Page 2 of 32

Rachel Ricciardi, Chemical Review Manager

Rose Kyprianou, Team Leader

Lance Wormell, Branch Chief

Risk Management Branch 2 (RMB2)

Antimicrobials Division (7510P)

Executive Summary

Following is the Health Effects Division’s (HED’s) and Antimicrobials Division’s (AD’s)

human health scoping document for the triazole-derived fungicide tebuconazole to support 

Registration Review. To evaluate the scope of work necessary to support Registration Review, 

previous risk assessments for tebuconazole have been considered; updates to its toxicity, 

exposure, and usage databases; and the latest Agency science policy and risk assessment 

methodologies. The most recent HED aggregate risk assessment for tebuconazole was 

completed in 2013 (D412600, B. O’Keefe, 12/31/2013). AD has not conducted a risk 

assessment for tebuconazole since the chemical was initially registered.

Tebuconazole is registered for use in/on numerous agricultural field and orchard crops, as a postharvest use on several fruits, on commercial ornamentals and golf course turf; and on residential 

ornamentals and flowers. Additionally, there are registered uses of tebuconazole as an 

antimicrobial pesticide, including the preservation of wood, and as a material preservative in 

adhesives, coatings, glues, plastics and metalworking fluids.

The toxicological database for tebuconazole is complete. The target organs in both rodents and 

non-rodents are the liver, adrenals, and hematopoietic system. In addition, ocular lesions are 

seen in dogs (including lenticular degeneration and increased cataract formation) following

subchronic and chronic exposure. Some of the toxicological effects of tebuconazole are 

consistent with those of other triazole-derivative chemicals. In particular, developmental toxicity 

and hepatocellular tumors are effects common to a number of these class of pesticides. The data 

indicated that with in-utero exposure to tebuconazole resulted in developmental effects in fetuses 

(rat, mouse and rabbit) and pups (rats). The point of departure for dietary (acute and chronic) 

and non- dietary (incidental oral, dermal and inhalation exposures) is based on decreases in body 

weights, absolute brain weights, brain measurements and motor activity in offspring seen in the 

rat developmental neurotoxicity study at the lowest observed adverse effect level (LOAEL). A 

no observed adverse effect level (NOAEL) was not seen in the study. The Food Quality 

Protection Act (FQPA) Safety Factor is retained in the form of a LOAEL to NOAEL factor since 

a LOAEL was used for overall risk assessment. A 3X as opposed to a 10X was deemed 

appropriate based on quantifiable data and lack of residual uncertainties for pre and/or post-natal 

toxicity. Tebuconazole is classified as a Group C Chemical; “Possible Human Carcinogen”. A 

human cancer risk assessment is not required since the chronic reference dose (cRfD) will be

considered protective of all effects including cancer. 

For Tebuconazole Conventional Uses

The residue chemistry database for tebuconazole is adequate to support current data 

requirements. Adequate metabolism studies (crops, livestock, and rotational crops), storage 
Page 3 of 32

stability, magnitude of the residue, and processing data are available to support the registered 

uses. Adequate methods are available for enforcement of the currently established tolerances. 

New dietary risk assessments are not anticipated during Registration Review, unless there are 

increases to the drinking water exposure estimates that need to be incorporated.

Residential and occupational handler and post-application exposure assessments are reflective of

maximum application rates and current exposure policies and data, and did not identify risks of 

concern. Updated occupational and residential handler exposure assessments are not anticipated 

to be needed during Registration Review. Although existing occupational and residential postapplication assessments are reflective of current exposure policies and data, turf transferrable 

residue (TTR) and dislodgeable foliar residue (DFR) studies are not available and are required 

for tebuconazole during Registration Review, because estimated post-application exposures 

using default TTR and DFR values are not minimal in comparison to the level of concern. 

Therefore, HED may need to reassess these exposures using the results of the required TTR and 

DFR studies during Registration Review.

HED will also examine the need for a volatilization assessment, as well as evaluate the potential 

for exposure from spray drift during Registration Review. However, for tebuconazole, several 

end-use products are labeled for use on residential turf. Thus, the risk assessment for residential 

turf may potentially be considered protective of any type of exposure that would be associated 

with spray drift. Residential bystander exposures resulting from off-site transport (i.e., 

volatilization) may occur as a result of occupational applications of tebuconazole. The need for a 

bystander risk assessment for tebuconazole will be considered during Registration Review.

For Tebuconazole Antimicrobial Uses

AD anticipates the need to conduct new occupational risk assessments for all the antimicrobial 

uses of tebuconazole during Registration Review to ensure that the assessment is consistent with 

current AD policies and standards. In addition, AD will need to reassess residential exposures to 

treated wood products based on new wipe data that are anticipated as needed based on potential 

risks identified in the past residential risk assessment. Additional occupational and residential 

risk assessments will be conducted during Registration Review.

Exposure studies and use data will be needed for assessing the risk from the antimicrobial uses of 

tebuconazole. AD anticipates the need to conduct new occupational exposure assessments for 

Registration Review to support wood and material preservative uses and to conduct new 

residential applicator assessments to support the wood stain use. Dermal (Guideline 875.1200) 

and inhalation (Guideline 875. 1400) surrogate applicator data will be needed to assess human 

health risks for occupational exposure for uses of tebuconazole as a wood preservative (sapstain 

and pressure treatment) and material preservatives (liquid pour). Occupational as well as 

residential surrogate data are also needed for the wood stain use (airless sprayer and paint 

brush/roller). Product use data (Guideline 875.1700) are needed to clarify uses (particularly the 

use in plastics), application rates (wood retentions), and application equipment.

AD anticipates the need to conduct a residential post-application risk assessment based on 

potential risk concerns from the previous risk assessment (D346795, B. O’Keefe, 11/26/2007; 
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updated in D397518, B. O’Keefe, 04/30/2012). A wipe study will be needed (Guideline 

875.2300) to quantify residues from treated decks at the highest wood retention rate for 

tebuconazole. Product use data (Guideline 875.1700) will also be needed. The new residue data 

are needed to refine the previous residential post-application assessment, which was based on 

surrogate data.

Aggregate

Aggregate exposure to tebuconazole is currently not of concern to HED. However, the shortterm aggregate risk estimates will need reevaluation during Registration Review based on the 

submitted wood, TTR, and DFR studies.

Introduction

Tebuconazole is a triazole fungicide active ingredient that acts by inhibiting C14-demethylase, 

an enzyme which plays a role in sterol production in fungi. The most recent human health risk 

assessment for tebuconazole was completed in 2013 for tolerances on imported oranges and 

orange commodities (D412600, B. O’Keefe, 12/31/2013). 

For Tebuconazole Conventional Uses

Tebuconazole is currently registered for use in/on the following use sites: 1) field and 

orchard/tree crops: almonds, apple, asparagus (domestic use and import), bananas, barley (field 

and seed treatment), beans, Brassica leafy greens, bulb vegetables, cherries, corn (sweet corn, 

field corn, field corn grown for seed, and popcorn, plus seed treatment), cotton, cucurbits, 

fruiting vegetables, garden beets, grapes, grasses (grown for seed), hops, lychee, oats (seed 

treatment), okra, peaches, peanuts, pistachios, plantain, pome fruit, soybean, stone fruit, 

sunflower, tree nuts, triticale (seed treatment), turnips, watermelon, wheat (field and seed 

treatment), and wine grapes; 2) post-harvest uses on cherry, mango and plum; 3) commercial 

ornamentals and golf course turf; and 4) residential ornamentals and flowers. There are existing 

tolerances with no US registration on coffee, garlic, onions, and oranges.

Tebuconazole end use products are formulated as liquids, flowable concentrates, granulars and 

ready-to-use solutions. Tebuconazole is also formulated into products with other fungicides. 

Applications can be made with ground, aerial, airblast, chemigation, hand held, or seed treatment 

equipment, as well as postharvest sprays. 

