome Fruit
3.9 0.0063 lb ai/gal 1000 gallons 0.000305 160,000
Small Fruit Vine Climbing 0.0031 lb ai/gal 0.000151 330,000

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 24 of 40 1 Based on the “Occupational Pesticide Handler Unit Exposure Surrogate Reference Table”; Level of mitigation: Baseline or Eng. Controls (enclosed cockpits for aerial applications). 2 Based on registered or proposed label s (Reg. No s

. 81880

- 18 and 81880

- 2 ). 3 Exposure Science Advisory Council Policy #9.1. 4 Inhalation Dose = Inhalation Unit Exposure ( μ g/lb ai) × Conversion Factor (0.001 mg/ μ g) × Application Rate (lb ai/acre or gal) × Area Treated or Amount Handled Daily (A or gal/day) ÷ BW ( 80 kg). 5 Inhalation MOE = Inhalation NOAEL ( 10 mg/kg/day) ÷ Inhalation Dose (mg/kg/day). Table 9 .1. 2 . Occupational Handler Intermediate

- Term Exposure and Risk Estimates for Halosulfuron

- Methyl

.

Exposure Scenario Crop or Target Level of Concern Inhalation Unit

Exposure ( μ g/lb ai) 1 Maximum

Application Rate 2 Area Treated or

Amount Handled Daily 3 Inhalation

Baseline Dose (mg/kg/day) 4 MOE 5

Mixer/Loader

Mixing/Loading for Aerial Application Pome Fruit

100 8.96 0.094 lb ai/A
350 acres 0.00369 2,700

Small Fruit Vine Climbing 0.047 lb ai/A 0.00184 5,400

Mixing/Loading for Groundboom Application Pome Fruit
8.96 0.094 lb ai/A
40 acres 0.000421 24,000
Small Fruit Vine Climbing 0.047 lb ai/A 0.00021 48,000

Applicator

Applying Sprays via Aerial Equipment Pome Fruit

100 0.0049 (engineering control

- enclosed cockpit) 0.094 lb ai/A
350 acres 0.00000201 5,000,000
Small Fruit Vine Climbing 0.047 lb ai/A 0.00000101 9,900,000

Applying Sprays via Groundboom Equipment Pome Fruit
0.34 0.094 lb ai/A
40 acres 0.0000160 630,000
Small Fruit Vine Climbing 0.047 lb ai/A 0.00000799 1,300,000

Flagger

Flagging for Aerial Applications Pome Fruit
100 0.35 0.094 lb ai/A
350 acres 0.000144 69,000
Small Fruit Vine Climbing 0.047 lb ai/A 0.0000720 140,000

Mixer/Loader/Applicator
Mixing/Loading/Applying via Backpack Sprayer (Soil Directed) Pome Fruit

100 2.58 0.0063 lb ai/gal 40 gallons 0.00000806 1,200,000

Small Fruit Vine Climbing 0.0031 lb ai/gal 0.00000040 2,500,000

Mixing/Loading/Applying via Mechanically Pressurized Handgun (Soil Directed) Pome Fruit
3.9 0.0063 lb ai/gal 1000 gallons 0.000305 33,000
Small Fruit Vine Climbing 0.0031 lb ai/gal 0.000151 66,000

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 25 of 40 9.2 Short

- /Intermediate

- Term Post

- Application Risk

HED uses the term post

- application to describe exposures that occur when individua ls are present in an environment that has been previously treated with a pesticide (also referred to as re

entry exposure). Such exposures may occur when workers enter previously treated areas to perform job functions, including activities related to crop production, such as scouting for pests or harvesting. Post

- application exposure levels vary over time and depend on such things as the type of activity, the nature of the crop or target that was treated, the type of pesticide application, and the chemica l’s degradation properties. In addition, the timing of pesticide applications, relative to harvest activities, can greatly reduce the potential for post

- application exposure.

9.2.1 Dermal Post

- A pplication Risk

There is no hazard identified for halosulfuron

- methyl via the dermal route of exposure; therefore, an occupational dermal post

- application assessment and a dislodgeable foliar residue ( DFR ) study are not required at this time (see Appendix F ).

Restricted Entry Interval

Since short

- and intermediate

- term post

- app lication risk estimates are not of concern on day 0 for all post

- app lication activities, t he REI specified on the proposed label is based on the acute toxicity of halosulfuron

- methyl. Halosulfuron

- methyl is classified as Toxicit y Category III via the dermal route and Toxicity Category IV for skin irritation potential. It is not a skin sensitizer. Under 40 CFR 156.208 (c) (2) (iii), ai’s classified as Acute III or IV for acute dermal, eye irritation and primary skin irritation a re assigned a 12

- hour REI. Therefore, the 40 CFR 156 subpart K Worker Protection Statement interim REI of 12 hours is adequate to protect agricultural workers from post

- application exposures to halosulfuron

- methyl.

