### UNITED STATES ENV I RONMENTA L PROTECTION AG E NCY

WAS HI NG T ON, D.C. 2046 0



### M E MORA N D U M

D A TE: Septembe r 1 0

, 2015 OFFICE OF CHEMICAL SAFETY AND
POLLUTION PREVENTION



### SUB J EC T: Primi s ulfuron-M e th y l. Human Health Draft Ri s k Assess m ent for Registrat i o n
R ev iew.

P C Code: 1289 73

D eci s io n No.: 499855

Pe li lion No.: NA DP Barcode: 0 425535

R eg i s t ra ti on Nos.: Various

R eg ul a t o r y Ac ti o n : R eg i st ration Revi ew Cas e No.: NA Ri s k 

### A ss ess m e n t Ty p e: Single C h e mica l/Agg r ega t e TX R No.: NA CAS No.: 86209-5 1 -0

.t O CFR: § 180.452 M RID No. : NA



### F R OM: S h a lu S helat

, I ndu st rial H yg i e ni s t

## S?J;**~** Juli e Van Alstine

, Environmental Hea l tl cientist

C hri s t op h e r Sc hl osse r , Toxicologist

Risk Assessment Bran ch V I

Health Effects Division (7509 P )



### THRO U GH: D o nn a 

### S

. Davi s , Act i n g Br a n c h Chief

Risk Assessment Br a nch V I



### T O : H ea lth Effects Division (7509 P )

C hri s tina Scheltcma, Chem i ca l Rev i ew M a n age r Kelly Sherman. Ac tin g B ranc h C hi ef

Risk Management a nd Imp leme ntati o n Br anc h 3

Pesticide R e- R eg i strat ion Di v i s ion (7508 P )

Primisulfuron-methyl i s a sys t em i c herbi c id e be l onging t o the s ulfon y lurea g roup of herb i cides.

The mechanism of action i s th e inhibition of ami n o ac id sy nthe s i s in p l a nts thr ough inhibiti on of

acetolactate synthase (ALS). T hi s document eva lu ates th e ex i st in g u ses of primi s ulfuron-m et h y l

as part of R eg i s tr a t i on Revi ew and repre se nt s the draft ri s k assessm e n t (ORA). Th e Agenc y i s

r ev i ew in g all the s ulfon y lur ea h e rbic i d es joint l y und e r R eg i stration R ev i ew.

S in ce th e last huma n h ea lth risk assess m ent (W. Hazel

, D280923, 6 / 28 / 20 0 2) and scop in g docume nt (M. Sa h afeya n , 0 394824, 3/7 / 20 1 2), the following updat es have been incorporat e d for primisu l furon

- m et hy l.



### • A screening-level es tim a t ed drinking wa t e r concen trati on (EDWC) value was used to

assess primisulfuron-m e thyl d i etary exposure and ri sk.

• Tox i cological endpoints and points of depa rtur e (PODs) u:iedfor risk assess m ent have
been updated to r eflec t cu rr e n t p o li c i es.
Page I of34Primi s ulfuron-meth y l 0425535



### • The occupational risk assess m en t has been updated to incorporate new science policies.

• A spray drift as sess ment was completed as part of R eg istration R ev i e w.

Page 2 of 34Primisulfuron

- methyl D42 5535

Page 3 of 34 

### Table of Contents

1.0 Executive Summary

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

................................ ................................ ................................ ...... 4
2.1 Tolerance Considerations

................................ ................................ ................................ . 4
2.2 Data Deficiencies

................................ ................................ ................................ ............. 4

3.0 Introduction

................................ ................................ ................................ .......................... 4
3.1 Use Profile & Anticipated Exposure Pathways

................................ ................................ 4
3.2 Consideration of Environmental Justice

................................ ................................ .......... 6

4.0 Hazard Identification/Toxicology

................................ ................................ ........................ 7 4.1 Summary of Toxicological Effects

................................ ................................ ....................... 7 4.2 Safety Factor for Infants and Children (FQPA Safety Factor)

................................ ............. 8 4.3 Toxicity Endpoint and Point of Departure Selection s

................................ .......................... 8
4.4 Endocrine Disruptor Screening Program

................................ ................................ ......... 9

5.0 Residue Chemistry

................................ ................................ ................................ ............. 10
6.0 Di etary Risk Assessment

................................ ................................ ................................ ... 10
6.1 Water Residue Profile

................................ ................................ ................................ .... 11
6.2 Dietary (Food + Water) Exposure Assessment

................................ .............................. 11

7.0 Residential (Non

- Occupational) Exposure/Risk Characterization

................................ .... 12
8.0 Non

- Occupational Spray Drift Exposure and Risk Estimates

................................ ........... 12
8.1 Risk Estimates from Lawn Deposition Adjacent to Applications

................................ .. 12

9.0 Non

- Occupational Bystander Post

- Application Inhalation Exposure and Risk Estimates 13
10.0 Aggregate Exposure/Risk Characterization

................................ ................................ ....... 14
11.0 Cumulative Exposure/Risk Characterization

................................ ................................ ..... 14
12.0 Occupational Exposure/Risk Characterization

................................ ................................ .. 14 12.1 Occupational Handler Exposure/Risk Estimates

................................ .............................. 14
12.2 Occupational Post

- application Exposure/Risk Estimates

................................ .............. 17

13.0 Public Health and Pesticide Epidemiology Data

................................ ............................... 18
14.0 References

................................ ................................ ................................ .......................... 18 Appendix A: Data Deficiencies

................................ ................................ ................................ 19 Appendix B: Toxicity Profile of Primisulfuron

- Methyl

................................ ............................... 20 Appendix C: Chemical Identity

................................ ................................ ................................ .... 25 Appendix D: Dietary Exposure/Risk Modeling Inputs and Outputs

................................ ............ 26 Appendix E: Spray Drift Assessment for Primisulfuron

- methyl

................................ .................. 29 Appendix F. TTR and DFR Data Waiver Rationale

................................ ................................ .... 32 Appendix G: Review of Human Research

................................ ................................ ................... 34Primisulfuron

- methyl D42 5535

Page 4 of 34 

### 1.0 Executive Summary

Primisulfuron

- methyl ( methyl 2

- [[[[[4,6

- bis(difluoromethoxy)

- 2

- pyrimidinyl]amino]carbonyl]amino]sulfonyl]benzoate) is a sulfonylurea (selective post

emergence) herbicide absorbed and transported throughout the plant roots and foliage

. Primisulfuron

- methyl is registered for use to control grass weeds and many types of broad leaf
weeds. It is currently registered for use on field corn (grown for grain, silage, and seed) and popcorn. In addition, several states have FIFRA §24(c) Special Local Need (SLN) registrations for use on Kentucky blue grass grown for seed and sod production . It is formulated as a w ater

dispersible granule (WG) and in water

- soluble bags (WSP)

. Since the last risk assessment ( D280923 ) and scoping document ( D394824 )

, there have been no changes to the primi sulfuron

methyl use or residue profile s

. However, toxicological endpoints and points of departure (PODs)
used for risk assessment have been updated to reflect current policies

. D ietary exposure to primi sulfuron

- methyl has been reevaluated in order to incorporate updated consumption data and drinking water modeling estimates. Non

- dietary exposure has also been reevaluated to incorporate changes to occupational exposure assessment methodologies (unit expo sures) and to incorporate a spray drift assessment. There are no risk estimate s of concern for the existing uses
of primi sulfuron

- methyl; however there are some data deficiencies that remain outstanding.

2 .0 HED Recommendations

2.1 Tolerance Cons iderations

The existing tolerances for residues of primisulfuron

- methyl (40 CFR § 180. 452 ) are supported by the av ailable residue chemistry data. Codex has not established maximum residue limits (MRLs) for residues of primisulfuron

- methyl . Canada has est ablished MRLs for primisulfuron

methyl which are harmonized with U.S. tolerances.

HED notes that the tolerance expression for primisulfuron

- methyl in 40 CFR § 180.452 requires revision to state the following:

(a) General. Tolerances are established for residues of primisulfuron

- methyl, including its metabolites and degradates, in or on the commodities in the table below. Compliance with the tolerance levels specified below is to be determined by measuring only primisulfuron

- methyl (methyl 2

- [[[[[4,6

- bis (difluoromethoxy)

- 2

- pyrimidinyl]amino]carbonyl]amino]sulfonyl]benzoate) in or on the commodity.

2. 2 Data Deficiencies

The analytical reference standard s for primisulfuron

- methyl expired on 4/30/ 20 15 and are

current ly unavailable in EPA’s National Pesticide Standards Repository ( NPSR ; email
communication betwe en G. Verdin and J. Van Alstine; 5/7/20 15 )

. T he registrant is required to
maintain reasonable amount s of the reference standard s for primisulfuron

- methyl in the NPSR as long as tolerances rema in published in 40 CFR §180. 452

. (See Appendix A for more details

. )

3 .0 Introduction

3.1 Use Profile & Anticipated Exposure PathwaysPrimisulfuron

- methyl D42 5535

Page 5 of 34 

### Primi sulfuron

- methyl is formulated as water soluble packets (WSP) and water

- dispersible granule (W D G) formulations

, and only registered for use on corn and bluegrass . Currently registered labels include one technical label, four agricultural labels, and eight special local need (SLN) state labels. In general, primi sulfuron

- methyl may be applied to corn and bluegrass once or twice per year or per growing season. The registered a pplication rates range from 0.018 to

0.0 3 6 lb ai/A. Primi sulfuron

- methyl may be applied using groundboom and aerial application equipment; application via chemigation is not permitted. The pr imi sulfuron

- methyl labels require occupational handlers to wear baseline personal protective equipment (PPE): long sleeved shirts, long pants, shoes, and socks; and chemical resistant gloves

. The restricted entry intervals (REIs) listed on the primi sul fur on

- methyl labels are generally 12 hours ; however, one label (EPA Reg No. 100

- 923) has an REI listed f or 24 hours. This product is co

- formulated with
43.9% sodium salt of dicamba.

Individuals may be exposed to primi sulfuron

- methyl via their diet (food and drinking water) and agricultural workers may be exposed (dermal and inhalation) to primi sulfuron

- methyl during mixing, loading, and/or applying the herbicide as well as during post

- application activities.
There ar e no registered uses for primi sulfuron

- methyl that will result in direct non

- dietary non

occupational (i.e., residential) exposures. However, there is the potential for indirect exposure (incidental oral and dermal) to primi sulfuron

- methyl related to spra y drift.

