Page 1 of 47 UNITED STATES ENVIRONMENTA L PROTECTION AGENCY WA SHINGTON, D.C. 20460 OFFICE OF PREVENTION, PESTICIDES AND TOXIC SUBSTANCES Date: April 5 , 2010 MEMORANDUM SUBJECT: Halosulfuron - M ethyl : Human Health Risk Assessment for IR - 4 Proposed Us e s

on C rop Group 6B Succulent Shelled Pea and Bean Subgroup , Crop Group 1C Tuberous and Corn Vegetables Subgroup , Crop Group 6C Dried Shelled Pea and Bean ( Except Soybean) , Subgroup 13 - 07B Bushberry , O kra, Apples, and R hubarb. PC Code: 128721 DP Barcode: D 3 66410 Decision No.: 414896 Re gistration No. : 81880 - 18 Petition No . : 9E7577 Regulatory Action: Section 3 Risk A ss essment Type : Single C hemical/A ggregate Case No.: NA T XR No. : NA CAS No.: 100784 - 20 - 1 MRID No . : NA 40 CFR: 180.479 FROM : Whang Phang, Toxicologist , Risk Assessor

Nancy Tsaur, Chemist, ORE A ssessor Risk Assessment Branch 3 Health Effects Division (7509P) Debra Rate , Biologist , Residue Chemistry and Dietary

Assessor RIMUERB/RD (7505P) THRU: Paula A. Deschamp, Branch C hief

Risk Assessment Branch 3 Health Effects Division (7509P) TO: Sidney

Jackson/Barbara Madden, RM 05 RIMUERB/Registration Division (750 5P) IR - 4 has proposed the establishment of a permanent tolerance for residues of the herbicide halosulfuron - methyl [methyl 5 - [(4,6 - dimethoxy- 2 - py rimidinyl)amino] carbonylaminosulfonyl - 3 - chloro - 1 - methyl - 1 H

- py razole - 4 - carbox yl ate] in/on the following agricultural commodity : Pea and bean, succulent shelled, Subgroup 6B ................................ ... 0.05 ppm Vegetable, tuberous and corm, Subgroup 1C ................................ ...... 0.05 ppm Pea and bean, dried shelled, except soy bean, Subgroup 6C ................ 0.05 ppm Bushberry , Subgroup 13 - 07B ................................ .............................. 0.05 ppm Rhubarb ................................ ................................ ............................... 0.05 ppmPage 2 of 47

Apple ................................ ................................ ................................ ... 0.05 ppm Okra ................................ ................................ ................................ ..... 0.05 ppm The most recent human health risk assessment was conducted for uses on soy bean (D358031, W. Phang, 6/30/2009) . Since then, no new toxicology data have been submitted. The hazard characterization and toxicity endpoints for risk assessment remain unchanged since the 2006 risk assessment for uses on alfalfa (D331643, M. Rust , 9/21/2006). The det ails of hazard c haracterization and the rationale for toxicity endpoint selection will not be repeated in this risk assessment. However, the salient features will be summarized for these two topics and for the Food Quality Protection Act ( FQPA ) safety fact or discussion . A summary

of the findings and an assessment of human risk resulting from the proposed and registered uses of halosulfuron - methyl are provided in this document and its attachments. The residue chemistry

data submitted in support of this petition were reviewed by Debra Rate , who also conducted the dietary assessment . The occupational/residential assessment was performed by Nancy Tsaur . The drinking water assessment was conducted by Michael Barrett of the Environmental Fates and Effects Divi sion ( EFED ) . The toxicology evaluation and risk assessment were performed by Whang Phang. Recommendations for Tolerance Pending submission of a revised Section B, a revised Section F, and reference standard s , HED con cludes that the toxicology and residue chemistry

databases, the dietary , residential, aggregate, and occupational risk assessments support the requested uses on the following crops and establishment of the following tolerance s : Pea and bean, succulent shelled, Subgroup 6B ................................ ... 0.05 ppm Vegetable , tuberous and corm, Subgroup 1C ................................ ...... 0.05 ppm Bushberry , Subgroup 13 - 07B ................................ .............................. 0.05 ppm Rhubarb ................................ ................................ ............................... 0.05 ppm Apple ................................ ................................ ................................ ... 0.05 ppm Okra ................................ ................................ ................................ ..... 0.05 ppm At this time, HED is unable to recommend establishment of the proposed tolerance for dried s helled b ean ( e xcept s oybean) and p ea , Crop Subgroup 6C because data are required for dried pea including the forages and hay of field pea cultivars. In addition, concomitant with the establishment of a tolerance for Subgroup 6 B, the individual tolerance for ‘bean, snap, succulent’ should be revoked.Page 3 of 47 Table of Contents 1.0 EXECUTIVE SUMMARY ................................ ................................ ................................ 4 2.0 IN GREDIENT PROFILE ................................ ................................ ................................ ... 8 2.1 Summary

of Proposed Uses ................................ ................................ .................... 8 2.3 Phy sical/Chemical Properties Characterization ................................ .................... 11 3.0 HAZARD CHARACTERIZATION ................................ ................................ ................ 13 3.1 FQPA Safety Factor for Infants and Children ................................ ...................... 16 3.2 Endocrine Disruption ................................ ................................ ............................ 17 4.0 DI ETARY EXPOSURE/RI SK CHARACTERIZATION ................................ ................ 18 4.1 Pesticide Metabolism and Environmental Degradation ................................ ........ 18 4.2 Dietary

Exposure and Risk ................................ ................................ ................... 26 5.0 RESIDENT IA L (Non - Occupational) EXPOSURE/RI SK CHARACTERIZATION ...... 27 5.1 Residential Handler Expos ure ................................ ................................ ............... 28 5.2 Residential Postapplication Exposure ................................ ................................ ... 28 5.3 Other (Spray

Drift, etc.) ................................ ................................ ........................ 29 6.0 AGGREGATE RISK ASSES SMENTS AND RI SK CHARACTERIZATION .............. 29 6.1 Acute Aggregate Risk ................................ ................................ ........................... 29 6.2 Short - Term Aggre gate Risk ................................ ................................ .................. 30 6.3 Intermediate - Term Aggregate Risk ................................ ................................ ...... 30 7.0 CUMULAT IVE RISK CHARACTERIZATION/ASSESSM ENT ................................ .. 31 8.0 OCCUPATI ONAL EXPOSURE/RI SK PATHWAY ................................ ....................... 32 8.1 Short - and Intermediate - Term Handler Exposure and Risk ................................ . 32 8.2 Postapplication Exposure/Risk ................................ ................................ ............. 38 8.2.1 Data and Assumptions for Postapplication Exposure Scenarios .............. 38 8.2.2 Agricultural Post - application Exposure and Risk ................................ ..... 39 9.0 DATA NEEDS/LABEL REC OMMENDATIONS ................................ .......................... 40 9.1 Toxicology ................................ ................................ ................................ ............ 40 9.2 Residue Chemistry ................................ ................................ ................................ 40 REFERENCES ................................ ................................ ................................ ............................. 41 Attachment A: Toxicology Profile ................................ ................................ ................................ 43 Attachment B: Rationale for Requiring the Studies ................................ ................................ ..... 46Page 4 of 47

1.0 EXECUTIVE SUMMARY Halosulfuron - methyl is a selective herbicide belonging to the sulfonylurea group of herbicides, which inhibits the action of acetolacetate sy nthase enzy

me, a specific plant enzy

me. Halosulfuron - methyl is used for the pre - and postemergence control of annual broadleaf weeds and nutsedges in selected crops, as w ell as residential turf grass and ornamentals . It is formulated as a water dispersible granule (WD G) . The petitioner, Interregional Research Project No. 4 (IR - 4), has proposed new uses of halosulfuron - methyl on apple; bushberry Subgroup 13 - 07B; okra; succulent - shelled pea and bean Subgroup 6B; dried shelled pea and bean, except soy bean, Subgroup 6C; rhubarb; and tuberous and corm vegetable Subgroup 1C. In conjunction with the requested amended use, IR - 4 has submitted a petition, PP#9E7577, to propose the establishment of permanent tolerances for residues of the herbicide halosulfuron - methyl (methyl 3 - chloro - 5 - [[[[(4,6 - dimethoxy- 2 - py rimidinyl)amino]carbonyl]amino]sulfonyl] - 1 - methyl - 1 H - py razole - 4 - carboxylate) in/on the following raw agricultural commodi ties: Pea and bean, succulent shelled, Subgroup 6B ................................ ... 0.05 ppm Vegetable, tuberous and corm, Subgroup 1C ................................ ...... 0.05 ppm Pea and bean, dried shelled, except soy bean, Subgroup 6C ................ 0.05 ppm Bushberry , Subgroup 13 - 07B ................................ .............................. 0.05 ppm Rhubarb ................................ ................................ ............................... 0.05 ppm Apple ................................ ................................ ................................ ... 0.05 ppm Okra ................................ ................................ ................................ ..... 0.05 ppm HED has conducted a human health risk assessment for halosulfuron - methyl for the purpose of establish ing the proposed tolerance s for uses in or on the above agricultural commodities. In addition, concomitant with the establishment of a toleranc e for Subgroup 6 B, the individual tolerance for ‘bean, snap, succulent’ should be revoked. There are currently

no established Codex or Canadian maximum residues limits (MRL s) for halosulfuron - methyl. Hazard Assessment and Dose - Respo nse Assessment The toxicology

database is adequate to support the current petition for establishing the proposed tolerances for uses in/on the above raw agricultural commodities , with the exception of an immunotoxicity

study required under the new rule in 40 CFR Part 158 . This study is required as a condition of registration for this action. However, an additional safety factor is not needed to account for lack of this study because the current data suggest halosulfuron - methyl does not directly target the immune sy stem. Halosulfuron - methyl has low acute toxicity via the oral, dermal, and inhalation routes. It is a non - irritant for skin and eyes and is not a dermal sensitizer. With repeated dosing, halosulfuron produces non - specific effects , which are frequently characterized by reduced body weight and body weight gains in the test animals. Carcinogenicity studies in rats and mice show no increasePage 5 of 47

in treatment - related tumor incidence, and it is classified as “not likely to be carcinogenic to humans . ” Halosulfuron - methyl is negative for mutagenicity in a battery of genotox icity studies . Although the data indicated an increase in qualitative susceptibility in fetuses following prenatal exposure in rats and rabbits , the developmental effects were seen in the presence of maternal effects and clear NOAEL s and LOAEL s were established for both maternal and developmental effects. In addition, the developmental effects in rats were seen at doses approaching the limit dose (1000 mg/kg) . It was concluded that th e degree of concern was low and there w as no residual uncertainty

in either the rat or rabbit developmental toxicity study . The FQPA safety factor was reduced to 1X . The toxicity

endpoints and points of departure (POD) for risk assessment were selected f or the following exposure scenarios : acute and chronic dietary , short - and intermediate - term incidental oral , dermal and inhalation . A summ ary of toxicity

endpo i nts and points of depart is presented in Table 3.1 . Because of a common effect ( i.e., body wei ght gain changes ) seen in the studies selected for the endpoints for all three routes of exposure, MOE s and exposures can be aggregated where appropriate. The POD and toxicity endpoints for current risk assessment are summarized in Table 1. The level of c oncern (LOC) for residential and occupational exposures via dermal and inhalation routes is for an MOE < 100. Acute Dietary

Exposure Estimates An acute dietary exposure anal ys is for halosulfuron - methyl was conducted using tolerance - level residues and 100 % crop treated (CT) for all existing and recommended uses. E stimated drinking surface water concentrations (EDWCs) from EFED ( 59.2 ppb based on modeled use on rice) were incorporated directly into the exposure anal ys is. The only population with a toxico logical endpoint attributable to a single dose of halosulfuron - methyl was females 13 - 49 year s old. The results of the anal ys is indicate that acute risk from the dietary exposure to halosulfuron - methyl is less than 1% of the acute population adjusted dose ( aPAD ) for females 13 - 49 year s old , and therefore does not exceed HED’s LOC. Chronic Dietary

Exposure Estimates A chronic dietary

analy sis for halosulfuron - methyl was conducted using tolerance levels and 100% CT for all existing and recommended uses. The EDWC for surface water from EFED (5 9.2 ppb based on modeled use on rice) was incorporated directl y into the exposure anal ys is. The drinking water estimate should be considered highl y conservative. The results of the anal ys is indicate that chronic risk f rom the dietary exposure to halosulfuron - methyl does not exceed HED’s LOC for the general U.S. population or any population subgroup. The estimated risk for the general U.S. population is 2 % of the c hronic PAD (cPAD) , and the highest exposure is to all in fants ( <1 year old) at 5 % of the cPAD. Drinking Water Assessment Halosulfuron - methyl is a mobile and persistent compound which may reach ground and surface waters, including those used as drinking water source s. The EDWCs for halosulfuron - methyl are base d on a maximum annual application rate of 0.125 lb ai/A for rice. The two screening models, FIRST and SCI - GROW, were used for estimating EDWCs of halosulfuron - methyl. Estimates for halosulfuron - methyl in surface water based on the FIRST model results for rice arePage 6 of 47