Permanent tolerances are established for residues of tebuconazole in/on various plant 

commodities at levels ranging from 0.05 ppm in/on asparagus, bananas, field and popcorn grain, 

pome fruits, tree nuts, and sunflower seed to 55.0 ppm in/on grass seed screenings [40 CFR 

§180.474(a)(1)]. Permanent tolerances are also established for the combined residues of 

tebuconazole and its metabolite 1-(4-chlorophenyl)-4,4-dimethyl-3-(1H-1,2,4-triazole-1-ylmethyl)-pentane-3,5-diol (HWG 2061) at 0.2 ppm in/on meat-byproducts of cattle, goats, horses, 

and sheep, and at 0.1 ppm in milk [40 CFR §180.474(a)(2)]. Tolerances with regional 

registrations are established in 40 CFR §180.474(c) on turnip roots at 0.5 ppm and turnip tops at 

7.0 ppm.

Refer to Attachment 1 (Table 1) for the chemical identity of tebuconazole.
Page 5 of 32

For Tebuconazole Antimicrobial Uses

Tebuconazole is registered for the preservation of wood intended for above-ground and/or inground contact, such as Ponderosa pine, Scots pine, Southern yellow pine, beech, oak, birch, and 

other wood species susceptible to decay by rotting fungi. Such uses include fence posts, poles, 

decks, millwork, posts, etc. Wood treatment applications may include sapstain and pressure 

treatment. Tebuconazole is commonly used in combination with copper and propiconazole for 

different copper azole formulations. In addition to its major use as a wood preservative, 

tebuconazole is also registered for use as a material preservative in adhesives, coatings, glues, 

plastics and metalworking fluids.

Hazard Identification/Toxicology

No new toxicity data have been submitted since the last risk assessment (D412600, B. O’Keefe. 

12/31/2013). The toxicological database for tebuconazole is complete for risk assessment. 

Developmental toxicity studies are available in rats, rabbits, and mice; developmental toxicity 

studies in rats and mice were administered via the oral and dermal routes. A developmental 

neurotoxicity in rats is also available and currently provides the most sensitive toxicity endpoints 

and is used for establishing the points of departure (POD) for risk assessment for all exposure 

scenarios (Attachment 3). 

With repeated dosing, the common effects were seen in the liver, adrenals, and hematopoietic 

system in both rodent and non-rodent species. In addition, ocular lesions are seen in dogs 

(including lenticular degeneration and increased cataract formation) following subchronic or 

chronic exposure. 

Tebuconazole induced developmental effects in many oral developmental toxicity studies in rats, 

rabbits, and mice. In all three species the developmental effects mostly occurred at similar dose 

levels where maternal effects were found; however, the maternal effects were minimal and did 

not increase substantially in severity at higher dose levels. The prominent developmental effect 

was on the developing nervous system manifested as increased malformations of the nervous 

system and skull (including exencephaly and acrania, skull bone and vertebral anomalies). The 

developmental toxicity studies, including the developmental neurotoxicity study, demonstrate 

both quantitative and qualitative developmental susceptibility. Decreased absolute brain weight, 

morphometric measurements, and decreased motor activity were seen in the offsprings of rats in 

the developmental neurotoxicity study. In the reproductive toxicity study, adverse effects on 

offspring were manifested only as decreased pup body weight. However, prolonged gestation 

and dystocia, as well as decreased offspring survival (fewer pups born alive, more stillborn pups, 

and pup deaths during the first week after birth), were seen in the developmental neurotoxicity 

study. 

In contrast, tebuconazole did not produce any developmental effects in dermal developmental 

toxicity studies in rats and mice at dose levels up to the limit dose (1000 mg/kg/day). 

Furthermore, the 28-day dermal toxicity study in rabbits found no effect at the limit dose (1000 

mg/kg/day). However, none of these dermal development and dermal toxicity studies conducted 

measurements on brain morphometric measurements and absolute brain weight in the developing 

animals.
Page 6 of 32

Tebuconazole induced an increase in the incidence of hepatocellular adenomas, carcinomas and 

combined adenomas/carcinomas in male and female mice, but it showed no mutagenic potential. 

Based on these findings, tebuconazole was classified as a Group C Chemical; “Possible Human 

Carcinogen”. A human cancer risk assessment is not required since the chronic reference dose 

will be protective of all effects including cancer. 

The target organs with tebuconazole are consistent with those of other triazole-derivative 

chemicals. In particular, developmental toxicity and hepatocellular tumors are effects common 

to a number of these pesticides in this class. Tebuconazole also shares common metabolites with 

other chemicals in this group, including free triazole (1,2,4-triazole) and triazole-conjugated 

plant metabolites (such as triazole alanine). These common metabolites were the subject of a 

recent aggregate risk assessment document (D426493, T. Morton, 04/09/13) updated to 

incorporate new uses of triazole-derivative fungicides.

The DNT was selected as the critical study for establishing the Point of Departure (POD) for 

overall risk assessment. The LOAEL of 8.8 mg/kg/day is based on decreased absolute brain 

weight, morphometric measurements, and decreased motor activity observed in the offsprings; a 

NOAEL was not established. Since a LOAEL was selected as the POD, the FQPA Safety Factor 

is retained in the form of a LOAEL to NOAEL uncertainty factor ((UFL). Typically, the default 

10X will be retained. However, in the case of tebuconazole, the FQPA Safety Factor is reduced 

to 3 based on quantifiable data as discussed below:

A Bench Dose (BMD) analyses of the endpoints of concern in the DNT showed that all 

of the BMDLs (benchmark dose limit) to be 1-2x lower than the LOAEL. Therefore, an 

extrapolated NOAEL is not likely to be 10X lower than the LOAEL, therefore, a 3X 

uncertainty factor is adequate; 

The use of a 3X UF to the POD results in an extrapolated NOAEL of 2.9 mg/kg/day (8.8 

mg/kg/day÷ 3= 2.9 mg/kg/day) which is comparable to the developmental NOAEL (3 

mg/kg/day) established in the pre-natal developmental toxicity study in rats;

The toxicology database is complete and there are no residual uncertainties for pre and/or 

post-natal toxicity. 

Please refer to Attachment 3 for a summary of the toxicity endpoints, points of departure (PODs) 

and safety factors for tebuconazole, and to Attachment 4 for the complete toxicity profile tables 

for tebuconazole. 

Conclusion: The toxicology database is adequate to support the existing registered uses and there 

are no additional data requirements at this time.
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Residue Chemistry and Dietary Exposure

For Tebuconazole Conventional Uses

The nature of the residue in primary/rotational crops and livestock has been adequately defined.

Tebuconazole (parent) is the residue of concern for risk assessment and for the tolerance 

expression for primary/rotational crops. For poultry and ruminant livestock, tebuconazole and 

free and conjugated HWG-2061 are the residues of concern for risk assessment and for the 

tolerance expression. For drinking water, the residue of concern is tebuconazole (parent only).

HED also has concern for residues of 1,2,4-triazole, triazolylalanine (TA), and triazolylacetic 

acid (TAA) in plants and livestock as a result of the use of tebuconazole. However, because 

separate endpoints for these compounds have been established, exposure and risk from free 

triazole and its conjugates will be addressed separately.

The existing residue chemistry database for tebuconazole is adequate to support current 

Registration Review data requirements. Adequate metabolism, enforcement methods, 

multiresidue methods, storage stability, field trials, processing and rotational crop data are 

available to support the registered uses.

Analytical reference standards for tebuconazole are currently available in the EPA National 

Pesticide Standards Repository with an expiration date of 4/26/2023 (personal communication 

with Theresa Cole, Analytical Chemistry Branch (ACB), 10/15/2015). An analytical reference 

standard for the t-butylhydroxy metabolite is currently available at the Repository with an 

expiration date of 3/24/2016.

Acute and chronic aggregate dietary (food and drinking water) exposure and risk assessments 

were conducted in 2013 (D416473, M. Negussie, 12/18/2013). The acute and chronic dietary 

assessments were somewhat refined. For the acute assessment, anticipated residues for grapes, 

grape juice, and peaches were derived using the latest United States Department of Agriculture 

(USDA) Pesticide Data Program (PDP) monitoring data. Anticipated residues for all other 

registered and proposed food commodities were based on field trial data. Available processing 

data were used to refine anticipated residues for apples/pears (dried and juice), apricots (dried), 

cherry (juice), coffee (roasted bean), grapes (juice), orange (juice), plums (prunes/prune juice), 

peanut (oil), and tomatoes (paste and puree). For all other processed commodities, Dietary 

Exposure Evaluation Model (DEEM) (ver. 7.81) default processing factors were assumed.

