Page 3 of 18

Introduction

HED has evaluated the most recent human health risk assessment (D388621) for 

triflusulfuron-methyl to determine whether sufficient data are available and whether a new 

human health risk assessment is needed to support Registration Review. HED has considered 

the most recent risk assessments for triflusulfuron-methyl, updates to its toxicity, exposure and 

usage databases, and current Agency science policies and risk assessment methods. 

Use Profile 

Triflusulfuron-methyl is a sulfonylurea herbicide, registered by E. I. du Pont de Nemours and 

Company, that inhibits the biosynthesis of branched-chain amino acids in plants (via inhibition 

of the plant enzyme acetolactate synthase). Marketed as UpBeet®, a dry flowable (DF) 

formulation containing 50% active ingredient (ai), triflusulfuron-methyl is currently registered 

for use on sugar beet commodities, garden beets, and chicory using broadcast (ground- or aerialbased) or band application methods at seasonal rates of up to 0.078 pounds ai per acre (lb ai/A). 

UpBeet® is not to be applied via any type of irrigation system. The existing label for UpBeet® 

lists a pre-harvest interval (PHI) of 60 days for sugar beet, garden beet, and chicory. There are no 

current or pending residential uses associated with triflusulfuron; therefore, a residential 

exposure assessment was not performed nor required.

The chemical structure and nomenclature of triflusulfuron-methyl are presented in Table 1. The 

physicochemical properties of the technical grade of triflusulfuron-methyl are presented in 

Appendix 1, Table 1 of the Appendix.

TABLE 1. Triflusulfuron-Methyl Structure and Nomenclature.

Compound Chemical Structure

Common name Triflusulfuron-methyl

Company experimental name DPX 66037

IUPAC name methyl 2-[4-dimethylamino-6-(2,2,2-trifluoroethoxy)-1,3,5-triazin-2-

ylcarbamoylsulfamoyl]-m-toluic acid

CAS name methyl 2-[[[[[4-(dimethylamino)-6-(2,2,2-trifluoroethoxy)-1,3,5-triazin-2-yl]amino] 

carbonyl]amino]sulfonyl]-3-methylbenzoate

CAS # 126535-15-7

End-use product/(EP) UpBeet Herbicide

SO2NHCONH

N

N

N

N(CH3)

2

CH3

OCH2CF3

CO2CH3
Page 4 of 18

Hazard Identification/Toxicology

The primary target organs of toxicity identified for triflusulfuron-methyl are the liver, testes and 

red blood cells. Hematological and histopathological changes consistent with mild hemolytic 

anemia were observed in the rat and the dog. Increased incidence of testicular interstitial 

hyperplasia was observed following subchronic or chronic-term dietary administration to the rat; 

the incidence of testicular interstitial adenomas was also increased with chronic exposure. In the 

dog, testicular atrophy and reduced size were observed following subchronic or chronic 

exposure. Liver effects were observed in the dog (increased weight, altered serum enzyme 

profile and histopathology) and mouse (increased weight and histopathology), but not in the rat. 

There was no indication of frank neurotoxicity in the available studies, including the acute and 

subchronic neurotoxicity studies. Although a statistically significant increase in sciatic nerve 

myelin/axon degeneration in high dose female rats was observed in the rat combined chronic 

toxicity/carcinogenicity study, the incidence was high in all dose groups, no increases were seen 

in the interim sacrifice groups or in shorter-term studies and the lesion is commonly observed in 

older rats. Therefore, HED did not consider this finding to be evidence of frank neurotoxicity. 

A developmental neurotoxicity (DNT) study is, therefore, not required. The only potential 

evidence of immunotoxicity observed for triflusulfuron-methyl was hemolytic anemia, an effect 

that is associated with exposure to some sulfonylurea compounds as an immune-mediated 

cytotoxicity. However, there are currently no data demonstrating that hemolytic anemia from 

triflusulfuron-methyl is immune-mediated. No effects of treatment were reported in a 21-day 

repeated application dermal toxicity study in the rabbit. Dermal absorption studies were not 

submitted.

Triflusulfuron-methyl is of low acute toxicity when administered orally (Toxicity Category IV), 

dermally (Category III), or via inhalation (Category IV). It is not a dermal sensitizer or irritant 

(Category IV) and causes only minor transient irritation to the eye (Category III).