5 9.2 ppb for acute and chronic concentrations. It should be noted that the drinking water estimate based on rice applicatio n is an upper bound estimate. The estimate for halosulfuron methyl in ground water based on the SCI - GROW model result is 0 .065 ppb. Residential Exposure Estimates No residential uses are being requested in this petition; however, h alosulfuron - methyl is currentl y registered for use on residential turf grass and ornamentals. Short - term exposures may occur during adult residential handling activities. Short - and intermediate - term exposures may occur during postapplication activities for adults and children. Combined MOEs for adult and children ’s dermal exposure and toddler ’ s incidental oral exposure from all residential activ ities are greater than the LOC of 100, and therefore are not of concern. Acute Aggregate Risk For acute aggregate risk, drinking water estimates were incorporated directly into the dietary anal ys is for female 13 - 49 years old. Exposure through food and dri nking water sources occupies less than 1% of the aPAD; thus, estimated risk does not exceed HED’s level of concern. Short - Term Aggregate Risk The short - term aggregate risk assessment estimates risks likely to result from exposure to halosulfuron - methyl residues from food, drinking water, and residential pesticide uses. High - end estimates of residential exposure are used, while average values are used for food and drinking water exposure ( i.e. , chronic exposures). Short - term aggregate MOEs range from 2, 8 00 to 4, 8 00 . The MOE for the U.S. Population is 4, 7 00 . The most highly exposed subgroup is All Infants (less than 1 year old), with a MOE of 2, 8 00. These estimates of short - term aggregate risk do not exceed HED’s level of concern. Intermediate - Term Ag gregate Risk The intermediate - term aggregate risk assessment estimates risks likely to result from exposure to halosulfuron - methyl residues from food, drinking water, and residential pesticide uses. Although unlikely due to the use pattern (no more than 4 applications to turf per season), residential exposure was included in the intermediate - term aggregate risk assessment. High - end estimates of residential exposure are used, while average values are used for food and drinking water exposure ( i.e. , chronic exposures). Intermediate - term aggregate MOEs ranged from 500 to 680 . The MOE for the U.S. Population is 500 . The most highly exposed children’s subgroup was All In fants (less than 1 ye ar old), with a MOE of 680 . These estimates of aggregate risk do no t exceed HED’s level of concern. Occupational Exposure and Risk For occupational handlers, short - and intermediate - term exposure may occur during mixing, loading and application. For occupational postapplication activities, exposure may occur over short - and intermediate - term periods. Chronic exposure (  6 months of continuous exposure) is not expected. Agricultural Handler R isk No chemical - specific handler exposure data were submitted in support of this registration. Itis the policy of the HED to us e data from the Pesticide Handlers Exposure Database (PHED) , V ersion 1.1 as presented in PHED Surrogate Exposure Guide (8/98) to assess handler exposuresPage 7 of 47

for regulatory

actions when chemical - specific monitoring data are not available (HED ExpoSAC Standard Operating Procedure (SOP) No. 7, dated 1/28/99). Data from the Outdoor Residential Exposure Task Force (ORETF) are also used when appropriate. All handler scenarios resulted in MOEs greater than the LOC (MOEs ≥ 100) at some level of risk mitigation. The inhalation risk estimates to handlers do not exceed HED’s LOC at baseline (no respirator) for any of the handler scenarios where baseline data are available. The combined dermal and inhalation risks to handlers do not exceed HED’s LOC with baseline attire (i.e., long sleeve d shirt, long pants, shoes, and socks) where baseline data are available. There are no data to assess the mixing/loading/appl yi ng handgun scenario at baseline attire. The short - and intermediate - term combined dermal and inhalation risks do not exceed HED’s LOC for mixing/loading/appl yi ng with handgun equipment when baseline attire plus chemical - resistant gloves are used. Agricultural Postapplication Risk No chemical - specific dislodg eable foliar residue (DFR) data are available for halosulfuron methyl to assess postapplication dermal risks. Using the default assumption that 20 % of the application rate is retained on foliage on day 0 yi elds the dermal MOEs for occupational postapplication workers on the day of application greater than 100, demonstrating that there are minimal potential risks to workers re - entering fields treated with postemergent applications of halosulfuron - methyl . Based on the use pattern, as well as the acute toxic ity of halosulfuron methyl, the 12 - hour restricted entry interval (REI) appearing on the label is adequate. Recommendations for Tolerance Pending submission of a revised Section B, a revised Section F, and anal ytical reference standard s , there are no ad ditional residue chemistry issues that would preclude granting a Section 3 registration for the requested uses or the establishment of a tolerance for residues of the herbicide halosulfuron - methyl, methyl 3 - chloro - 5 - [[[[(4,6 - dimethox y- 2 - py rimidinyl) amino ]carbonyl]amino]sulfonyl] - 1 - methyl - 1 H - pyrazole - 4 - carbox yl ate, as follows: Pea and bean, succulent shelled, S ubgroup 6B ................................ ... 0.05 ppm Vegetable, tuberous and corm, S ubgroup 1C ................................ ...... 0.05 ppm Bushberry , S ubgroup 13 - 07B ................................ .............................. 0.05 ppm Rhubarb ................................ ................................ ............................... 0.05 ppm Apple ................................ ................................ ................................ ... 0.05 ppm Okra ................................ ................................ ................................ ..... 0.05 ppm At this time, HED is unable to recommend for a registration and tolerance for dried s helled b ean ( e xcept s oy

bean) and p ea , Crop Subgroup 6C because data are required for dried pea including the forages and hay

of field pea cultivars. In additi on, concomitant with the establishment of a tolerance for Subgroup 6 B, the individual tolerance for ‘bean, snap, succulent’ should be revoked. 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 studies, which comprise the PHED,Page 8 of 47

the Outdoor Residential Exposure Task Force (ORETF), and the Agricultural Reentry Task Force (ARTF) have been determined to require a review of their ethi cal conduct, and have received that review. 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 Acti ons to Address Environmental Justice in Minority Populations and L ow - Income Populations," http://www.eh.doe.gov/oepa/guidance/justice/eo12898.pdf ). As a part of every

pesticide risk assessment, OPP considers a large variety of consumer subgroups according 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 USDA under the Continuing Survey of Food Intake by

Individuals (CSFII) and are us ed in pesticide risk assessments for all registered food uses of a pesticide. These data are anal yz ed and categorized by

subgroups based on age, season of the year, ethnic group, and region of the country . Additionally , OPP is able to assess dietary expo sure to smaller, specialized subgroups and exposure 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 on treated areas postapplication are evaluated. Further considerations are currentl y in development as OPP has committed resources and expertise to the development of specialized software and models that co nsider exposure to b ys tanders and farm workers as well as lifestyl e and traditional dietary patterns among specific subgroups . 2.0 INGREDIE N T PROFILE 2.1 Summary of Proposed U ses H alosulfuron - methyl is a sulfonylurea herbicide proposed for pre - and post - emergence control of broadleaf weeds and nutsedge . The end - use products (EPs) relevant to this registration action are Sandea® Herbicide (EPA Reg. No. 81880 - 18) and GWN - 3061 Herbicid e (EPA Reg. No. 81880 - 2). Both products are currently registered to Gowan Company and are classified as WDG formulation s containing 75% halosulfuron - methyl. The petitioner , IR - 4, is proposing to add the following crops to the Sandea® Herbicide label: apple, bushberry

Subgroup 13 - 07B, okra, succulent shelled pea and bean Subgroup 6B, dried shelled pea and bean (except soy bean) Subgroup 6C, rhubarb, and tuberous and corm vegetables Subgroup 1C and also to amend the product label for GWN - 3061 Herbicide in clude uses on dried shell ed pea and bean (except soy bean) Subgroup 6C . The proposed use patterns are presented in Table 2.1.Page 9 of 47

Table 2.1. Proposed Use Pattern for Halosulfuron - Methyl.

Crop Treatm ent

Type/Target of Application Application

Equipment Maximum

Application Rate (lb ai/A) Treatm ent

Interval Preharvest

Interval Sandea® Herbicide, EPA Reg. No. 81880 - 18, WDG 75% ai Succulent shelled peas and beans (subgroup 6B) Ground Groundboom 0.023 lb ai/acre Not applicable Not provided Tuberous and corm vegetables (subgroup 1C) Ground & Foliage Groundboom 0.047 lb ai/acre Not provided 45 days Rhubarb Ground Groundboom, Handgun 0.047 lb

ai/acre Not applicable 60 days Bushberry (subgroup 13 - 07B) Ground & Foliage Groundboom,

Handgun 0.047 lb

ai/acre 45 d ays 14 days Dried shelled peas and beans (except soybean, subgroup 6C) (West of Rockies) Ground & Foliage Groundboom,

Handgun 0.047 lb

ai/acre Not applicable 30 days Dried shelled peas and beans (except soybean, subgroup 6C) (East of Rockies) Ground & Fo liage Groundboom,

Handgun 0.031 lb

ai/acre Not applicable 30 days Apples (West of Rockies) Ground Groundboom, Handgun 0.094 lb

ai/acre Not provided 14 days Apples (East of Rockies) Ground Groundboom, Handgun 0.047 lb

ai/acre Not provided 14 days Okra Gr ound Groundboom, Handgun 0.047 lb

ai/acre Not applicable 30 days 2.2 Direction s for Use The directions for use of halosulfuron - methyl are summarized in Table 2.2. The submitted labels for Sandea® Herbicide (EPA Reg. No. 81880 - 18) and GWN - 3061 Herbicide (EPA Reg. No. 81880 - 2) are adequate to allow evaluation of the residue data relative to the proposed use s . However, the petitioner is required to : (1) amend the proposed use directions of Sandea® Herbicide (EPA Reg. No. 81880 - 18) on Crop Subgroup 6B to prohibit applications to legumes grown for livestock feeds because no residue data are available for cowpea forage and hay ; (2) amend the proposed use directions of Sandea® Herbicide (EPA Reg. No. 81880 - 18) on Crop Subgroup 13 - 07B (bushberry) to remove the instructions pertaining to the use of a non - ionic surfactant; and (3 ) remove the use directions from both labels for Crop Subgroup 6C (dried pea and bean (except soy

bean)).Page 10 of 47

Table 2.2. Summ ary of Directions for Use of Halosulfuron - Methyl . Applic. Timing, Ty pe, and Equip. Form

ulation [EPA Reg. No.] Applic.

Rate (lb ai/A) Max. No.

Applic. per Season Max. Seasonal

Applic. Rate (lb ai/A) PHI

(days) Use Directions and

Limitations Apple; East of the Rocky Mts. Broadcast to orchard floor; Ground ( ≥15 gal/A) 75% WDG

[81880 - 18] 0.023 -

0.047 Not

specified (NS) 0.094 14 Single or sequential applications may be made on each side of the tree row . Use of a non - ionic surfactant (NIS) is recommended. Application to trees established less than one year is prohibited . Apple; West of the Rocky Mts. Broadcast to orchard floor; Ground ( ≥15 gal/A) 75% WDG

[81880 - 18] 0.035 -

0.094 NS 0.094 14 Single or sequential applications may be made on each side of the tree row . Use of an NIS or a penetrating type surfactant is recommended. Application to trees established less than one year is prohibited. Bushberry Subgroup 13 - 07B

Soil broadcast; Ground ( ≥15 gal/A) 75% WDG

[81880 - 18] 0.023 -

0.047 NS 0.094 14 Single or sequential applications may be made on each side of the row with a minimum retreatment interval (RTI) of 45 days for sequential appli cations. Use of an NIS is recommended. Application to plants established less than one year is prohibited. Fruiting Vegetables Group Including But Not Limited to Eggplant, Okra, Pepper, and Tomato Row middle/furrow applications; Ground ( ≥15 gal/A; ≥20 gal/A for okra from Section B) 75% WDG

[81880 - 18] 0.023 -

0.047 NS 0.094 30 Applications are to be made between rows of direct - seeded or transplanted fruiting vegetables. Pea and Bean, Succulent Shelled, Subgroup 6B 1 [Any succulent shelled cultivar of bean (Phaseolus, spp.), or immature soybean seed (Glycine max), or any Vigna spp., and garden pea (Pisum, spp.)] Preemergence; Soil broadcast; Ground ( ≥15 gal/A) 75% WDG

[81880 - 18] 0.023 1 0.023 30 Timing is after planting but before crop emergence.Page 11 of 47

Table 2.2. Summ ary of Directions for Use of Halosulfuron - Methyl . Applic. Timing, Ty pe, and Equip. Form

ulation [EPA Reg. No.] Applic.

Rate (lb ai/A) Max. No.

Applic. per Season Max. Seasonal

Applic. Rate (lb ai/A) PHI

(days) Use Directions and

Limitations Pea and Bean (Except Soybean), Dried Shelled, Subgroup 6C 1 ; East of the Rocky Mts. Postemergence ; Broadcast or directed; Ground ( ≥15 gal/A) 75% WDG

[8188 0 - 2] [81880 - 18] 0.023 -

0.031 1 0.047 (per crop cycle) 0.094 (per year) 30 Application is to be made when plants have 2 to 4 trifoliate leaves, but before flowering. An NIS is to be used. Directed sprays are recommended. Pea and Bean (Except Soybean), Dri ed Shelled, Subgroup 6C; West of the Rocky Mts. Postemergence ; Broadcast; Ground ( ≥15 gal/A) 75% WDG

[81880 - 2] [81880 - 18] 0.023 -

0.047 1 0.047 (per crop cycle) 0.094 (per year) 30 Application is to be made when plants have 2 to 4 trifoliate leaves, but before flowering. An NIS is to be used. Directed sprays are recommended. Rhubarb Dormant; Broadcast; Ground ( ≥15 gal/A) 75% WDG

[81880 - 18] 0.023 -

0.047 1 0.047 60 Application is to be made as close as possible to breaking of dormancy. An NIS is to be used if labeled weeds have emerged. Tuberous and Corm Vegetables, Subgroup 1C [Arrac acha; arrow

root; artichoke, Chinese; artichoke, Jerusalem; canna, edible; cassava, bitter and sweet; chayote (root); chufa; dasheen (taro); ginger; leren; potato; sweet potato; tanier; turmeric; yam bean; yam, true] Preemergence; Soil broadcast; Ground ( ≥15 gal/A) 75% WDG

[81880 - 18] 0.023 -

0.047 2 0.047 45 First application is to be made after planting but prior to crop emergence; if necessary, a second application may be made 45 days before harvest. If a second application is made, an NIS should be used in the second application. Postemergence Foliar broadcast Ground ( ≥15 gal/A) 1 Individual crop uses of Sandea® Herbicide (EPA Reg. No. 81880 - 18) are currently registered on succulent beans and dry beans ; the petitioner now requests uses on Subgrou ps 6B and 6C . The EP, GWN - 3061 Herbicide (EPA Reg. No. 81880 - 2), is also currently registered on soybeans. 2. 3 P h ysical/Chemical Properties Characterization The chemical structure and nomenclat ure of halosulfuron - methyl and the 3 - chlorosulfonamide moiety ( 3 - CSA ) are presented in Table 2. 3 .1 . The phy sicochemical properties of the technical grade of halosulfuron - methyl are presented in Table 2 . 3 .2 .Page 12 of 47

Table 2. 3 .1 . Halosulfuron - M ethyl Nom encla ture . Chemical structure

N N C H 3 Cl

N N N H N H O S O O

O C H 3 O C H 3 O O C H 3

Common name halosulfuron - methyl Com pany experimental name MON 12000, NC - 319 IUPAC name methyl 3 - chloro - 5 - (4,6 - dimethoxy py rimidin - 2 - ylcarb amoyl sulf amoyl) - 1 - methylpyrazole - 4 - carboxylate CAS name methyl 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 (EP) 75% WDG ( GWN - 3061 Herbicide ; EPA Reg. No. 81880 - 2) Che mical structure of 3 - chlorosulfonamide moiety (3 - CSA) N N C H 3 Cl NH 2

