Triflusulfuron-methyl Dietary Exposure Assessment DP Barcode: D376268

PC Code: 129002

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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF CHEMICAL SAFETY AND

 POLLUTION PREVENTION

MEMORANDUM

DATE: February 17, 2011

SUBJECT: Triflusulfuron-methyl: Chronic Aggregate Dietary Exposure (Food and Drinking 

Water) and Risk Assessment for the Section 3 Registration on Garden Beet

PC Code: 129002 DP Barcodes: D376268

Decision No.: 425459 Registration No.: 352-569

Petition No.: 9E7669 Regulatory Action: Section 3 Registration

Risk Assessment Type: Single Chemical 

Aggregate, Dietary

Case No.: NA

TXR No.: NA CAS No.: 126535-15-7

MRID No.: NA 40 CFR: §180.492

 

REVIEWER: Elizabeth Holman, Chemist

Risk Assessment Branch II (RAB2)

Health Effects Division (HED; 7509P)

THROUGH: Debra Rate, Ph.D., Biologist

David Soderberg, Chemist

Dietary Exposure Science Advisory Council

Health Effects Division (HED; 7509P)

and

Richard Loranger, Ph.D., Branch Senior Scientist

Risk Assessment Branch II (RAB2)

Health Effects Division (HED; 7509P)

TO: Laura Nollen, Risk Manager Reviewer

Barbara Madden, Review Manager #5

Daniel (Dan) Rosenblatt, Chief

Risk Integration, Minor Use, and Emergency Response Branch

Registration Division (7505P)
Triflusulfuron-methyl Dietary Exposure Assessment DP Barcode: D376268

PC Code: 129002

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Executive Summary

A chronic aggregate dietary risk assessment (food and drinking water) was conducted using the 

Dietary Exposure Evaluation Model (DEEM-FCIDTM, Version 2.03), which uses food 

consumption data from the U.S. Department of Agriculture (USDA’s) Continuing Surveys of 

Food Intakes by Individuals (CSFII) from 1994-1996 and 1998. The analysis was performed to 

support a Section 3 registration for use of triflusulfuron-methyl [methyl 2-[[[[[4-

(dimethylamino)-6-(2,2,2-trifluoroethoxy)-1,3,5-triazin-2-yl]amino]carbonyl]amino]sulfonyl]-3-

methylbenzoate] on garden beets. Triflusulfuron-methyl is currently registered for use on sugar 

beets and chicory. 

Acute Dietary Exposure (Food and Drinking Water) Results and Characterization

No appropriate endpoint attributable to a single dose was identified. As no acute dietary

endpoint was identified, an acute exposure analysis was not performed.

Chronic Dietary (Food and Drinking Water) Exposure Results and Characterization

The chronic analysis is based on tolerance level residues and 100% crop treated assumptions. 

The HED-recommended tolerance level for each raw agricultural commodity (RAC) was entered 

as listed below: 

Beet, garden, roots ......................................................0.01 ppm

Beet, garden, tops........................................................0.02 ppm

Additionally, the existing tolerances for sugar beet (roots and tops) and chicory were also entered 

(a value of 0.05 ppm for each commodity). The general U.S. population and all population 

subgroups have risk estimates that are well below HED’s level of concern (i.e., 100% of the 

chronic population adjusted dose (cPAD)). Estimated exposures are less than 1% of the cPAD 

for the U.S. population and all population subgroups, including those of infants and children.

Cancer Dietary (Food and Drinking Water) Exposure Results and Characterization

Triflusulfuron-methyl is a Group C (1986 Cancer Guidelines - possible human carcinogen)

chemical, based on increased incidence of testicular cell adenomas in rats. The chronic RfD is 

considered adequately protective of these effects and a quantitative cancer risk assessment using 

a cancer potency factor is not required. 

I. Introduction

Dietary risk assessment incorporates both exposure and toxicity of a given pesticide. For acute 

and chronic assessments, the risk is expressed as a percentage of a maximum acceptable dose 
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PC Code: 129002

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(i.e., the dose which HED has concluded will result in no unreasonable adverse health effects). 