There was no quantitative or qualitative evidence of increased pre- and/or post-natal 

susceptibility in rat or rabbit developmental toxicity studies or in the rat reproductive study. No 

developmental effects were seen in the rat developmental study, whereas maternal toxicity 

(decreased body weight gain, food consumption and feed efficiency) was observed at the highest 

two doses. Abortions were observed in the rabbit developmental toxicity study at a dose that 

also caused significant maternal toxicity, including mortality, clinical signs, sharply reduced food 

consumption and decreased weight gain. In the rat reproductive toxicity study, decreased 

parental body weight/weight gain and F1 pup weight during lactation were observed at the mid 

and high doses. No reproductive effects were observed.

In metabolism studies conducted in the rat, triflusulfuron-methyl was well-absorbed and 

extensively metabolized; however, at high doses, the extent of absorption was somewhat lower 

and the parent compound was the major radiolabeled component. The majority of the 

administered radioactivity was excreted in the urine at low doses, but at high doses, the major 

route of excretion was the feces. The major urinary metabolite was N-desmethyl triflusulfuronmethyl.
Page 5 of 18

Triflusulfuron-methyl was classified as a “Group C” (possible human) carcinogen under the 

1986 Agency Guidelines for Carcinogen Assessment. The classification was based on an 

increased incidence of testicular interstitial cell adenomas in male rats at two doses and evidence 

of clastogenicity in some in vitro genotoxicity studies. A special mechanistic study that 

evaluated hormonal changes in male rats provided insufficient information to establish a 

nonlinear mode of action for the formation of these tumors. Although the incidence of 

hepatocellular adenomas was increased in mice, it was within historical control range and not 

considered as part of the weight-of-evidence for determination of cancer classification. Cancer 

risk was not quantified using a cancer potency factor because the tumors were benign and seen 

only in one species; the use of the reference dose (RfD) in risk assessment was therefore 

considered to be protective of potential carcinogenicity.

Studies available for the risk assessment of triflusulfuron-methyl include acute lethality (oral, 

dermal and inhalation routes); primary eye and dermal irritation, dermal sensitization, subchronic 

oral toxicity (rat, mouse and dog), rabbit 21-day dermal toxicity, dog chronic toxicity, rat chronic 

toxicity and combined chronic toxicity/carcinogenicity, mouse carcinogenicity, developmental 

toxicity (rat and rabbit), rat two-generation reproductive toxicity, genotoxicity, rat metabolism 

and acute and subchronic neurotoxicity studies in the rat. An in vitro mode of action study on 

hepatic aromatase activity and testosterone/estradiol levels in Leydig (interstitial) cells was also 

submitted. Summaries of these studies and endpoint selection are provided in Tables 3, 4 and 5 

of Appendix 1.

Toxicity Data Requirements

The immunotoxicity study is a new data requirement under 40 CFR Part 158 as a part of the data 

requirements for registration of a pesticide (food and non-food uses). A subchronic inhalation 

study is not available but is not required due to low use rates, low vapor pressure and high 

Margins of Exposure (MOEs) attained using an oral POD for assessing risks with handler 

exposure (HASPOC memo, TXR No. 0056291). 

Hazard Conclusions

Endpoint selection and uncertainty factors may need to be re-evaluated to ensure that points of 

departure reflect current policy. The Agency believes the existing database is adequate for risk 

assessment.

Dietary and Drinking Water Exposure

The most recent dietary exposure and risk assessment was performed in conjunction with the 

April 2011 human-health risk assessment conducted by HED (D388621, E. Holman, et al.; 13-

APR-2011). An acute dietary assessment was not performed because no appropriate endpoint 

was available to determine the aRfD for the general population or any population subgroup. An 

unrefined chronic dietary exposure and risk assessment was performed using 100% CT for all 

crops; tolerance-level residues, and DEEM-FCIDTM software. Dietary risk estimates were 

determined considering exposures from food plus drinking water using estimated drinking water 
Page 6 of 18

concentrations (EDWCs) for groundwater sources provided by the Environmental Fate and 

Effects Division (EFED).