Table 3.1. Summary of Directions for Use of Primis ulfuron

- Methyl.

Applic. Timing, Type, and Equip. Formulation

[EPA Reg. No.] Applic.

Rate (lb ai/A) Max. No.

Applic. per
Season Max.

Seasonal Applic. Rate (lb ai/A) REI

(Hours) Use Directions and

Limitations

Corn (grain, silage, and seed) and Popcorn

Aerial and
Ground Equipment* Water

Soluable
Packets [100

- 705] 0.036 1

- 2 0.036 12 PGI

- 30 days ; PHI s ilage

– 45 days; PHI grain

- 60

days Over the top foliar post

emergence with 4

- 20 inches crop height. Ground equipment applications applied 15
inches above corn

canopy

Water

D ispersible

G ranule [100

- 774] 0.018 1 0.018 12 PGI

- 30 days; PHI s ilage

– 40 days; PHI grain

- 60

days Over the top foliar post

emergence with 4

- 20 inches crop height.

Gro und equipment applications applied 15
inches above corn

canopy

Water

D ispersible

G ranule [100

- 911] 0.027 1 0.027 12 PGI

- 30 days; PHI s ilage

– 40 days; PHI grain

- 60

days Over the top foliar post

emergence with 4

- 20 inches crop height. Ground equipment applications applied 15Primisulfuron

- methyl D42 5535

Page 6 of 34 

### Table 3.1. Summary of Directions for Use of Primis ulfuron

- Methyl.

Applic. Timing, Type, and Equip. Formulation

[EPA Reg. No.] Applic.

Rate (lb ai/A) Max. No.

Applic. per
Season Max.

Seasonal Applic. Rate (lb ai/A) REI

(Hours) Use Directions and

Limitations

inches above corn

canopy

Water

D ispersible

G ranule [100

- 923] 0.023 1 0.023 24 PGI

- 30 days; PHI s ilage

– 45 days; PHI grain

- 60

days Over the top foliar post

emergence with 4

- 20 inches crop height. Ground equipment applications applied 15
inches above corn

canopy Kentucky Bluegrass grown for sod production

Water Soluble
Packets [CO

- 05

- 0004;

IL

- 060002;

NJ

- 080001;

NY

- 080015 ] 0.036 1

- 2 0.036 12 None

Kentucky Bluegrass grown for seed production

Water Soluble
Packets [ ID

- 990007;

MN

- 060003;;

OR

- 960025;

WA

- 960002] 0.036 1

- 2 0.036 12 None

*Chemigation is not permitted on the registered labels.

REI = Reentry Interval

. PGI = Pre

- grazing Interval. PHI = Pre

- harvest Interval.



### 3

. 2 Consideration of Environmental Justice

Potential areas of environmental justice concerns, to the extent possible, were considered in the preliminary human health risk assessment for primisulfuron

- methyl , in accordance with U.S. Executive Order 12898, "Federal Actions to Address Environmental Justice in Minority Populations and Low

- Income Populations," http://epa.gov/compliance/ej/resources/policy/exec_order_12898.pdf . As a part of every pesticide risk a ssessment, 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 w ater 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 National Health and Nutrition Examination Surveys/What We Eat in Am erica (NHANES/WWEIA) and are used in pesticide risk assessments for all registered food uses of a pesticide. These data are analyzed and categorized by subgroups based on age and ethnic group. Additionally, OPP is able to assess dietary exposure to small er, 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, you ths, and adults entering or playing on treated areas
post

- application are evaluated. Further considerations are currently in development as OPP hasPrimisulfuron

- methyl D42 5535

Page 7 of 34 

### committed resources and expertise to the development of specialized software and models that consider expos ure to bystanders and farm workers as well as lifestyle and traditional dietary patterns among specific subgroups.

4.0 Hazard Identification/Toxicology

The toxicology database for primi sulfuron

- methyl is complete and adequate for risk assessment.
The last risk assessment for primi sulfuron

- methyl was conducted in 200 2 ( W

. Hazel; D 280923 ; 6/28/2002 ). In 2012 , a scoping document ( M. Sahafeyan; D 394824 ; 3/7/2012 ) was completed which outlined data gaps for several toxicity studies as required in accordance with the current

40 CFR Part 158 Guidelines

. The studies included inhalation toxicity, immunotoxicity and acute and subchronic neurotoxicity studies. However, HED has determined that the se studies are not required at this time (TXR# 00 53979, Hazard and Science Policy Council

, 0056723 )

. The endpoints/PODs selected for risk assessment have been updated to reflect current policy . See Appendix B for the primi sulf uron

- methyl toxicology profile.

4.1 Summary of Toxicological Effects

The most consistent effect across the database was decreases in body weights observed in rats, dogs and mice. In dogs, primisulfuron

- methyl also targ et ed the thyroid (decreased organ weights and hyperplasia), liver (decreased organ weights and vacuolization), and the hematopoietic system (decreased RBC, hemoglobin, and hematocrit). In mice, liver, kidney, testes, teeth and bone toxicity were observed fo llowing chronic exposure. These e ffects were observed following
sub

- chronic and chronic exposure with no progression of toxicity over time. No toxicity was observed following a 21

- day dermal toxicity study in rabbits. However, a conservative upper

bound dermal absorption factor of 30% was estimated using a NOAEL/LOAEL extrapolation
from the 21

- day dermal toxicity (no effects at limit dose of 1000 mg/kg) and developmental toxicity (decreased body weight gain at 300 mg/kg) studies in rabbits.

There were no tumors in the rat chronic toxicity/carcinogenicity study. Primisulfuron

- methyl produced hepatocellular adenoma, carcinomas, and adenomas/carcinomas combined in both sexes in the mouse study. However, t he doses where the tumors occurred in mice were

cons idered to be excessively toxic by the Cancer Peer Review Committee

. T here was no indication of mutagenicity in the battery of available studies. Primisulfuron

- methyl is classified

as Group D “not classifiable as to human carcinogen icity .”

Increased quant itative susceptibility was observed in the rat developmental toxicity study.
Primisulfuron

- methyl produced delayed ossification in fetal rats in the absence of maternal toxicity

. No developmental toxicity was observed in the rabbit. Primisulfuron

- methyl a ffected reproductive parameters in rats including decreases in testicular/spermatic function. This did not affect litter size. Offspring toxicity was also manifested as decreased pup weight. Both reproductive and offspring toxicity observed in the two

- ge neration toxicity study were observed at the same dose as overt maternal toxicity (decreased parental body weights). No evidence of increased susceptibility was seen in the rabbit developmental or rat reproduction toxicity studies.

In acute lethality st udies, p rimisulfuron

- methyl is not acutely toxic via acute oral and inhalation exposures (Toxicity Category IV) and is moderately toxic by dermal exposure (Toxicity Category III). It is also an eye irritant (Toxicity Category III) but not a skin sensitizer or a
d ermal irritant (Toxicity Category IV).Primisulfuron

- methyl D42 5535

Page 8 of 34 

### In a pharmacokinetic/metabolism study in rats, primisulfuron

- methyl was rapidly absorbed, metabolized, and eliminated in the urine and feces. No bioaccumulation was observed. There appear to be several metabolic p athways for primisulfuron

- methyl. The main pathway is hydroxylation of the pyrimidine ring to give rise to the 5

- hydroxyprimidinyl metabolite of the parent compound (i.e. CGA

- 239769) followed by isomerization of the pyrimidinyl moiety. Bridge cleavage re sults in the formation of 2

- carboxymethylbenzene sulfonamide in the feces and saccharin (a cyclization product) in the urine. The corresponding pyrimidinyl moiety is
further metabolized. There were no major sex differences regarding any aspects of metaboli sm.

4.2 Safety Factor for Infants and Children (FQPA Safety Factor)

HED recommends that the FQPA Safety Factor (10X) be reduced to 1X for primisulfuron

methyl. The toxicology database is complete, and there are no concerns/residual uncertainties with regard to pre

- and/or postnatal toxicity, and no concern for neurotoxicity. Although increased quantitative susceptibility was observed in the development al rat study, HED has low
concern for effects to infants and children because 1) no developmental effects were seen in the rabbit developmental or rat reproduction studies, 2) there are clear NOAELs/LOAELs for the
fetal effects observed in the developmenta l rat study, and 3) the endpoints and PODs selected for risk assessment are protective of the effects observed in the study. In addition, exposure estimates are unlikely to underestimate risk.

4.3 Toxicity Endpoint and Point of Departure Selections

The t oxicological endpoints/PODs selected for risk assessment have been changed since the previous assessment to reflect current endpoint selection practices

. However, i t should be noted
that the NOAELs and LOAEL s of the selected endpoints/PODs and those presented in the toxicology profile table (Appendix B ) have not been updated to comply with current policies

. T herefore, the endpoints/PODs selected for risk assessment may be conservative. The PODs selected for risk assessment are protective of the effec ts observed in the primi sulfuron

- methyl database. A summary of toxicological doses and endpoints used in the primi sulfuron

- methyl
human health risk assessments is presented below:

Table 4.3.1 Summary of Primisulfuron

- me thyl Doses and Endpoints for Use in Dietary and Non

Occupational Risk Assessments. Exposure/
Scenario Point of Departure

(POD) Uncertainty/

FQPA Safety

Factors LOC for Risk

Assessment Study and Toxicological Effects

Acute dietary ( General Population and
females 13

- 49) No single dose effect relevant to the general US population including infants and children and

females 13

- 49 years of age was identified in the toxicity studies conducted with primisulfuron

methyl.

Chronic dietary (all populations) NOAEL =

25 mg/kg/day U F A = 10x

UF H = 10x FQPA SF= 1x cPAD = 0.25

mg/kg/day Chronic toxicity study in dogs.