This dose is referred to as the population adjusted dose (PAD). The PAD is equivalent to the 

point of departure (POD, NOAEL, LOAEL, e.g.) divided by the required uncertainty or safety

factors.

For acute and non-cancer chronic exposures, HED is concerned when estimated dietary risk 

exceeds 100% of the PAD. HED is generally concerned when estimated cancer risk exceeds one 

in one million. References which discuss the acute and chronic risk assessments in more detail 

are available on the EPA/pesticides web site: “Available Information on Assessing Exposure 

from Pesticides, A User’s Guide,” 6/21/2000, web link: 

http://www.epa.gov/fedrgstr/EPA-PEST/2000/July/Day-12/6061.pdf ; or see SOP 99.6 

(8/20/99).

A dietary risk assessment for triflusulfuron-methyl on sugar beet was completed in 2000 

(D260469, M.Doherty, 8/28/2000). This assessment is for the new proposed use on garden beet, 

which also incorporates the existing uses on sugar beet and chicory. Chicory was not included in 

the 2000 dietary assessment. 

II. Residue Information

Triflusulfuron-methyl is a sulfonylurea herbicide that inhibits the biosynthesis of branched-chain 

amino acids in plants (via inhibition of the plant enzyme acetolactate synthase). The herbicide is 

currently registered for food uses on sugar beet and chicory.

The petitioner has proposed a new Section 3 use on garden beets. See Table 1 below for a 

summary of the HED-recommended tolerances. 

Table 1. Summary of HED- Recommended Tolerances for Proposed New Use.

Commodity Recommended Tolerance (ppm)

Beet, garden, roots 0.01

Beet, garden, tops 0.02

For both the existing and proposed uses, triflusulfuron-methyl parent serves as an adequate 

measure of misuse based on its percentage of the total radioactive residues (TRR) in the 

metabolism studies and the residues seen in crop field trials. 

HED is making the conservative assumption of 100% crop treated.

In a previously submitted processing study for sugar beet, even at exaggerated rates (8X) for the 

field trial used to generate the processing study samples, no triflusulfuron-methyl was found in 

the sugar beet roots or processed commodities (MRID 42496869; see 6/7/93 G. J. Herndon 

review, D184250). Therefore, processed commodities of sugar beet were conservatively
Triflusulfuron-methyl Dietary Exposure Assessment DP Barcode: D376268

PC Code: 129002

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estimated to have tolerance-level residues of the raw agricultural commodity of sugar beet. 

III. Drinking Water Data

The drinking water residues used in the dietary risk assessment were provided by the 

Environmental Fate and Effects Division (EFED) in the following memorandum: “Estimated 

Drinking Waters Concentrations (EDWCs) of Triflusulfuron-methyl for the Use in the Human 

Health Risk Assessment: New Use (IR-4) of the Chemical on Garden Beets” (D373494, J.

Meléndez, 7/22/2010) and incorporated directly into this dietary assessment. Water residues 

were incorporated in the DEEM-FCIDTM into the food categories “water, direct, all sources” and 

“water, indirect, all sources.” 

The EDWCs are based on the maximum application rates specified in the product label for the 

existing use on sugar beet. The registrant is proposing the new use of the chemical on garden 

beets. Based on an inspection of the new use of triflusulfuron-methyl, it was found that sugar 

beet still represents the scenario with the highest exposure. The previously modeled use covers 

the new use. Therefore, the drinking water assessment results do not change from the previous 

ones. For electronic copy of the previous drinking water assessment refer to DP Barcode 

D260078. 

Surface water estimates were calculated using the Tier II Pesticide Root Zone Model (PRZM, 

v3.12.2, 5/12/2005) and the Exposure Analysis Modeling System (EXAMS, v2.98.4.6, 

4/25/2005). These simulation models are coupled to generate daily exposures and 1-in-10 year 

estimated drinking water concentrations of triflusulfuron-methyl residues that may occur in 

surface water bodies adjacent to application sites receiving triflusulfuron-methyl through runoff 

and spray drift. Groundwater estimates were calculated using the Screening Concentration in 

Ground Water (SCI-GROW v2.3, Jul. 29, 2003) regression model. These models and their 

descriptions are available at the EPA internet site: http://www.epa.gov/oppefed1/models/water/. 