A distribution of estimated concentrations of tebuconazole in drinking water was provided by the 

Environmental Fate and Effects Division (EFED) and incorporated directly into the acute dietary 

assessment (D412862, A. Shelby, 07/03/2013). The acute assessment was conducted using the 

full 30-year distribution of estimated residues in surface water generated by the Pesticide Root 

Zone Model/Exposure Analysis Modeling System (PRZM-EXAMS) model. The highest 

exposure in surface water resulted from application of tebuconazole to Florida turf. For the 

chronic dietary exposure, the 1-in-10 year annual mean (chronic) concentration of 68.8 μg/L was 

used. Due to the chemical properties of tebuconazole, surface water estimated drinking water 
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concentrations (EDWCs) are much larger than ground water EDWCs, and therefore, PRZM-GW 

estimates do not impact the findings.

The acute dietary exposure to tebuconazole is below HED’s level of concern for all population 

subgroups (<100% of the acute Population Adjusted Dose (aPAD)). Combined acute dietary 

exposure from food and drinking water at the 99.9th percentile of exposure utilized 45% of the 

aPAD for the general U.S. population and 84% of the aPAD for children 1 to 2 years old, the 

highest exposed population subgroup.

Chronic dietary exposure estimates for food and drinking water are well below HED’s level of 

concern (<100% of the chronic Population Adjusted Dose (cPAD)) for all population subgroups. 

The chronic dietary exposure from food and drinking water utilized 6.7% of the cPAD for the 

general U.S. population and 14% of the cPAD for all infants (<1 year old), the highest exposed 

population subgroup.

For Tebuconazole Antimicrobial Registrations

EPA has not established tolerances or tolerance exemptions for residues for the antimicrobial 

uses of tebuconazole. Tebuconazole has not been cleared as a food additive by the US Food and 

Drug Administration (US FDA) under the Federal Food, Drug, and Cosmetic Act (FFDCA) 

Section 409. Although there are registered antimicrobial uses that could result in indirect food 

contact, these uses are expected to result in minimal dietary exposure compared to the 

conventional agricultural uses of tebuconazole (i.e., direct treatment to growing crops intended 

for human or animal consumption). Additionally, the conventional agricultural uses of 

tebuconazole do not result in dietary risks of concern. Therefore, a dietary exposure assessment 

is not anticipated for the antimicrobial uses of tebuconazole.

Conclusions: At the time of the Registration Review risk assessment, HED will review updates 

to the PDP monitoring data, the percent crop treated information, and changes in drinking water 

exposure estimates, and will conduct a revised dietary assessment if there are likely to be 

increases to the dietary exposure estimates.

Residential Exposure

For Tebuconazole Conventional Uses

There are existing uses of tebuconazole on golf course turf, flower gardens, trees, and 

ornamentals in residential settings that were previously assessed to reflect HED’s 2012 

Residential SOPs1along with policy changes for body weight assumptions. Residential exposure 

is expected to be short-term only; intermediate-term exposures are not likely because of the 

intermittent nature of applications in residential settings. Dermal and inhalation exposures for 

residential handlers were combined since the same endpoint and POD is used for both routes of 

exposure. All combined short-term risk estimates for residential handlers are not of concern to 

HED with margins of exposure (MOEs) ranging from 2,800 to 91,000. Adults and children 

golfing and adults working in gardens may receive post-application exposure to tebuconazole

residues. Residential dermal post-application MOEs for all life stages range from 570 to 6,200.

 

1 Available: http://www.epa.gov/pesticides/science/residential-exposure-sop.html
Page 9 of 32

Turf Transferable Residue (TTR): In accordance with the updated Part 158 data requirements 

(2007), a TTR study is required for all occupational (e.g., sod farms, golf courses, parks, and 

recreational areas) or residential turf uses. As part of the recent revision to the Health Effects 

Division’s 2012 Standard Operating Procedures for Residential Pesticide Exposure Assessment, 

HED analyzed all available data and selected new liquid and granular default values for the 

fraction of the application rate available for transfer after a turf application (FAR).2 These 

defaults are 1% for formulations applied as liquids (i.e., emulsifiable concentrates, liquids, 

wettable powders, dry flowables, etc.) and 0.2% for granular formulations. Of the available TTR 

studies submitted to the Agency, the maximum FAR value seen using a liquid product was 6.1% 

or 6.1 times higher than the default residue transfer value. The maximum FAR value seen in a 

TTR study using a granular product was 0.69% or 3.5X the default residue transfer value. 

Therefore, for both liquid and granular formulations, a calculated MOE of approximately 10 

times higher than the level of concern (e.g., an MOE >1,000 if the LOC = 100) using the default 

residue transfer values would provide an adequate margin of safety for any potentially higher 

residues seen in a chemical-specific TTR study (Guidance for Requiring/Waiving Turf 

Transferrable Residue (TTR) and Dislodgeable Foliar Residue (DFR) Studies. 6/7/2012, 

Exposure Science Advisory Council). For tebuconazole, the LOC is 300, and therefore, an MOE 

>3,000 is needed to negate the requirement for a new TTR study. As a result, since the existing 

uses of tebuconazole result in post-application risk estimates < 3,000 using default values for the 

fraction of application rate available for transfer after a turf application, a TTR (875.2100) study 

is required for tebuconazole. 

Spray Drift and Volatilization: Residential bystander exposures resulting from off-site transport 

(e.g., spray drift or volatilization) may occur as a result of applications of tebuconazole. The 

potential for spray drift will be quantitatively evaluated for each pesticide during the Registration 

Review process that ensures that all uses for that pesticide will be considered concurrently. The 

approach is outlined in the revised (2012) Standard Operating Procedures for Residential Risk 

Assessment (SOPs) – Residential Exposure Assessment Standard Operating Procedures, draft

Addenda 1: Consideration of Spray Drift. This document outlines the quantification of indirect 

non-occupational exposure to drift. In terms of volatilization, the agency has developed a 

Volatilization Screening Tool and a subsequent Volatilization Screening Analysis 

(http://www.regulations.gov/#!docketDetail;D=EPA-HQ-OPP-2014-0219). During Registration 

Review, the agency will utilize this analysis to determine if data (i.e., flux studies, route-specific 

inhalation toxicological studies) or further analyses are required for specific chemicals. 

However, for tebuconazole, several end-use products are labeled for use on residential turf. 

Thus, the risk assessment for that use may be considered protective of any type of exposure that 

would be associated with spray drift.

For Tebuconazole Antimicrobial Uses

AD anticipates the need to conduct a residential post-application risk assessment during 

Registration Review to reevaluate or evaluate existing uses of tebuconazole in treated stains and 

wood products, based on potential risk concerns from the last risk assessment (D346795, B. 

O’Keefe, 11/26/2007; updated in D397518, B. O’Keefe, 04/30/2012). A previous assessment 

was conducted for the residential use in order to assess aggregate exposure. AD anticipates the 

need to conduct residential handler dermal and inhalation risk assessments for the application of 

 

2 http://www.epa.gov/pesticides/science/residential-exposure-sop.html
Page 10 of 32

treated stains. The residential exposure scenarios applicable to this use include applicator 

brush/roller and airless sprayer. Wood products commercially treated with end use products 

containing tebuconazole may be used for decks and children’s play sets. Based on the previous

risk assessment (D346795, B. O’Keefe, 11/26/2007; updated in D397518, B. O’Keefe, 

04/30/2012), wipe studies (Guideline §875.2300) are needed to measure residues from treated 

decks at the highest wood retention rate for tebuconazole in order to refine the risk estimates. 

Because tebuconazole is also registered for use in plastics, the Agency will also need product use 

information (Guideline §875.1700) to clarify whether tebuconazole is used to manufacture toys; 

if tebuconazole may be used in toys, a post-application incidental oral exposure assessment from 

use in/on plastics will be conducted during Registration Review. 