S O O O H O

3 - chloro - 1 - methyl - 5 - sulfamoyl - 1 H -py razole - 4 - carboxylic acid Rearrangement ester (RRE) of halosulfuron - methyl

N N O C H 3

O C H 3 N H N N C H 3 Cl O O

C H 3

Table 2. 3 .2 . Physicochemical Properties of Halosulfuron - M ethyl . Parameter Value Reference Melting point/range 175.5 - 177.2 oC MRID 42139403; D173627 & D 180565, 7/30/92, G.J. Herndon pH 4.11 at 25 oC (1% w /v slurry) Density 1.618 g/mL at 25 oCPage 13 of 47

3.0 HAZARD C HARA C TERIZATION A detailed hazard characterization for halosulfuron - methyl is presented in a risk assessment conducted in 2006 ( DP331643, M. Rust, et al., 9/21/06 ). Briefly , the toxicology database for halosulfuron - methyl is sufficient and of good quality . However, recent changes to 40 CFR §158 make the immunotoxicity study (OPPTS Guideline 870.7800) required for pesticide registration. In the absence of specific immunotoxicity studies, HED has evaluated the available toxicity database to determine whether an additional database uncertainty factor is needed to account for potential immunotoxicity . The toxicology database of this chemical does not show any evidence of biologicall y relevant effects on the immune s ys tem. The overall weight of evid ence suggests that this chemical does not directly target the immune sy stem . HED does not believe that immunotoxicity

testing will result in a NOAEL less than that (10 mg/kg/day) used to derive the current cRfD of 0.1 mg/kg/day . Consequently , HED believes the existing data are sufficient for endpoint selection for exposure/risk assessment scenarios and for evaluation of the requirements under the F QPA, and an additional database uncertainty factor (UF DB ) does not need to be applied at this time. Halosulfuron - methyl is a member of the sulfonylurea herbicides, and it i nhibit s acetolactate sy nthase , a specific plant enzy me not found in mammals. The m ode of action in mammals for halosulfuron - methyl is undetermined. The metabolism data indicated that with oral administration, halosulfuron - methyl was absorbed rapidly with incomplete absorption from the GI tracts. Within 72 hours, the absorbed halosul furon - methyl was eliminated in the urine and feces. Desmeth ylNC - 319 an d the 5 - hydrox y derivative were the major urinary and fecal metabolites. No tissue retention was demonstrated. The absorption , elimination , and metabolism showed no sex dependence. H alosulfuron - methyl has low acute toxicity (Toxicity Category III - IV ) b y oral, dermal, and inhalation routes of exposure. It is not a dermal sensitizer. With repeated dosing, the available data show that the dog is the most sensitive mammalian species . In the dog, decrease d body weight was seen in the chronic oral toxicity study and decreased body weight gain was observed in females in the subchronic oral toxicity study . In the rat and mouse, there was a decrease in body weight gains at high dose leve ls in short - and long - term oral and dermal studies. The results of both acute and subchronic neurotoxicity studies showed no neurotoxic effects. There was no quantitative evidence for increased susceptibility following pre - and/or post - natal Water solubility at 20 oC pH 5 0.0015 g/100 mL pH 7 0.165 g/100 mL pH 9 0.747 g/100 mL Solvent solubility at 20 oC methanol 0.1616 g/100 mL n - hexane 0.001278 g/100 mL Vapor pressure <1 x 10 - 7 mm Hg at 25 oC Dissociation constant, Ka 3.61 x 10 - 4 at 22.4 oC Octanol/water partition coefficient, Log(KOW) at 23 oC 1.67 at pH 5

- 0.0186 at pH 7

- 0.542 at pH 9 UV/visible absorption spectrum Not availablePage 14 of 47

exposure. H owever, there was qualitative evidence for increased susceptibility . In the rat study , increases in resorptions, soft tissue (dilation of the lateral ventricles) and skeletal variations, and decreases in body weights were seen in the fetuses compared to c linical signs and decreases in body weights and food consumption in the maternal animals. In the rabbit study , increases in resorptions and post - implantation losses and decrease in mean litter size was seen in the presence of decrease s in body

weight and food consumption in maternal animals. Thus, in both species, the developmental effect was considered to be qualitatively more severe than maternal effects (i.e., qualitative evidence for susceptibility). In both studies, there are clear NOAELs/LOAELs for developmental and maternal toxicities, developmental effects were seen in the presence of maternal toxicity, and the effect s were onl y seen at the high dose. Additionally , in rats developmental effects were seen at a dose which is approaching the limit - d ose. The degree of concern is low and there are no residual uncertainties for prenatal toxicity in both rats and rabbits. Halosulfuron - methyl is negative for mutagenicity in a battery

of genotoxicity

studies. Halosulfuron - methyl is classified as “not like ly to be carcinogenic to humans” based on lack of evidence for carcinogenicity in mice and rats following long - term dietary administration. Cancer risk assessment will not be conducted for halosulfuron methyl.. The PODs and toxicity

endpoints selected f

or various exposure scenarios applicable to this risk assessment are summarized in Table s 3.1 (Non - O ccupation al ) and 3.2 (Occupational). Table 3.1 . Toxicological Doses and Endpoints for Halosulfuron - M ethyl for Non - Occupational Hum an Health

Risk Assessme nts . Exposure/ Scenario Point of

Departure Uncertainty/

FQPA Safety Factors RfD, PAD,

Level of Concern for Risk Assessment Study and Toxicological Effects

Ac ute Dietary (Females 13 - 49 years of age) NOAEL=

50 mg/kg/day UF A= 10x

UF H= 10x FQPA SF= 1x Ac ute R fD = 0.5

mg/kg/day aPAD =0.5 mg/kg/day Developm ental Toxicity - Rabbit

LOAEL = 150 mg/kg/day based on decreased mean litter size, increased number of resorptions (total and per dam) and increased postimplantation loss (developmental toxicity) . Ac ute Diet ary (General Population including Infants and Children) N/A N/A N/A No adverse effect attributable to a single dose wa s identified; therefore, no dose/endpoint wa s 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 gains in females. Incidental Oral Short - Term

(1 - 30 days) NOAEL=

50 mg/kg/day UF A= 10x

UF H= 10x FQP A SF= 1x Residential LOC

for MOE = 100 Developm ental Toxicity - Rabbit

LOAEL = 150 mg/kg/day based on decreased body weight gain, food consumption, and food efficiency (maternal toxicity) .Page 15 of 47

Table 3.1 . Toxicological Doses and Endpoints for Halosulfuron - M ethyl for Non - Occupational Hum an Health

Risk Assessme nts . Exposure/ Scenario Point of

Departure Uncertainty/

FQPA Safety Factors RfD, PAD,

Level of Concern for Risk Assessment Study and Toxicological Effects

Incidental Oral Intermediate Term (1 - 6 mo nths) NOAEL=

10 mg/kg/day UF A= 10x

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

for MOE = 100 13 Week Subchronic Toxicity - Dog

LOAEL = 40 mg/kg/day based on decreased body weight gain s and food efficiency along with hematological and clinical chemistry changes . Dermal Short Term (1 - 30 days) NOAEL=

100 mg/kg/day UF A= 10x

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

for MOE = 100 21 - Day Derm al Toxicity Study - Rat

LOAEL = 1000 mg/kg/day based on decreased body weight gain in males. Dermal Intermediate Term (1 - 6 mo nths) + NOAEL=10

mg/kg/day UF A= 10x

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

for MOE = 100 13 Week Subchronic Toxicity - Dog

LOAEL = 40 mg/kg/day based on decreased body weight gain s and food efficiency along with hematological and clinical chemistry changes . Inhalation Short - Term (1 - 30 days) NOAEL =

50 mg/kg/day UF A= 10x

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

for MOE = 100 Developm ental Toxicity - Rabbit

LOAEL = 150 mg/kg/day based on decreased body weight gain, food consumption, and food efficiency (maternal toxicity) . Inhalation Intermediate Term (1 - 6 mo nths) NOAEL=

10 mg/kg/day UF A= 10x

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

for MOE = 100 13 Week Subchronic Toxicity - Dog

LOAEL = 40 mg/kg/day based on decreased body weight gain s and food efficiency along with hematological and clinical chemistry changes . Cancer (oral, dermal, inhalation) Classification: "not likely to be carcinogenic to hum ans" by the oral route, based on no

evidence of carcinogenicity from studies in rats and mice . + : A 75% dermal absorption factor should be used in route - to - route extrapolation for the intermediate term dermal exposure risk. Absorption via the inhalation route is presumed to be equivalent to oral absorption. NOAEL = no observed adverse effect level. LOAEL = lowest observed adverse effect level. UF = uncertainty factor. UF A = extrapolation from animal to human ( int e r - species ). UF H = potential variation in sensitivity among members of the human population ( intr a - species ). FQPA SF = FQPA Safety Factor. PAD = population adjusted dose (a = acute, c = chronic). RfD = reference dose. MOE = margin of exposure. LOC = level of concern. N/A = not applicable.Page 16 of 47

Table 3.2 . Summary of Toxicological Doses and Endpoints for Halosulfuron - M ethyl for Occupational Hum an

Health Risk Assessments . Exposure/ Scenario Point of

Departure (m g/kg/day) Uncertainty

Factors Level of Concern

for Risk Assessment Study and Toxicological Effects Dermal Short Term (1 - 30 days) NOAEL=

100 UF A= 10x

UF H= 10x Occupational LOC

for MOE = 100 21 - Day Derm al Toxicity Study - Rat

LOAEL = 1000 mg/kg/day based on decreased body weight gain in males. Dermal Intermediate Term (1 - 6 mo nths) + NOAEL=10 UF A= 10x UF H= 10x Occupational LOC

for MOE = 100 13 Week Subchronic Toxicity - Dog

LOAEL = 40 mg/kg/day based on decreased body weight gain s and food efficiency along with hematological and clinical chemistry changes . Inhalation Short - Term

(1 - 30 days) NOAEL=50 UF A= 10x UF H= 10x Occupational LOC

for MOE = 100 Developm ental Toxicity – Rabbit

LOAEL = 150 mg/kg/day based on decreased body weight gain, food consumption, and food efficiency (maternal toxicity) . Inhalation Intermediate term (1 - 6 mo nths) NOAEL=

10 UF A= 10x

UF H= 10x Occupational LOC

for MOE = 100 13 Week Subchronic Toxicity - Dog

LOAEL = 40 mg/kg/day based on decreased b ody weight gain s and food efficiency along with hematological and clinical chemistry changes . Cancer (oral, dermal, inhalation) Classification: "not likely to be carcinogenic to hum ans" by the oral route, based on no

evidence of carcinogenicity from studi es in rats and mice . + : A 75% dermal absorption factor should be used in route - to - route extrapolation for the intermediate term dermal exposure risk. Absorption via the inhalation route is presume d to be equivalent to oral absorption. NOAEL = no observed adverse effect level. LOAEL = lowest observed adverse effect level. UF = uncertainty factor. UF A = extrapolation from animal to human ( intra - species ). UF H = potential variation in sensitivity among members of the human population ( inter - species ). MOE = margin of exposure. LOC = level of concern. 3.1 FQ PA S afety F actor for Infants and Children A detail ed analy sis of the data supporting HED’s FQPA evaluation is presented in a previous risk as sessment ( D331643 , M. Rust, 9/21/06 ). No additional data have been submitted and no new policy

changes have been implemented that would change the conclusion s of the 2006 risk assessment . With the exception of a new data requirement for an immunotoxicity study , the conclusion s regarding the FQPA Safety Factor in the previous risk assessment are applica ble to the current action and are summarized below. HED has determined that reliable data show it would be safe for infants and children to reduce the FQPA safety factor to 1X. Th e d ecision is based on the following findings:

1. The adequacy

of the halosulfuron - methyl data has been described in Section 3.0. To reiterate, the toxicity

database for halosulfuron - methyl is complete for FQPA safety evaluation and toxicity endpoint and points of departure evaluation. However, under the new rule for registration an immunotoxicity study is required . After anal ys is of the database, an additional factor (UF DB ) for databasePage 17 of 47 uncertainty is not needed to account for the lack of this study because the available data do not suggest that this chemical affects the immune s ys tem . 2. There is no evidence of increased susceptibility of young rats in the reproduction study with halosulfuron - methyl . Although there is qualitative evidence of increased susceptibility

in the prenatal developmental studies in rats and rabbits, the risk assessment team did not identify any residual uncertainties after establishing toxicity

endpoints and uncertainty factors to be used in the risk assessm ent of halosulfuron - methyl . The degree of concern for pre - and/or post natal toxicity

is low and there are no residual uncertainties . 3. There is no indication in the toxicity data which in c lude acut e and subchronic neurotoxicity

studies that h alosulfuron - me thyl is a neurotoxic chemical , and there is no need for a developmental neurotoxicity study or additional f

actors (UFs) to account for neurotoxicity. 4. There are no residual uncertainties identified in the exposure databases. The dietary food exposure a ssessments were performed based on 100% CT and tolerance - level residues , and conservative (protective) assumptions in the ground water and surface water modeling were used to assess exposure to halosulfuron methyl in drinking water. S imilarly conservativ e assumptions were also used to assess post - application exposure of children as well as incidental oral exposure of toddlers. These assessments will not underestimate the exposure and risks posed by halosulfuron - methyl . 3. 2 Endocrine Disruption As requi red under FFDCA section 408(p), EPA has developed the Endocrine Disruptor Screening Program (EDSP) to determine whether certain substances (including pesticide active and other ingredients) may have an effect in humans or wildlife similar to an effect prod uced by a “naturally

occurring estrogen, or other such endocrine effects as the Administrator may designate.” The EDSP employ s a two - tiered approach to making the statutorily required determinations. Tier 1 consists of a battery of 11 screening assay s to identify the potential of a chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal sy stems. Chemicals that go through Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal sy stems w ill proceed to the next stage of the EDSP where EPA will determine which, if any , of the Tier 2 tests are necessary based on the available data. Tier 2 testing is designed to identify any adverse endocrine related effects caused by the substance, and estab lish a quantitative relationship between the dose and the E, A, or T effect. Between October 2009 and February 2010, EPA issued test orders/data call - ins for the first group of 67 chemicals, which contains 58 pesticide active ingredients and 9 inert ingre dients. This list of chemicals was selected based on the potential for human exposure through pathway s such as food and water, residential activity , and certain post - application agricultural scenarios. This list should not be construed as a list of known or likely endocrine disruptors.Page 18 of 47