The resulting chronic dietary risk estimates for food and drinking water combined are below 

HED’s LOC [i.e., <100% of the chronic population-adjusted dose (cPAD) of 0.0244 mg/kg 

bw/day] for the overall U.S. population and all population subgroups. Using DEEM-FCID , 

dietary risk is estimated at <1% of the cPAD for the U.S. population and all populations 

subgroups. Potential dietary cancer risk concerns due to long-term consumption of 

triflusulfuron-methyl residues are adequately addressed by the chronic exposure analysis using 

the cPAD.

EFED has provided Tier II EDWCs for use in drinking water assessments when triflusulfuronmethyl is used according to registered labeling on sugar beets (Memo, J. Melendez, 22-JULY2010; DP# 373494). Because monitoring data are unavailable, estimates of triflusulfuron-methyl

concentrations were made only with models. The models PRZM/EXAMS were used to conduct 

surface water exposure assessments and SCI-GROW for groundwater exposure assessments. 

EDWCs were generated for the total residues of concern for risk assessment; parent 

triflusulfuron-methyl. The highest estimated drinking water concentration was associated with 

the groundwater estimate. Water residues (groundwater EDWC of 0.0005 ppm) were 

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

indirect, all sources” for the chronic assessment.

Conclusions

The dietary-exposure database is adequate to support the existing registrations. HED has 

assessed dietary exposures. Risks from these exposures, including aggregate exposures, are 

below the level of concern. However, a new dietary exposure and risk assessment may be 

required during Registration Review to incorporate potential changes to the triflusulfuron-methyl

toxicological PODs and EDWCs. In addition, the assessment would likely include updated 

consumption information and utilize the newest version of DEEM-FCID.

Tolerances and International Harmonization

The residue chemistry database is complete to support the currently registered uses. Sugar beet 

metabolism data are sufficient to support the registered uses of triflusulfuron-methyl. The 

metabolism of triflusulfuron-methyl in ruminants is adequately understood. Confined rotational 

crop studies were conducted using wheat, beetroot (red beet), and lettuce, using triflusulfuronmethyl labeled in each ring (in separate studies). The tolerance expression should include only 

the parent compound, triflusulfuron-methyl. The current tolerance expression is in concert with 

recent guidance (Knizner, 20091). At this time, no tolerances are required for residues of 

triflusulfuron-methyl in livestock commodities. Suitable analytical methods are available to 

enforce tolerances for residues of triflusulfuron-methyl. The residue definition of triflusulfuronmethyl is presented in Table 2 of the Appendix. The tolerance expression is up to current 

standards.

 

1

Knizner, S. 2009. “Interim Guidance on Tolerance Expressions.” EPA Memorandum, May 27, 2009.
Page 7 of 18

Occupational and Residential Exposure

The most recent occupational and residential exposure (ORE) assessment was performed in 

conjunction with the April 2011 human-health risk assessment for use on garden beet (D388621, 

E. Holman, et al.; 13-APR-2011). Triflusulfuron-methyl is currently registered for use on sugar 

beet commodities, garden beets, and chicory, marketed as UpBeet®, a dry flowable (DF) 

formulation containing 50% active ingredient. UpBeet® is labeled to be applied as broadcast 

(ground- or aerial-based) or band application methods at seasonal rates of up to 0.078 pounds ai 

per acre (lb ai/A) with applications made in 5-10 day intervals; not to be applied via any type of 

irrigation system. The existing label for UpBeet® lists a pre-harvest interval (PHI) of 60 days 

for sugar beet, garden beet, and chicory. For sugar beet, UpBeet may be broadcast applied via 

ground or air equipment at up to 0.032 lb ai/A/application. For chicory, the maximum single 

application rate is 0.024 lb ai/A, with a maximum seasonal application rate of 0.048 lb ai/A. For 

garden beets, the maximum single application rate is 0.0156 lb ai/acre.

Non-Cancer Inhalation Handler and Post-Application Exposure Results

The inhalation handler exposure assessment resulted in MOEs greater than 100 which is the level 

of concern (LOC) for this chemical based on its toxicologic database, and, therefore, is not of 

concern. A quantitative post-application inhalation exposure assessment was not performed for 

triflusulfuron-methyl because of the low acute inhalation toxicity (Toxicity Category IV), low 

vapor pressure (less than 1.0 x 10-7 mm Hg), and the low application rate (0.032 lb ai/A). 