Conclusions: Short-term residential exposures are expected from existing uses on golf course 

turf, ornamentals, treated plastics, and treated wood products and the exposure and risk 

assessments may need to be updated during Registration Review. The following studies will be 

needed to update the risk assessments: Guideline §875.2100 Turf transferable residues; 

Guideline §875.1700 Product Use Data on the use of tebuconazole in plastics and wood; and 

Guideline §875.2300 Wipe Study from the use of tebuconazole on treated wood.

The Agency will examine the need for a volatilization assessment, as well as evaluate the 

potential for exposure from spray drift during Registration Review. However, for tebuconazole, 

several end-use products are labeled for use on residential turf. Thus, the risk assessment for 

residential turf may be considered protective of any type of exposure that would be associated 

with spray drift. Residential bystander exposures resulting from off-site transport (i.e., 

volatilization) may occur as a result of occupational applications of tebuconazole. The need for a 

bystander risk assessment for tebuconazole will be considered during Registration Review.

Aggregate Risk Assessment

In accordance with the Food Quality Protection Act, HED must consider and aggregate pesticide 

exposures and risks from three major sources: food, drinking water, and residential exposures. 

The acute and chronic aggregate risk assessments included food and drinking water. The shortterm aggregate risk assessment included food, drinking water, and residential exposures. No 

intermediate-term aggregate risk assessment was conducted since all residential/recreational 

exposures are anticipated to be short-term in duration.

Acute and Chronic Aggregate: The 2013 acute and chronic aggregate risk assessments included 

exposure to tebuconazole residues in food and drinking water. Acute and chronic dietary risk 

estimates for food and drinking water exposure are below HED’s level of concern (<100% of the 

aPAD and cPAD).

Short-term Aggregate: In 2013, a short-term aggregate risk assessment was completed for 

tebuconazole. For adults and children 6 to <11 years old, the short-term aggregate assessment 

combined the average food and drinking water exposures with post-application dermal exposures 

from garden ornamentals. For youths 11 to <16 years old, the short-term aggregate assessment 

combined the average food and drinking water exposures with post-application dermal exposures 
Page 11 of 32

from golf course turf. For small children (1 to <2 years old), the short-term aggregate 

assessment combined the average food and drinking water exposures with post-application 

incidental oral (hand-to-mouth) exposures from contact with pressure treated wood surfaces. 

As noted in the Residential section above the residential exposure assessment will likely be 

needed once the new studies have been received. The short-term aggregate assessment will be 

re-evaluated when the residential assessment is updated.

Conclusions: Aggregate exposure to tebuconazole is currently not of concern to HED. 

However, the short-term aggregate risk estimates will likely need reevaluation during 

Registration Review based on the submitted wood, TTR, and DFR studies.

Occupational Exposure

Most occupational exposure scenarios for currently registered agricultural uses were previously 

assessed using updated exposure assessment policies and body weight assumptions. However, 

occupational exposure scenarios for some antimicrobial uses have not been previously assessed. 

For conventional uses, occupational handlers and post-application workers can become exposed 

to tebuconazole over short- or intermediate-term durations. Additionally, for some antimicrobial 

uses occupational handlers can become exposed to tebuconazole at short-, intermediate-, and 

long-term durations.

For Tebuconazole Conventional Uses

Occupational Handlers: Previous occupational handler exposure and risk assessments for 

tebuconazole were conducted at the maximum application rates and assumed the maximum area 

treated per day for all the registered use sites. Applications can be made with ground, aerial, 

airblast, chemigation, hand-held, or seed treatment equipment. Occupational exposure 

assessments have been updated in accordance with current HED policies and standard operating 

procedures. Risk estimates for all scenarios are not of concern, and therefore, unless new data 

comes in, HED does not anticipate the need to reassess these exposures during Registration 

Review. MOEs ranged from 300 to 17,000 for conventional field and tree crops, 400 to 19,000 

for seed treatments, 2,300 to 18,000 for post-harvest fruit treatments and 700 to 8,700 for golf 

course turf. 

Occupational Post-Application: Based on the Agency's current practices, a quantitative 

occupational post-application inhalation exposure assessment was not performed for 

tebuconazole. 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 tebuconazole.

Dermal post-application exposures for occupational workers have been previously assessed for 

all non-antimicrobial uses of tebuconazole. Risk estimates for the day of application for all crops 

are not of concern to HED with MOEs ranging from 300 to 12,000. 

Turf Transferable Residue (TTR): As detailed above in the Residential Exposure section, in 

accordance with the updated Part 158 data requirements (2007), a TTR study is required for all 

occupational (e.g., sod farms, golf courses, parks, and recreational areas) or residential turf uses. 
Page 12 of 32

For tebuconazole, the LOC is 300, and therefore, an MOE >3,000 is needed to negate the 

requirement for a new TTR study. As a result, since the existing uses of tebuconazole result in 

post-application risk estimates < 3,000 using default values for the fraction of application rate 

available for transfer after a turf application, a TTR study is required for tebuconazole.

Note: In 1996, Bayer CropScience submitted a TTR study to EPA (MRID 44108303). The TTR 

data from this study were previously used as an estimate of day zero tebuconazole residues on 

treated turf (DP361303, B. O’Keefe, 12/28/09). However, based on a complete review of this 

study (D414822, B. O’Keefe, 10/31/2013) HED concluded that the study data should not be used 

as an estimate of day zero residues on turf.

Dislodegable Foliar Residue (DFR): In accordance with 40 CFR §158, 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 postapplication 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 DFR studies, which resulted in the selection of a 

revised default values for the fraction of the application rate available for transfer after a foliar 

application (FAR). This value is based on an analysis of 19 DFR studies. Since that time, the 

Agricultural Re-entry Task Force has submitted information (MRID 49299201) that corrects an 

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 of this submission, the default value of 25% was not 

changed as it still reflects a high-end, conservative value. However, it is important to note that 

the range of FAR values was revised from 2% - 89% to 2% - 47%. In the data, a large range of 

transferability is observed and this variability can potentially be attributable to many factors such 

as active ingredient; formulation; field conditions in the studies; weather conditions (e.g., 

humidity); or many other difficult to quantify factors. Although witnessed across multiple 

chemicals, this range in FAR values is not expected when considering DFR data for a single 

chemical. Because DFR data are not available for tebuconazole, 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 tebuconazole (i.e., there is a small chance that the FAR value may exceed the applicable 

default value), it is likely that the health-protective aspects of EPA’s occupational postapplication 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 zero-day (i.e., day of 

application ) residues every day of the assessed exposure duration (i.e., EPA assumes that no 

dissipation or degradation occurs, it doesn’t rain, etc); individuals perform the same postapplication 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 highend amount of time every day (represented by data reflecting time spent gardening based on 

survey data).

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. 
Page 13 of 32

Since the estimated post-application exposure for occupational exposures for some crop use sites

using default DFR values for tebuconazole is not minimal in comparison to the level of concern 

(i.e., the calculated MOE is not greater than 2 times higher than the level of concern, MOE = 600

compared to the LOC of 300); future refinements of this post-application exposure for 

tebuconazole may be necessary due to increased use of tebuconazole or advances in EPA risk 

assessments. Therefore, EPA is requiring the 40 CFR DFR data requirement to facilitate any 

necessary exposure assessments refinements and to further EPA’s general understanding of the 

availability of dislodgeable foliar pesticide residues.

For Tebuconazole Antimicrobial Uses

Occupational exposure assessments for antimicrobial uses of tebuconazole have not been 

updated since the chemical was initially registered. As a result, AD will need to conduct new 

occupational risk assessments for all the specified antimicrobial uses in Registration Review in 

accordance with current policies.

Occupational Handlers: EPA will need to conduct an occupational exposure assessment for 

Registration Review to support wood and material preservation uses for tebuconazole. AD 

specific occupational exposure assessments will be needed to support current AD policies and 

standard operating procedures. Occupational workers are anticipated to become exposed to 

tebuconazole wood preservatives during wood treatment activities such as sapstain, pressure 

treatment, and remedial uses such as applying wood stains using a brush/roller and/or airless 

sprayer on decks. In addition, occupational workers could potentially become exposed through 

the dermal and inhalation routes from material preservatives from pouring liquids or from mists 

and vapors during metalworking operations (e.g., machinists). The agency anticipates the need to 

call in data (Guidelines §875.1200, §875.1400, and §875.1700) and use surrogate exposure to 

assess all of these handler exposures during Registration Review. The duration of exposure for 

the occupational uses for workers at wood treatment plants and for machinists at metal working 

fluids are considered to represent short (1 to 30 days), intermediate (30 days to 6 months), and 

long-term (> 6 months) durations of exposure as workers in these settings. All other exposures 

from uses such as staining and pouring activities are more episodic and will be of short- and 

intermediate-term durations.