The EDWCs for the human health risk assessment are presented in Table 2. RAB2 has selected 

the most conservative estimate in order to be sufficiently protective of human health. The 

maximum estimate of 0.50 ppb comes from the groundwater (SCI-GROW) estimate and was 

used in the chronic dietary analysis. 

Table 2. Estimated Drinking Water Concentrations (EDWCs) for 

Human Health Risk Assessment for Aerial Application of 

Triflusulfuron-Methyl on Sugar Beets.

Chemical

Chronic Surface Water 

PRZM/EXAMS (ppb)

Acute and Chronic Ground Water 

SCI-GROW (ppb)*

Triflusulfuronmethyl 0.005 0.50
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IV. DEEM-FCID Program and Consumption Information

A triflusulfuron-methyl chronic dietary exposure assessment was conducted using the DEEMFCID, Version 2.03, which incorporates consumption data from USDA’s CSFII, 1994-1996 

and 1998. The 1994-96, 98 data are based on the reported consumption of more than 20,000 

individuals over two non-consecutive survey days. Foods “as consumed” (e.g., apple pie) are 

linked to EPA-defined food commodities (e.g. apples, peeled fruit - cooked; fresh or N/S; baked; 

or wheat flour - cooked; fresh or N/S, baked) using publicly available recipe translation files 

developed jointly by USDA/ARS and EPA. For chronic exposure assessment, consumption data 

are averaged for the entire U.S. population and within population subgroups, but for acute 

exposure assessment are retained as individual consumption events. Based on analysis of the 

1994-96, 98 CSFII consumption data, which took into account dietary patterns and survey

respondents, HED concluded that it is most appropriate to report risk for the following 

population subgroups: the general U.S. population, all infants (<1 year old), children 1-2, 

children 3-5, children 6-12, youth 13-19, adults 20-49, females 13-49, and adults 50+ years old.

For chronic dietary exposure assessment, an estimate of the residue level in each food or foodform (e.g., orange or orange juice) on the food commodity residue list is multiplied by the 

average daily consumption estimate for that food/food 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.

V. Toxicological Information

The Health Effects Division (HED) has evaluated the toxicology database for triflusulfuronmethyl. The RAB2 risk assessment team reviewed the toxicology data for triflusulfuron-methyl

with regard to the acute and chronic reference doses and the toxicological endpoint selection. 

Table 3 below provides a summary of the doses and endpoints recommended for use in the 

dietary exposure assessments. Triflusulfuron-methyl is a Group C (1986 Cancer Guidelines -

possible human carcinogen) chemical, based on increased incidence of testicular cell adenomas 

in rats. The chronic RfD is considered adequately protective of these effects and a quantitative 

cancer risk assessment using a cancer potency factor is not required. The FQPA safety factor 

was reduced to 1x for all exposure scenarios. 
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Table 3. Summary of Toxicological Doses and Endpoints for Triflusulfuron-Methyl for 

Use in Dietary and Non-Occupational Human Health Risk Assessments.

Exposure/

Scenario

Point of 

Departure

Uncertainty/FQPA 

Safety Factors

RfD, PAD, 

Level of 

Concern for 

Risk 

Assessment

Study and Toxicological Effects

Acute Dietary, 

General 

Population 

(including 

Infants and 

Children and 

Females age 13 

to 49)

Not required. An appropriate endpoint for this risk assessment was not identified.

Chronic Dietary 

(All 

Populations)

NOAEL= 

2.44 

mg/kg/day

UFA= 10x

UFH= 10x

FQPA SF= 1x 

Chronic RfD = 

0.0244

mg/kg/day

cPAD = 0.0244

mg/kg/day

Chronic oral toxicity/carcinogenicity in 

the rat 

LOAEL = 30.6 mg/kg/day, based on

decreased body weight/weight gain, 

hematological changes (primarily males) 

and increased interstitial cell hyperplasia 

(males).