However, there are multiple potential sources of post-application inhalation exposure to 

individuals performing post-application activities in previously treated fields. These potential 

sources include volatilization of pesticides and resuspension of dusts and/or particulates that 

contain pesticides. The Agency sought expert advice and input on issues related to volatilization 

of pesticides from its Federal Insecticide, Fungicide, and Rodenticide Act Scientific Advisory 

Panel (SAP) in December 2009, and received the SAP’s final report on March 2, 2010 

(http://www.epa.gov/scipoly/SAP/meetings/2009/120109meeting.html). The Agency is in the 

process of evaluating the SAP report as well as available post-application inhalation exposure 

data generated by the Agricultural Reentry Task Force and may, as appropriate, develop policies 

and procedures, to identify the need for and, subsequently, the way to incorporate occupational 

post-application inhalation exposure into the Agency's risk assessments. If new policies or 

procedures are put into place, the Agency may revisit the need for a quantitative occupational 

post-application inhalation exposure assessment for triflusulfuron-methyl.

Spray drift is always a potential source of exposure to residents nearby to spraying operations. 

This is particularly the case with aerial application, but, to a lesser extent, could also be a 

potential source of exposure from ground–based applications of triflusulfuron-methyl. The 

Agency has been working with the Spray Drift Task Force, EPA Regional Offices and State 

Lead Agencies for pesticide regulation and other parties to develop the best spray drift 

management practices (see the Agency’s Spray Drift website for more information at 

http://www.epa.gov/opp00001/factsheets/spraydrift.htm). On a chemical by chemical basis, the 

Agency is now requiring interim mitigation measures for aerial applications that must be placed 

on product labels/labeling. Other potential sources of residential exposure include volatilization 

of pesticides and re-suspension of dusts and/or particulates that contain pesticides. 
Page 8 of 18

Non-Cancer Dermal Handler and Post-Application Exposure Results

No systemic toxicity was seen at the limit dose (1000 mg/kg/day) of a 28-day dermal toxicity 

study in the rabbit. Therefore, neither a quantitative dermal handler nor post-application 

exposure assessment was performed. 

Residential Exposure

There are no current or pending residential uses associated with triflusulfuron; therefore, a 

residential exposure assessment was not performed nor required.

Cancer Risk

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

chemical, based on increased incidence of testicular cell adenomas in rats. The study on which 

the chronic reference dose (RfD) is based is considered to be adequately protective of these 

effects. 

Restricted Entry Interval

The restricted entry interval (REI) is based on the acute toxicity of triflusulfuron-methyl

technical material. Triflusulfuron-methyl is classified as Toxicity Category III by the dermal 

route, Toxicity Category IV for eye irritation potential, and Toxicity Category IV for skin 

irritation potential. Under the Worker Protection Standard for Agricultural Pesticides, active 

ingredients classified as acute toxicity categories III or IV for these routes are usually assigned a 

12-hour REI. However, triflusulfuron-methyl meets the criteria in PR Notice 95-3 for low risk 

pesticides that are permitted to have a 4-hour REI. Therefore, HED has no objections to the 4-

hour REIs on the existing registered label (for sugar beet and chicory uses) and the proposed 

supplemental label for garden beet. In addition, no dermal endpoints were identified, therefore,

dermal post-application risks are not anticipated.

Conclusions for Residential and Occupational Exposure

Since there are no currently registered residential uses for triflusulfuron-methyl, it is not 

anticipated that a residential assessment will need to be conducted during registration review. 

Due to recent occupational exposure science policy updates, existing occupational scenarios may 

have to be reassessed. These updates include changes to data sources and default assessment 

inputs for both occupational handler and post-application assessments. In addition, the 

assessment may need to be updated to reflect any potential changes to the points of departure 

(PODs) or uncertainty factors for triflusulfuron-methyl. 

Aggregate Exposure

Since there are no residential exposures to triflusulfuron-methyl, aggregate exposure is equal to 

the dietary exposure from food and water. 

Incident Report

The OPP Incident Data System (IDS) was utilized to retrieve pesticide incident data on the active 

ingredient triflusulfuron-methyl. Based on the low frequency and severity of incident cases

reported for triflusulfuron-methyl, there does not appear to be a concern at this time that would 
Page 9 of 18

warrant further investigation (D399193). The Agency will continue to monitor the incident 

information and if a concern is triggered, additional analysis will be included in the risk 

assessment.