Occupational Post-application: AD does not anticipate the need to conduct a post-application 

exposure assessment. Any exposure for wood pressure treatment plants and machinists will 

already be captured in the occupational handler assessment. 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 tebuconazole.

Conclusions: The occupational handler and post-application exposure assessments for 

conventional uses are reflective of current exposure policies and data. There is sufficient 

information available to assess these occupational handler exposures, and therefore, updated 

occupational handler exposure assessments for these uses are not anticipated to be needed during 

Registration Review. However, some antimicrobial use sites will need to be assessed for 

occupational handler exposures. Post-application exposure assessments may need to be updated 
Page 14 of 32

during Registration Review, since new TTR and DFR studies are needed. These data may 

necessitate the need to update the post-application exposure assessments for some use sites.

Public Health and Pesticide Epidemiology Data

In the Main OPP Incident Data System (IDS), from January 1, 2010 to May 27, 2015, there were

eight (8) incidents reported for the single chemical tebuconazole only in the database. These 

incidents were classified as moderate severity. 

In the Aggregate IDS, from January 1, 2010 to May 27, 2015, there were 444 incidents reported 

involving tebuconazole. These incidents were classified as minor severity.

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 RiskPesticides (SENSOR)-Pesticides database for 1998-2011 identifies 16 cases involving 

tebuconazole; two of which involve a single active ingredient. Both single active ingredient 

cases were low in severity. One case was an agricultural worker who was exposed while 

conducting routine fieldwork. The case reported a skin rash, cough, nausea, vomiting, stomach 

pain, and headache. The second case was a homeowner who applied the product in windy 

conditions and inhaled the product. This case reported dermal and ocular symptoms (skin pain 

and conjunctivitis).

The Agricultural Health Study (AHS) is a high quality, prospective epidemiology study 

evaluating the link between pesticide use and various health outcomes, including cancer. The 

AHS includes private and commercial pesticide applicators and their spouses. Tebuconazole is 

not included in the AHS, and therefore, this study does not provide information for this report.

Conclusion: Although there were a moderate number of tebuconazole incidents reported to 

Main and Aggregate IDS and SENSOR-Pesticides, most of these incidents were classified as low 

severity. The effects experienced were generally minimally traumatic and resolved rapidly and

usually involved skin, eye or respiratory irritation. Based on the generally low severity of 

incidents reported to both IDS and SENSOR-Pesticides, there does not appear to be a concern at 

this time. The Agency will continue to monitor the incident data and if a concern is triggered, 

additional analysis will be conducted.

Tolerance Assessment and International Harmonization

Tolerances are established for plant commodities under 40 CFR §180.474(a)(1) for residues of 

tebuconazole. Compliance with the tolerance levels is to be determined by measuring only 

tebuconazole [α-[2-(4-chlorophenyl) ethyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol].

Tolerances are established for livestock commodities under 40 CFR §180.474(a)(2) for residues 

of tebuconazole. Compliance with the tolerance levels is to be determined by measuring the sum 

of tebuconazole [α-[2-(4-chlorophenyl) ethyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol]

and its diol metabolite (1-(4-chlorophenyl)-4,4-dimethyl-3-(1H-1,2,4-triazole-1-yl-methyl)-

pentane-3,5-diol), calculated as the stoichiometric equivalent of tebuconazole.
Page 15 of 32

Tolerances with regional registrations are established for residues of tebuconazole in/on turnip 

roots at 0.5 ppm and turnip tops at 7.0 ppm 40 CFR §180.474(c). 

The tolerance expression under 40 CFR §180.474 is correct and reflects both the measurement 

and compliance statements addressing tebuconazole residues. Compliance with the tolerance 

levels is to be determined by measuring only tebuconazole in plants and the sum of tebuconazole 

and its diol metabolite in livestock commodities.

The US and Canadian tolerance expressions for plants and livestock are harmonized; whereas,

the US and Codex tolerance expressions are harmonized for plants only. The Codex tolerance 

expression for livestock commodities includes parent only. Residue definition in the US

includes parent and the metabolite. There are Codex and Canadian maximum residue limits 

(MRLs) established for residues of tebuconazole. The US and Codex MRLs are in harmony only 

on banana, cotton undelinted seed, plum (except prunes), tree nuts, and wheat grain. The US 

livestock tolerances are not harmonized with Codex except for byproducts of sheep and hogs. 

The US and Canadian tolerances are harmonized for several plant and livestock commodities. 

Please refer to Attachment 6.

Notes to CRM: The existing US tolerances for pistachio (0.05 ppm) need to be removed from 40 

CFR §180.474(a) since this commodity is included in crop group tree nuts (0.05 ppm). 

The established tolerances (listed below) need to be revised to include an additional significant 

figure (1.0 ppm rather than 1 ppm). This is in order to avoid the situation where rounding of a 

residue result to the level of precision of the tolerance expression would be considered nonviolative (such as 1.4 ppm being rounded to 1 ppm). 

Note to CRM: The existing regional registration for turnip tops (7.0 ppm) and roots (0.05 ppm)

need to be removed from 40 CFR §180.474 (c) to 40 CFR §180.474 (a) (1) since the required 

additional data was submitted (D403309, 12/06/12).

Table 1. Tolerance Recommendations for Tebuconazole.

Commodity Established 

Tolerance 

(ppm)

Recommended 

Tolerance 

(ppm)

Comments

Pistachio 0.05 None Remove

Nut, tree, group 14 (0.05 ppm)

Peach 1.0 None Remove

Fruit, stone, group 12, except 

cherry (1.0 ppm)

Plum 1.0

Tolerance Revisions for Correct Commodity Definition 

Brassica, leafy greens, subgroup 5B 2.5 2.5 Brassica, leafy greens, subgroup 

5B, except turnip greens 

Cherry, sweet, pre- and post-harvest 5.0 5.0 Cherry

Cherry, tart, pre- and post-harvest 5.0 5.0

Grain aspirated fractions 16.0 16 Grain, aspirated grain fractions
Page 16 of 32

Table 1. Tolerance Recommendations for Tebuconazole.

Commodity Established 

Tolerance 

(ppm)

Recommended 

Tolerance 

(ppm)

Comments

Mango, postharvest 0.15 0.15 Mango

Tolerance Revisions for Significant Figure (a)General (1)

Apple, wet pomace 0.1 0.10

Barley, grain 0.3 0.30

Bean, dry seed 0.1 0.10

Bean, succulent 0.1 0.10

Coffee, roasted bean1 0.3 0.30

Cotton, gin byproducts 25.0 25

Grass, hay 25.0 25

Grass, seed screenings 55.0 55

Grass, straw 30.0 30

Hop, dried cones 35.0 35

Onion, bulb, subgroup 3-07A 0.2 0.20

Peanut 0.1 0.10

Sunflower, meal 0.2 0.20

Sunflower, refined oil 0.2 0.20

Vegetable, cucurbit, group 9 0.4 0.40

Tolerance Revisions for Significant Figure (a)General (2)

Cattle, meat byproducts 0.2 0.20

Goat, meat byproducts 0.2 0.20

Horse, meat byproducts 0.2 0.20

Milk 0.1 0.10

Sheep, meat byproducts 0.2 0.20

Cumulative

Tebuconazole is a member of the triazole-containing class of pesticides. Although conazoles act 

similarly in plants (fungi) by inhibiting ergosterol biosynthesis, there is not necessarily a 

relationship between their pesticidal activity and their mechanism of toxicity in mammals. 

Structural similarities do not constitute a common mechanism of toxicity. Evidence is needed to 

establish that the chemicals operate by the same, or essentially the same, sequence of major 

biochemical events. In conazoles, however, a variable pattern of toxicological responses is 

found; some are hepatotoxic and hepatocarcinogenic in mice. Some induce thyroid tumors in 

rats. Some induce developmental, reproductive, and neurological effects in rodents. 