Cancer (oral, 

dermal, 

inhalation)

Classification: Group C (1986 Cancer Guidelines), based on increased incidence of testicular 

interstitial cell adenomas in rats. The chronic RfD is considered adequately protective of these 

effects and a quantitative assessment of cancer risk using a cancer potency factor is not required.

Point of Departure (POD) = A data point or an estimated point that is derived from observed dose-response data and 

used to mark the beginning of extrapolation to determine risk associated with lower environmentally relevant human 

exposures. NOAEL = no observed adverse effect level. LOAEL = lowest observed adverse effect level. UF = 

uncertainty factor. UFA = extrapolation from animal to human (interspecies). UFH = potential variation in sensitivity 

among members of the human population (intraspecies). FQPA SF = FQPA Safety Factor. PAD = population 

adjusted dose (a = acute, c = chronic). RfD = reference dose. MOE = margin of exposure. LOC = level of concern. 

VI. Results/Discussion

As stated above, for acute and chronic assessments, HED is concerned when dietary risk exceeds 

100% of the PAD. The DEEM-FCID analysis estimates the dietary exposure of the U.S. 

population and various population subgroups. The results reported in Table 5 are for the general 

U.S. Population, all infants (<1 year old), children 1-2, children 3-5, children 6-12, youth 13-19, 

females 13-49, adults 20-49, and adults 50+ years.

Results of Acute Dietary (Food and Drinking Water) Exposure Analysis

No appropriate endpoint attributable to a single dose was identified. As no acute dietary

endpoint was identified, an acute exposure analysis was not performed.
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PC Code: 129002

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Results of Chronic Dietary (Food and Drinking Water) Exposure Analysis

The summary table below lists the results of the chronic dietary exposure analysis. Estimated 

chronic dietary risk estimates are less than 1% of the cPAD for the U.S. population and all 

population subgroups, including those of infants and children. Thus, all population exposures 

are well below HED’s level of concern. 

Table 4. Summary of Dietary Exposure and Risk for Triflusulfuron-Methyl.

Population Subgroup*

Acute Dietary Chronic Dietary Cancer

Dietary 

Exposure 

(mg/kg/day) % aPAD

Dietary 

Exposure

(mg/kg/day) % cPAD

Dietary 

Exposure

(mg/kg/day) Risk

General U.S. Population N/A

No acute 

dietary 

endpoint 

was 

identified

N/A 0.000025 <1%

N/A N/A All Infants (< 1 year old) 0.000050 <1%

Children 1-2 years old 0.000052 <1%

Children 3-5 years old 0.000056 <1%

Children 6-12 years old 0.000041 <1%

Youth 13-19 years old 0.000023 <1%

Adults 20-49 years old 0.000020 <1%

Adults 50+ years old 0.000019 <1%

Females 13-49 years old 0.000021

<1%

VII. Characterization of Inputs/Outputs

As the exposure estimates to all population subgroups were so low, it was not necessary to make 

refinements to the chronic dietary analysis. If it had been necessary to refine the analysis, 

average field trial values could have been used in place of tolerance level residues. In addition, 

estimates of percent crop treated could have been used.

VIII.Conclusions

Based on very conservative assumptions, the chronic dietary risk estimates are well below HED’s 

level of concern for the general U.S. population and all population subgroups, including those 

comprised of infants and children. In addition, cancer risk from dietary exposure to 

triflusulfuron-methyl is not of concern to HED (the cRfD is protective of cancer effects). Based 

on the conservative nature of the chronic dietary endpoint and the drinking water assessment, 

exposure and risk to triflusulfuron-methyl are not expected to be underestimated. 
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PC Code: 129002

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IX. List of Attachments

Attachment 1: Residue Input File for Chronic Analysis

Attachment 2: Results of Chronic Dietary Exposure Analysis
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Attachment 1: Triflusulfuron-methyl Residue Input File