LOAEL 125 mg/kg/day based on (i) decreased erythrocytes, hemoglobin, and hematocrit; (ii) increased platelets; (iii) increased relative (to body) liver weights; (iv) increased incidence of pale livers, vacuolar liver changes, and thyroid hyperplasia.Primisulfuron

- methyl D42 5535

Page 9 of 34 Table 4.3.1 Summary of Primisulfuron

- me thyl Doses and Endpoints for Use in Dietary and Non

Occupational Risk Assessments. Exposure/
Scenario Point of Departure

(POD) Uncertainty/

FQPA Safety

Factors LOC for Risk

Assessment Study and Toxicological Effects

Incidental oral (short

- term) NOAEL=

50 mg/kg/day UF A = 10x

UF H = 10x FQPA SF= 1x LOC for MOE

= 100 2

- Generation repro study in rats

LOAEL = 250 mg/kg/day based on
decre ased pup body weights.

Dermal short

- (1

- 30 days) and
intermediate

term (1

- 6 months) NOAEL = 100

mg/kg/day (30%) dermal absorption UF A = 10x

UF H = 10x FQPA SF= 1x LOC for MOE

= 100 Developmental Toxicity in Rats

LOAEL = 500 mg/kg/day based on incomplete or lack of ossification of several bones hyoids, interparietals, ischium, os pubis and bipartite centrum/vertebrae)

Cancer (oral) Primisulfuron

- methyl was classified as Group D “not classifiable as a human carcinogen” by

the Cancer Peer Review Committee Point of Departure (POD) = a data point or estimated point derived from observed dose

- response data, which is used to mark the beginning of extrapolation to determine risk associated with lower environmentally relevant human

exposures. UF = Uncertainty Factor. UF A = extrapolation from animal to human (interspecies). UF H = potential variation in sensitivity among members of the human population (intra

- species). FQPA SF = FQPA Safety Factor.
NOAEL = No Observed Adverse Effect Level. LOAEL = Lowest Observed Adverse Effect Level. PAD = Population Adjusted Dose (a = acute, c = chronic). RfD = Reference Dose. LOC= Level of Concern.

Table 4.3.2 Summary of Primisulfuron

- m ethyl Doses and Endpoints for Use in Occupational Risk
Assessment s. Exposure/
Scenario Point of Departure

(POD) Uncertainty /

FQPA Safety

Factors LOC for Risk

Assessment Study and Toxicological Effects

Dermal short

- (1

- 30 days) and
intermediate

term (1

- 6 months) NOAEL = 100

mg/kg/day (30%) dermal absorption UF A = 10x

UF H = 10x FQPA SF= 1x LOC for MOE

= 100 Developmental Toxicity in Rats

LOAEL = 500 mg/kg/day based on incomplete or lack of ossification of several bones hyoids, interparietals, ischium, os pubis and bipartite centrum/vertebrae)

Inhalation short

- (1

- 30 days) and
intermediate

term (1

- 6 months) NOAEL=

50 mg/kg/day UF A = 10x

UF H = 10x FQPA SF= 1x LOC for MOE

= 100 2

- Generation repro study in rats

LOAEL = 250 mg/kg/day based on decreased pup body weights.

Point of Departure (POD) = a data point or estimated point derived from observed dose

- response data, which is used to mark the beginning of extrapolation to determine risk associated with lower environmentally relevant human

exposures. UF = Uncertainty Factor. UF A = extrapolation from animal to human (interspecies). UF H = potential variation in sensitivity among members of the human population (intra

- species). FQPA SF = FQPA Safety Factor.
NOAEL = No Observed Adverse Effect Level. LOAEL = Lowest Observed Adverse Effect Level. PAD = Population Adjusted Dose (a = acute , c = chronic). MOE = Margin Of Exposure. LOC = Level Of Concern.



### 4.4 Endocrine Disruptor Screening Program

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse outcomes from exposure to chemicals. Collectively, t hese studies include acute, subchronic and chronic toxicity, including assessments of carcinogenicity, neurotoxicity, developmental, reproductive, and general or systemic toxicity. These studies include endpoints which may be susceptible to endocrine influ ence, including effects on endocrine target organ histopathology, organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, reproductive loss, and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests andPrimisulfuron

- methyl D42 5535

Page 10 of 34 

### chronic studies that assess growth, developmental and reproductive effects in different taxonomic groups. As part of its most recent registration decision for primisulfuron

- methyl., EPA reviewed these data and selected the most sensitive endpoints for relevant risk assessment scenarios from the existing hazard database. However, as required by FFDCA section 408(p), primisulfuron

- methyl is subject to the endocrine screening part of the Endocrine Disruptor Screening Program (EDSP).

EPA has developed t he EDSP to determine whether certain substances (including pesticide active and other ingredients) may have an effect in humans or wildlife similar to an effect produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrat or may designate.” The EDSP employs a two

- tiered approach to making the statutorily required determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal
systems. chemicals that go through Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA will determine which, if any, of the Ti er 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
establish a dose

- response relationship between the dose and the E, A, or T effect.

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. 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 ingredients. A s econd list of chemicals identified for EDSP screening was published on June 14, 2013 1 

### and includes some pesticides scheduled for Registration Review and chemicals found in water

. Neither of these lists should be construed as a list of known or likely endo crine disruptors.

For further information on the status of the EDSP, the policies and procedures, the lists of chemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit our
website. 2



### 5 .0 Residue Chemistry

The existing residue chemistry database for primisulfuron

- methyl is complete and adequate for risk assessment purposes. No residue chemistry data are required at this time. The qualitative nature of the residues of primisulfuron

- methyl in plants and anim als are adequately understood.
HED determined that the residue of concern for risk assessment and tolerance enforcement in plants

, livestock commodities , and drinking water is primisulfuron

- methyl only ( W. Hazel,
Metabolism Assessment Review Committee ; D2 82837 ; 5/15/ 20 02 ). Adequate methods are available for the enforcement of the current tolerance expression ( W. Hazel et al. ; D280923 ; 06/28/2002 )

.

The structure and the physical/chemical properties are summarized in Appendix C

.

6. 0 Dietary Risk Assessment

1 See http://www.regulations.gov/#!documentDetail;D=EPA

- HQ

- OPPT

- 2009

- 0477

- 0074 for the final second list of
chemicals.

2 http://w ww.epa.gov/endo/Primisulfuron

- methyl D42 5535

Page 11 of 34 

### An updated dietary exposure assessment has been completed for primisulfuron

- methyl for the DRA to incorporate updated food consumption data and drinking water modeling estimates. The use pattern, PODs, and residue inputs to the dietary assessm ent have not changed since the previous assessment.

6 .1 Water Residue Profile

Screening ground water

- sourced drinking water exposure estimates were generated with the Pesticide Root Zone Model for GroundWater ( PRZM

- GW; v.1.07) for use in the sulfonylurea (SU) dietary risk assessments. Rather than produce chemical

- specific estimated drinking water concentrations (EDWCs) following the usual assessment procedures, EFED provided coarse

screen estimates that should exceed upper

- bound chemical

- specific EDWCs for any SU. This was achieved by using model inputs that represent the use pattern of highest exposure from any SU, the highest soil mobility of any SU residue of concern, and persistence to any route of degradat ion over time. The resulting highest coarse

- screen EDWCs from PRZM

- GW can be used as a conservative estimate of exposure and are summarized in Table 6.1 .1 ( G. Orrick; D427429; 8/12/ 20 15 ).

The chronic dietary assessment for primisulfuron

- methyl used the coarse

- screen post

breakthrough mean value of 492 μg/L (0.492 ppm).

Table 6

. 1 .1 PRZM

- GW Coarse

- Screen EDWCs for Sulfonylureas 1

.

Modeled Scenario K d or K OC Initial Application Dates (days post

emergence) Max. Daily Conc.

(μg/L) Mean

Breakthrough Time ( yrs) Post

breakthrough Mean (μg/L)

WI corn K d 7 449 11.5 415

K OC 7 504 6.9 425

Delmarva ( DMV )

corn K d 7 489 5.3 369

K OC 7 560 3.3 378

FL citrus K d 7 429 3.2 351

K OC 7 467 2.3 349

FL potato K d 7 375 2.6 272

K OC 7 407 2.2 275

GA peanut K d 7 197 5.2 156

K OC 7 206 3.9 158

NC cotton K d 7 640 8.7 492

K d 37 641 8.7 491

K d 67 637 8.7 490

K OC 7 742 5.7 484

K OC 37 751 5.7 483

K OC 67 744 5.7 482

1 Maximum values are bold ed.



### 6 .2 Dietary (Food + Water) Exposure Assessment

HED has conducted a screening

- level chronic dietary risk assessment for primisulfuron

- methyl using tolerance

- level residues in foods and the sulfonylurea

- class

- wide screening

- level estimate of residues in drinking water ( G. Orrick; D427429 ; 8/12/ 20 15 ). Ex posure and risk estimates were obtained from the Dietary Exposure Evaluation Model using the Food Commodity Intak ePrimisulfuron

- methyl D42 5535

Page 12 of 34 

### Database (DEEM

- FCID; version 3.18 ). The model uses foo d consumption data from the 2003

- 2008 National Health and Nutrition Examination Survey /What We Eat in America (NHANES/WWEIA) database, coupled with recipe files and residues in foods, to derive estimates of dietary exposure and risk.

Generally, HED is concerned when chronic dietary exposure estimates exceed 100% of the
chronic population adjusted dose ( c PAD). Chronic dietary risk estimates (food and drinking water) are not of concern for the general U.S. population or any other population subgroup ( Table 6.2.1 ) . The chronic exposure estimate utilized 4.3 % of the cPAD for the gen eral U.S. population and 11% of the cPAD for all infants (<1 year old), the most highly

- exposed population subgroup

. Because of the very conservative assumptions used in the analysis (tolerance

- level residues, 100% crop treated, upper

- bound modeled drinking wa ter estimates), actual exposure and risk are expected to be much lower than those shown in Table 6 .2.1 . The listings of inputs and outputs to the assessment are included in Appendix D . HED did not conduct an acute dietary exposure/risk assessment due to the lack of an endpoint appropriate for acute dietary assessment. P rimisulfuron

- methyl is classified as Group D , “ Not Classifia ble as to Human Carcinogenicity ; ” therefore, a cancer dietary assessment was not conducted for primisulfuron

- methyl

.

Table 6 .2

. 1 Summary of Chronic Dietary Exposure (Food and Drinking Water) and Risk for
Primisulfuron

- methyl 1

.