Furthermore, the conazoles produce a diverse range of biochemical events including altered 

cholesterol levels, stress responses, and altered DNA methylation. It is not clearly understood 

whether these biochemical events are directly connected to their toxicological outcomes. Thus, 

there is currently no evidence to indicate that conazoles share common mechanisms of toxicity 

and EPA is not following a cumulative risk approach based on a common mechanism of toxicity 

for the conazoles. For information regarding EPA’s procedures for cumulating effects from 

substances found to have a common mechanism of toxicity, see EPA’s website at 
Page 17 of 32

http://www2.epa.gov/pesticide-science-and-assessing-pesticide-risks/cumulative-assessmentrisk-pesticides.

Human Studies

The risk assessments which have been previously conducted for tebuconazole relied in part on 

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

determine their dermal and inhalation exposure. Many such studies, involving exposure to many 

different pesticides, comprise generic pesticide exposure databases such as the Pesticide 

Handlers Exposure Database (PHED), the Agricultural Handler Exposure Task Force (AHETF) 

database, the Outdoor Residential Exposure Task Force (ORETF), the Agricultural Reentry Task 

Force (ARTF) Database and the Antimicrobial Exposure Assessment Task Force II (AEATF II).

EPA has reviewed all the studies supporting these multi-pesticide generic exposure databases, 

and has found no clear and convincing evidence that the conduct of any of them was either 

fundamentally unethical or significantly deficient relative to the ethical standards prevailing at 

the time the research was conducted. All applicable requirements of EPA’s Rule for the 

Protection of Human Subjects of Research (40 CFR Part 26) have been satisfied, and there is no 

regulatory barrier to continued reliance on these studies.

Data Deficiencies

Occupational and residential exposure data are needed to support the registered uses of 

tebuconazole are listed in Table 2.

Table 2. Exposure Studies Needed for Tebuconazole.

Study Needed Guideline Applicator or Post-application Exposure Scenario

Foliar Dislodgeable Residue 

Dissipation Data

875.2100 Post-application worker or residential exposure

Turf Transferrable Residue

Dissipation Data

875.2100 Post-application worker or residential exposure

Dermal Applicator Data 875.1200* -Worker exposure to sapstain and pressure treatment

-Open pour liquid preservatives

-Applying wood stains using a brush/roller and/or airless sprayer on decks.

Inhalation Applicator Data 875.1400* -Worker exposure to sapstain and pressure treatment

-Open pour liquid preservatives

-Applying wood stains using a brush/roller and/or airless sprayer on decks.

Product Use Data 875.1700 All Antimicrobial Uses 

Product use data is needed to clarify uses (particularly the use of plastics in 

toys), application rates and wood retentions, and application equipment.

Indoor Residue Data (wipe 

study)

875.2300 Dermal and Incidental Oral Exposures to Children playing on pressure 

treated decks and playground equipment (children aged 1 to 2).

* For products with both indoor and outdoor uses, and similar conditions of use, data are generally required for the indoor applications only.
Page 18 of 32

References

Recent Memoranda Relevant to Registration Review of Tebuconazole

Author DP/TXR # Date Title

Human Health Risk Assessments

B. O’Keefe DP412600 12/31/13 Tebuconazole: Human Health Risk Assessment for Tolerance on 

Imported Oranges.

T. Morton DP414592 10/24/13 Common Triazole Metabolites: Updated Aggregate Human Health Risk 

Assessment to Address The New Section 3 Registrations For Use of 

Propiconazole on Rapeseed Crop Subgroup 20A; Use of Difenoconazole 

on Rapeseed Crop Subgroup 20A; and Use of Tebuconazole on Imported 

Oranges.

B. O’Keefe DP402457 01/31/13 Tebuconazole: Human Health Risk Assessment for Tolerance Increases 

Based on Submission of Condition of Registration Requirements for 

Barley and Cantaloupe; and Crop Group Expansion for Fruiting 

Vegetable Crop Group 8-10.

B. O’Keefe DP387596 11/30/11 Tebuconazole: Human Health Risk Assessment for Proposed Use on 

Almond, Apple, Cherry, Peanut, Pecan, Pistachio, Tree Nuts, 

Watermelon, and Wine Grapes.

B. O’Keefe DP384949 02/14/11 Tebuconazole: Human Health Risk Assessment to Harmonize Tolerances 

of Tebuconazole in/on Oats and Wheat with Canada

B. O’Keefe DP373948 02/19/10 Tebuconazole: Amended Human Health Risk Assessment to Clarify 

Anticipated Residue and Percent Crop Treated Information.

B. O’Keefe DP3613058 12/28/09 Tebuconazole: Human Health Risk Assessment for Proposed Use on 

Ornamentals and Golf Course Turf.

B. O’Keefe DP362718 12/28/09 Tebuconazole: Human Health Risk Assessment for Proposed Uses on 

Fruiting Vegetables (Crop Group 8).

S. Winfield DP354807 07/22/08 Tebuconazole: Amendment to D258383 Human Health Risk assessment 

for Tebuconazole; Proposed Tolerances for Cherry, Plum, and 

Commodity Definition for Hops.

S. Winfield DP353954 06/30/08 Tebuconazole: Amendment to D258383 Human Health Risk assessment 

for Tebuconazole; Proposed Tolerances for Tree Nut Group 14 and 

Pistachios

S. Winfield DP252188 04/30/08 Tebuconazole: Amendment to D258383 Human Health Risk assessment 

for Tebuconazole; Proposed Tolerances for Tree Nut Group 14 and 

Pistachios

S. Winfield DP252188 04/30/08 Tebuconazole: Addendum to Human Health Risk Assessment

S. Winfield DP256074/ 

DP276447

04/18/08 Tebuconazole: Human Health Risk Assessment to support tolerances 

in/on Asparagus, Barley, Beans, Beets, Brassica leafy greens, Bulb 

Vegetables, Coffee (import), Commercial Ornamentals, Corn, Cotton, 

Cucurbits, Hops, Lychee, Mango, Okra, Pome fruit, Soybean, Stone fruit, 

Sunflower, Tree Nut Crop Group, Turf, Turnips and Wheat. 

Residue Chemistry

M. Negussie DP416474 12/18/13 Tebuconazole. Request to Establish a Tolerance for Imported Oranges. 

Summary of Analytical Chemistry and Residue Data.

Dietary Exposure Assessment

M. Negussie DP416473 12/18/13 Tebuconazole: Acute and Chronic Aggregate Dietary Exposure and Risk 

Assessments for Establishment of a Tolerance for Imported Oranges.

Occupational and Residential Exposure Assessments

B. O’Keefe DP408080 10/31/13 Tebuconazole. Occupational and Residential Exposure Assessment for a 

New Use on Home Lawns, Athletic Fields, and Sod.
Page 19 of 32

Recent Memoranda Relevant to Registration Review of Tebuconazole

Author DP/TXR # Date Title

B. O’Keefe DP405729 06/06/13 Tebuconazole. Occupational and Residential Exposure Assessment for a 

New Granular Formulation for Use on Golf Course Turf and Residential 

Ornamentals.

B. O’Keefe DP397518 04/30/12 Tebuconazole: Occupational Exposure and Risk Assessment for Proposed 

Increase in Application Rate for Golf Course Turf.

B. O’Keefe DP389289 08/05/11 Tebuconazole: Occupational Exposure and Risk Assessment for Proposed 

Increase in Application Rate for Golf Course Turf.

B. O’Keefe DP376329 04/09/10 Amendment: Tebuconazole: Occupational and Residential Exposure 

Assessment for Proposed Uses on Ornamentals and Golf Course Turf

B. O’Keefe DP375909 03/29/10 Tebuconazole: Occupational and Residential Exposure Assessment for 

Proposed Uses on Barley, Pecan, Soybean, and Wheat on the Absolute 

500 SC Fungicide Label

B. O’Keefe DP361303 12/28/09 Tebuconazole: Occupational and Residential Exposure Assessment for 

Proposed Uses on Ornamentals and Golf Course Turf

B. O’Keefe DP362766 12/28/09 Tebuconazole: Occupational and Residential Exposure Assessment for 

Proposed Uses on Fruiting Vegetables (crop group 8)

B. O’Keefe DP315464 04/16/08 Tebuconazole: Occupational Exposure and Risk Assessment to Support 

Requests for Proposed Uses on Asparagus, Beans (Fresh & Dry), Bulb 

Vegetables, Corn, Cotton, Cucurbits, Garden Beet, Hops, Leafy Brassica

Greens, Lychee, Okra, Pome Fruit, Soybean, Stone Fruit, Sunflower, 

Turnips, Golf Course Turf, Ornamentals, plus Post-Harvest Use on 

Cherry, Plum & Mango, & Seed Treatment of Corn Seed.