9.2.2 Inhalation Post

- A pplication Risk

There are multiple potential sources of post

- application inhalation exposure to individuals performing post

- application activities in previously treated fields. These potential sources include volatilization of pesticides and resuspension of dusts and/or particulates that contain pesticides. The agency sought expert advice and input on issues related to volatilization of pesticides from its Federal Insecticide, Fungicide, and Rodenticide Act Scientific Advisory Panel (SAP) in December 2009, and rec eived the SAP’s final report on March 2, 2010 ( http://www.epa.gov/scipoly/SAP/meetings/2009/120109meeting.html ). The agency has evaluated the SAP report and has developed a Volatilization Screening Tool and a subsequent Volatilization Screening Analysis ( http://www.regulations.gov/#!docketDetail;D=EPA

- HQ

OPP

- 2014

- 0219 ). During Registration Review, the agency will utilize this analysis to determine if data (i.e., flux stu dies, route

- specific inhalation toxicological studies) or further analysis is required for halosulfuron

- methyl.

In addition, the Agency is continuing to evaluate the available post

- application inhalation exposure data generated by the Agricultural Reentry Task Force. Given these two efforts, the

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 26 of 40 Agency will continue to identify the need for and, subsequently, the way to incorporate occupational post

- application inhalation exposure into the agency's risk assessments.

Although a quantitative occupational p ost

- application inhalation exposure assessment was not performed, an inhalation exposure assessment was performed for occupational/commercial handlers. Handler exposure resulting from application of pesticides outdoors is likely to result in higher exposu re than post

- application exposure. Therefore, it is expected that these handler inhalation exposure estimates would be protective of most occupational post

- application inhalation exposure scenarios.

10.0 References

M. Barrett; 04/15/2015; D421820. Halo sulfuron

- methyl Drinking Water Assessment for Additional Food/Feed Uses on Pome Fruits Group 11

- 10 and Climbing Vines Subgroup 13

- 07F.

S. Healy; 03/25/2013; D404095. Halosulfuron

- Methyl: Human Health Risk Assessment for Proposed New Uses on Artichoke and Caneberry ( Crop subgroup 13

- 07A)

. K. Rury; 08/06/2013; TXR0056723. Sulfonylureas: Summary of Hazard and Science Policy Council (HASPOC) Meeting on July 18, 2013: Recommendations on Data Requirement for Immunotoxicity Studies for Sulfonylurea Pestic ides.

K. Rury; 05/ 25 /2015; D425728. Halosulfuron

- Methyl. Occupational and Residential Exposure Assessment for a Proposed Use on Pome Fruit Crop Group 11

- 10 and Small Fruit Vine Climbing Subgroup, Except Fuzzy Kiwifruit, Subgroup 13

- 07F.

K. Rury; 05/ 25 /2015; D426724. Halosulfuron

- Methyl. Acute and Chronic Aggregate Dietary (Food and Drinking Water) Exposure and Risk Assessments for the Section 3 Registration Action on Pome Fruit Group 11

- 10 and Fruit, Small Vine Climbing Subgroup 13

- 07F.

D. Smegal ; 02/22/2012; TXR0054045. H alosulfuron

- methyl : Summary of Hazard and Science Policy Council (HASPOC) Meeting of February 9, 2012: Recommendations on waiver requests for 28

- day inhalation study.

N. Tsaur; 06/12/2013; D396460. Halosulfuron

- Methyl. Occupational Exposure Assessment for Proposed New Uses on Proso Millet and Crop Group 17 (Grass, Forage, Fodder, and Hay) with An Updated Residential Exposure Assessment of All Existing Residential Uses.

W. Drew; 05/ XX /2015; D426614. Petition to Establish Permanent Tolerances, and Associated Section 3 Registration, for Residues Resulting from Use of the Herb icide o n P o m e Fruit Group 11

- 1 0 and S mall Vine C limbing F ruit Except Fuzzy K iwifruit S ubgroup 13

- 07F (Regional Registration)

. Summary of Ana lytical Chemistry and Residue Data.

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 27 of 40 A ppendix A

. Toxicology Profile and Executive Summaries

A.1 Toxicology Data Requirements The requirements (40 CFR 158.500) for f ood u se for h alosulfuron

- methyl are in Table 1. Use of the new guideline numbers does not imply that the new (1998) guideline protocols were used.