Population Subgroup Chronic Dietary Dietary Exposure (mg/kg/day) % cPAD

General U.S. Population 0.010704 4.3 All Infants (<1 year old) 0.027032 11

Children 1

- 2 years old 0.016319 6.5

Children 3

- 5 years old 0.013565 5.4

Children 6

- 12 years old 0.009683 3.9

Youth 13

- 19 years old 0.007893 3.2

Adults 20

- 49 years old 0.010595 4.2

Adults 50

- 99 years old 0.010422 4.2

Females 13

- 49 years old 0.01053 4.2

1 Population with the greatest exposure is in bold. Exposure and risk estimates calculated using DEEM version 3.18

.



### 7.0 Residential (Non

- Occupational) Exposure/Risk Characterization

There are no registered residential uses or occupational uses resulting in residential exposure to primi sulfuron

- methyl. Therefore, a quantitative residential exposure assessment was not performed.

8

. 0 Non

- Occupational Spray Drift Exposure and Risk Estimates

A detailed description about HED’s spray drift policy and how to evaluate the drift potential and

associated risks is available in Appendix E

.

8.1 Risk Estimates from Lawn Deposition Adjacent to Applications

A spray drift assessment was conducted to address the deposition of residues from adjacent commercial pesticide applications. The spray drift risk estimates are based on an estimated deposited residue concentration as a result of the screening level agric ultural applicationPrimisulfuron

- methyl D42 5535

Page 13 of 34 

### scenarios. Primisulfuron

- methyl is an herbicide registered for use on corn ( grown for grain, silage

, and seed) and bluegrass (grown for seed and sod production ) . Registered use products can be applied via groundboom and aerial equipme nt. The recommended drift scenario screening level options are listed below:

 Aerial applications are based on the use of AgDrift® Tier 1 aerial option for a fine to medium spray type and a series of other parameters(e.g., wind vector assumed to be 10 mph in a downwind direction for en tire application/drift event).

 Groundboom applications are based on the AgDrift ® 

### option for high boom height and using very fine to fine spray type using the 90 th 

### percentile results.

Risk estimates for C hildren (1 to <2 years old) , from combined incidental oral and dermal

exposure, and for adult s from dermal exposure to primisulfuron

- methyl related to spray drift are

not of concern at the field edge for groundboom and aerial applications (Table 8. 1.1 and 8.1. 2 ).
Based on the total applicable LOC of 100, all MOEs are ≥100.

Table 8

. 1.1 Adult Dermal Risk Estimates (MOEs) Related to Spray

- Drift Exposure for Primisulfuron

methy l.

Lifestage Crop Application

Method Spray Type /

Nozzle Configuration Application

Rate (lb ai/A) Estimated

TTR t (ug/cm2) Dermal MOE At Edge

Adult Corn Aerial High Boom Very fine to
Fine 0.036 0.004 83 ,000

Groundboom Fine to

Medium 110 ,000

MOE= Margins of Exposure. TTR t = Turf Transferable Residue

Table 8.1

. 2 Children (1 to < 2 years old) Dermal & Incidental Oral Risk Estimates (MOEs) Related to Spray

- Drift Exposure for Primisulfuron

- methy l.

Lifestage Crop Application

Method Spray Type /

Nozzle Configuration Application

Rate (lb ai/A) Estimated

TTR t (ug/cm2) Dermal

MOE At Edge Incidental

Oral MOE At Edge

Children (1 to < 2 years old) Corn Aerial High Boom Very fine to
Fine 0.036 0.004 49,000 350,000

Groundboom Fine to

Medium 67,000 490,000

MOE= Margins of Exposure. TTR = Turf Transferable Residue



### 9

. 0 Non

- Occupational Bystander Post

- Application Inhalation Exposure and Risk
Estimates

Volatilization of pesticides may be a source of post

- application inhalation exposure to individuals nearby pesticide applications. The agency sought expert advice and input on issues
relat ed to volatilization of pesticides from its Federal Insecticide, Fungicide, and Rodenticide Act Scientific Advisory Panel (SAP) in December 2009, and received the SAP’s final report on March 2, 2010 (http://www.epa.gov/scipoly/SAP/meetings/2009/120109meeti ng.html). The agency has evaluated the SAP report and has developed a Volatilization Screening Tool and a subsequent Volatilization Screening Analysis. 3 

### During Registration Review, the agency will

3 Available at: http://www.regulations.gov/#!docketDetail;D=EPA

- HQ

- OPP

- 2014

- 0219

.Primisulfuron

- methyl D42 5535

Page 14 of 34 

### utilize this analysis to determine if data (i.e., flux st udies, route

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

- methyl

.

10.0 Aggregate Exposure/Risk Characterization

The Food Quality Protection Act of 1996 directs EPA to assess aggregate exposure to pesticide chemical residues, including all anticipated dietary exposures and all other exposures for which
there is reliable information. In the case of primisulfuron

- meth yl, aggregate exposure and risk estimates are equivalent to the dietary exposure and risk estimates in Section 6 and are not of

concern.

11.0 Cumulative Exposure/Risk Characterization

In 2015, EPA’s Office of Pesticide Programs released a guidance document entitled, Pesticide Cumulative Risk Assessment: Framework for Screening Analysis [ http://www.epa.gov/oppfead1/cb/csb_page/updates/2015/framework

- for

- screening

analysis.html ]. This do cument provides guidance on how to screen groups of pesticides for cumulative evaluation using a two

- step approach beginning with the evaluation of available toxicological information and if necessary, followed by a risk

- based screening approach. This
fra mework supplements the existing guidance documents for establishing common mechanism groups (CMGs) 4 

### and conducting cumulative risk assessments (CRA) 5



### . The Agency has utilized this framework to evaluate the SUs of which primisulfuron

- methyl is a member (J. D’Agostino; D428798; 9/9/ 20 15). Although the SUs share some chemical and toxicological characteristics, the toxicological database does not support a testable hypothesis for a common mechanism of
action. No further mechanistic data are required and no f urther cumulative evaluation is

necessary.

12.0 Occupational Exposure/Risk Characterization

Based on current labeling, types of equipment and techniques that can potentially be used, occupational handler exposure is expected from the registered uses of primi sulfuron

- methyl on corn and bluegrass

. Occupational handlers are anticipated to have short

- term (1

- 30 days) and
intermediate

- term (1

- 6 months) dermal and inhalation exposures. Long

- term exposures (more than 6 months) are not anticipated.

1 2 .1 Occupational Handler Exposure/Risk Estimates

In support of Registration Review, an updated occupational exposure assessment for primisulfuron

- methyl was conducted for mixers/loaders and applicators for aerial and groundboom applications of the WSP and WDG formulation s . The assessment was based on the maximum registered application rate of 0.027 lbs ai/A for WDG formulations and 0. 036 lb ai/A
for WSP formulations a nd maximum area treated per day

.

Handler exposure and risk were calculated at baseline (lo ng pants, a long

- sleeved shirt, no
chemical

- resistant gloves, and no respirator)

. 

### Personal Protective Equipment ( PPE )

4 Guidance For Identifying Pesticide Chemicals and Other Substances that have a Common Mechanism of Toxicity (USEPA, 1999)

5 Guidance on Cumulative Risk Assessment of Pesticide Chemicals That Have a Common Mechanism of Toxicity (USEPA, 2002)Primisulfuron

- methyl D42 5535

Page 15 of 34 

### recommended on registered primisulfuron

- methyl labels typically includes the addition of
chemical

- resistant gloves.

The standard body w eight for the general population (80 kg) was used for all inhalation exposure scenarios covered in this risk assessment since the endpoints selected for the inhalation route were not developmental and/or fetal effects. However, si nce the dermal PODs are ba sed on developmental and/or fetal effects, the body weight appropriate for dermal assessments is 69 kg.

A dermal absorption factor of 30% was used for the exposure assessment and is based on a NOAEL/LOAEL extrapolation from the 21

- day dermal toxicity (no effects at limit dose of 1000 mg/kg) and developmental toxicity (decreased body weight gain at 300 mg/kg) studies in rabbits. 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.

For all scenarios, dermal and i nhalation risk estimates were not of concern (i.e., MOEs ≥ 100)

with either baseline protection (long

- sleeved shirt, long pants, shoes plus socks, no gloves, or respirator) or with the use of gloves, as recommended on some labels (see Table 1 2 .1.1).Page 16 of 34

Table 1 2 .1 .1. Summary of Occupational Handler Exposure and Risk Estimates for Primisulfuron

- methyl.

Scenario Crop / Target

Category Application

Rate a Amount

Handled /

Area
Treated b Dermal Unit

Exposures (ug/lb ai) Mitigation c Inhalation Unit

Exposures (ug/lb ai) Mitigation c Dermal Dose

(mg/kg/day) d Dermal

MOE e Inhalation

Dose (mg/kg

day) f Inhalation

MOE g

Mixer/Loader

WDG Aerial application Corn 0.027 1200 227
SL/No G 8.96

No

- R 0.032 3,100 0. 00 36 1 4 ,000

WDG
Groundboom application Corn 0.027 200 227
SL/No G 8.96

No

- R 0.00535 1 9 ,000 0. 000 605 83 ,000

WSP Aerial application Bluegrass 0.036 350 9.8

EC 0.24

EC 0.000535 190,000 0. 0000 378 1, 3 00,000

Corn 1200 0.00184 54,000 0. 0001 3 3 8 0,000

WSP
Groundboom application Bluegrass
0.036 80 9.8
EC 0.24

EC 0.000123 810,000 0.0000 09 5, 8 00,000

Corn 200 0.000307 330,000 0.000021 6 2, 3 00,000

Applicator

Aerial application Bluegrass 0.036 350 2.08
EC 0.0049

EC 0.000114 880,000 0.000000 77 6 5 ,000,000

Corn 1200 0.000391 260,000 0.00000 27 1 9 ,000,000

Groundboom application Bluegrass 0.036 80 78.6
SL/No G 0.34

No

- R 0.000983 100,000 0.000012 4,1 00,000

Corn 200 0.00246 41,000 0. 000031 1, 6 00,000 Flagger

Aerial application Corn and

Bluegrass 0.036 350 11
SL/No G 0.35

No

- R 0.000604 170,000 0. 000055 910 ,000

a. Based on maximum single application rates on registered labels ( Table 3.1 ). b. Based on the Science Advisory Council for Exposure Policy 9.1: Standard Values for Daily Acres Treated in Agriculture.
c. Based on the “ Occupational Pesticide Handler Unit Exposure Surrogate Reference Table ” (March, 2013). Mitigation Level: SL/No G = single layer clothing/no gloves; SL/G = single layer of clothing/gloves; No