Endocrine Disruption

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse 

outcomes from exposure to chemicals. Collectively, these 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 influence, 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 and 

chronic studies that assess growth, developmental and reproductive effects in different 

taxonomic groups. As part of its reregistration decision, 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), triflusulfuron-methyl is subject to the 

endocrine screening part of the Endocrine Disruptor Screening Program (EDSP). 

EPA has developed the 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 

Administrator 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 Tier 2 tests are necessary based on the available 

data. Tier 2 testing is designed to identify any adverse endocrine-related effects caused by the 

substance, and 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. Triflusulfuronmethyl is not among the group of 58 pesticide active ingredients on the initial list to be screened 

under the EDSP. Accordingly, as part of registration review, EPA will issue future EDSP 

orders/data call-ins, requiring the submission of EDSP screening assays for triflusulfuronmethyl. For further information on the status of the EDSP, the policies and procedures, the list 

of 67 chemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit our

website: http://www.epa.gov/endo/.

Cumulative

EPA does not have, at this time, available data to determine whether triflusulfuron-methyl has a 

common mechanism of toxicity with other substances. EPA has not made a common 
Page 10 of 18

mechanism of toxicity finding for triflusulfuron-methyl and any other substances and, 

triflusulfuron-methyl does not appear to produce a toxic metabolite produced by other substances 

which have tolerances in the U. S. Therefore, EPA has not assumed that triflusulfuron-methyl

has a common mechanism of toxicity with other substances.

Human Studies

The occupational exposure and risk assessment for triflusulfuron-methyl relied in part on data 

from studies in which adult human subjects were intentionally exposed to a pesticide or other 

chemical. These studies required a review of their ethical conduct and have received the 

appropriate review by the Human Studies Review Board (HSRB). Many such studies, involving 

exposure to many different pesticides, comprise generic pesticide exposure databases such as the 

PHED and the Agricultural Reentry Task Force (ARTF) Database. EPA has reviewed all the 

studies in these multi-pesticide generic exposure databases, and on the basis of available 

evidence has found them to have been neither fundamentally unethical nor significantly deficient 

relative to standards of ethical research conduct prevailing when they were conducted. There is 

no regulatory barrier to continued reliance on these studies, and all applicable requirements of 

EPA’s Rule for the Protection of Human Subjects of Research (40 CFR Part 26) have been 

satisfied.

Environmental Justice

Potential areas of environmental justice concerns, to the extent possible, were considered 

in the human-health risk assessment, in accordance with U.S. Executive Order 12898, “Federal 

Actions to Address Environmental Justice in Minority Populations and Low-Income 

Populations,” (http://www.hss.energy.gov/nuclearsafety/env/guidance/justice/eo12898.pdf). The 

OPP typically considers the highest potential exposures from the legal use of a pesticide when 

conducting human-health risk assessments, including, but not limited to, people who obtain 

drinking water from sources near agricultural areas, the variability of diets within the U.S., and 

people who might be exposed when harvesting crops. Should these highest exposures indicate 

potential risks of concern, OPP further refines the risk assessments to ensure that the risk 

estimates are based on the best available information.

Conclusions/Future Actions Needed

The actions needed in the future Registration Review for triflusulfuron-methyl are listed below.

Hazard Identification and Endpoint Selection

Based on the additional toxicity studies that are required, the toxicity database for triflusulfuronmethyl may need to be re-evaluated. Specifically, endpoint selection and uncertainty factors 

may need to be re-evaluated to ensure that points of departure reflect current policy. 

Dietary and Drinking Water Exposure and Risk

The dietary and drinking water exposure assessments are adequate based on current 

methodologies. However, an updated assessment may be required during the registration review 

process to include any new data submitted as conditions of registration, revised points of 
Page 11 of 18

departure (PODs) or uncertainty factors or new drinking water data. The revised assessments 

should be conducted using the newest version of DEEM-FCID which includes updated 

consumption information. 

Residential Exposure and Risk

There are no current or pending residential uses associated with triflusulfuron-methyl. If 

residential uses are identified, then a risk assessment needs to be conducted in accordance with

current policies and SOPs. 