B. O’Keefe DP349913 03/13/08 Tebuconazole: Occupational Exposure and Risk Assessment of Proposed 

Uses on Wheat, Barley, and Tree Nuts.

B. O’Keefe DP349926 03/13/08 Tebuconazole: Residential Exposure and Risk Assessment of Proposed 

Use on Golf Course Turf and Existing Uses on Residential Ornamentals.

B. O’Keefe DP346795 11/26/07 Tebuconazole: Residential Exposure and Risk Assessment of Existing 

Antimicrobial Uses on Wood Products and in Paints.

Incident Report

S. Recore D429846 10/28/15 Tebuconazole: Tier I Review of Human Incidents

Attachments

1. Chemical Identity Table

2. Physicochemical Properties of Technical Grade Tebuconazole Table

3. Endpoint Selection Table

4. Toxicity Profile Tables

5. Toxicology Data Requirements Table

6. Tolerance/MRL Table
Page 20 of 32

Attachment 1

Chemical Identity Table

Table A.1. Nomenclature of Tebuconazole and its Regulated Metabolite.

Compound

Common name Tebuconazole

Company experimental name HWG 1608

IUPAC name (RS)-1-p-chlorophenyl-4,4-dimethyl-3-(1H-1,2,4-triazol-1-ylmethyl)pentan-3-ol

CAS name α-[2-(4-chlorophenyl)ethyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol

CAS registry number 107534-96-3

Molecular weight 307.8

End-use products (EP) FOLICUR® 25EW (25% w/v 250 g/L ; EPA Reg. No. 264-748)

Metabolite

Common name t-butylhydroxy-tebuconazole

Company experimental name HWG 2061

IUPAC name Not available

CAS name 1-(4-chlorophenyl)-4,4-dimethyl-3-(1H-1,2,4-triazole-1-ylmethyl)-pentane-3,5-diol

CAS registry number Not available 

Molecular weight 323.8

Cl OH CH3

CH3

CH3

N

N

N

Cl OH CH3

CH3

CH2OH

N

N

N
Page 21 of 32

Attachment 2

Table A.2. Physicochemical Properties of Tebuconazole.

Parameter Value Reference

Melting point/range 104.7 °C PP#9F3724/9F3818, 5/9/91, 

G. Otakie pH Not soluble enough

Specific gravity (20 oC) 1.202 g/mL

Water solubility (20 °C) 32 mg/L

Solvent solubility (g/L at 20oC) n-hexane 2-5 

dichloromethane >200

2-propanol 100-200

toluene 50-100

Vapor pressure 1.3 x 10-3 mPa (20 oC) 

3.1 x 10-3 mPa (25 oC)

Dissociation constant, pKa does not dissociate

Octanol/water partition coefficient, Log(KOW) 3.7 at 20 oC

UV/visible absorption spectrum Not available
Page 22 of 32

Attachment 3

Summary of Toxicity Endpoints and Points of Departure of Tebuconazole

Table A.3. Summary of Toxicological Doses and Endpoints for Tebuconazole for Use in Dietary and NonOccupational 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)

LOAEL = 8.8 

mg/kg/day

UFA= 10x

UFH=10x

(UFL)= 3x

FQPA=1X

Acute RfD = 0.029 

mg/kg/day

aPAD = 0.029 

mg/kg/day

Developmental Neurotoxicity Study - Rat.

LOAEL = 8.8 mg/kg/day based on 

decreases in body weights, absolute brain 

weights, brain measurements and motor 

activity in offspring.

Chronic Dietary 

(All Populations)

LOAEL = 8.8 

mg/kg/day

UFA= 10x

UFH=10x

(UFL)= 3x

FQPA=1X

Chronic RfD = 0.029

mg/kg/day

cPAD =0.029 

mg/kg/day

Developmental Neurotoxicity Study - Rat.

LOAEL = 8.8 mg/kg/day based on 

decreases in body weights, absolute brain 

weights, brain measurements and motor 

activity in offspring.

Incidental Oral 

Short-Term (1-30 

days) and 

Intermediate-term 

(30 days – 6 

months)

LOAEL = 8.8 

mg/kg/day

UFA= 10x

UFH=10x

(UFL)= 3x

FQPA=1X

Residential LOC for 

MOE = 300

Developmental Neurotoxicity Study - Rat.

LOAEL = 8.8 mg/kg/day based on 

decreases in body weights, absolute brain 

weights, brain measurements and motor 

activity in offspring.

Dermal (All 

durations)

LOAEL = 8.8 

mg/kg/day

UFA= 10x

UFH=10x

UFL= 3x

DAF = 13%

Residential LOC for 

MOE = 300

Developmental Neurotoxicity Study - Rat.

LOAEL = 8.8 mg/kg/day based on 

decreases in body weights, absolute brain 

weights, brain measurements and motor 

activity in offspring.

Inhalation (All 

durations)

LOAEL = 8.8 

mg/kg/day

UFA= 10x

UFH=10x

UFL= 3x

Residential LOC for 

MOE = 300

Developmental Neurotoxicity Study - Rat.

LOAEL = 8.8 mg/kg/day based on 

decreases in body weights, absolute brain 

weights, brain measurements and motor

activity in offspring.

Cancer (oral, 

dermal, inhalation)

Classification: Group C- possible human with no quantification. The chronic risk assessment is considered 

to be protective of any cancer effects; therefore, a separate quantitative cancer risk assessment 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. 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. DAF = dermal absorption factor.
Page 23 of 32

Attachment 4

Toxicity Profile for Tebuconazole

Table A.4.1. Acute Toxicity Profile for Tebuconazole

Guideline No. Study Type MRID(s) Results Toxicity 

Category

870.1100 Acute oral [rat] 40700917 LD50 (fasted) = > 5000 mg/kg (M); 

3933 mg/kg (F);

(unfasted)=4264 mg/kg (M); 3352 

mg/kg (F)

III

870.1200 Acute dermal [rat] 40700917

41290801

LD50 = >5000 mg/kg (M & F) III

870.1300 Acute inhalation [rat] 40700922 LC50 (4 h, aerosol)= >371 mg/m3

LC50 (4 h, dust)= >5093 mg/ m3

II

870.2400 Acute eye irritation [rabbit] 40700925

40700917

Slight to Mild irritant III

870.2500 Acute dermal irritation 

[rabbit]

40700917

40995910

Non-irritant IV

870.2600 Skin sensitization 

[guinea pig]

40700928

41290802

No evidence of skin sensitization 

using the Buehler test

NA

Table A.4.2. Subchronic, Chronic and Other Toxicity Profile for Tebuconazole Technical.

Guideline No.

Study Type

MRID No. (year)

Doses/ Classification Results

870.3100

90-Day oral toxicity

- rat

40700930 (1986)

(0, 100, 400, 1600 ppm in diet); 

0, 8.6, 34.8, 171.7 mg/kg/d (m); 

0, 10.8, 46.5, 235.2 mg/kg/d (f)

Acceptable/guideline

Male: NOAEL = 34.8 mg/kg/d; LOAEL= 171.7 

mg/kg/d based on decreased body wt., body wt. 

gain, and histopathology findings.

Female: NOAEL=10.8 mg/kg/d, LOAEL= 46.5 

mg/kg/d based on histopathological changes in the 

adrenal gland.