- R = no respirator; EC = engineering controls (e.g., enclosed cockpit for aerial applicators). d. Dermal Dose (mg/kg/day) = [Rate (lb ai/A or lb ai/gal) * UE (mg/lb ai) * Acres Tre ated or Amount handled (A or gal/day)] * Dermal Absorption (30 %) /BW (69 kg). e. Dermal MOE = POD (100 mg/kg/day)/ Dermal Dose (mg/kg/day). LOC = 100. f. Inhalation Dose (mg/kg/day) = [Rate (lb ai/A or lb ai/gal) * UE (mg /lb ai) * Acres Treated or Amount handled (A or gal/day)] /BW (80 kg). g. Inhalation MOE = POD (50 mg/kg/day)/ Inhalation Dose (mg/kg/day). LOC = 100.Primisulfuron

- methyl D42 5535



### Page 17 of 34 1 2 .2 Occupational Post

- application Exposure/Risk Estimates

Occupational exposures to workers re

- entering primisulfuron

- methyl treated agricultural use
sites are expected ; therefore, a quantitative post

- application assessment was conducted for those sites. Based on the use directions on product labels, foliar exposure is expected since

ap plications are genera lly made post

- emergent when the corn is 4

- 20 inches in height and post

emergent to grass (target weed) growth

. Chemical

- specific turf transferable residue data and dislodgeable foliar residue data were not available for primisulfuron

- methyl ; therefore, de fault assumptions were used to estimate transferable residue. A discussion of the dislodgeable foliar residue and turf transferable residue data is provided in Appendix F.

The results of the dermal post

- application exposure and risk assessment indicate th at dermal MOEs ≥ LOC (MOEs ≥ 100) on day 0 for all scenarios, and, therefore, are not of concern to

HED.

Table 1 2 .2.1. Summary of Occupational Post

- application Dermal Exposure and Risk Estimates.

Crop Crop Height /

Foliage Density Activity Transfer
Coefficient (cm 2 /hr) Residue 1,2

(ug/cm 2 ) Dermal Dose 2

(mg/kg

- day) MOE 3

DAT (Day After Treatment) = 0 (12

hours)

Corn Field / row crop, tall Irrigation (hand set) 1,900

0.1 1 0.007 15,000

Field / row crop, tall Scouting 1,100 0.004 26,000

Field / row crop, tall Scouting 210 0.001 140,000

Field / row crop, tall Hand weeding 70 0.00025 410,000

Kentucky Bluegrass (grown for seed production) Field / row crop,

low / medium Irrigation (hand set) 1,900

0.1 1 0.007 15,000

Field / row crop,
low / medium Scouting 1,100 0.004 26,000

Kentucky Bluegrass (grown for sod production) Turf / sod Maintenance 6700

0.004 2 0.001 110,000

Turf / sod Harvesting, Slab 6700 0.001 110,000

Turf / sod Transplanting/Planting 6700 0.001 110,000

1 . DFR = Application Rate × F × (1

- D) t × 4.54E8 μg/lb × 2.47E

- 8 acre/cm 2 ; where F = 0.25 and D = 0.10 per day
2. TTR = Application Rate × F × (1

- D) t × 4.54E8 μg/lb × 2.47E

- 8 acre/cm 2 ; where F = 0.1 and D = 0.10 per day.

3. Daily Dermal Dose = [DFR (μg/cm 2 ) × Transfer Coefficient × 0.001 mg/μg × 8 hrs/day × dermal absorption ( 30 %)]  BW (69 kg). 4. MOE = POD (100 mg/kg/day) / Daily Dermal Dose.



### Primisulfuron

- methyl is not acutely toxic via acute oral and inhalation exposures (Toxicity Category IV) and is moderately toxic by dermal exposure (Toxicity Category III). It is also an eye irritant (Toxicity Category III) but not a skin sensitizer or a dermal irritant (Toxicity Category IV). Under 40 CFR 156.208 (c) (2) (iii), pesticide active ingredients classified as Toxicity Category III or IV for acute dermal, eye irritation

, and primary skin irritation are assigned a 12

- hour Restricted Entry Interv als (REI). Therefore, the Worker Protection Sta ndard

REI 6 

### of 12 hours is adequate to protect workers from post

- application exposures to primisulfuron

- methyl. The occupational post

- application assessment indicated no risks of

6 As specified in 40 CFR part 156 subpart KPrimisulfuron

- methyl D42 5535



### Page 18 of 34 concern on the day of applica tion as well; therefore, HED recommends a 12

- hour REI for the primisulfuron

- m ethyl labels.

13.0 Public Health and Pesticide Epidemiology Data

Incident databases w ere previou sly reviewed for p rimisulfuron

- methyl in 2011 (S. Recore;
D396007 ; 12/8/2011 ) and upd ated in 2015 (S. Recore; D428297; 7/23/ 20 15)

. T here were no incidents reported to the OPP Incident Data System ( IDS ) from January 1, 2006 to November 2,

2011. It was concluded that “there does not appear to be a concern at this time that would

warrant fu rther investigation.” The current IDS analysis

, from January 1, 2012 through May 27, 2015, shows no incidents reported in Main or Aggregate IDS involving the active ingredient primisulfuron

- methyl. Additionally, a query of the Centers for Disease Control and Prevention/National Institute for Occupational Safety and Health (CDC/NIOSH) Sentinel Event Notification System for Occupational Risk

- Pesticides (SENSOR) 1998

- 2011 identifies one case involving primisulfuron

- methyl. Thi s case was low severity and involved multiple active ingredients.

Based on the continued low frequency and low severity of incident cases reported for primisulfuron

- methyl in both IDS and NIOSH SENSOR

- Pesticides, there does not appear to be a

concern at this time that would warrant further investigation. Primisulfuron

- methyl is also not included in the Agricultural Health Study (AHS), and therefore this study does not provide any additional information on primisulfuron

- methyl. The Agency will continu e to monitor the incident information and if a concern is triggered, additional analysis will be conducted.

1 4 .0 References

Table 14.1 References

Author Barcode Date Title M. Sahafeyan
et al. D 394824 03/07/2012 Primisulfuron

- methyl. Health Effects Division (HED) Scoping Document for Registration Review.

W. Hazel et al. D280923 06/28/2002 PP# 6F4752. Primisulfuron

- methyl. Proposed Use and Tolerances in/on Kentucky Bluegrass Grown for Seed. Human Health Risk
Assessment and Tolerance Reassessment. DP Barcode D280923.
P.C. Code 128973. Case 287952. Submission S610273.

W. Hazel D282837 05/15/2002 Primisulfuron

- methyl (128973): Results of the HED Metabolism Assessment Review Committee (MARC) Electronic Review. DP
Barcode: D282837.

G. Orrick D427429 8/12/ 2015 Drinking Water Exposure Assessment for the Registration Review of 22 Sulfonylurea Herbicides.

S. Recore D428297 7/23/ 20 15 Primisulfuron

- methyl : Tier I Update Revi ew of Human Incidents/Epidemiology for Draft Risk Assessment S. Hanley D280999 5/22/ 20 02 Primisulfuron

- methyl: Occupational and Residential Exposure and
Risk Assessment/Characterization for the Proposed use on Kentucky BluegrassPrimisulfuron

- methyl D42 5535



### Page 19 of 34 Appendix A : Data Deficiencies

Submittal of Analytical Reference Standards (860.1650)

The analytical reference standard s for primisulfuron

- methyl expired on 4/30/ 20 15 and are

current ly unavailable in EPA’s National Pesticide Standards Repository ( NPSR ; email communication between G. Verdin and J. Van Alstine, 5/7/20 15 )

. T he registrant is required to
maintain reasonable amount s of the reference standard s for primisulfuron

- methyl in the NPSR as long as tolerances rema in published in 40 CFR §180. 452

. When necessary, new reference
standard s, or updated certificates of analysis ( COA s), should be sent to the Analytical Chemistry Branch ( ACB ) , which is located at Fort Meade, MD. It should be sent to the attention of eithe r Theresa Cole or Thuy Nguyen at the address listed below, along with a letter of transmittal.
Please note that the full 9

- digit Z IP Code is required , or the mail will be returned to the registrant.

USEPA

National Pesticide Standards Repository

A nalytical Chemistry Branch/BEAD/OPP 701 Mapes Road Fort George G. Meade, MD 20755

- 5350

The letter of transmittal should include the assay of the standard, name of the analytical method used, a statement of principal impurities, purification procedure s employed, storage requirements, and special precautions for safe handling. Replacement of standards , or updated COAs, may be required periodically if supplies are exhausted, if the standards expire, or if decomposition occurs during storage. Material Safety Data Sheets (MSDSs) must accompany all analytical standards as specified by the Occupational Safety and Health Administration (OSHA)
in 29CFR §1910.1200.Primisulfuron

- methyl D42 5535



### Page 20 of 34 Appendix B : Toxicity Profile of Primisulfuron

- Methyl

B .1. Toxicity Requirements

The toxi cology requirements (40 CFR 158.340) for Primis ulfuron

- methyl are presented below.

TABLE B .1 Toxicology Data Requirements for Primi sulfuron Methyl

.