Aggregate Exposure and Risk

Since there are no residential exposures to triflusulfuron-methyl, aggregate exposure is equal to 

the dietary exposure from food and water. 

Occupational Exposure and Risk

The occupational exposure assessment may need to be updated to reflect current SOPs and to 

incorporate any new endpoints or uncertainty factors selected based on the required toxicity 

studies. 

Incident Report

Based on the absence of incident cases with triflusulfuron-methyl, there does not appear to be a 

concern at this time that would warrant further investigation. The Agency will continue to 

monitor the incident information and if a concern is triggered, additional analysis will be 

included in the risk assessment.

Data Requirements

Toxicity Data Requirements

The immunotoxicity study is a new data requirement under 40 CFR Part 158 as a part of the data 

requirements for registration of a pesticide (food and non-food uses).

Residue Chemistry Data Requirements

The residue chemistry database is complete to support the currently registered uses. 

References

D388621: Triflusulfuron-methyl: Revised Human Health Risk Assessment for Use in Garden 

Beet. April 13, 2011.

D260076: Triflusulfuron-methyl: Human Health Risk Assessment for the Section 3 

Registration on Sugar Beets (PP#4F4278) and Chicory (PP#0E6214). February 12, 2002.

D399193: Triflusulfuron-methyl: Review of Human Incidents. May 3, 2012.

HASPOC memo. April 12, 2012. TXR No. 0056291.
Page 12 of 18

 

Attachments: Appendix 1
Page 13 of 18

TABLE 1 Physicochemical Properties of the Triflusulfuron-Methyl.

Parameter Value Reference

Melting point/range 155-158oC Petition Administrative 

Materials

pH Not indicated

Density (g/mL) 1.45 absolute

0.56 (Bulk)

Water solubility ( 25°C) pH ppm

3 1.0

5 2.7

7 110

9 11 000

Low solubility at pH3 and pH 5; soluble at 

pH 7; very soluble at pH 9. Solubility 

increases with increasing pH.

Solvent solubility (mg/L) solvent mg/L

hexane <0.0016

octanol 0.026

toluene 2.0

methanol 7.0

ethyl acetate 27

acetonitrile 80

acetone 120

chloroform 160

methylene chloride 580

Vapor pressure at 25°C <1 x 10-7 mm Hg

A relatively non-volatile compound; low 

potential for losses due to volatilization.

Dissociation constant (pKa) 4.4

This compound will dissociate and exist in its 

anionic form at most environmentally 

relevant pHs.

Octanol/water partition coefficient (KOW) pH Kow at 25°C

5 220

7 9.2

9 0.86

Low potential for bioaccumulation in biota.

UV/visible absorption spectrum λmax = 395 nm

absorption at λ>400 nm is not anticipated

Potential to absorb sunlight in the UV/visible 

range of 290-400 nm.
Page 14 of 18

Table 2. Residue Definition for Triflusulfuron-methyl

Matrix Risk Assessment Tolerance

Plants Primary Crop Triflusulfuron-methyl Triflusulfuron-methyl

Rotational Crop Not applicable at this time Not applicable at this time 

Livestock Ruminant Not applicable at this time Not applicable this time 

(under 40 CFR 180.6 

(a)(3))

Poultry Not applicable at this time Not applicable at this time 

(under 40 CFR 180.6 

(a)(3))

Drinking Water Triflusulfuron-methyl Not Applicable
Page 15 of 18

Table 3. Toxicity Data

Test Triflusulfuron-methyl, Technical

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 (nonrodent) .........................................

870.3200 21-Day Dermal ..............................................................

870.3250 90-Day Dermal ..............................................................

870.3465 90-Day Inhalation..........................................................

yes

yes

yes

no

no

yes

yes

yes

-

-

870.3700a Developmental Toxicity (rodent)...................................

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

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

yes

yes

yes

yes

yes

yes

870.4100a Chronic Toxicity (rodent) ..............................................

870.4100b Chronic Toxicity (nonrodent)........................................

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...

870.5550 Mutagenicity—Other Genotoxic Effects.......................

yes

yes

yes

yes

yes

yes

yes

yes

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 Develop. Neurotoxicity .................................................

no

no

yes

yes

no

--

--

yes

yes

--

870.7485 General Metabolism ......................................................

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

yes

no

yes

no

870.7800 Immunotoxicity series......................................................... yes no

Special Studies for Ocular Effects

Acute Oral (rat)...........................................................