Halosulfuron - methyl is not among the group of 58 pesticide active ingredients on the initial list to be screened under the EDSP. Under FFDCA sec. 408(p) the Agency must screen all pesticide chemicals. Accordingl y, EPA anticipates issuing future EDSP orders/data call - ins for all Registration Review cases, including those for which EPA has already opened a Registration Review docket for a pesticide active ingredient. For further information on the status of the EDSP, the policies and procedures, the list of 67 chemicals, the test guidelines and the Tier 1 screening battery , please visit our website: http://www.epa.gov/endo/. 4.0 D IETARY E XPOSURE/RISK CHARACTERIZATION 4.1 Pesticide Metabolism and Enviro n mental Degradation Nature of the Residue - Plants The nature of the residue in plants is adequatel y understood based on acceptable metabolism studies reflecting pre - and postemergence modes of applications on corn, sug arcane, and soy bean . The metabolism of halosulfuron - methyl was similar in the three tested crops but dependent on the mode of application . When halosulfuron - methyl was applied preemergence, initial breakdown of the herbicide in the soil and preferential uptake of the py razole moieties resulted in the primary

residue being 3 - chlorosulfonamide ( 3 - CSA ) , which has been determined to be less toxic than the parent. With a postemergence application, the major residue was the parent compound with minimal translo cation of the herbicide in the plant, except in grain where the major residue was 3 - CSA. Based on the very

low toxicity

of the metabolite 3 - CSA, relatively low toxicity

of the parent compound, and low residue levels of both parent c ompound and the 3 - CSA metabolite, HED has concluded that the residue of concern in plants is the parent compound, halosulfuron - methyl. Nature of the Residue - Livestock Acceptable livestock metabolism studies conducted on goats and hens were previously s ubmitted in conjunction with petitions for uses on corn and sorghum. In goat milk and tissues, the major extractable residue was the parent; acid hydrol ys is released bound or conjugated residues of aminopy rimidine and 3 - CSA. HED has concluded that the re sidue of concern in ruminants is halosulfuron - methyl; 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 - CSA, tolerances for resi dues in livestock commodities are expressed in terms of halosulfuron - methyl and its metabolites determined as 3 - CSA, expressed as halosulfuron - methyl equivalents. There are no poultry

feedstuffs associated with the recommended tolerances and crop uses addressed in this action. In addition, Due to low use rates, low residue levels of halosulfuron - methyl in poultry feed items, and the low transfer rate of residues to poultry tissues, tolerances for halosulfuron - methyl residues in poultry commodities are n ot required (PP#Page 19 of 47

2G4073 , G. J. Herndon , 3/8/94) . Therefore, a discussion of the metabolism of halosulfuron methyl in poultry

is not need ed in this action . Residue Analytical Methods Plants : The residue anal ytical methods data are adequate to satisfy dat a requirements for the subject action. An acceptable residue anal ytical method (GC) is available for tolerance enforcement purposes for residues in/on crop commodities (i.e., Monsanto Analy tical Method RES - 109 - 97 - 4 (MRID 44495801)) . Residues of halosulfuron - methyl in/on the crop commodities from the magnitude of the residue studies were determined using an acceptable data collection method. Residue in plants were anal yz ed as the RRE of halosulfuron - methyl (structure is shown in Table 2.3.1). Livestock : An adequate analy tical method is available for enforcement of tolerances for secondary residues of halosulfuron - methyl in livestock commodities. The method (GC) has been validated as an enforcement method by the Anal yt ical Chemistry Branch (ACB)/BEAD at a limit of quanti fic ation of 0.01 ppm in milk and liver (D. Swineford, 4/28/95). Multiresidue Methods Adequate multiresidue method data for halosulfuron - methyl and 3 - CSA were submitted previously

in conjunction with PP# 3F4193 (D189198, G.J. Herndon , 3/8/94) . Residues of halosulfuron - methyl and 3 - CSA are not recoverable by the FDA Multiresidue Protocols A through E. The results have been forwarded to FDA. A dditional Reference Standards As indicated in the most recent risk assessment (D358031, W. Phang, 6 /30/09), the registrant must submit analy

tical reference standards for the 3 - CSA (3 - chlorosulfonamide acid) metabolite and the rearrangement ester (RRE) of halosulfuron - methyl to the EPA National Pesticide Standards Repository . Storage Stability A dequate storage stability data are available to support the storage conditions and durations of samples collected from the magnitude of the residue and processing studies on apples, blueberry , dry bean seed, succulent pea seed, potato tuber, potato processed commo dities, and rhubarb. As residues of halosulfuron - methyl have been found to be stable in tested crop matrices, which are representative of the currently proposed crops proposed crops , storage stability corrections need not be applied to the recommended tol erances for halosulfuron - methyl residues in this action. Meat, Milk, Poultry, and Eggs The livestock feedstuffs derived from registered and proposed uses w ould not significantl y increase the dietary

burden s of halosulfuron - methyl to beef and dairy cattle p rovided the petitioner amends the proposed use directions of Sandea® Herbicide on Crop Subgroup 6B to prohibit applications to legumes grown for livestock feeds. The available dairy cattle feeding study is adequate, and HED conclude s that tolerances for halosulfuron - methyl residues of concern need not be established for the milk, meat, and fat of cattle, goat, hog, horse, and sheep. The established tolerance s of 0.1 ppm for the meat by products of cattle, goat, hog, horse, and sheep remain adequate. There are no poultry and swine feedstuffs associated with thePage 20 of 47

recommended tolerances and crop uses. The petitioner should note that if additional uses are proposed in the future which would result in an increase in the dietary burdens, HED will re assess the adequacy

of established animal tolerances. Crop Field Trials IR - 4 has submitted magnitude of the residue studies on apples, blueberry , dry bean, succulent pea, potato, and rhubarb. The results from these field trials are discussed below and the residue data are summarized in Table 4. 1. 2 . Table 4. 1. 2. Summary of Residue Data fromCrop Field Trials with Halosulfuron - M ethyl . Crop Matrix Total Applic.

Rate (lb ai/A) PHI

(days) Residues of Halosulfuron - methyl (ppm)

n Min. Max. HAFT 1 Median Me an Std. Dev. Apple (proposed use = 0.094 lb ai/A total application rate, 14 - day PHI) Apple (fruit) 0.092 - 0.104 13 - 14 26 <0.05 a <0.05 <0.05 0.05 0.05 -- Bushberry Subgroup 13 - 07B (proposed use = 0.094 lb ai/A total application rate, 14 - day PHI) Blueberry (fruit) 0.093 - 0.099 13 - 14 12 <0.05 <0.05 <0.05 0.05 0.05 -- O kra (proposed use = 0.094 lb ai/A total application rate, 30 - day PHI) Okra No okra data were submitted. Pea and Bean, Succulent Shelled, Subgroup 6B (proposed use = 0.023 lb a i/A total application rate, 30 - day PHI) Pea seed 0.032 55 - 68 4 <0.05 <0.05 <0.05 0.05 0.05 --

0.060 - 0.070 55 - 72;

166 2 18 <0.05 <0.05 <0.05 0.05 0.05 -- Pea seed in pods 0.065 - 0.066 69 - 77 6 <0.05 <0.05 <0.05 0.05 0.05 -- Pea and Bean (Except Soybean), Dried Shelled, Subgroup 6C (proposed use = 0.047 lb ai/A total application rate per crop cycle and 0.094 lb ai/A total application rate per year, 30 - day PHI) Dry bean seed 0.061 - 0.075 27 - 31 24 <0.05 <0.05 <0.05 0.05 0.05 -- Rhubarb (proposed use = 0.047 lb ai/A total application rate, 60 - day PHI) Rhubarb petiole 0.093 - 0.101 61 - 78 8 <0.05 <0.05 <0.05 0.05 0.05 -- Tuberous and Corm Vegetables, Subgroup 1C (proposed use = 0.047 lb ai/A total application rate, 45 - day PHI) Potato tuber 0.094 - 0.103 42 - 46 28 <0.05 <0.05 <0.05 0.05 0.05 -- a L OQ = 0.05 ppm Apple The submitted field trial data for halosulfuron - methyl on apples are adequate with regard to the number (13) and locations (6 regions) of field trials. The application rate and PHI reflect the propos ed use pattern, and the data are supported by concurrent storage stability data. Although the apple data did not reflect the use of a nonionic surfactant as recommended on the proposed label , this is not an issue as the application is directed to the orch ard floor and presence/absence of surfactant is not expected to change the residue level on the apple fruit. The available data will support the proposed tolerance of 0.05 ppm for appl e.Page 21 of 47

Bushberry Subgroup 13 - 07B The submitted field trial data for halos ulfuron - methyl on blueberries and the representative commodity

of Crop Subgroup 13 - 07B are adequate with regard s to the number and location of field trials. The number of field trials is a 25% reduction of the OPPTS 860.1500 guidance ; this number is consi dered sufficient to support the Subgroup 13 - 07B tolerance based on the lack of quantifiable residues. The application rate and PHI reflect the proposed use pattern, and the data are supported b y concurrent storage stability data. However, the blueberry data did not reflect the use of a nonionic surfactant as recommended on the proposed label. The blueberry data support the proposed tolerance of 0.05 ppm for the b ushberry Subgroup 13 - 07B provided the label for Sandea® Herbicide is amended to remove the ins tructions pertaining to the use of a non - ionic surfactant on crops belonging to the Subgroup 13 - 07B. If it is IR - 4’s intention to add a nonionic surfactant when Sandea® Herbicide is applied on Subgroup 13 - 07B, then additional field trial data are required . Although the spray is directed to the rows between blueberry bushes, there is a finite possibility of the spray

contacting the bushes, and the presence/absence of surfactant might impact the residue on the blueberries. Okra No residue data were submi tted to support the proposed use on okra. Okra was listed by the petitioner in its proposed labels as part of the fruiting vegetables crop group. The ChemSAC meeting of 10/18/2006 has recommended the inclusion of okra in Crop Group 8 (fruiting vegetables ). The ChemSAC has also determined that a separate tolerance for okra should be listed in the appropriate section of the CFR entry until the new crop group regulation is published. A tolerance of 0.05 ppm for residues of halosulfuron - methyl has been esta blished on the fruiting vegetable Crop Group 8 based on field trial data for tomato and pepper (D267423, A. Acierto, 4/25/2002). The available field trial data for fruiting vegetables will be translated to okra. HED recommends for the establishment of a tolerance of 0.05 ppm for residues of halosulfuron - methyl in/on okra. This recommendation is identical to the level proposed b y the petitioner. Pea and Bean, Succulent Shelled, Subgroup 6B The representative crops of Subgroup 6B are any s ucculent shelled cultivar of bean ( Phaseolus spp.) and garden pea (

Pisum spp.). IR - 4 has submitted field trial data for halosulfuron - methyl on succulent shelled and edible podded peas from 12 field trials conducted in the United States during the 2003 - 2004 growing season s. The field trial data for succulent peas do not fully support the proposed use pattern because the trials were conducted at exaggerated rates (1.4 X or 2. 8X ) and the collected samples did not reflect the proposed 30 - day PHI (the earliest PHI tested was 5 5 day s). The available data for succulent beans, previously submitted under PP#1E06322 (D278587, A. Acierto, 6/15/20 02) to support the established individual tolerance of 0.05 ppm , also do not reflect the proposed use on Subgroup 6B because these data rep resent foliar application whereas the new proposed use pattern is for preemergence soil application. HED will not require additional data on succulent peas since treatment at 1X will likely result in residues below 0.05 ppm, even when harvested at a PHI of 30 - days. HED also will not require additional data on succulent beans since soil treatment will likely result in residues below 0.05 ppm. HED recommends for the proposed tolerance of 0.05 ppm for the Subgroup 6B (p ea andPage 22 of 47

b ean, s ucculent s helled) . Co ncomitant with the establishment of a tolerance for Subgroup 6 B, the individual tolerance for ‘bean, snap, succulent’ should be revoked. Pea and Bean (Except Soybean), Dried Shelled, Subgroup 6C The representative commodities of Subgroup 6C are any one dried cultivar of bean ( Phaseolus spp.) and any one dried cultivar of pea (Pisum spp.) The submitted residue data for dry bean are adequate with regard to geographic representation of data; the data are supported by concurrent storage stability

data. The dry

bean data from the current submission reflect a single foliar broadcast application conducted at ~1.6 X the proposed application rate per crop cycle (or ~0.8 X the proposed total application rate per year), the use of a nonionic surfactant, and an approxi mate 30 - day PHI. Additional data for dry beans were submitted under PP#1E06322 (DP#278587, A. Acierto, 6/15/20 02) to support the established individual tolerance of 0.05 ppm. These data represent a single application of Permit 75 WDG Herbicide at 0 .032 lb ai/A made 0 to 6 day s after planting and a 86 - to 113 - day PHI. HED is unable to recommend for the proposed tolerance of 0.05 ppm for Crop Subgroup 6C ( Dried Shelled Bean (Except Soy bean) and Pea) at this time because residue data on dried pea including the forages and hay of field pea cultivars are required. When adequate residue data for dried peas become available, the petitioner may again request a tolerance for Subgroup 6C . A revised Section F should be submitted removing the request for Crop Subgroup 6C (dried shelled pea and bean (except soybean)). Rhubarb The submitted field trial data for halosulfuron - methyl on rhubarb are adequate with regard to the number and location of field trials. The data also reflected the use of nonionic surfact ant as recommended on the proposed label , samples were collected at appropriate PHI , and were supported by

concurrent storage stability data. However, the rhubarb data were generated using slightly exaggerated rates of ~2.0 - 2.1X. At this time, HED does n ot require additional data on rhubarb since treatment at 1X is likely to yield residues below 0.05 ppm. The available data are supportive of the proposed tolerance of 0.05 ppm for rhubarb. Tuberous and Corm Vegetables, Subgroup 1C The submitted field tri al data for halosulfuron - methyl on potato, the representative commodity of Crop Subgroup 1C, reflect the use of a nonionic surfactant as recommended on the proposed label and approximate the proposed PHI. The data are also supported b y concurrent storage stability data. The number and location of field trials do not fully conform to the OPPTS 860.1500 guideline ; however, all the residue level were below the LOQ when conducted at the exaggerated use rates. Therefore, HED is not requesting additional field trials. The available data support the proposed use pattern, and HED recommends for a tolerance of 0.05 ppm for Crop Subgroup 1C. Processed Food and Feed Apple An additional plot was established at the NJ site using a total seasonal rate of 0.484 lb ai/A (~5.1X the proposed maximum seasonal rate), to generate samples for processing; however,Page 23 of 47