Study Technical
Required Satisfied 870.1100 Acute Oral Toxicity

................................ ....................... 870.1200 Acute Dermal Toxicity

................................ .................. 870.1300 Acute Inhalation Toxicity

................................ .............. 870.2400 Acute Eye Irritation

................................ ....................... 870.2500 Acute Dermal Irritation

................................ ................. 870.2600 Skin Sensitization

................................ .......................... yes
yes
yes
yes
yes
yes Yes

yes
yes
yes
yes
yes 870.3100 90

- Day Oral Toxicity in Rodents

................................ .. 870.3150 90

- Day Oral Toxicity in Nonrodents

............................. 870.3200 21/28

- Day Dermal Toxicity

................................ .......... 870.3250 90

- Day Dermal Toxicity

................................ ............... 870.3465 90

- Day Inhalation Toxicity

................................ ........... yes
yes
yes

no CR Yes

yes
yes

no waived a 870.3700a Prenatal Developmental Toxicity (rodent)

.................... 870.3700b Prenatal Developmental Toxicity (nonrodent)

.............. 870.3800 Reproduction and Fertility Effects

................................ yes
yes
yes Yes

yes
yes 870.4100b Chronic Toxicity (nonrodent)

................................ ........ 870.4200b Carcinogenicity (mouse)

................................ ............... 870.4300 Combined Chronic Toxicity/Carcinogenicity

............... no
yes
yes Yes

yes
yes 870.5100 Mutagenicity

— Bacterial Reverse Mutation Test

.......... 870.5300 Mutagenicity

— Mammalian Cell Gene Mutation Test

.. 870.5375 Mutagenicity

— Structural Chromosomal Aberrations

... 870.5395 Mutagenicity

— Other Genotoxic Effects

....................... yes
yes
yes
yes Yes

yes
yes
yes 870.6200a Acute Neurotoxicity Screening Battery (rat)

................. 870.6200b 90

- Day Neurotoxicity Screening Battery (rat)

.............. 870.6300 Developmental Neurotoxicity

................................ ....... yes
yes

no Yes

yes

- 870.7485 Metabolism and Pharmacokinetics

................................ 870.7600 Dermal Penetration

................................ ........................ 870.7800 Immunotoxicity

................................ ............................. yes

no
yes Yes

- waived b

a : TXR 0054045; 02/22/2012. b : TXR 0056723; 08/06/2013.

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 28 of 40 A.2 Toxicity Profiles

Table 1. Acute Toxicity of Halosulfuron

- M ethyl Technical

.
OPPTS No. Study Type MRID Results Toxicity Category 870.1100 Acute Oral

- Rats 42139413 LD 50 : Males = 10,435 mg/kg Females = 7758 mg/kg Combined = 8866 mg/kg IV

870.1200 Acute Dermal

- Rats 42139415 LD 50 >2000 mg/kg (limit test) III 870.1300 Acute Inhalation

- Rats 42139417 LC 50 >6 mg/L IV 870.2400 Primary Eye Irritation

Rabbits 42139419 Mild transient (<24 hr) irritation involving the conjunctiva and iris. IV

870.2500 Primary Skin

Irritation

- Rabbits 42139421 Non

- irritant IV

870.2600 Dermal Sensitization

Guinea pigs 42139423 Not a skin sensitizer (maximization test) N/A

Table 2 . Toxicity Profile of Halosulfuron

- M ethyl Techni cal

.

Guideline No. Study Type MRID No. (Date)/Classification/ Doses Results

870.3100 (82

- 1) Subchronic oral

toxicity study in
rats 43616301 (1995)/

Acceptable/ Guideline Doses: 0, 100, 1000, 10000, or 20000 ppm (diet) (M / F: 6.7/7.6, 66.5/75.8, 682.8/772.8, 1400/1578 mg/kg/day) NOAEL = M > 1400, F = 75.8 mg/kg/day LOAEL = M not determined, F = 772.8 mg/kg/day based on decreased body weigh t gains.

870.3100 (82

- 1) Subchronic oral

toxicity study in
rats (28 day range

finder) 42171501 (1988)/

Acceptable/ Nonguideline Doses: 0, 100, 400, 1600, or 6400 ppm (diet) (M/F: 7.4/8.9, 28.8/37.3, 116/147, 497/640 mg/kg/day) NOAEL = M = 116, F =147 mg/kg/day LOAEL = M = 497, F = 640 mg/kg/day based on decreased organ weights and changes in clinical chemistry parameters.

870.3150 (82

- 1) Subchronic oral

toxicity study in nonrodents

- dogs 42171502 (1991)/

Acceptable/ Guideline Doses: 0, 2.5, 10, 40, and 160 mg/kg/day (capsule) NOAEL = 10 mg/kg/day LOAEL = 40 mg/kg/day based on ↓bwt, cholesterol, & albumin levels. The decrease was particularly marked at the next higher dose level

, 160 mg/kg/day.