Subchronic Oral (rat) ..................................................

Six-month Oral (dog)..................................................

no

no

no

--

--

--
Page 16 of 18

Table 4. 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/FQP

A 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 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). UFL = use of a LOAEL to extrapolate a 

NOAEL. UFS = use of a short-term study for long-term risk assessment. UFDB = to account for the absence of key 

data (i.e., lack of a critical study). FQPA SF = FQPA Safety Factor. PAD = population adjusted dose (a = acute, c 

= chronic). RfD = reference dose. MOE = margin of exposure. LOC = level of concern. N/A = not applicable.
Page 17 of 18

Table 5. Summary of Toxicological Doses and Endpoints for Triflusulfuron-Methyl for Use 

in Occupational Human Health Risk Assessments

Exposure/

Scenario

Point of 

Departure

Uncertainty 

Factors

Level of Concern 

for Risk 

Assessment

Study and Toxicological Effects

Dermal ShortTerm (1 to 30 

days) and 

IntermediateTerm (1 to 6 

months)

Not required. No toxicity was observed in the rabbit 21-day dermal toxicity study up to the limit 

dose of 1000 mg/kg/day.

Dermal LongTerm (> 6 

months)

Not required. Long-term dermal exposure is not anticipated from current and proposed uses.

Inhalation 

Short-Term (1 

to 30 days) and 

IntermediateTerm (1 to 6 

months)

NOAEL = 

6.56

mg/kg/day

(inhalation 

absorption 

rate = 

100%)

UFA=10x

UFH=10x Occupational LOC 

for MOE = 100

90-day oral toxicity in the rat

LOAEL = 133 mg/kg/day (males)/153 

mg/kg/day (females), based on decreased 

body weight gain (observed after the first 

week of dosing) and body weight, and in 

females, extramedullary hematopoiesis.

Inhalation 

Long-Term (> 

6 months)

Not required. Long-term inhalation exposure is not anticipated from current and proposed uses.

Cancer (oral, 

dermal, 

inhalation)

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

interstitial cell adenomas in rats. The 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). UFL = use of a LOAEL to extrapolate a 

NOAEL. UFS = use of a short-term study for long-term risk assessment. UFDB = to account for the absence of key 

data (i.e., lack of a critical study). MOE = margin of exposure. LOC = level of concern. N/A = not applicable.
Page 18 of 18

Tolerances and International Harmonization

International Residue Limits 

No CODEX MRLs have been established for triflusulfuron-methyl. The U.S. is in harmony with 

Canadian MRLs.

 Triflusulfuron-Methyl (PC Code 129002; Date of Request 4/12/12)

Summary of US and International Tolerances and Maximum Residue Limits 

Residue Definition:

US Canada Mexico2 Codex

40 CFR 180.492

Plant: triflusulfuron-methyl (methyl 2-

[[[[[4-(dimethylamino)-6-(2,2,2-

trifluoroethoxy)-1,3,5-triazin-2-

yl]amino]carbonyl]amino]sulfonyl]-3-

methylbenzoate) 

Livestock: NA

methyl 2-[4-

dimethylamino-6-(2,2,2-

trifluoroethoxy)-1,

3,5-triazin-2-

ylcarbamoylsulfamoyl]-mtoluate

None

Commodity1 Tolerance (ppm) /Maximum Residue Limit (mg/kg)

US Canada Mexico2 Codex

Beet, garden, roots 0.01

Beet, garden, tops 0.02

Beet, sugar, roots 0.05 0.05 sugar beets

Beet, sugar, tops 0.05 0.05 sugar beets

Chicory, roots 0.05 0.05

MRLs with NO US equivalent

Molasses 0.05

Sugar 0.05

Completed: M. Negussie; 04/13/2012

1Mexico adopts US tolerances and/or Codex MRLs for its export purposes.

2

* = absent at the limit of quantitation; Po = postharvest treatment, such as treatment of stored grains. PoP = 

processed postharvest treated commodity, such as processing of treated stored wheat. (fat) = to be measured on the 

fat portion of the sample. MRLs indicated as proposed have not been finalized by the CCPR and the CAC.