residues were not detectable in any apple fruit sample. An apple processing study and tolerances for apple processed commodities are not required for this action. Pot ato The submitted processing data for potato are acceptable. Residues of halosulfuron - methyl were nonquantifiable (<0.05 ppm) in/on potato tubers following treatments at 2 X the proposed seasonal rate. Residues were also nonquantifiable in processed potat o granules/flakes, chips, and wet peel. The Agency

would have preferred that a trial with an exaggerated rate equal to or higher than the maximum theoretical concentration factor of 5X for potato have been conducted. However, because of ph ytotoxicity lim itations as reported in the magnitude of the residue trials, a new potato processing study will not be required. Based on these data, tolerances for potato processed commodities are not needed. Confined/Field Accumulation in Rotational Crops Acceptable c onfined rotational and limited field rotational crop studies were previousl y submitted and review ed (D188144 & 188814 , G.J. Herndon , 3/11/93 ; D192510, G.F. Kramer, 8/30/93 ). The results of these studies indicate that metabolites containing the py razole moi ety may accumulate in harvested crops planted at intervals greater than one year. The confined rotational crop study, conducted at 0.19 lb ai/A, indicated that no measurable residues of halosulfuron - methyl were detected in any rotational crop commodities of wheat, soy bean, radish and lettuce at any plantback interval (30, 120, and 360 day s after treatment). The limited field rotational crop study, conducted at 0.22 lb ai/A in a split (preplant + postemergence) application, with rotated crops of winter whe at, spring wheat, soy bean, sugar beet, and leaf lettuce indicated that no measurable residues of halosulfuron - methyl were detected in any field rotational crop samples, except in one spring wheat forage sample at 0.090 ppm (364 - day plantback interval). HED previousl y concluded that the residue of concern in rotational crops is halosulfuron - methyl ( D225273, G.J. Herndon , 10/29/98 ) . Based on the absence of the parent compound in the confined studies and in the limited field rotational crop studies, with the exception of one forage sample, HED also concluded that rotational crop tolerances and restrictions are not required for halosulfuron - methyl. The proposed uses on okra, pea and bean (succulent shelled and dried), tuberous and corm vegetables, and rhu

barb are not expected to alter HED’s earlier assessment regarding the potential for inadvertent residues in rotat able crops addressed in this registration action. No additional data are required. Proposed Tolerances Halosulfuron - methyl tolerance s for p lant commodities have been established in 40 CFR § 180. 479 ( a) (2) and are expressed in terms of halosulfuron - methyl, methyl 5 - [(4,6 - dimethoxy- 2 - py rimidinyl)amino]carbonylaminosulfonyl - 3 - chloro - 1 - methyl - 1 H - py razole - 4 - carbox yl ate . The proposed tolerance expre ssion is consistent with the halosulfuron - methyl tolerances established in 40 CFR §180.479(a)(2) and reflect the residues of concern as previously determined by

HED. Halosulfuron - methyl t olerances for livestock commodities are listed in 40 CFR §180.479(a) (1) and are expressed in terms of halosulfuron - methyl and its metabolites determined as 3 - chloro - 1 -Page 24 of 47

methyl - 5 - sulfamoylpy

razole - 4 - carbox yl ic acid (also referred to as 3 - CSA, expressed as parent equivalents) . Residues of halosulfuron - methyl were below the LOQ of 0.05 ppm, when the test formulation was applied to the proposed crops according to the conditions and parameters used in the field trials. Table 4.1.4 presents the proposed/recommended tolerance levels and corrected commodity d efinition. HED is currently unable to recommend for a registration and tolerance for Crop Subgroup 6C (dried s helled b ean ( e xcept s oy bean) and p ea) because data are required for dried pea including the forages and hay of field pea cultivars . When adequat e residue data for dried peas become available, the petitioner may again request a tolerance for Subgroup 6C . Table 4.1.4 . Tolerance Summary for Halosulfuron - Me thyl. Comm odity (as Defined in Section F) Proposed Tolerance (ppm) Recommended

Tolerance (p pm) Comments; Correct Commodity

Definition PEA AND BEAN, SUCCULENT SHELLED, SUBGROUP 6B 0.05 0.05 HED recommends a label revision to prohibit applications to legumes grown for livestock feeds because no residue data are available for cow pea forage and hay . Pea and bean, succulent shelled, subgroup 6B VEGETABLE TUBEROUS AND CORM, SUBGROUP 1C 0.05 0.05 Vegetable, tuberous and corm, subgroup 1C RHUBARB 0.05 0.05 Rhubarb PEA AND BEAN, DRIED SHELLED, EXCEPT SOYBEAN, SUBGROUP 6C 0.05 None Revised Section F. When adequate residue data for dried peas become available, the petitioner may again request a tolerance for Subgroup 6C. Pea and bean, dried shelled, except soybean, subgroup 6C APPLE 0.05 0.05 The proposed label should be amended to remove the instructi ons pertaining to the use of a non - ionic surfactant. Apple OKRA 0.05 0.05 The recommended t olerance is based on translation of data from fruiting vegetables . Okra BUSHBERRY SUBGROUP 13 - 07B 0.05 0.05 The proposed label should be amended to remove the instructions pertaining to the use of a non - ionic surfactant. Bushberry subgroup 13 - 07B International Residue Limits There are no Codex or Canadian maximum residue limits ( MRL s ) established for residues of halosulfuron - methyl in/on crop or livestock commodi ties Table 4.1.5 .Page 25 of 47

Table 4.1.5. INTERNATIONAL RESIDUE LIMIT STATUS Chemical Name: methyl 5 - [(4,6 - dimethoxy - 2 - pyrimidinyl)amino]carbon ylaminosulfonyl - 3 - chloro 1 - methyl - 1 H

-py razole - 4 - carboxylate Common Name: Halosulfuron - methyl X Proposed tolerance □ Reevaluated tolerance □ Other Date: 10/2009

Codex Status (Maximum Residue Limits) U. S. Tolerances X No Codex proposal step 6 or above □ No Codex proposal step 6 or above for the crops requested Petition Number: PP# 9E7577 DP#: 367058 Other Identi fier: Residue definition (step 8/CXL): N/A Revie wer/Branch: P. Deschamp, N. Dodd/RAB3 Residue definition: halosulfuron - methyl Crop (s) MRL (mg/kg) Crop(s) Tolerance (ppm) Pea and bean, succulent shelled, Subgroup 6B 0.05 Vegetable, tuberous and corm , Subgroup 1C 0.05 Rhubarb 0.05 Pea and bean, dried shelled, except soybean, Subgroup 6C 0.05 Apple 0.05 Okra 0.05 Bushberry, Subgroup 13 - 07B 0.05 Limits for Canada Limits for Mexico X No Limits □ No Limits for the crops requested X No Limits □ No Limits for the crops requested Residue definition: N/A Residue definition: N/A Mexico defers to Codex MRLs or US tolerances for its export purposes. Crop(s) MRL (mg/kg) Crop(s) MRL (mg/kg) Not es/Special Instructions: S. Funk, 10/15/2009. Drinking Water Residue Profile The drinking water residues used in the dietary risk assessment were provided by EFED in the following memorandum: “Halosulfuron - methyl Drinking Water Assessment for Addition al Food Uses (including Proposed Use on Soy bean)” ( D358032, M. Barrett, 5/27/20 09) and incorporated directly into this dietary

assessment. Water residues were incorporated in the DEEM - FCID into the food categories “water, direct, all sources” and “water, indirect, all sources.” Since the application rates associated with the proposed new uses did not exceed the application rate on rice (0.125 lb ai/A), a new drinking water assessment was not required for this dietary anal ys is. The Tier I EDWCs f

or halosulfuron - methyl are based on a maximum annual application rate of 0.125 lb ai/A for rice. The two screening models, FQPA Index Reservoir Screening Tool (FIRST) and Screening Concentration in Ground Water (SCI - GROW), were used for estimatin g EDWCs ofPage 26 of 47

halosulfuron - methyl. Estimates for halosulfuron - methyl in surface water based on the FIRST model results for rice are 59.2 ppb for acute and chronic concentrations. It should be noted that the drinking water estimate based on rice application is an upper bound estimate. The estimate for halosulfuron - methyl in groundwater based on the SCI - GROW model result is 0.065 ppb. The results are summarized in Table 4.1.6. Table 4.1. 6 . Summary of Estimated Surface Water and Groundwater Concentrations for Halosu lfuron M ethyl. Surface Water Conc., ppb a Groundwater Conc., ppb b Ac ute 59.2 0.065 Chronic (non - cancer) 59.2 0.065 a From the FIRST model. b From the SCI - GROW model. 4. 2 Dietary Exposure and Risk Halosulfuron - methyl acute and chronic dietary exp osure assessments were conducted using the Dietary Exposure Evaluation Model software with the Food Commodity Intake Database DEEM - FCIDTM, Version 2.03, which incorporates consumption data from USDA’s Continuing Survey s of Food Intakes by Individuals (CSFII), 1994 - 1996 and 1998. Acute Dietary Exposure/ R isk For acute dietary

anal ys is, exposure assessment was conducted u sing tolerance levels and 100 %CT for all existing and proposed uses. EDWCs from EFED were incorporated directly into the exposure anal ys is. The only population with a toxicological endpoint attributable to a single dose of halosulfuron - methyl is identif ied to be females 13 - 49 y rs old. The results of the anal ys is indicate that acute risk from the dietary exposure to halosulfuron - methyl did not exceed HED’s level of concern for females 13 - 49 y rs old at less than 1% of the aPAD ( Table 4.2.1 ) . Chronic Diet

ary Exposure/

R isk For chronic dietary

exposure assessment, an estimate of the residue level in each food or food form (e.g., orange or orange juice) on the food commodity residue list is multiplied by the average dail y consumption estimate for that food/fo od form to produce a residue intake estimate. The resulting residue intake estimate for each food/food form is summed with the residue intake estimates for all other food/food forms on the commodity residue list to arrive at the total average estimated exposure. Exposure is expressed in mg/kg body weight/day and as a percent of the cPAD. This procedure is performed for each population subgroup. The results are summarized in Table 4.2.1. The resul ts show that the chronic dietary (food and drinking water) exposure to halosulfuron - methyl is below HED’s level of concern for the general U.S. population and all population subgroups. The chronic dietary risk estimates are 2 % of the cPAD for the general U.S. population and 5 % of the cPAD for all infants (<1 year old), the most highly exposed population subgroup.Page 27 of 47

Table 4.2.1. Summary of Dietary Exposure and Risk for Halosulfuron - M ethyl. Population Subgroup Acute Dietary (95th Percentile) Chronic Dietary Dietary Exposure (m g/kg/day) % aPAD Dietary Expo sure (m g/kg/day) % cPAD General U.S. Population N/A N/A 0.001705 2 All Infants (< 1 year old) 0.005059 5 Children 1 - 2 years old 0.003157 3 Children 3 - 5 years old 0.002823 3 Children 6 - 12 years old 0.001859 2 Youth 13 - 19 years old 0.001327 1 Adults 20 - 49 years old 0.001511 2 Adults 50+ years old 0.001558 2 Fem ales 13 - 49 years old 0.003401 <1 0.001503 2 The population subgroup with the highest estimated exposure/risk is bolded. 5 .0 RESIDENTIAL (Non - Occupational) EXPOSURE/RISK CHARACTE RIZATION The current petition focuses on the proposed agricultural use of halosulfuron - methyl on s ucculent shelled pea and bean, tuberous and corn vegetables subgroup dried shelle d pea and bean (except so ybean), bushberry, okra, apples, and rhubar b; no residential uses are being requested. However, some halosulfuron - methyl labels permit application to commercial and residential turf and on other non - crop sites including airports, cemeteries, fallow areas, golf courses, landscaped areas, public recreation areas, residential property , road sides, school grounds, sod or turf seed farms, sports fields, landscaped areas with established woody ornamentals and other similar use sites. Su ch residential handler and postapplication exposures were previousl y assessed (D331643, M. Rust, 9/21/2006). A major portion of that residential assessment is reproduced in this document for the purposes of conducting the aggregate exposure and risk asses sment. A product containing halosulfuron - methyl, Manage® (EPA Reg No. 524 - 465), which contains 75% halosulfuron - methyl, is currently registered for application to commercial and residential turf and other non - crop sites including airports, cemeteries, fal low areas, golf courses, landscaped areas, public recreation areas, residential property, road sides, school grounds, sod or turf seed farms, sports fields, landscaped areas with established woody ornamentals and other similar use sites. Manage® may be ap plied by

homeowners or commercial applicators at a rate of 0.031 to 0.062 lb ai/acre. No more than 4 applications may be made per use season, for a maximum total use rate of 0.125 lb ai/A per season. Residential handlers may receive short - term dermal and inhalation exposure to halosulfuron methyl when mixing, loading and applying the formulations. Adults and children may be exposed to halosulfuron - methyl residues through dermal contact with turf during postapplication activities. In addition, toddlers m ay receive short - and intermediate - term oral exposure from incidental ingestion during postapplication activities. A residential exposure and risk assessment was previousl y conducted for these exposure scenarios (D278588, K. O’Rourke, 8/28/02) and is summ arized in the following sectionsPage 28 of 47

5.1 Residential Handler Exposure No chemical - specific exposure data for handler activities were submitted to HED in support of the registered lawn uses. HED’s Draft Standard O perating Procedures (SOPs) for Residential Exposure Assessments, and Recommended Revisions (HED Policy Number 11, revised 22 Feb 2001), were used as the basis for the residential handler exposure calculations. The handler exposure data used in this assess ment are from the Outdoor Residential Exposure Task Force (ORETF) (MRID 44972201). The ORETF data were used in this assessment in place of PHED data for the garden hose - end sprayer scenario. The ORETF data were designed to replace the present PHED data w ith higher - confidence, higher quality data that contain more replicates than the PHED data for those scenarios. The upper - bound risk estimate for residential handlers and post - application exposure is a MOE of 5,200 (Table 5.1) , and it is not of risk concern. Table 5.1. Adult’s Combined Exposure and Risk Estim ates fromResidential Lawns .