Test Required Satisfied

870.1100 Acute Oral Toxicity

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

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

................................ ............................ 870.2400 Primary Eye Irritation

................................ ................................ .. 870.2500 Primary Dermal Irritation

................................ ............................ 870.2600 Dermal Sensitization

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

yes

yes

yes

yes

yes yes

yes

yes

yes

yes

yes

870.3100 Oral Subchronic (Rodent)

................................ ............................ 870.3150 Oral Subchronic (Non

- Rodent)

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

- Day Dermal

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

- Day Dermal

................................ ................................ ............ 870.3465 21/90

- Day Inhalation

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

yes

yes

no

no yes

yes

yes

no

no 1

870.3700a Developmental Toxicity (Rodent)

................................ ............... 870.3700b Developmental Toxicity (Non

- Rodent)

................................ ....... 870.3800 Reproduction

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

yes

yes yes

yes

yes

870.4100a Chronic Toxicity (Rodent)

................................ ........................... 870.4100b Chronic Toxicity (Non

- Rodent)

................................ .................. 870.4200a Oncogenicity (Rat)

................................ ................................ ....... 870.4200b Oncogenicity (Mouse)

................................ ................................ . 870.4300 Chronic/Oncogenicity

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

yes

yes

yes

yes yes

yes

yes

yes

yes

870.5100 Mutagenicity

– Gene Mutation (Bacterial)

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

– Gene Mutation (Mammalian)

............................. 870.5375 Mutagenicity

– Structural Chromosomal Aberrations

................. 870. 5395 Mutagenicity

– Mammalian Erythrocyte Micronucleus

.............. 870.5550 Mutagenicity

– Unscheduled DNA Synthesis

............................. 870.5915 Mutagenicity

– In Vivo Sister Chromatid Exchange

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

yes

yes

no

no

no yes

no 2

no 2

yes

yes

no

870.6100a Acute Delayed Neurotoxicity (Hen)

................................ ............ 870.6100b 90

- Day Neurotoxicity (Hen)

................................ ........................ 870.6200a Acute Neurotoxicity Screening Battery (Rat)

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

- Day Neurotoxicity Screening Battery (Rat)

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

................................ ...................... no

no

yes

yes

no no

no

no 1

no 1

no

870.7485 General Metabolism

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

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

no yes

no

870.7800 Immunotoxicity yes N o 1

1 ) The Hazard and Science Policy Council (HASPOC) determined that subchronic inhalation , acute and subchronic neurotoxicity

and immuno toxicity studies are not required.
2 ) Mutagenicity studies were submitted prior to the 1991 mutagenicity test battery update and are considered to fulfill the guideline requirements.Primisulfuron

- methyl D42 5535



### Page 21 of 34 B .2. Toxicity Profiles

TABLE B .2.1 Acute Toxicity Profile for Technical Primisulfuron

- M ethyl.

Guideline

Number Study Type MRID
Number Results Tox Category

870.11 Acute Oral

- Rat 40331206 LD 50 > 5050 mg/kg IV

870.12 Acute Dermal

- Rabbit 40331207 LD 50 > 2010 mg/kg III

870.13 Acute Inhalation

- Rat 40331208 LC 50 > 4.81 mg/L IV

870.24 Acute Eye Irritation

- Rabbit 40331209 No corneal opacity, conjunctivitis reversible by 72 hours III

870.25 Acute Dermal Irritation

-

Rabbit 40331210 Not a dermal irritant IV

870.26 Skin Sensitization

- Guinea Pig 40331211 Not a skin sensitizer N/A

870.11 Acute Oral

- Rat 40331206 LD 50 > 5050 mg/kg IV

870.12 Acute Dermal

- Rabbit 40331207 LD 50 > 2010 mg/kg III * NA = Not Applicable.

TABLE B .2.2 Subchronic, Chronic and Other Toxi city Profile for Primisulfuron

- Methyl.

Guideline
Number Study Title MRID Number Results

870.3100 90

- Day oral

toxicity in rats 40331218 (1987)

Acceptable/guideline 0, 10, 300, 3000, 10,000, or 20,000 ppm (equivalent to 0, 0.5, 15, 150, 500, or 1000 mg/kg/day based on 1 ppm = 0.05 mg/kg/day) NOAEL = 15 mg/kg/day

LOAEL = 150 mg/kg/day based on decreased body weight gain and food consumption/efficiency.

870.3150 90

- Day oral

toxicity in dogs 40331219 (1987)

Acceptable/guideline 0, 25, 1000, or 10,000 ppm (equivalent to 0, 0.6, 25, or 250 mg/kg/day) NOAEL = 25 mg/kg/day. LOAEL = 250 mg/kg/day based on decreased body weight, body weight gain, food consumption/efficiency, erythrocytes, Hb, hematocrit, and thyroid/parathyroid weight. Platelets and prothrombin time were increased. In the thyroid, mild to severe colloid deple tion in the small follicles and moderate to severe parafollicular cell hyperplasia were observed.

870.3200 21

- day dermal

rabbit 41337601 and

41135302 (1989) acceptable/guideline 10, 100, or 1000 mg/kg/day NOAEL = 1000 mg/kg/day (limit dose).

LOAEL = not observed

870.3700a Prenatal

developmental in

rats 40874701 (1988)

acceptable/guideline 0, 100, 500, or 1000 mg/kg/day maternal toxicity: NOAEL > 1000 mg/kg/day. (HDT)

developmental toxicity: NOAEL = 100 mg/kg/day. LOAEL = 500 mg/kg/day based on incomplete or lack of ossification of several bones hyoids, interparietals, ischium, os pubis and bipartite centrum/vertebrae)Primisulfuron

- methyl D42 5535



### Page 22 of 34 TABLE B .2.2 Subchronic, Chronic and Other Toxi city Profile for Primisulfuron

- Methyl.

Guideline

Number Study Title MRID Number Results

870.3700b 870.3700b

Prenatal developmental in
rabbits 40331220 (1987)

acceptable/guideline 0, 10, 300, or 600 mg/kg/day M aternal toxicity NOAEL = 10 mg/kg/day. LOAEL = 300 mg/kg/day based on abortion and decreased body weight gain

D evelopmental toxicity NOAEL = 600 mg/kg/day (HDT)

870.3800 Reproduction and

fertility effects in

rats 40512009 (1987)

acceptable/guideline 0, 10, 1000, or 5000

ppm (equivalent to 0, 0.5, 50, or 250 mg/kg/day based on 1 ppm = 0.05 mg/kg/day ) Parental Toxicity: NOAEL =50 mg/kg/day LOAEL =250 mg/kg/day based on decreased body weight (both generation)

.

Reproductive Toxicity: NOAEL =50 mg/kg/day LOAEL =250 mg/kg/day based on increased seminiferous tubule atrophy and aspermatogenesis with a relative aspermia in the epididymides (F1 generation)

Offspring Toxicity: NOAEL =50 mg/kg/day LOAEL =250 mg/kg/day based on decreased pup weight (F1 generation)

870.100b Chronic toxicity

dogs 40512008 (1987)

acceptable/guideline 0, 25, 1000, or 10,000/5000 ppm (equivalent to 0, 0.6, 25, or 250/125 mg/kg/day) NOAEL = 25 mg/kg/day

LOAEL= 250/125 mg/kg/day based on decreased erythrocytes, Hb, and hematocrit and increased platelets, relative liver weight, pale liver, vacuolar liver, and thyroid hyperplasia.

870.4300 Chronic toxicity

and carcinogenicity
in rats 40856502 (1988)

acceptable/guideline 0, 10, 300, 3000, 10,000 (reduced to 8000 after 13 weeks) (equivalent to 0, 0.5, 15, 150, or 500 mg/kg/day based on 1 ppm = 0.05 mg/kg/day) NOAEL = 15 mg/kg/day LOAEL= 150 mg/kg/day based on decreased body weight gain

At the doses tested, there was not a treatment related increase in tumor incidence when compared to controls. Dosing was considered adequate.

870.4300 Chronic toxicity

and carcinogenicity
in mice 40856503 and

41337602 (1988) acceptable/guideline 0, 1.35, 40.2, 408, and 1156 mg/kg/day in
males 1.72, 50.8, 512, and 1386 mg/kg/day in
females NOAEL = 40.2 mg/kg/day LOAEL= 408 mg/kg/day based on (i) increased mortality; (ii) decreased body weight gains; and (iii) kidney, liver, testes, teeth (hypoplasia), and bone toxicity

.

Hepatocellular adenoma, carcinomas, and
adenomas/carcinomas combined in both sexes at 2 highest doses (408, and 1156 mg/kg/day). These doses were considered to be excessively toxic by
the Cancer Peer Review Committee. cancer classification: Group DPrimisulfuron

- methyl D42 5535



### Page 23 of 34 TABLE B .2.2 Subchronic, Chronic and Other Toxi city Profile for Primisulfuron

- Methyl.

Guideline

Number Study Title MRID Number Results

870.5100 Gene Mutat ion

-

bacterial 40331221 (1983)

acceptable/guideline
Salmonella typhimurium strains TA98, TA100, TA1535, and TA1537 were exposed to primisulfuron methyl at concentrations of 1, 4, 16, 64, or 256 μg/plate in the presence or
absence of S9

- activation. The test was negative.

No treatment

- related increases in the number of revertants/plate were observed in any bacterial strain at any dose level of primisulfuron methyl up to cytotoxic levels in the presence or absence of S9

- activation.

870.5395 Cytogenetics In

Vivo Mammalian Cytogenetics

- Erythrocyte
Micronucleus assay in Chinese

Hamsters 40331222 (1987)

acceptable/guideline
Chinese hamsters (8/sex/dose/sample time) were dosed once via oral gavage (20 mL/kg) with primisulfuron methyl at doses of. 0, 1250, 2500, or 5000 mg/kg. The test was negative.

Bone marrow cells were harvested at 16, 24, or 48 hours post

- dosing. There w as no significant increase in the frequency of micronucleated polychromatic erythrocytes in bone marrow compared to controls.

870.5550 Unscheduled

DNA Synthesis in Rat Hepatocytes/
Mammalian Cell
Cultures 40331223 (1987)

acceptable/guideline Hepatocyte c ultures from male RAIF (SPF) rats were exposed to primisulfuron methyl at concentrations of 2, 10, 50, 100, 200, or 400 μg/mL (Trial 1) and 0.4, 2, 10, 20, 40, 60, 80, 100, 200, or 400 μg/mL (Trial 2). The te s t was negative.

There was no evidence that uns cheduled DNA synthesis, as determined by radioactive tracer procedures (nuclear silver grain counts), was
induced.

870.7485 Metabolism and

pharmacokinetics 40856502 and

40856403 (1988) acceptable/guideline
Rats were treated with [Pyrimidinyl

- 2

- 14 C]

CGA

- 136872 or [Phenyl

- U

14 C] CGA

136872 as follows: (i) Group 1 received a single gavage dose at 0.5 mg/kg; (ii) Group 2 received a single oral dose at 500 mg/kg; (iii) Group 3 received 14 daily oral doses of Recovery of radioactivity in the urine and feces:

88.5

- 102% within 7 days. At 0.5 mg/kg, (M: 23

- 31% dose in urine; 46

- 67% in feces) (F: 35.3

- 77% dose in urine; 13

- 48% in feces). At 500 mg/kg, 83

- 93% dose in feces in both

sexes Tissues: 0.5% of dose at 7 days post

- dose (highest in the liver)

.