Filename: F:\Triflusulfuron\Dietary\Triflusulfuron-methyl Chronic final.R98

Chemical: Triflusulfuron-methyl

RfD(Chronic): .0244 mg/kg bw/day NOEL(Chronic): 2.44 mg/kg bw/day

RfD(Acute): 0 mg/kg bw/day NOEL(Acute): 0 mg/kg bw/day

Date created/last modified: 02-17-2011/09:08:08/8 Program ver. 2.03

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

 EPA Crop Def Res Adj.Factors Comment

 Code Grp Commodity Name (ppm) #1 #2 

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

86010000 O Water, direct, all sources 0.000500 1.000 1.000 

86020000 O Water, indirect, all sources 0.000500 1.000 1.000 

01010500 1AB Beet, garden, roots 0.010000 1.000 1.000 

01010501 1AB Beet, garden, roots-babyfood 0.010000 1.000 1.000 

01010520 1A Beet, sugar 0.050000 1.000 1.000 

01010521 1A Beet, sugar-babyfood 0.050000 1.000 1.000 

01010530 1A Beet, sugar, molasses 0.050000 1.000 1.000 

01010531 1A Beet, sugar, molasses-babyfood 0.050000 1.000 1.000 

01011000 1AB Chicory, roots 0.050000 1.000 1.000 

02000510 2 Beet, garden, tops 0.020000 1.000 1.000 

02001010 2 Chicory, tops 0.050000 1.000 1.000 

 
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Attachment 2: Results of Triflusulfuron-methyl Chronic Dietary Exposure 

Analysis

U.S. Environmental Protection Agency Ver. 2.00

DEEM-FCID Chronic analysis for TRIFLUSULFURON-METHYL (1994-98 data)

Residue file name: F:\Triflusulfuron\Dietary\Triflusulfuron-methyl Chronic final.R98

 Adjustment factor #2 used.

Analysis Date 02-17-2011/09:16:12 Residue file dated: 02-17-2011/09:08:08/8

Reference dose (RfD, Chronic) = .0244 mg/kg bw/day

===============================================================================

 Total exposure by population subgroup

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 Total Exposure

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

 Population mg/kg Percent of 

 Subgroup body wt/day Rfd 

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

U.S. Population (total) 0.000025 0.1%

U.S. Population (spring season) 0.000026 0.1%

U.S. Population (summer season) 0.000026 0.1%

U.S. Population (autumn season) 0.000025 0.1%

U.S. Population (winter season) 0.000025 0.1%

Northeast region 0.000024 0.1%

Midwest region 0.000027 0.1%

Southern region 0.000024 0.1%

Western region 0.000026 0.1%

Hispanics 0.000026 0.1%

Non-hispanic whites 0.000025 0.1%

Non-hispanic blacks 0.000025 0.1%

Non-hisp/non-white/non-black 0.000025 0.1%

All infants (< 1 year) 0.000050 0.2%

Nursing infants 0.000019 0.1%

Non-nursing infants 0.000061 0.3%

Children 1-6 yrs 0.000054 0.2%

Children 7-12 yrs 0.000039 0.2%

Females 13-19 (not preg or nursing) 0.000022 0.1%

Females 20+ (not preg or nursing) 0.000020 0.1%

Females 13-50 yrs 0.000022 0.1%

Females 13+ (preg/not nursing) 0.000025 0.1%

Females 13+ (nursing) 0.000027 0.1%

Males 13-19 yrs 0.000024 0.1%

Males 20+ yrs 0.000019 0.1%

Seniors 55+ 0.000019 0.1%

Children 1-2 yrs 0.000052 0.2%

Children 3-5 yrs 0.000056 0.2%

Children 6-12 yrs 0.000041 0.2%

Youth 13-19 yrs 0.000023 0.1%

Adults 20-49 yrs 0.000020 0.1%

Adults 50+ yrs 0.000019 0.1%

Females 13-49 yrs 0.000021 0.1%

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