Adult’s Scenario Exposure Route Rate

(lb ai/ acre) Acres Treated (acres/ day) PHED

Unit Exposure (m g/lb ai) Short - term

Daily Dose (m g/kg/day) Short ter m MOE 1 Total

MOE 2 1. M ix/load and broadcast application of liquid formulation (garden hose - end sprayer) dermal 0.062 0.5 30 0.0043 2 3 ,000 5,200 inhalation 0.016 0.0000071 7,000,000 2. Postapplication exposure dermal 0.062 N/A N/A 0.014 7,000 1. Short - term

dermal NOAEL = 100 mg/kg/day; Short - term inhalation NOAEL = 50 mg/kg/day. 2. Total MOE = dermal + inhalation exposure from both handler and post - application activities; Total MOE=1/(1/dermal MOE+1/inhalation MOE) 5.2 Re sidential Postapplication Exposure The following postapplication exposure scenarios resulting from lawn treatment were assessed: (1) adult and children 3 to <6 years old post - application dermal exposure, (2) child 3 to <6 years old incidental ingestion of pesticide residues on lawns from hand - to - mouth transfer, (3) toddlers’ object - to - mouth transfer from mouthing of pesticide - treated turf grass, and (4) children 3 to <6 ye ars old incidental ingestion of s oil from pesticide - treated residential areas. Post - application exposures from various activities following lawn treatment are considered to be the most common and significant in residential settings. The exposure via incidental ingestion of other plant m aterial may

occur but is considered negligible. The exposure and risk estimates for the residential exposure scenarios are assessed for the day of application (day

“0") because it is assumed that adults and child 3 to <6 years old could contact the lawn immediately

after application. Both short - and intermediate - term exposure is expected. Dermal postapplication risk was assessed b y comparing the dermal exposure values to the NOAELs of 100 mg/kg/day and 10 mg/kg/day , respectivel y. Risk from short - and intermediate term incidental ingestion by child 3 to <6 ye ars old is assessed b y comparing these exposures to the NOAELs of 50 mg/kg/day and 10 mg/kg/day , respectivel y. Both short - term and intermediate - term MOEs for each scenario are above the LOC of 100, and are not of concern. As mentioned previousl y, a common effect (i.e., decreased body weightPage 29 of 47

gain) was observed in the studies selected for the endpoints for all routes of exposure; therefore, MOEs are to be combined where appropriate. The Total MOEs resulting from the combined MOEs for adults (summarized in Table 5.1 above) and children (summarized in Table 5.2), are also above the LOC of 100, and not of concern. Table 5.2 .. Children’s Combined Exposure and Risk Estim ates from Residential Lawn s . Children’s Scenarios TTR/GR/SR0

(ug/cm2 or g) 1 Short - Term

PDR0 - norm (m g/k g/day) Int - Term

PDR0 - norm (m g/k g/day) Short Term MOE Int - term

MOE Total

Short Term MOE Total

Int - term MOE (1) Dermal Contact 0.035 0.024 0.0090 4,200 1,100 3,800 1,000 (2) Hand - to - Mouth 0.035 0.00093 0.00044 54,000 23,000 (3) Mouthing Grass 0.14 0.00023 0.00023 220,000 43,000 (4) Soil Ingestion 0.47 3.1E - 6 3.1E - 6 16,000,000 3,200,000 1. TTR=turf transferable residue on day “0"; GR=grass residue on day “0"; SR0 =soil residue on day “0" ; Int=intermediate . 5.3 Other (Spray Drift, etc.) Recreational exposures to turf are expected to be similar to, or in many cases less than, those evaluated in Section 5 .2 , Residential Post - application Exposure; therefore, a separate recreational exposure assessment was not included. Spray drift is alway s a potential source of exposure to residents nearby to spraying operations. This is particularly

the case with aerial applications, but, to a lesser extent, could also be a potential source of exposure from ground application methods. As indicated in this assessment, halosulfuron - methyl is directl y applied to residential turf and does not result in exposures of - concern to HED. Based on this assessment, HED believes that it is unlikely that there is a higher potential for risk of exposure to spray drift from agricultural uses of this chemical. 6.0 AGGREGATE RISK ASSES SMENTS AND RISK CHAR ACTERIZATION 6.1 Acute Aggregate Risk An acute aggregate risk assessment was conducted for the population subgroup of concern, females 13 - 49 ye ars old. An appropriate endpoint for the general population was not identified; therefore, a corresponding assessment is not required. For the population of concern, the acute dietary risk assessment reported earlier in Section 4.2 represents acute aggregate risk since drinking water estimates were incorporated directly into the anal ys is. Exposure through food and drinking water sources occupies less than 1 % of the aPAD for the population of concern, Females 13 - 49 ye ars old; thus, estimated acute aggregate risk does not exceed HED’s level of concern ( Table 6.1 ) .Page 30 of 47

Table 6.1 Acute Aggregate Risk (Food+Water) . Population Subgroup aPAD(m g/kg/day) Exposure (mg/kg/day) % a PAD Females 13 - 50 years old 0.5 0.00 3 401 <1 6.2 Short - T erm Aggregate Risk The short - term aggregate risk assessment estimates risks likely to result from exposure to halosulfuron - methyl residues from food, drinking water, and residential pesticide uses. High - end estimates of residential exposure are used , while average values are used for food and drinking water exposure (i.e. , chronic exposures). Since the LOC is the same for all routes of exposure, e xposures are compared to the short - term NOAEL corresponding to the route of exposure to calculate a rout e - specific MOE. Then an aggregate MOE was calculated by combining MOEs across all relevant routes of exposure (oral, dermal and inhalation). A short - term risk assessment is required for adults because there is a residential handler exposure scenario. In addition, a short - term risk assessment is required for infants and children because there is a residential post - application exposure scenario for infants and children. Results of the short - term aggregate risk assessment are summarized in Table 6.2 be low. Short term aggregate MOEs ranged from 2, 8 00 to 4, 8 00 . The MOE for the U.S. p opulation is 4, 7 00 . The most highl y exposed subgroup was all i nfants ( < 1 year old), with a MOE of 2, 8 00. These estimates of short - term aggregate risk do not exceed HED’s level of concern. Table 6.2. Short - Term Aggregate Risk Calculations. Population LOC for

Aggregate Risk 1 MOE

food & water 2 MOE

oral3 MOE

derm al 4 MOE

inhalation 5 Aggregate MOE

(food and residential) 6 U.S. Population 100 29,000 N/A 5,500 7,000,000 4,7 00 Females, 13 - 49 years old 33,000 N/A 5,500 7,000,000 4,800 All Infants (<1 year old) 9,900 43,000 4,200 N/A 2,800 Adults 50+ years 32,000 N/A 5,500 7,000,000 4,700 1 HED’s LOC is a MOE of at least 100 (10X for inter - species variability and 10X fo r intra - species variability) 2 MOE food = [(short - term oral NOAEL=50 mg/kg/day) / (chronic dietary exposure)] Dietary exposure from Table 4.4.2. 3 MOE oral = [(short - term oral NOAEL=50 mg/kg/day) / (oral residential exposure)] Residential exposure from Tab le 5.2. 4 MOE dermal = [(short - term dermal NOAEL=100 mg/kg/day) / (high - end dermal residential exposure (for adult, included

mix/load plus post - application exposure ) ) ]. Residential exposure from Tables 5.1 and 5.2. 5 MOE inhalation = [(short - term inhalation NOAEL=50 mg/kg/day) / (high - end inhalation residential exposure)] Residential MOEs from Table 5.1. 6 Aggregate MOE (food and residential) = 1  [(1/MOE food) + (1/MOE oral) + (1/MOE dermal) + (1/MOE inhalation)]. 6.3 Intermediate - Term Aggregate RiskPage 31 of 47

The intermediate - term aggregate risk assessment estimates risks likely to result from exposure to halosulfuron - methyl residues from food, drinking water, and residential pesticide uses. High - end estimates of residential exposure are used, while average values are used for food and drinking water exposure (i.e. , chronic exposures). Intermediate - term exposures across all routes of exposure were summed and compared to the intermediate - term NOAEL (10 mg/kg/day) from the 13 - week subchronic t oxicity study in dogs , since this study

and endpoint are to be used for all intermediate - term risk assessments ( LOAEL = 40 mg/kg/day based on decreased body weight gains and food efficiency along with hemat ological and clinical chemistry changes ). The aggregate MOEs for adults include intermediate - term dermal and inhalation exposures for residential handlers and post - application dermal exposures from activities on turfgrass previously treated with halosulfuron - methyl. The inclusion of intermediate - term residential handler exposures in the aggregate MOE is conservative (protective), since intermediate - term exposure of handlers is unlikely . Results of the intermediate - term aggregate risk assessment are summarized in Table 6.3 below. Intermediate - term aggregate MOEs ranged from 500 to 680 . The MOE for the U.S. p opulation is 500 . The most highly

exposed children’s subgroup was all i nfants ( < 1 year old), with a MOE of 680 . These estimates of aggregate risk do not exceed HED’s level of concern. Table 6.3 . Interm ediate - Term (IT) Aggregate Risk Calculations Population LOC for

Aggregate Risk1 Exposure

Food & Water (mg/kg/day) Exposure oral

(mg/kg/day) 2 Dermal

Exposure (mg/kg/day) 3 Exposure

inhalation (mg/kg/day) 4 Aggregate

MOE (food and residential) 5 U.S. Population (total) 100 0.001705 N/A 0.0183 0.0000071 500 Females, 13 - 49 years old 0.001503 N/A 0.0183 0.0000071 500 All Infants (<1 year old) 0.005059 0.0006731 0.009 0 N/A 680 Adults 50+ years old 0.001558 N/A 0.0183 0.0000071 500 1. LOC=100 ( 10x for inter - species variability*10x for intra - species variability) . 2. Incidental oral exposure applies only to subpopulations consisting of infants and children . From Table 5.2. 3 Dermal exposure from Tabl e 5.1 (0.0043 + 0.014 mg/kg/day = 0.0183 mg/kg/day) . 4. Inhalation exposure from Table 5.1. 5 Aggregate MOE (food, water and residential) = IT NOAEL (10 mg/kg/day)/(food & water exposure + dermal exposure + inhalation exposure + incidental oral exposure) . 7.0 CUMULATIVE RISK CHAR ACTERIZATION/ASSESSM ENT Unlike other pesticides for which EPA has followed a cumulative risk approach based on a common mechanism of toxicity, EPA has not made a common mec hanism of toxicity finding for halosulfuron - methyl and any other substances, and halosulfuron - methyl does not appear to produce a toxic metabolite produced b y 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 whichPage 32 of 47

chemicals have a common mechanism of toxicity and to evaluate the cumulative effects of such chemicals, see the polic y statements released b y EPA’s OPP concerning common mechanism determinations and procedures for cumulating effects from substances found to have a common mechanism on EPA’s website at http://www .epa.gov/pesticides/cumulative/. 8.0 O CCUPATIONAL E XPOSURE/RISK PATHWAY Workers may

be exposed to halosulfuron - methyl during mixing, loading, appl yi ng, and postapplication activities . Based on the proposed application rates, short - and intermediate - term exposure may

occur. Chronic exposure (  6 months of continuous exposure) is not expected. 8.1 Short - and Intermediate - Term H a ndler Exposure and Risk Halosulfuron - methyl may be applied using handgun and groundboom equipment. The application methods, maximum application rates, and use sites are summarized in Table s 2.1 and 2. 2. Chemical - specific data for assessing exp osure during pesticide handling activities were not submitted to the Agency

in support of this Section 3 application. It is HED policy to use data from PHED Version 1.1 to assess handler exposures for regulatory actions when chemical specific data are not available (HED ExpoSAC , SOP No.7, January 1999) or from the Outdoor Residential Exposure Task Force (ORETF). Standard values established by the ExpoSAC were used for acres treated per day and body weight. For short - term dermal occupational exposure, the toxicity endpoint was d ecreased body weight gain, and the point of departure was 100 mg/kg/day (NOAEL) based on the results of a 21 - day dermal toxicity

study in rats. For intermediate - term dermal exposure assessment, the toxicity endpoint was also decrease d body weight gains and reduced food efficiency along with hematological changes; the point of departure was 10 mg/kg/day (NOAEL) based on a 13 - week oral toxicity

in dogs. Because this point of departure is derived from an oral study , intermediate ter m dermal doses were adjusted to account for 75% dermal absorption. For short - term inhalation occupational exposure, the point of departure (50 mg/kg/day) was derived from an oral developmental rabbit study in which decreased body weight gains were observe d at the LOAEL of 150 mg/kg/day . For the intermediate - term inhalation occupational exposure, the point of departure (10 mg/kg/day) was based on an oral 13 - week oral toxicity study in dogs in which decreased body weight gains and food efficiency along with hematology

and clinical chemistry

changes were observed at the LOAEL of 40 mg/kg/day . Since no inhalation absorption data are available, toxicity by the inhalation route is considered to be equivalent to the estimated toxicity

by the oral route of exposure. Resulting dermal and inhalation risk estimates were combined into total risk estimates because of a common effect ( i.e. , body weight gain decreases) seen in the studies selected for the endpoints for both routes of exposure . The LOC for occupational exposure is for MOEs less than 100. Halosulfuron - methyl is characterized as “not likely to be carcinogenic to humans” based on lack of evidence from oral studies in rats and mice . Therefore, cancer risk was not assessed.Page 33 of 47

S ummaries of the exposure and risk estimates for occupational handlers are presented in Table 8.1.1 (Short - Term) and Table 8.1.2 (Intermediate - Term) . All combined MOEs exceed the LOC of 100, and therefore, are not of concern.Page 34 of 47 Table 8.1.1 . Short - Term Agricultural Handler Exposure and Risk for Halosulfuron - Me thyl. Exposure Scenario Crop or Target App Rate a (lb ai/A) Acres Treated Daily b Unit Exposure c Dose (mg/kg/day) MOEs Baseline Dermal mg/lb ai PPE - G

Dermal mg/lb ai Baseline

Inhalation μg/lb ai Baseline

Dermal d,h PPE - G

Derm al i Baseline

Inhalation e ,h Baseline

Dermal f PPE - G

Dermal Baseline

Inhalation g Combined

Baseline Dermal + Inhalation

j Combined PPE - G + Baseline Inhalationk Mixer/Loader

Mixing/Loading Dry Flowable s for Gr oundboom Applications (PHED) Succulent shelled p eas and bean 0.023 80 0.066 0.066 0.77 0.0017 0.0017 0.00002 58 , 000 58 , 000 2 , 500 , 000 56 , 000 56 , 000 Tuberous and corm vegetables; Rhubarb; Bushberry; Dried shelled pea and bean (except soybean) (West of the Rockies); Okra; Apples (East of the Rockie s) 0.047 80 0.066 0.066 0.77 0.0035 0.0035 0.000041 28 , 000 28 , 000 1 , 200 , 000 28 , 000 28 , 000