Metabolic Pathway: Mainly hydroxylation of the pyrimidine ring to give rise to the 5

- hydroxyprimidinyl

- CGA

- 136872 (i.e. CGA

239769) followed by isomerization of the pyrimidinyl moiety. Bridge cleavage results in the
formation of 2

- carboxymethylbenzene sul fonamide in the feces and saccharin (a cyclization product) inPrimisulfuron

- methyl D42 5535



### Page 24 of 34 TABLE B .2.2 Subchronic, Chronic and Other Toxi city Profile for Primisulfuron

- Methyl.

Guideline

Number Study Title MRID Number Results

unlabeled CGA

- 136872 followed by an oral
dose of [ 14 C] CGA

136872 (0.5 mg/kg) on Day 15; and (iv) Group
4 received an i.v. dose at 0.5 mg/kg. the urine. The corresponding pyrimidinyl moiety is
further metabolized.Primisulfuron

- methyl D42 5535



### Page 25 of 34 Appendix C : Chemical Identity

Chemical Identity

Common Name Primisulfuron methyl

IUPAC name methyl 2

- [4,6

- bis(difluoromethoxy)pyrimidin

- 2

- ylcarbamoylsulfamoyl]benzoate

CAS name methyl 2

- [[[[[4,6

- bis(difluoromethoxy)

- 2

- pyrimidinyl]amino]carbonyl]amino]sulfonyl]benzoate

PC Code 128973 CAS registry number 86209

- 51

- 0 Registration Review

Case No. 3034

Chemical StructurePrimisulfuron

- methyl D42 5535



### Page 26 of 34 Appendix D : Dietary Exposure/Risk Modeling Input s and Output s

Filename: C: \ Users \ jlangsda \ Documents \ Chemicals \ SUs \ Primisulfuron

- methyl \ Dietary

Assessment \ Primisulfuron

- methyl_Chronic.r08

Chemical: Primisulfuron

- methyl RfD(Chronic): .25 mg/kg bw/day NOEL(Chronic): 0 mg/kg bw/day RfD(Acute): 0 mg/kg bw/day NOEL(Acute): 0 mg/kg bw/day Date created/last modified: 03

- 23

- 2015/11:30:33 Program ver. 3.16, 03

- 08

- d

------------------------ ----------------------------------------------------------- EPA Crop Def Res Adj.Factors Comment Code Grp Commodity Name (ppm) #1 #2

---------- ---- ------------------------------- ---------- ------ ------ ------- 1500120000 15 Corn, field, flour 0.020000 1.000 1.000 1500120001 15 Corn, field, flour

- babyfood 0.020000 1.000 1.000 1500121000 15 Corn, field, meal 0.020000 1.000 1.000 1500121001 15 Corn, field, meal

- babyfood 0.020000 1.000 1.000 1500122000 15 Corn, field, bran 0.020000 1.000 1.000 1500123000 15 Corn, field, starch 0.020000 1.000 1.000 1500123001 15 Corn, field, starch

- babyfood 0.020000 1.000 1.000 1500124000 15 Corn, field, syrup 0.020000 1.500 1.000 1500124001 15 Corn, field, syrup

- babyfood 0.020000 1.500 1.000

1500125 000 15 Corn, field, oil 0.020000 1.000 1.000 1500125001 15 Corn, field, oil

- babyfood 0.020000 1.000 1.000 1500126000 15 Corn, pop 0.020000 1.000 1.000 3100044000 31 Beef, meat 0.100000 1.000 1.000 3100044001 31 Beef, meat

- babyfood 0.100000 1.000 1.000 3100045000 31 Beef, meat, dried 0.100000 1.920 1.000 3100046000 31 Beef, meat byproducts 0.1000 00 1.000 1.000 3100046001 31 Beef, meat byproducts

- babyfood 0.100000 1.000 1.000 3100047000 31 Beef, fat 0.100000 1.000 1.000 3100047001 31 Beef, fat

- babyfood 0.100000 1.000 1.000

31000 48000 31 Beef, kidney 0.100000 1.000 1.000 3100049000 31 Beef, liver 0.100000 1.000 1.000 3100049001 31 Beef, liver

- babyfood 0.100000 1.000 1.000 3200169000 32 Goat, meat 0.100000 1.000 1.000 3200170000 32 Goat, meat byproducts 0.100000 1.000 1.000 3200171000 32 Goat, fat 0.100000 1.000 1.000 3200172000 32 Goat, kidney 0.10 0000 1.000 1.000 3200173000 32 Goat, liver 0.100000 1.000 1.000 3300189000 33 Horse, meat 0.100000 1.000 1.000 3400290000 34 Pork, meat 0.100000 1.000 1.000 3400290001 34 Pork, meat

- babyfood 0.100000 1.000 1.000 3400291000 34 Pork, skin 0.100000 1.000 1.000 3400292000 34 Pork, meat byproducts 0.100000 1.000 1.000 3400292001 34 Pork, mea t byproducts

- babyfood 0.100000 1.000 1.000 3400293000 34 Pork, fat 0.100000 1.000 1.000 3400293001 34 Pork, fat

- babyfood 0.100000 1.000 1.000 3400294000 34 Pork, kidney 0.100000 1.000 1.000 3400295000 34 Pork, liver 0.100000 1.000 1.000 3500339000 35 Sheep, meat 0.100000 1.000 1.000 3500339001 35 Sheep, meat

- babyfood 0.100000 1.000 1.000 3500340000 35 Sheep, meat byproducts 0.100000 1.000 1.000 3500341000 35 Sheep, fat 0.100000 1.000 1.000 3500341001 35 Sheep, fat

- babyfood 0.100000 1.000 1.000 3500342000 35 Sheep, kidney 0.100000 1.000 1.000 3500343000 35 Sheep, liver 0.100000 1.000 1.000 3600222000 36 Milk, fat 0.020000 1.000 1.000 3600222001 36 Milk, fat

- baby food/infant formu 0.020000 1.000 1.000 3600223000 36 Milk, nonfat solids 0.020000 1.000 1.000 3600223001 36 Milk, nonfat solids

- baby food/in 0.020000 1.000 1.000 3600224000 36 Milk, water 0.020000 1.000 1.00 0 3600224001 36 Milk, water

- babyfood/infant form 0.020000 1.000 1.000 3600225001 36 Milk, sugar (lactose)

- baby food/ 0.020000 1.000 1.000 3800221000 38 Meat, game 0.100000 1.000 1.000

3900312000 39 Rabbi t, meat 0.100000 1.000 1.000Primisulfuron

- methyl D42 5535



### Page 27 of 34 4000093000 40 Chicken, meat 0.100000 1.000 1.000 4000093001 40 Chicken, meat

- babyfood 0.100000 1.000 1.000 4000094000 40 Chicken, liver 0.100000 1.000 1.000 4000095000 40 Chicken, meat byproducts 0.100000 1.000 1.000 4000095001 40 Chicken, meat byproducts

- babyfoo 0.100000 1.000 1.000 4000096000 40 Chicken, fat 0.100000 1.000 1.000 4000096001 40 Chicken, fat

- babyfood 0.100000 1.000 1.000 4000097000 40 Chicken, skin 0.100000 1.000 1.000 4000097001 40 Chicken, skin

- babyfood 0.100000 1.000 1.000 5000382000 50 Turkey, meat 0.100000 1.000 1.000 5000382001 50 Turkey, meat

- babyfood 0.100000 1.000 1.000 5000383000 50 Turkey, liver 0.100000 1.000 1.000 5000383001 50 Turkey, liver

- babyfood 0.100000 1.000 1.000 5000384000 50 Turkey, meat byproducts 0.100000 1.000 1.000 5000384001 50 Turkey, meat byproducts

- babyfood 0.100000 1.000 1.000 5000385000 50 Turkey, fat 0.100000 1.000 1.000 5000385001 50 Turkey, fat

- babyfood 0.100000 1.000 1.000 5000386000 50 Turkey, skin 0.100000 1.000 1.000 5000386001 50 Turkey, skin

- babyfood 0.100000 1.000 1.000 6000301000 60 Poultry, other, meat 0.100000 1.000 1.000 6000302000 60 Poultry, other, liver 0.100000 1.000 1.000 6000303000 60 Poultry, other, meat byproducts 0.100000 1.000 1.00 0 6000304000 60 Poultry, other, fat 0.100000 1.000 1.000 6000305000 60 Poultry, other, skin 0.100000 1.000 1.000 7000145000 70 Egg, whole 0.100000 1.000 1.000 7000145001 70 Egg, whole

- babyfood 0.100000 1.000 1.000 7000146000 70 Egg, white 0.100000 1.000 1.000 7000146001 70 Egg, white (solids)

- babyfood 0.100000 1.000 1.000 7000147000 70 Egg, yolk 0.100000 1.000 1.000 7000147001 70 Egg, yolk

- babyfood 0.100000 1.000 1.000 8601000000 86A Water, direct, all sources 0.492000 1.000 1.000 8602000000 86B Water, indirect, all sources 0.492000 1.000 1.000



### DEEM

- FCID Chronic Results File

US EPA Ver. 3.16, 03

- 08

- d

DEEM

- FCID Chronic analysis for PRIMISULFURON

- METHYL NHANE S 2003

- 2008 2

- day

Residue file name: C: \ Users \ jlangsda \ Documents \ Chemicals \ SUs \ Primisulfuron

- methyl \ Dietary

Assessment \ Primisulfuron

- methyl_Chronic.r08 Adjustment factor #2 used. Analysis Date 03

- 23

- 2015 /11:35:13 Residue file dated: 03

- 23

- 2015/11:30:33 Reference dose (RfD, Chronic) = .25 mg/kg bw/day

=============================================================================== Total exposure by population subgroup

--------------- ----------------------------------------------------------------

Total Exposure

----------------------------------- Population m g/kg Percent of Subgroup body wt/day Rfd

-------------------------------------- ------------- ---------------- Total US Population 0.010704 4 .3% Hispanic 0.010323 4.1%

Non

- Hisp

- White 0.010980 4.4%

Non

- Hisp

- Black 0.008899 3.6%

Non

- Hisp

- Other 0.012305 4.9% Nursing Infants 0.009507 3.8%

Non

- Nursing Infants 0.034860 13.9%

Female 13+ PREG 0.010030 4.0%

Children 1

- 6 0.014352 5.7%

Children 7

- 12 0.009209 3.7%

Male 13

- 19 0.007518 3.0%

Female 13

- 19/NP 0.008262 3.3%

Male 20+ 0.009925 4.0% Female 20+/NP 0.011081 4.4%

Seniors 55+ 0.010217 4.1%Primisulfuron

- methyl D42 5535



### Page 28 of 34 All Infants 0.027032 10.8%

Female 13

- 50 0.010540 4.2%
Children 1

- 2 0.016319 6.5%

Children 3

- 5 0.013565 5.4%

Children 6

- 12 0.009683 3.9%

Youth 13

- 19 0.007893 3.2%

Adults 20

- 49 0.010595 4.2%

Adults 50

- 99 0.010422 4.2%

Female 13

- 49 0.010530 4.2%Primisulfuron

- methyl D42 5535



### Page 29 of 34 Appendix E: Spray Drift Assessment for Primisulfuron

- methyl

Off

- target movement of pesticides can occur via many types of pathways and it is governed by a variety of factors. Sprays that are released and do not deposit in the application area end up off

target and can lead to exposures to those it may directly contact. They can also dep osit on surfaces where contact with residues can eventually lead to indirect exposures ( e.g. , children playing on lawns where residues have deposited next to treated fields). The potential risk estimates from these residues can be calculated using drift modeling onto 50 feet wide lawns coupled with methods employed for residential risk assessments for turf products.