870.3200 (82

- 2) 21

- day dermal

toxicity in rats 42661417 (1990)/

Acceptable/ Guideline Doses: 0, 10, 100, or 1000 mg/kg/day No adverse effects was seen at the highest dose level

. NOAEL = 100 0 mg/kg/day (Highest dose tested) (limit dose)

870.3 465 (82

- 4 ) 90

- day inhalation

study in rats The requirement of this study was waived ( TXR 0054045 ; 02/22/12 )

870.4100 (83

- 1b) 42396211 (1991)/ Acceptable/ Guideline NOAEL = 10 mg/kg/day

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 29 of 40 Table 2 . Toxicity Profile of Halosulfuron

- M ethyl Techni cal

.

Guideline No. Study Type MRID No. (Date)/Classification/ Doses Results

Chronic oral toxicity study in dogs (1

- year) Doses: 0, 0.25, 1.0, 10.0, or 40

mg/kg/day (capsule). LOAEL = 40 mg/kg/day based on ↓bwt (9

- 13%); ↓RBC, hematocrit, & hemoglobin; ↓ cholesterol

870.4300 (83

- 5) Combined

Chronic/ Carcinogenicity in
rats 42661418 (1992)/

Acceptable/Guideline Doses: 0, 10, 100, 1000, or 2500, 5000 (males only) ppm (diet) (M/F: 0.44/0.56, 4.4/5.6, 43.8/56.3, 108.3/138.6, 225.6 (M) mg/kg/day) NOAEL = M=108.3, F=56.3 mg/kg/day LOAEL = M=225.6, F=138.6 mg/kg/day based on marginal decrease in body weight gain in both males and females.

No evidence of carcinogenicity.

870.4200 (83

- 2) Carcinogenicity

study in mice 42661419 (1992)/

Acceptable/ Guideline Doses: 0, 30, 300, 3000, or 7000 ppm (diet) (M/F: 4.0/5.2, 41.1/51.0, 410.0/509.1, or 971.9/1214.6 mg/kg/day) NOAEL = M=410.0, F > 1214.6 mg/kg/day LOAEL = M=971.9, F> 1214.6 mg/kg/day based on necropsy findings (increase incidence of microconcretion/mineralization in the testis and epididymis).

No evidence of carcinogenicity.

870.3700 (83

- 3) Developmental

toxicity in rats 42139425 (1990)/

Acceptable/ Guideline Doses: 0, 75, 250, or 750 mg/kg/day (gavage) Maternal NOAEL = 250 mg/kg/day. Maternal LOAEL = 750 mg/kg/day, based on increased incidence of clinical observations, reduced food consumption and food efficiency. Developmental NOAEL = 250 mg/kg/day. Devel opmental LOAEL = 750 mg/kg/day, based on decreased mean fetal body weight and mean litter size, increased fetal and litter incidences of soft tissue and skeletal variations.

870.3700 (83

- 3b) Developmental

toxicity study in rabbits 42139426 (1990)/

Acceptable/ Guideline Doses: 0, 15, 50, or 150 mg/kg/day (gavage) Maternal NOAEL = 50 mg/kg/day Maternal LOAEL = 150 mg/kg/day based on reduced body weight gain, food consumption and food efficiency. Developmental NOAEL = 50 mg/kg/day Developmental LOAEL = 150 mg/kg/day based on group decreased mean litter size, increased number of resorptions and resorptions per dam, and increased postimplantation loss.

870.3700 (83

- 3b) Developmental

toxicity study in rabbits 43621901 (1995) 3

-

chlorosulfonamide acid Metabolite/ Acceptable/Guideline Doses: 0, 30, 300, or 1000 mg/kg/day Maternal Toxicity NOAEL => 1000 mg/kg/day Maternal Toxicity LOAEL > 1000 mg/kg/day Developmental Toxicity NOAEL => 1000 mg/kg/day Developmental Toxicity LOAEL > 1000 mg/kg/day

870.3800 (83

- 4) Two

- Generation

reproduction study in rats 42139427 (1991)/

Acceptable/ Guideline Doses: 0, 100, 800, or 3600 ppm (diet) ( F 0 Males: 6.3, 50.4, and 223.2 mg/kg/day; F 0 Females: 7.4, 58.7, and 261.4 mg/kg/day) Parental/Systemic NOAEL = M=50.5, F=58.7 mg/kg/day Parental/Systemic LOAEL = M=223.2, F=261.4 mg/kg/day based on decreased body weights and reduced food consumption during the premating period in both sexes. Offspring NOAEL = 51/59 mg/kg/day

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 30 of 40 Table 2 . Toxicity Profile of Halosulfuron

- M ethyl Techni cal

.