Dried shelled pea and bean (except soybean) (East of the Rockies) 0.031 80 0.066 0.066 0.77 0.0023 0.0023 0.000027 43 , 000 43 , 000 1 , 800 , 000 42 , 000 42 , 000 Apples (West of the Rockies) 0.094 80 0.066 0.066 0.77 0.0071 0.0071 0.000083 14 , 000 14 , 000 600 , 000 14 , 000 14 , 000 Applicator

Applying Sprays via Gr oundboom Equipment (PHED) Succulent shelled

peas and bean 0.023 80 0.014 0.014 0.74 0.00037 0.00037 0.000019 270 , 000 270 , 000 2 , 600 , 000 250 , 000 250 , 000 Tuberous and corm vegetables; Rhubarb; Bushberry; Dried shelled pea and bean (except soybean) (West of the Rockies); Okra; Apples (East of the Rockies) 0.047 80 0.014 0.014 0.74 0.00075 0.00075 0.00004 130 , 000 130 , 000 1 , 300 , 000 120 , 000 120 , 000Page 35 of 47 Table 8.1.1 . Short - Term Agricultural Handler Exposure and Risk for Halosulfuron - Me thyl. Exposure Scenario Crop or Target App Rate a (lb ai/A) Acres Treated Daily b Unit Exposure c Dose (mg/kg/day) MOEs Baseline Dermal mg/lb ai PPE - G

Dermal mg/lb ai Baseline

Inhalation μg/lb ai Baseline

Dermal d,h PPE - G

Derm al i Baseline

Inhalation e ,h Baseline

Dermal f PPE - G

Dermal Baseline

Inhalation g Combined

Baseline Dermal + Inhalation

j Combined PPE - G + Baseline Inhalationk Dried shelled pea and bean (except soybean) (East of the Rockies) 0.031 80 0.014 0.014 0.74 0.0005 0.0005 0.000026 200 , 000 200 , 000 1 , 900 , 000 180 , 000 180 , 000 Apples (West of the Rockies) 0.094 80 0.014 0.014 0.74 0.0015 0.0015 0 .000079 66 , 000 66 , 000 630 , 000 60 , 000 60 , 000 Mixer/Loader/Applicator

Mixing/Loading/Applying Dry Flowables Concentrates with a Handgun Sprayer (LCO ORETF data) Rhubarb; Bushberry;

Dried shelled pea and bean (except soybean) (West of the Rockies); Apples (East of the Rockies); Okra 0.047 25 No Data 0.58 22 No Data 0.0097 0.00037 No Data 10 , 000 140 , 000 No Data 9 ,3 00 Dried shelled pea and bean (except soybean) (East of the Rockies) 0.031 25 No Data 0.58 22 No Data 0.0064 0.00024 No Data 16 , 000 210 , 000 No Data 14 , 000 Apples (West of the Rockies) 0.094 25 No Data 0.58 22 No Data 0.019 0.00074 No Data 5 , 100 68 , 000 No Data 4 , 800 a Application Rates based on proposed uses on label for halosulf uron - m ethyl product Sandea® Herbicide (EPA Reg. No. 81880 - 18) . b E xposure Science Advisory Council Policy No. 9.1 c Unit Exposures based on PHED Version 1.1. d Dermal Dose (mg/kg/day) = daily unit exposure (mg/lb ai) x application rate (lb ai/acre) x acres treated / body weight ( 7 0 kg). e Inhalation Dose (mg/kg/d ay) = daily unit exposure (μg/ lb ai) x application rate (lb ai/acre) x acres treated / body weight ( 7 0 kg). f Dermal MOE = NOAEL (100 mg/kg/day) / dermal daily dose (mg/kg/day). Level of concern = 100. g Inhalation MOE = NOAEL ( 50 mg/kg/day) / inha lation daily dose (mg/kg/day). Level of concern = 100. h Baseline Dermal: Long - sleeve shirt, long pants, and no gloves; Baseline I nhalation: no respirator. i B aseline plus Gloves Dermal: Baseline plus chemical - resistant gloves. j Combined Baseline Derma l + I nhalation M OE = 1 / (1/Baseline Dermal MOE + 1/Baseline I nhalation MOE). k Combined PPE - G + Baseline I nhalation MO E = 1 / (1/PPE - G Dermal MOE + 1/Baseline I nhalation MOE).Page 36 of 47 Table 8.1.2 . Intermediate - Ter m Agricultural Handler Exposure and Risk for Halosulfuron - Methyl. Exposure Scenario Crop or Target App Rate a (lb ai/A) Acres Treated Daily b Unit Exposure c Dose (mg/kg/day) MOEs Baseline Dermal mg/lb ai PPE - G

Dermal mg/lb ai Baseline

Inhalation μg/lb ai Baseline

Dermal d,h PPE - G

Dermal i Baseline

Inhalation e ,h Baseline

Dermal f PPE - G

Dermal Baseline

Inhalation g Combined

Baseline Dermal + Inhalation

j Combined PPE - G + Baseline Inhalationk Mixer/Loader

Mixing/Loading Dry Flowable s for Gr oundboom Applications (PHED) Succulent shelled peas and bean 0.023 80 0.066 0.066 0.77 0.0013 0.0013 0.00002 7 , 700 7 , 700 490 , 000 7 , 600 7 , 600 Tuberous and corm vegetables; Rhubarb; Bushberry; Dried shelled pea and bean (except soybean) (West of the Rockies); Okra; Apples (East of the Rockies) 0.047 80 0.066 0.066 0.77 0.0027 0.0027 0.000041 3 , 800 3 , 800 240 , 000 3 , 700 3 , 700 Dried shelled pea and bean (except soybean) (East of the Rockies) 0.031 80 0.066 0.066 0.77 0.0018 0.0018 0.000027 5 , 700 5 , 700 370 , 000 5 , 600 5 , 600 Apples (West of the Rockies) 0.094 80 0.066 0.066 0.77 0.0053 0.0053 0.000083 1 , 900 1 , 900 120 , 000 1 , 900 1 , 900 Applicator

Applying Sprays via Gr oundboom Equipment (PHED) Succulent shelled peas and bean 0.023 80 0.014 0.014 0.74 0.00028 0.00028 0.000019 36 , 000 36 , 000 510 , 000 34 , 000 34 , 000 Tuberou s and corm vegetables;Rhubarb; Bushberry;Dried shelled pea and bean (except soybean) (West of the Rockies); Okra;Apples (East of the Rockies) 0.047 80 0.014 0.014 0.74 0.00056 0.00056 0.00004 18 , 000 18 , 000 250 , 000 17 , 000 17 , 000 Dried shelled pea and bean (except soybean) (East of the Rockies) 0.031 80 0.014 0.014 0.74 0.00037 0.00037 0.000026 27 , 000 27 , 000 380 , 000 25 , 000 25 , 000 Apples (West of the Rockies) 0.094 80 0.014 0.014 0.74 0.0011 0.0011 0.000079 8 , 900 8 , 900 130 , 000 8 , 300 8 , 300Page 37 of 47 Table 8.1.2 . Intermediate - Ter m Agricultural Handler Exposure and Risk for Halosulfuron - Methyl. Exposure Scenario Crop or Target App Rate a (lb ai/A) Acres Treated Daily b Unit Exposure c Dose (mg/kg/day) MOEs Baseline Dermal mg/lb ai PPE - G

Dermal mg/lb ai Baseline

Inhalation μg/lb ai Baseline

Dermal d,h PPE - G

Dermal i Baseline

Inhalation e ,h Baseline

Dermal f PPE - G

Dermal Baseline

Inhalation g Combined

Baseline Dermal + Inhalation

j Combined PPE - G + Baseline Inhalationk Mixer/Loader/Ap plicator Mixing/Loading/Applying Dry Flowables Concentrates with a Handgun Sprayer (LCO ORETF data) Rhubarb; Bushberry;

Dried shelled pea and bean (except soybean) (West of the Rockies); Apples (East of the Rockies); Okra 0.047 25 No Data 0.58 22 No Dat a 0.0073 0.00037 No Data 1 , 400 27 , 000 No Data 1 , 300 Dried shelled pea and bean (except soybean) (East of the Rockies) 0.031 25 No Data 0.58 22 No Data 0.0048 0.00024 No Data 2 , 100 41 , 000 No Data 2 , 000 Apples (West of the Rockies) 0.094 25 No Data 0.58 22 No Data 0.015 0.00074 No Data 680 14 , 000 No Data 650 a Application Rates based on proposed uses on label for halosulf uron - methyl product Sandea® Herbicide (EPA Reg. No. 81880 - 18) . b Exposure Science Advisory Council Policy No. 9.1 . c Unit Exposures based on PHED Version 1.1. d Dermal Dose (mg/kg/day) = daily unit exposure (mg/lb ai) x application rate (lb ai/acre) x acres treated x dermal absorption factor ( 75 %) / body weight ( 7 0 kg). e Inhalation Dose (mg/kg/day) = daily unit exposure (μg/ lb ai) x application rate (lb ai/acre) x acres treated / body weight ( 7 0 kg). f Dermal MOE = NOAEL (10 mg/kg/day) / dermal daily dose (mg/kg/day). Level of concern = 100. g Inhalation MOE = NOAEL ( 10 mg/kg/day) / inhalation daily dose (mg/kg/day). Level of concern = 100. h Baseline Dermal: Long - sleeve shirt, long pants, and no gloves; Baseline I nhalation: no respirator. i Baseline plus Gloves Dermal: Baseline plus chemical - resistant gloves. j Combined Baseline Dermal + I nhalation MOE = 1 / (1/Baseline Dermal MOE + 1/Baseline I nhalation MOE). k Combined PPE - G + Baseline I nhalation MOE = 1 / (1/PPE - G Dermal MOE + 1/Baseline I nhalation MOE).Page 38 of 47

8 .2 Postapplication Exposure/Risk 8. 2.1 Data and Assumptions for Postapplication Exposure Scenarios Inhalation : Based on the Agency's current practices, a quantitative postapplication inhalation exposure assessment was not performed for halosulfuron - methyl at this time primaril y because it is not applied using airblast aerial equipment or another method that could result in higher postapplication inhalation exposure than other application methods. Further halosul furon - methyl has low vapor pressure. However, volatilization of pesticides may be a potential source of postapplication inhalation exposure to individuals nearb y to pesticide applications. The Agency sought expert advice and input on issues related to vol atilization of pesticides from its Federal Insecticide, Fungicide, and Rodenticide Act Scientific Advisory Panel (SAP) in December 2009. The Agency

received the SAP’s final report on March 2, 2010. ( http://www. epa.gov/scipol y/ SAP/meetings/2009/ 120109meeting.html ). The Agency is in the process of evaluating the SAP report and may , as appropriate, develop policies and procedures to identify the need for and, subsequently , the way

to incorporate postapplication inhalation exposure into the Agency's risk assessments. If new policies or procedures are put into place, the Agency may revisit the need for a quantitative postapplication inhalation exposure assessment for halosulfuron - methyl. Dermal : Most of the prop osed uses for halosulfuron - methyl are ground - directed uses where no crop foliage is treated. Currentl y, HED has no transfer coefficients (TCs) or other data to assess postapplication dermal exposures to soil by occupational workers. In general, such expo sures are considered to be negligible. Therefore, for the proposed soil - directed uses, postapplication exposures and risks to occupational workers were not quantitatively assessed. However, s ome of the proposed uses for halosulfuron - methyl are for postemergent applications when crop foliage is present. Postapplication exposure and risk were assessed for these proposed uses. This assessment is considered to be a Tier I, screening level estimate, demonstrating that there are minimal potential risks to workers re - entering fields treated with postemergent applications of halosulfuron - methyl. Since no postapplication data was submitted in support of this registration action, dermal exposures during postapplication activities were estimated using dermal TCs from the ExpoSAC SOP No. 003.1: Agricultural Transfer Coefficients, August 2000, and the following assumptions:

 Application Rate = 0.047 lb ai/A for tuberous and corm vegetables, bushberries , and dried shelled peas and beans (West of the Rockies); and 0.031 lb ai/A for dried shelled peas and beans (East of the Rockies).  Exposure Duration = 8 hours per day  Body Weight = 70 kg for average adult  Dermal Absorption = 100% for short - term and 75% for intermediate - term  Fraction of ai retained on foliage is assumed to be 20% (0.2) on day zero for agricultural crops. This fraction is assumed to further dissipate at the rate of 10% (0.1) per day on following day s. These are default values established by HED ExpoSAC. Foliar residue is expected to be very l ow during postapplication activities. Since halosulfuron -Page 39 of 47

methyl is ty

pically applied earl y in the season prior to flowering, the postapplication tasks are unlikely to encounter foliar residues of concern. The dermal exposure risk estimates for postapplic ation activities are summarized below in Table 8.2.1.1 . Table 8.2.1.1 . Anticipated Postapplication Activities and Derm al Transfer Coefficients. Proposed Crop Policy Crop Group Category Exposure

Potential Transfer

Coefficients (cm2 /hr) Activities Tubero us and Corm Vegetables Vegetable, “Root” Medium 1,500 Irrigation, Scouting Lo w 300 Hand Weeding Bushberries Vine/Trellis Lo w 500 Hedging, Irrigation, Hand Weeding, Scouting Dried Shelled Peas and Beans Field/Row Crop,

Lo w/Medium Lo w 100 Irrigation, Sc outing, Hand Weeding 8.2.2 Agricultural Post- application Exposure and Risk The postapplication exposure associated with agricultural crops is summarized in Table 8.2.1.2 . All scenarios res ulted in MOEs greater than 100 on day 0 (12 hours after application) and , therefore , do not exceed HED ’s LOC. Table 8.2.1.2. Postapplication Exposure and Risk for Halosulfuron - Methyl. Crop Activity Transfer Coefficient a (cm 2 /hr) DAT b DFRc (μg/cm2 ) Short - Term Intermediate - Term

Daily Dermal Dose d (mg/kg/day) MOE e Daily Dermal Dose d (mg/kg/day) MOE e Tuberous and corm vegetables Irrigation, scouting 1,500 0 (12 hours) 0.1054 0.018 5,500 0.014 740 Hand weeding 300 0 (12 hours) 0.1054 0.0036 28,000 0. 0027 3,700 Bushberry Hedging, irrigation,

hand weeding, scouting 500 0 (12 hours) 0.1054 0.0060 17,000 0.0045 2,200 Dried shelled peas and beans (West of Rockies) Irrigation,

Scouting, Hand weeding 100 0 (12 hours) 0.1054 0.0012 83,000 0.00090 11,000 Dried shelled peas and beans (East of Rockies) Irrigation,