The approach to be used for quantitatively incorporating spray drift into risk assessment is based on a premise of compliant applications wh ich, by definition, should not result in direct exposures to individuals because of existing label language and other regulatory requirements intended to prevent them. 7 

### Direct exposures would include inhalation of the spray plume or being sprayed directly . Rather, the exposures addressed here are thought to occur indirectly through contact with impacted areas, such as residential lawns, when compliant applications are conducted. Given this premise, exposures for children (1 to 2 years old) and adults who have contact with turf where residues are assumed to have deposited via spray drift thus resulting in an indirect exposure are the focus of this analysis analogous to how exposures to turf products are
considered in risk assessment.

In order to evaluat e the drift potential and associated risks, an approach based on drift modeling coupled with techniques used to evaluate residential uses of pesticides was utilized. Essentially, a residential turf assessment based on exposure to deposited residues has bee n completed to address drift from the agricultural applications of primisulfuron

- methyl. In the spray drift scenario, the deposited residue value was determined based on the amount of spray drift that may occur at varying distances from the edge of the tr eated field using the AgDrift ( v2.1.1) model and
the Residential Exposure Assessment Standard Operating Procedures Addenda 1: Consideration of Spray Drift Policy

. Once the deposited residue values were determined, the remainder of the spray drift assessmen t was based on the algorithms and input values specified in the recently revised (2012) Standard Operating Procedures For Residential Risk Assessment (SOPs)

. A screening approach was developed based on the use of the AgDrift model in situations where

spec ific label guidance that defines application parameters is not available. 8

, 9 

### AgDrift is appropriate for use only when applications are made by aircraft, airblast orchard sprayers, and groundboom sprayers. When AgDrift was developed, a series of screening values (i.e., the Tier 1 option) were incorporated into the model and represent each equipment type and use under varied conditions. The screening options specifically recommended in this methodology were selected because they are plausible and represent a reasonable upper bound level of drift for common application methods in agriculture. These screening options are consistent with how spray drift is considered in a number of ecological risk assessments and in the process used to develop drinking water c oncentrations used for risk assessment. In all cases, each scenario is to

7 This approach is consistent with the requirements of the EPA’s Worker Protection Standard.

8 http://www.agdrift.com/

9 Note that for many cases the scenarios outlined in the screening approach represent actual use practice so risk assessors sho uld be aware and characterize these appropriately.Primisulfuron

- methyl D42 5535



### Page 30 of 34 be evaluated unless it is not plausible based on the anticipated use pattern (e.g., herbicides are not typically applied to tree canopies) or specific label prohibitions (e.g., aeri al applications are not allowed). The tables below provide the drift related risk estimates. In many cases, risks are of concern when the screening level estimates for spray drift are used as the basis for the analysis. In order to account for this issu e and to provide additional risk management options additional spray drift deposition fractions were also considered. These drift estimates represent plausib le options for pesticide labels. In the case of primisulfuron

- methyl,
there are no risks of concer n at the edge of the field.

Table E.1 Adult Risk Estimates (MOEs) Related to Indirect Exposure to Spray Drift for
Primisulfuron

- methyl for the Dermal Route of Exposure

Crop/Rate Group Spray Type/ Nozzle Configuration Appl

. Rate (lb ai/A) TTR (ug/cm2) At Edge

Corn and Bluegrass

Aerial Fine to Medium

0.036 0.0040014 83,000

Medium to Coarse 100,000

Coarse to Very Coarse 120,000

Very Fine to Fine 57,000

AT401, M, 10 mph, 37% SD 91,000

WASP, M, 10 mph, 37% SD 98,000

AT401, C, 10 mph, 25% SD 110,000

WASP, C, 10 mph, 25% SD 120,000

AT401, VC, 10 mph, 20% SD 120,000

WASP, VC, 10 mph, 20% SD 150,000

Groundboom High Boom Very fine to Fine 110,000

Low Boom Very fine to Fine 250,000

High Boom Fine to
Medium/Coarse 430,000

Low Boom Fine to
Medium/Coarse 650,000

Table E .2 Children (1<2 years old) Risk Estimates (MOEs) Related to Indirect Exposure to Spray
Drift fo r Primisulfuron

- methyl for the Dermal Routes of Exposure

Crop/Rate Group Spray Type/ Nozzle Configuration Appl

. Rate (lb ai/A) TTR (ug/cm2) At Edge

Corn and Bluegrass

Aerial Aerial

0.036 0.0040014 49,000

Medium to Coarse 59,000

Coarse to Very Coarse 68,000

Very Fine to Fine 33,000
AT401, M, 10 mph, 37% SD 53,000
WASP, M, 10 mph, 37% SD 57,000Primisulfuron

- methyl D42 5535



### Page 31 of 34 AT401, C, 10 mph, 25% SD 63,000
WASP, C, 10 mph, 25% SD 73,000 AT401, VC, 10 mph, 20%

SD 71,000

WASP, VC, 10 mph, 20%

SD 90,000

Groundboom High Boom Very fine to

Fine 67,000

Low Boom Very fine to Fine 150,000

High Boom Fine to
Medium/Coarse 250,000

Low Boom Fine to
Medium/Coarse 380,000

Table E

. 3 Children (1<2 years old) Risk Estimates (MOEs) Related to Indirect Exposure to Spray
Drift for Primisulfuron

- methyl for the Oral Routes of Exposure

Crop/Rate Group Spray Type/ Nozzle Configuration Appl

. Rate (lb ai/A) TTR (ug/cm2) At Edge

Corn and Bluegrass

Aerial Aerial

0.036 0.0040014 350,000

Medium to Coarse 430,000

Coarse to Very Coarse 500,000

Very Fine to Fine 240,000
AT401, M, 10 mph, 37% SD 390,000
WASP, M, 10 mph, 37% SD 420,000
AT401, C, 10 mph, 25% SD 460,000
WASP, C, 10 mph, 25% SD 530,000 AT401, VC, 10 mph, 20%

SD 520,000

WASP, VC, 10 mph, 20%

SD 660,000

Groundboom High Boom Very fine to
Fine 490,000

Low Boom Very fine to Fine 1,100,000

High Boom Fine to
Medium/Coarse 1,900,000

Low Boom Fine to
Medium/Coarse 2,800,000Primisulfuron

- methyl D42 5535



### Page 32 of 34 Appendix F. TTR and DFR Data Waiver Rationale

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

- application exposure to turf. In the absence of chemical

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

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

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

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

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

- methyl , EPA is using the default value of [appropriate value for liquid or granular product]. Although there may be a small degree of uncertainty in the use of the default TTR
value for primisulfuron

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

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

- protective aspects of EPA’s occupational
post

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

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

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

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

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

- application activities for a high

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

- end levels of activity will not occur every day.

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

Since the estimated occupational post

- application exposure for sod farms using default TTR
values for primisulfuron

- methyl is minimal in comparison to the level of concern (i.e., the calculated MOE is greater than 10 times higher than the level of concern, MOE = 110,000 compared to the LOC of 100 ); EPA is waiving the 40CFR DFR data requirement. In this instance, it is unlikely that che mical

- specific TT R data would be needed to further refinePrimisulfuron

- methyl D42 5535



### Page 33 of 34 exposure assessments or would add appreciably to our overall understanding of the availability
of turf transferable pesticide residues for primisulfuron

- methyl

.

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

application exposure to foliage. In the absence of chemical

- specific DFR data, EPA uses default
values. The 2012 Standard Operating Procedures for Residential Pesticide Exposure

Assessment includes an analysis of a number of DF R studies, which resulted in the selection of a revised default values for the fraction of the application rate available for transfer after a foliar application (F AR 

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

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

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

### values was revised from 2%

- 89% to 2%

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

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

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

- methyl

, EPA is using the default value of 25%. Although there may be a small degree of uncertainty in the use of the default DFR value for primisulfuron

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

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

- protective aspects of EPA’s occupational post

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

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

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

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

- application activities for a high

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

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

Since the highest estimated occupational post

- application exposure using default DFR values for primisulfuron

- methyl is minimal in comparison to the level of concern (i.e., the calculated MOE is greater than 2 times higher than the level of concern, MOE = 15,000 compared to the LOC of

100 ); EPA is waiving the 40CFR DFR data requirement. In this instance, it is unlikely that
chemical

- specific DFR data would be needed to further refine exposure assessments or would add appreciably to our overall understanding of the availabil ity of dislodgeable foliar pesticide
residues for primisulfuron

- methyl

.Primisulfuron

- methyl D42 5535



### Page 34 of 34 Appendix G: 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 chem ical. These data are subject to ethics review pursuant to 40 CFR 26, have received that review, and are compliant with applicable ethics requirements. For certain studies that review may have included review by the Human Studies Review Board. Descriptio ns of data sources as well as guidance on their use can be found at: http://www.epa.gov/pesticides/science/handler

- exposure

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

- app

- exposure

- data.html

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