Guideline No. Study Type MRID No. (Date)/Classification/ Doses Results

Offspring LOA EL = 223.2/261.4 mg/kg/day based on decreased body weight in the F 1 pups and marginal decreased body weight in F 2 pups. Reproductive NOAEL > = 223.2/261.4 mg/kg/day

.

870.6200a (82

- 7) Acute

neurotoxicity in
rats. 45754701 (1994) and

46199501 (1989)[positive control study]/ Acceptable/ Guideline Doses: 0, 200, 600, or 2000 mg/kg (limit dose) NOAEL = 600 mg/kg. LOAEL = 2000 mg/kg (limit dose) based on mortality in males.

870.6200b (82

- 7) Subchronic

neurotoxicity study in rats. 45754702 (1992)/

Acceptable/ Guideline Doses: M: 0, 100, 1000, or 10,000 ppm; F: 0, 100, 1000, or 4000 ppm (diet) (M/F: 0/0, 6.3/8.1, 62.8/82.6, or 706.0/315.9 mg/kg/day) NOAEL = M = F = 1000 ppm (M/F: 62.8/82.6 mg/kg/day). LOAEL = M = 10,000 ppm; F =4000 ppm (M : 706.0 mg/kg/day) in males based on decreased body weight and body weight gain and (F: 315.9 mg/kg/day) in females based on decreased body weight gain.

870. 7485 (83

- 6) Metabolism 42139433 (1990)/ Acceptable/ Guideline 5 or 250 mg/kg single dose or 5 m g/kg/day repeated doses Absorption was rapid, incomplete and similar in both sexes. Elimination was most ly by urine and feces within 72 hours, appearing to be independent of dose and sex. Desmethyl NC

- 319 and the 5

- hydroxy derivative were the major urinary and fecal metabolites.

870. 7800 ( 83

- 6) Immunotoxicity This requirement of this study was waived (TX: 00 56723; 08/06/2013)

870.5100 (84

- 2 a) Mutagenic

- Ames

Salmonella typhimurium and E. Coli

. 42139428 (1991)/ Acceptable

(+/

- S9) 5 strains S. typh. Conc.: 1

- 10000 μg /plate; E. Coli WpuvrA Conc.: 333

- 10000 μg /plate Negative. Concentrations => 5000 micro g m /plate found to be insoluble and/or cytotoxic.

870.5100 (84

- 2 a) Mutagenic

- Gene

Mutation 43616302 (1995)/ Acceptable

(+/

- S9) 5 strains S. typh. Conc.: 50

- 5000 μg /plate Negative. Conducted with 3

- chlorosulfonamide acid

- the principal soil metabolite of halo s ulfuron

- methyl.

870.5300 (84

- 2) Mutagenic

- Gene

Mutation

- Hamster (Chinese) 43616303 (1995)

- Metabolite/

Acceptable (+/

- S9) Conc.: 350

- 3100 μg/ m L Negative. Conducted with 3

- chlorosulfonamide acid

- the principal soil metabolite of halo s ulfuron

- methyl.

870.5300 (84

- 2) Mutagenic

-

(HGPRT)

- Hamster (Chinese). 42139431 (1991)

- Metabolite/

Unacceptable Conc.: 100

- 1000 μg /m L Conclusions indefinite due to partly to relatively high negative and low positive control values, solubility problems with test article.

870.5300 (84

- 2) Mutagenic

-

(HGPRT)

- Hamster (Chinese). 42661420 (1993)/ Acceptable

(+/

- S9) Conc.: 50

- 900 μg / mL Negative. Did not induce forward mutations at the HGPRT locus in Chinese Hamster ovary cells. Concentrations above 700 ug/m L were insoluble.

870.5375 (84

- 2) Mutagenic

- In

vitro Clastogenic

- Ham s ter (Chinese) 42139429 (1989)/ Acceptable

(+/

- S9) Conc.: 449

- 1810
μg / /mL Negative. No chromosomal aberrations.

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 31 of 40 Table 2 . Toxicity Profile of Halosulfuron

- M ethyl Techni cal

.

Guideline No. Study Type MRID No. (Date)/Classification/ Doses Results

870.5395 (84

- 2) Mutagenic

-

Micronucleus Assay

- Mouse (CD

- 1) 43616304 (1995)

-

Metabolite/ Acceptable Doses: 1250, 2500 or 5000 mg/kg Negative. Conducted with 3

- chlorosulfonamide acid

the principal soil metabolite of halo s ulfuron

- methyl. No overt toxicity for t he treated animals or cytotoxicity for the target organ (bone marrow cells) was observed.

870.5395 (84

- 2) Mutagenic

-

Micronucleus Assay

- Mouse 42139430 (1989)/ Acceptable

Doses: 500, 1667 0r 5000 mg/kg. Negative. Did not induce significant elevations in the frequencies of micronucleated polychromatic erythrocytes.