Scouting, Hand weeding 100 0 (12 hours) 0.0695 0.00079 130,000 0.00060 17,000

a Transfer coefficients and associated activities from ExpoSAC SOP No. 003.1 “Agricultural Transfer Coefficients,” 8/17/2000. b DAT = Days after treatment needed to reach the LOC of 100; DAT 0 = the day of treatment, after sprays have dried; assumed to be approximately 12 hours. c DFR (μg/cm2 ) = Application rate (lb ai/A) x (1 - daily dissipation rate) t x CF (4.54E+8 μg/lb) x CF (2.47E - 8 A/cm2) x 20% DFR after initial treatment. d Daily Dose = [(DFR x TC x Dermal absorption x 8 - hr Exposure Time)] / [(CF: 1000 μg/mg) x (70 kg Body Weight)] (Short term dermal absorption factor = 100%; Intermediate - term dermal absorption factor = 75%). e MOE = NOAEL/Daily Dose (Short - Term Dermal NOAEL = 100 mg/kg/day; Intermediate - Term Dermal NOAEL = 10 mg/kg/day).Page 40 of 47

Restricted

- Entry interval The halosulfuron - methyl technical material has been classified in Toxicity Category III for acute dermal toxicity

and Toxicity

Category IV for primary

eye irritation and primary skin irritation. Per the Worker Protection Standard (WPS), a 12 - hr restricted entry interval (REI) is required for chemicals classified under Toxicity Category III or IV. The current GWN - 3061 label has a 12 - hour REI , which complies with the WPS. 9.0 DATA NEEDS/LABEL RE COMMENDATIONS 9.1 Toxicology 870.3465 28 - Day

Inhalation

– Rat A 28 - day inhalation toxicity

study in the rat is required due to concern for repeated exp osure via the inhalation route based on the use pattern. 870.7800 Immunotoxicity Under the new rule for data requirement s as presented in 40 CFR Part 158, an immunotoxicity

study is required. 9.2 Residue Chemistry 860.1200 Directions for Use ● For Crop Subgroup 6B (p ea and b ean, s ucculent s helled), the label(s) should be amended to prohibit applications to legumes grown for livestock feeds because no residue data are available for cowpea forage and hay . ● For Crop Subgroup 13 - 07B (b ushberry), the label( s) should be amended to remove the instructions pertaining to the use of a non - ionic surfactant . If it is IR - 4’s intention to add a nonionic surfactant when Sandea® Herbicide is applied to these crops, then additional field trial data are required.

 F or C rop Subgroup 6C (dried pea and bean (except soy bean)) , the labels should be amended to remove the use directions for Crop Subgroup 6C . 860.1500 Crop Field Trials Prior to granting a registration on Crop Subgroup 6C ( dried s helled pea and b ean ( e xcept s o ybean)), data on dried pea including the forages and hay of field pea cultivars are required from a minimum of five field trials. The requested field trials should reflect total application rates of 0.047 lb ai/A per crop cycle or 0.094 lb ai/A per year, a minimum 30 - day

PHI, and the incorporation of a non - ionic surfactant in the spray mixture. A revised Section F should be submitted removing the request for Crop Subgroup 6C (dried shelled pea and bean (except soy bean)).Page 41 of 47

860.1650 Submittal of Analy tical Reference Standards Analy tical reference standards for the 3 - CSA (3 - chlorosulfonamide acid) m etabolite and the RRE of halosulfuron - methyl must be submitted to the EPA National Pesticide Standards Repository .

REFERENCES 2002 Haza rd Assessment HALOSULFURON

- METHYL: - Report of the Hazard Identification Assessment Review Committee. 08/23/20 02. 2006 Risk Assessment Halosulfuron - methyl: Human Health Risk Assessment for Pro pose Uses on Alfalfa. D331643, M. Clock -R us t , 09/21/200 6. 2009 Risk Assessment Halosulfuron - methyl: Human Health Risk Assessment for Pro pose Uses on Soybean. D35803, W. Phang, 06/30/2009 Residue Chemistry Assessment Halosulfuron - methyl. Application for Section 3 Registration of Sandea® Herb icide (EPA Reg. No. 81880 - 18) and GWN - 3061 Herbicide (EPA Reg. No. 81880 - 2) to Add New Uses on: Pea and Bean, Succulent Shelled, Subgroup 6B; Vegetable, Tuberous and Corm, Subgroup 1C; Rhubarb; Bushberry Subgroup 13 - 07B; Pea and Bean, Dried Shelled, Excep t Soybean, Subgroup 6C; Apple; and Okra. Summary of Analytical Chemistry and Residue Data. D367058, Debra Rate, 03/03/2010 Dietary Exposure Analysis Halosulfuron - methyl Acute and Chronic Aggregate Dietary (Food and Drinking W ater) Exposure and Risk Assessments for the Section 3 Registration Action on Pea and Bean, Succulent Shelled, Subgroup 6B; Vegetable, Tuberous and Corm, Subgroup 1C; Rhubarb; Bushberry Subgroup 13 - 07B; Apple; and Okra. D367059, Debra Rate, 03/04/2010 Occupational and Residential Expo sure Assessment Halosulfuron -

Methyl . Occupational and Residential Exposure Assessment f or Proposed Field Use of Halosulfuron -

Methyl on Succulent Shelled Peas and Beans (Subgroup 6B), Tuberous and Corm Vegetables (Subgroup 1C), Rhubarb, Bushberry (Subgroup 13 - 07B), Dried Shelled Peas and Beans (Except Soybean, Subgroup 6C), Apples, and Okra. D367060Page 42 of 47

Drinking Water Assessment Halosulfuron -

Methyl Drinking W

ater Assessment for Additional Food Uses (Including Proposed Use on Soybeans

). D358031 , M. Barrett , 0 5 /27 /2009 .Page 43 of 47

Attachment A: Toxicology Profile Table 1. Acute Toxicity of Halosulfuron - M ethyl Technical . OPPTS No. Study Type MRID Results Toxicity Category 870.1100 Ac ute Oral - Rats 42139413 LD 50 : Males = 10,435 mg/kg Females = 7758 mg/kg Combined = 8866 mg/kg IV 870.1200 Ac ute Dermal - Rats 42139415 LD 50 >2000 mg/kg (limit test) III 870.1300 Ac ute 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 P rofile of Halosulfuron - M ethyl Technical (Repeated dosing and others) . 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 weight gains.

870.3100 (82 - 1) Subchronic o ral

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 body weight gains, decreased organ weights and changes in clinical chemistry parameters. 870.3150 (82 - 1) Subchronic oral

toxicity study in nonrodents - dogs 42171502 (1991)/

Acceptable/

Nonguideline Doses: 0, 2.5, 10, 40, and 160 mg/kg/day (capsule) NOAEL = 10 mg/kg/day LOAEL = 40 mg/kg/day based on decreased body weight gains and food efficiency along with hematology and clinical chemistry changes. 870.3200 (82 - 2) 21 - day dermal

toxicity in rats 42661417 (1990)/

Ac ceptable/ Guideline Doses: 0, 10, 100, or 1000 mg/kg/day NOAEL = 100 mg/kg/day LOAEL = 1000 mg/kg/day based on a dose - related decrease in total body weight gain in males. Total body weight gain was also decreased in the 100 mg/kg/day group females, but th e 1000 mg/kg/day group females were comparable to the control group. 870.4100 (83 - 1b) Chronic oral

toxicity study in dogs 42396211 (1991)/

Acceptable/ Guideline Doses: 0, 0.25, 1.0, 10.0, or 40 mg/kg/day (capsule). NOAEL = 10 mg/kg/day LOAEL = 40 mg/kg/day based on decreased body weight gains in males and females, decreased relative food efficiency in females along with hematological and clinical chemistry changes. 870.4300 (83 - 5) Combined

Chronic/ Carcinogenicity in rats 42661418 (1992)/

Acc eptable/Guideline Doses: 0, 10, 100, 1000, or 2500, 5000 (males only) ppm 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.Page 44 of 47

Table 2. Toxicity P rofile of Halosulfuron - M ethyl Technical (Repeated dosing and others) . Guideline No. Study Type MRID No. (Date)/Classification/ Doses Results (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) 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 decreased body w eight gains and 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 cli nical observations, reduced body weight gains, reduced food consumption and food efficiency. Developmental NOAEL = 250 mg/kg/day. Developmental 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 inc reased 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, body weight gains , and reduced food consumption during the premating period in both sexes. Offspring NOAEL = 51/59 mg/kg/day Offspring LOAEL = 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 NO AE L > = 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.Page 45 of 47

Table 2. Toxicity P rofile of Halosulfuron - M ethyl Technical (Repeated dosing and others) . Guideline No. Study Type MRID No. (Date)/Classification/ Doses Results 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 706.0/3 15.9 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. 870.6300 (83 - 6) Metabolism 42139433 (1990)/ Acceptable/ Guideline 5 or 250 mg/kg single dose or 5 mg/kg/day repeated doses Absorption was rapid, incomplete and similar in both sexes. Elimination was mostly by urine and feces within 72 hours, ap pearing to be independent of dose and sex. Desmethyl NC - 319 and the 5 - hydroxy derivative were the major urinary and fecal metabolites. 870.5100 (84 - 2 a) Mutagenic - Ames

Salmonella typhimurium and E. Coli . 42139428 (1991)/ Acceptable

(+/ - S9) 5 str ains S. typh. Conc.: 1 - 10000 microgm/plate; E. Coli WpuvrA Conc.: 333 - 10000 microgram

/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 microgm/plate Negative. Conducted with 3 - chlorosulfonamide acid - the principal soil metabolite of halo sulfuron - methyl. 870.5300 (84 - 2) Mutagenic - Gene

Mutation - Hamster (Chinese) 43616303 (1995) - Me tabolite/

Acceptable (+/ - S9) Conc.: 350 - 3100 microgm/mL Negative. Conducted with 3 - chlorosulfonamide acid - the principal soil metabolite of halo sulfuron - methyl. 870.5300 (84 - 2) Mutagenic -

(HGPRT) - Hamster (Chinese). 42139431 (1991) - M etabolite/

Unacceptable Conc.: 100 - 1000 microgm /mL 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 (19 93)/ Acceptable

(+/ - S9) Conc.: 50 - 900 micro g m/mL Negative. Did not induce forward mutations at the HGPRT locus in Chinese Hamster ovary cells. Concentrations above 700 ug/mL were insoluble. 870.5375 (84 - 2) Mutagenic - In

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

(+/ - S9) Conc.: 449 - 1810 micro g m/mL Negative. No chromosomal aberrations. 870.5395 (84 - 2) Mutagenic -

Micronucleus Assay - Mouse (CD - 1) 43616304 (1995) -

M etabolite/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 the treated animals or cytotoxicity for the target organ (bone marrow cells) was observed. 870.5395 (84 - 2) Mutagenic -

Micro nucleus 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 sy nthesis - Rat 42139432 (1990)/ Acceptable

(+/ - S9) Conc.: 25 - 1000 microgm/mL Negative. Fail to induce unscheduled DNA synthesis in primary rat hepatocytes.Page 46 of 47

Attachment B: Rationale for Requiring the Studies Guideline Number: 870.3465 Study Title: 90 - Day In halation Toxicity Rationale for Requiring the Data The 28 - day

inhalation toxicity

study evaluates the potential hazard of a pesticide chemical following repeated inhalation exposures. This study is critical for pesticides with use pattern in which there is potential for repeated human exposures (e.g., professional applicators, green house use etc) exposure. The study design simulates the route of human exposure (inhalation). In this study animals are exposed (nose/whole body) to aerosol concentration s of the test material for 6 hours/day , 5 day /week for 28 day s. A detailed toxicological examination including the histopathology of the respiratory sy stem is conducted. This is route - specific study would provide data for hazard characterization, dose re sponse assessment, and a dose and endpoint for assessing potential risks via the inhalation route. Practical Utility of the Data How did the Agency make its re - registration decision without these data? A subchronic inhalation study provides critic al scientific information needed to characterize potential hazard to human population on the respiratory s ys tem from pesticide exposure. In the case of halosufluron - methyl , subchronic inhalation study is not available; an oral toxicity study i s employed f or toxicity

endpoint and points of departure selection s . Absorption via the inhalation route is presumed to be equivalent to oral absorption, and the effects seen in the oral toxicity study are also presumed to be similar to those resulted from the inhalation study . A 28 - day repeated exposure study that follows the Test Guidelines (870.3465) will characterize hazard and provide data for a much accurate inhalation risk assessment. How will the data be used? This study

will identify

hazard (i.e., provide a dose and endpoint) following longer repeated exposures, this data will be used in risk assessments, and will result in the removal of the database uncertainty factor.Page 47 of 47

Guideline Number: 870.7800 Study Title : Immunotoxicity Rationale for Requiring t he Data This is a new data requirement under 40 CFR Part 158 as a part of the data requirements for registration of a pesticide (food and non - food uses). The Immunotoxicity

Test Guideline (OPPTS 870.7800) prescribes functional immunotoxicity

testing and is designed to evaluate the potential of a repeated chemical exposure to produce adverse effects (i.e., suppression) on the immune sy stem. Immunosuppression is a deficit in the ability of the immune sy stem to respond to a challenge of bacterial or viral infections such as tuberculosis (TB), Severe Acquired Respiratory

Sy ndrome (SARS), or neoplasia. Because the immune s ys tem is highly complex, studies assessing functional immunotoxic endpoints are helpful in fully characteriz ing a pesticide’s potential immunotoxicity . These data will be used in combination with data from hematology , l ymphoid organ weights, and histopathology in routine chronic or subchronic toxicity studies to characterize potential immunotoxic effects . Practical Utility of the Data H ow will the data be used? These animal studies can be used to select endpoints and doses for use in risk assessment of all exposure scenarios and are considered a primary data source for reliable reference dose calculation. For example, animal studies hav e demonstrated that immunotoxicity in rodents is one of the more sensitive manifestations of TCDD (2,3,7,8 - tetrachlorodibenzo p - dioxin) among developmental, reproductive, and endocrinologic toxicities. Additionally , the EPA has established an oral referen ce dose (RfD) for tributyltin oxide (TBTO) based on observed immunotoxicity in animal studies (IRI S, 1997). How could the data impact the Agency's future decision - making? If the immunotoxicity

study shows that the test material poses either a greater or a diminished risk than that given in the interim decision’s conclusion, the risk assessments for the test material may

need to be revised to reflect the magnitude of potential risk derived from the new data. If the Agency

does not have this data, a 10X database uncertainty factor may be applied for conducting a risk assessment from the available studies.