870.5500 (84

- 2) Mutagenic

-

Unscheduled DNA synthesis

- Rat 42139432 (1990)/ Acceptable

(+/

- S9) Conc.: 25

- 1000 μg/mL Negative. Fail to induce unscheduled DNA synthesis in primary rat hepatocytes.

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 32 of 40 A ppendix B : Sulfonyl u re a s: comparative physical chemical propertie s and percent d ermal absorption
( Data excerpted from a DuPont submission, MRID 48904001)

# NAME CAS
NUMBER MOLECULA

R WEIGHT LOG

Kow (PH 7) PKA % DERMAL ABSORPTION STUDY DESIGN REFERENCE I COMMENTS

CONCENTRATE DILUTE

1 Bensulfuron

methyl 83055

- 99

- 6 410.4 0.79 5

. 2 4.7 1

. 7 In vivo, rat DuPont HLR 120

- 90

2 Foramsulfuron 173159

- 57

- 4 45 2

. 5

- 0

. 78 4

. 6

- <2 In vivo,
rat European Commission

Foramsulfuron,
SANCOI 1 0324/2002 fina l

, 29 November 2002

3 Meso sulfuron 400852

- 66

- 6 503.6

- 0.48 4.35 9 14 In vitro European Commission; Mesosulfuron,
SANC0/10298/2003

- final,
23 June 2003

4a Nic osulfuron 111991

- 09

- 04 410.4

- 1

. 74 4

. 3 0

. 021 1.05 In vitr o , Human skin DuPont

- 21540

4b Nicosulfuron " " " " 0

. 23 0.41 In
vitro
, Huma

n skin DuPont

- 25519

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 33 of 40 # NAME CAS
NUMBER MOLECULA

R WEIGHT LOG

Kow (PH 7) PKA % DERMAL ABSORPTION STUDY DESIGN REFERENCE I COMMENTS

CONCENTRATE DILUTE

5 Oxas ulfuron 144651

- 06

- 9 406.4

- 0.81 5

. 1 1 1 In vitro Rat & Human skin; In vivo Rat European Commission;

Oxasulfuron,
SANC0/4323/2002

- final, 26 November 2002

6 Primisulfuron methyl 86209

- 51

- 0 46 8

. 3 1

. 15 (pH
5

. 0) 3.47

- 21 In vivo,
rat Pest Management Regulatory Agency (PMRA ) ; Proposed Reg Decision Document: PRDD2001

- 0 2 ; Primisulfuron Methyl,

March 29, 2001; includes skin residues

7a Rimsulfuron 122931

- 48

- 0 431.4

- 1.46 4 0

. 24 3

. 21 In vitro, Human skin DuPont

- 24335

7b Rimsulfuron " " " " 0.4 1

. 63 In vitr o , Human skin DuPont

- 25519

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 34 of 40 # NAME CAS
NUMBER MOLECULA

R WEIGHT LOG

Kow (PH 7) PKA % DERMAL ABSORPTION STUDY DESIGN REFERENCE I COMMENTS

CONCENTRATE DILUTE

7c Rimsulfuron " " " " 0.18 2.45 In vitr o , Human skin Dupont

- 24600

8a Thifensulfuron methyl 79277

- 27

-

3 387.4

- 1.66 4 0

. 19 2

. 29 In vitr o , Human skin DuPont

- 24600

8b Thifensulfuron methyl " " " " 0.15 2.51 In vitr o , Human

s k i n DuPont

- 29190

9 Triasulfuron 82097

- 50

- 5 40 1

. 8

- 0

. 59 4

. 64 - 1 No details provided European Commissio n ;

Triasulfuron, SANC0/7589NI/97

- fina l

, 30 November 2000

10 Tribenuron methyl 101200

-

48

- 00 395.4 0

. 78 4

. 7 3

. 1 1 7

. 7 In vivo,

ra t ; 1 0

- hour data DuPont report AMR

- 1 096

- 8 8 ; includes skin residues

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 35 of 40 # NAME CAS
NUMBER MOLECULA

R WEIGHT LOG

Kow (PH 7) PKA % DERMAL ABSORPTION STUDY DESIGN REFERENCE I COMMENTS

CONCENTRATE DILUTE

1 1 a Triflusulfuron

methyl 126535

-

15

- 7 492.4 0.96 4. 4 0

. 01 1 0

. 5 In vitro
, Human skin DuPont

- 12132

1 1 b Triflusulfuron

methyl " " " "

- 3

. 24 In vitr o , Human skin DuPont

- 20077

12 T ritosulfuron 142469

- 14

- 5 44 5

. 3 0

. 62 4. 69 1 2 In vitro
Rat &
Human skin; In vivo Rat European Commission;

Tritosulfuron, SANC0/1256/08

- rev.1, 4 March 2008

Halosulfuron

methyl 100784

- 20

- 1 0.0186 3. 5

Test substance s inc lude und i luted formulation or concentrate and d i luted concentrate.

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 36 of 40 Appendix C

. Physical/Chemical Properties

TABLE C.1. Physicochemical Properties of Halosulfuron

- methyl.

Parameter Value Reference Melting point/range 175.5

- 177.2oC MRID # 42139403 ( D173627 ; G.J. Herndon ; 30 July 19 92 ) pH 4.11 at 25oC (1% w/v slurry) Density 1.618 g/mL at 25oC Water solubility at 20oC pH 5 0. 0 15 g/L pH 7 1

. 65 g/L pH 9 7

. 47 g/L Solvent solubility at 20oC m ethanol 1

. 616 g/L

n

- h exane 0 .01278 g/ L Vapor pressure <1 x 10

- 7 mm Hg at 25 oC Dissociation constant, K a 3.61 x 10

- 4 at 22.4 oC Octanol/water partition coefficient, Log(K OW ) at 23oC 1.67 at pH 5

- 0.0186 at pH 7

- 0.542 at pH 9 UV/visible absorption spectrum Not available

.

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 37 of 40 Appendix D. International Residue Limit

Halosulfuron

- methyl (PC Code 128721) Summary of US and International Tolerances and Maximum Residue Limits Residue Definition :

US Canada Mexico 1 Codex 40 CFR § 180.4 79 (a)General. (2) Halosulfuron

- methyl ( methyl 5

- [(4,6

- dimethoxy

- 2

- pyrimidiny)amino] carbonylaminosulfonyl]

- 3

- chloro

- 1

- methyl

- 1H

- pyrazole

- 4

- carboxylate ) Methyl 3

- chloro

- 5

- [[[[(4,6

- dimethoxy

- 2

- pyrimidinyl)amino]carbonyl] amino]sulfonyl]

- 1

- methyl

1H

- pyrazole

- 4

- carboxylate None

Commodity 1 Tolerance (ppm) /Maximum Residue Limit (mg/kg)

US Canada Mexico 1 Codex Fruit, pome, group 11

- 10 0.05 0.05 apples Small vine climbing fruit, except fuzzy kiwifruit, subgroup 1 3

- 07F 0.05

Completed: M. Negussie; 04/10/2015

1 Includes only commodities of interest for this action. Tolerance values should be the HED recommendations and not those proposed by the applicant.

2 Mexico adopts US tolerances and/or Codex MRLs for its export purposes.

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 38 of 40 Appendix E

. Review of Human Research

This risk assessment relies in part on data from studies in which adult human subjects were intentionally exposed to a pesticide or other chemical. These data, which include Pesticide Handlers Exposure Database Versi on 1.1 (PHED 1.1); the Agricultural Handler Exposure Task Force (AHETF) database; t he Residential SOPs (Lawns & Turf), and other registrant

- submitted exposure monitoring studies (MRID 44339801)

, are (1) subject to ethics review pursuan t to 40 CFR 26, (2) h ave received that review, and (3) are compliant with applicable ethics requirements. For certain studies, the ethics review may have included review by the Human Studies Review Board. Descriptions of data sources, as well as guidance on their use, can be found at the Agency website 3



### .

3 http://www.epa.gov/pesticides/science/handler

- exp osure

- data.html and http://www.epa.gov/pesticides/science/post

- app

- exposure

- data.html

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 39 of 40 Appendix F

. TTR and DFR Waiver Summary

Turf Transferable Residue (TTR): In accordance with 40 CFR158, TTR data are required for all occupational (e.g., sod farms, golf courses, parks, and recreational areas) or reside ntial turf uses that could result in post

- application exposure to turf. In the absence of chemical

- specific TTR data, EPA uses default values. The 2012 Standard Operating Procedures for Residential Pesticide Exposure Assessment includes an analysis of all TTR data, available at the time, which resulted in the selection of revised liquid and granular default values for the fraction of the application rate available for transfer after a turf application (F AR 

### ). These values are based on an analysis of 59 TTR studies performed with the Modified California Roller Method (36 studies using liquids, 11 studies using wettable powders/water dispersible granules, and 12 studies using granules). The liquid results (N=131) indicate a range of F AR 

### values from 0.0005 % to 6.1% and the granular results (N=37) indicate a range of 0.00064% to 0.69%. In both the liquid and granular data, a large range of transferability is observed and this variability can potentially be attributable to many factors such as active ingredi ent; formulation; field conditions in the studies; weather conditions (e.g., humidity); or many other difficult to quantify factors. Although witnessed across multiple chemicals, this range in F AR 

### values is not expected when considering TTR data for a sin gle chemical. HED selected 1% and 0.2% as high

- end default values for liquid and granular products, respectively. Because TTR data are not available for halosulfuron

methyl , EPA would use the default value of 1%

. Although there may be a small degree of uncertainty in the use of the default TTR value for halosulfuron

- methyl (i.e., there is a small chance that the F AR 

### value may exceed the applicable default value ), it is likely that the health

protective aspects of EPA’s residential post

- application turf assessment methodology would more than compensate for this potential uncertainty (i.e., the methodology is likely to overestimate exposure by a factor greater than the factor than the highest measured F AR 

### values exceed the defaults ). For example, when assessing residential post

- application turf exposure, EPA assumes the following: exposures occur to zero

- day (i.e., day of application ) residues every day of the assessed exposure duration (i.e., EPA assumes that no dissipation or degradation occurs, it doesn’t rain, the grass is not mowed, etc); individuals perform the same post

application activities performed in the turf transfer coefficient study day after day (e.g., tumbling, playing on turf with toys, etc.); and individuals engage in these post

- app lication activities for a high

- end amount of time every day that is represented by data reflecting time children spend outdoors and not specifically engaged in activities on turf, when in actuality children do not spend all of their outdoor time on turf a nd high

- end levels of activity will not occur every day.

Given the conservatisms discussed above and the potential compounding nature of these conservatisms, EPA is able to rely upon the calculated exposure estimates with confidence that exposure is no t being underestimated.

Since the estimated post

- application exposure for residential turf using default TTR values for halosulfuron

- methyl is minimal in comparison to the level of concern (i.e., the calculated MOE is greater than 10 times higher than the level of concern, MOE = 24,000 compared to the LOC of 100); EPA is waiving the 40 CFR TTR data requirement. In this instance, it is unlikely that chemical

- specific TTR data would be needed to further refine exposure assessments or would

### Halosulfuron

- Methyl Human Health Risk Assessment DP No. D421819

Page 40 of 40 add appreciably to our general understanding of the availability of turf transferable pesticide residues.

Dislodgeable Foliar Residue (DFR): In accordance with 40 CFR158, DFR data are required for all occupational (e.g., crop, nursery, greenhouse use sites) or residential (e.g., ornamental and vegetable gardens, pick your own farms, retail tree farms) uses that could result in post

application exposure to foliage. In the absence of chemical

- sp ecific DFR data, EPA uses default values. The 2012 Standard Operating Procedures for Residential Pesticide Exposure Assessment includes an analysis of a number of DFR studies, which resulted in the selection of a revised default values for the fraction of the application rate available for transfer after a foliar application (F AR 

### ). These values are based on an analysis of 19 DFR studies. Since that time, the Agricultural Re

- entry Task Force has submitted information (MRID 49299201) that corrects an appl ication rate error made in the original submission of “ARF039

– Determination of Dermal and Inhalation Exposure to Reentry Workers During Chrysanthemum Pinching in a Greenhouse” (EPA MRID 45344501). As a result, the range of F AR 

### values was revised from 2%

- 89% to 2%

- 47%. In the data, a large range of transferability is observed and this variability can potentially be attributable to many factors such as active ingredient; formulation; field conditions in the studies; weather conditions (e.g., humidity) ; or many other difficult to quantify factors. Although witnessed across multiple chemicals, this range in F AR 

### values is not expected when considering DFR data for a single chemical. At this time, the ARTF submission did not alter the selection of 25% as the reasonable, high

- end default value. Because DFR data are not available for halosulfuron

- methyl , EPA would use the default value of 25%. Although there may be a small degree of uncertainty in the use of the default DFR value for halosulfuron

- methyl ( i.e., there is a small chance that the F AR 

### value may exceed the applicable default value ), it is likely that the health

- protective aspects of EPA’s occupational post

- application assessment methodology would more than compensate for this potential uncertainty. For example, when assessing residential and occupational post

- application exposure to gardens and ornamentals, EPA assumes the following: exposures occur to zero

- day (i.e., day of application ) resi dues every day of the assessed exposure duration (i.e., EPA assumes that no dissipation or degradation occurs, it doesn’t rain, etc); individuals perform the same post

- application activities performed in the transfer coefficient study day after day (e.g., weeding, harvesting, pruning, etc.); and individuals engage in these post

- application activities for a high

- end amount of time every day (represented by data reflecting time spent gardening based on survey data).

Given the conservatisms discussed above an d the potential compounding nature of these conservatisms, EPA is able to rely upon the calculated exposure estimates with confidence that exposure is not being underestimated.

There is no hazard identified for halosulfuron

- methyl via the dermal route of exposure; therefore, a DFR study is not required at this time.