870.3150

90-Day oral toxicity 

- dog

40700934 (1987)

(0, 200, 1000, 5000 ppm in diet); 

0, 73.7, 368.3, 1749.1 mg/kg/d 

(m);

0, 73.4, 351.8, 1724.8 mg/kg/d

(f)

Acceptable/guideline

NOAEL = 73.4/73.7 mg/kg/d (m/f)

LOAEL = 368.3/ 351.8 mg/kg/d (m/f) based on 

decreased body wt. gain, food consumption and 

increased liver enzyme activities.

870.3200

21/28-Day dermal 

toxicity - rabbit

40700937 (1984)

0, 50, 250, 1000 mg/kg/day

Acceptable/guideline

NOAEL = 1000 mg/kg/day.

No dermal or systemic toxicity was seen.

870.3465

21-Day inhalation 

toxicity 

- rat

40700938 (1985)

0, 1.2, 10. 6, 155.8 mg/m3

Acceptable/non-guideline

NOAEL = 10.6 mg/m3/day (≈2.0 mg/kg/day)

LOAEL = 155.8 mg/m3/d (≈28 mg/kg/day) based 

on clinical signs (bristling coat).

870.3700a

Prenatal developmental

- rat

40700943 (1988)

0, 30, 60 , 120 mg/kg/d, GD 6-15

Acceptable/guideline

Maternal NOAEL = 30 mg/kg/day

LOAEL=60 mg/kg/d based on increased liver 

wieght and liver/body weight ratios.

Developmental NOAEL=30 mg/kg/day 

LOAEL =60 mg/kg/d based on delayed 

ossification of several bones and increased 

numbers of fetuses with supernumerary ribs.
Page 24 of 32

Table A.4.2. Subchronic, Chronic and Other Toxicity Profile for Tebuconazole Technical.

Guideline No.

Study Type

MRID No. (year)

Doses/ Classification Results

870.3700a

Prenatal developmental

- rat (Dermal)

41450801 (1988)

0, 100, 300, 1000 mg/kg/d, GD 

6-15

Acceptable/guideline

Maternal NOAEL= 1000 mg/kg/d

Developmental NOAEL= 1000 mg/kg/d

No evidence of maternal or developmental toxicity 

seen via dermal route. 

870.3700a

Prenatal developmental

- mouse

40821501 (1988)

0, 10, 30, 100 mg/kg/d, GD 6-15 

40821500 (1988)

Supplementary study

0, 10, 20, 30, 100 mg/kg/d GD 6-

15 

Acceptable/guideline

Maternal NOAEL = 30 mg/kg/d

LOAEL = 100 mg/kg/d based on increased hepatic 

triglycerides, pale lobular liver, increased severity 

of hepatic vacuoles and lipidosis.

Developmental NOAEL = 10 mg/kg/d

LOAEL = 30 mg/kg/d based on increased number 

of runts.

870.3700a

Prenatal developmental

- mouse

43776201, 43776202(1995)

0, 10, 30, 100 mg/kg/d, GD 6-15 

Supplementary group

0, 1, 3 mg/kg/d GD 6-15

Acceptable/guideline

Maternal: NOAEL = 3 mg/kg/d

LOAEL = 10 mg/kg/d based on increased hepatic 

enzyme induction and severity of vacuolization in 

liver cells.

Developmental: NOAEL= 3 mg/kg/d

LOAEL=10 mg/kg/d based on increased external, 

visceral, and skeletal malformation/variation in the 

head and skull.

870.3700a

Prenatal developmental

- mouse (Dermal)

42010301 (1990)

0,100,300,1000 mg/kg/d GD 6-

15

Acceptable/guideline

Maternal NOAEL= 1000 mg/kg/d

Developmental NOAEL= 1000 mg/kg/d

No evidence of maternal or developmental toxicity 

seen via dermal route.

870.3700b

Prenatal developmental

- rabbit

40700945 (1987)

0, 10,30,100 mg/kg/d, GD 6-18

Acceptable/guideline

Maternal NOAEL = 30 mg/kg/d

LOAEL = 100 mg/kg/d based on decreased body 

weight gain and food consumption.

Developmental NOAEL = 30 mg/kg/d

LOAEL = 100 mg/kg/d based on increased 

resorptions and post-implantation losses, decreased 

live fetuses/doe, and external and skeletal 

abnormalities.

870.3700b

Prenatal developmental

- rabbit

43776201 (1995)

0, 10, 30, 100 mg/kg/day GD 6-

18

Acceptable/guideline

Maternal NOAEL = Not established (<10 

mg/kg/d)

LOAEL = 10 mg/kg/d based on increased 

incidence of single cell necrosis in liver cells.

Developmental NOAEL = 10 mg/kg/d

LOAEL = 30 mg/kg/d based on increased external 

and visceral malformation/variations.

870.3800

Reproduction and 

fertility effects

- rat

40700946 (1987)

0, 100, 300, 1000 ppm in diet 

(equivalent to 0, 5, 15, 50 

mg/kg/day)

Acceptable/guideline

Parental/Systemic NOAEL = 15 mg/kg/day (m & 

f)

LOAEL = 50 mg/kg/day based on increased 

severity of 

splenic hemosiderosis (m & f), increased incidence 

of splenic hematopoiesis (m), and decreased 

weight gain during gestation (f)

Reproductive NOAEL = 50 mg/kg/day

LOAEL = not determined

Offspring NOAEL = 15 mg/kg/day

LOAEL = 50 mg/kg/day based on decreased pup 

body wt.
Page 25 of 32

Table A.4.2. Subchronic, Chronic and Other Toxicity Profile for Tebuconazole Technical.

Guideline No.

Study Type

MRID No. (year)

Doses/ Classification Results

870.4300

Chronic/ 

carcinogenicity

- rat

40700939, 40816401 (1988)

0, 100, 300, 1000 ppm in diet; 

M: 0, 5.2, 15.9, 55 mg/kg/d;

F: 0, 7.4, 22.8, 86.3 mg/kg/d

Acceptable/guideline

Males: NOAEL = 15.9 mg/kg/d; LOAEL=55 

mg/kg/day based on decreased testes weight.

Females: NOAEL= 7.4 mg/kg/d; LOAEL=22.8 

mg/kg/day based on decreased body wt. & wt. 

gain, decreased erythrocyte parameters and 

increased incidence of splenic hemosiderosis 

(increased erythrocyte clearance).

No evidence of carcinogenicity at the doses tested.

870.4100b

Chronic toxicity 

- dog

40700940 (1987)

0, 40, 200, 1000/2000 ppm in 

diet; 

0, 15.5, 77.3, 483 mg/kg/d

Acceptable/guideline

NOAEL = 15.5 mg/kg/day

LOAEL = 77.3 mg/kg/day based on ocular lesions 

and changes in erythrocyte morphology 

(anisocytosis)

870.4100b

Chronic toxicity 

- dog

42030601 (main) (1989) & 

42537201 (suppl.) (1992); 

0, 100, 150 ppm; 

M: 0, 2.96, 4.39 mg/kg/d 

F: 0, 2.94, 4.45 mg/kg/d 

Acceptable/guideline together 

with 40700940

NOAEL = 2.96 mg/kg/day (m), 2.94 mg/kg/d (f)

LOAEL = 4.39 mg/kg/day (m), 4.45 mg/kg/d (f) 

based on lesions in the adrenal gland.

870.4200b

Carcinogenicity

- mouse

40700941 (1988)

0, 20, 60, 180 ppm in diet; 

M: 0, 5.9, 18.2, 53.1 mg/kg/d

F: 0, 9.0, 26.1, 80.5 mg/kg/d

42175001

0, 500, 1500 ppm

M: 0, 84.9, 279 mg/kg/day

F: 0, 103.1, 365.5 mg/kg/day

Acceptable/guideline

Male mice had statistically significant, doserelated increasing trends in hepatocellular 

adenomas, carcinomas and combined adenomas 

and/or carcinomas. There were also statistically 

significant differences in the pair-wise 

comparisons of the controls with the 1500 ppm 

dose group for hepatocellular adenomas (29% vs. 

5% controls), hepatocellular carcinomas (21% vs. 

0% controls) and combined adenomas and/or 

carcinomas (47% vs. 5% controls).

870.5100 

Salmonella point 

mutation

40700947 & 40700948 (1988)

Acceptable/guideline

Negative with or without activation at doses 

ranging from 39.5 to 450 μg/plate

870.5300

CHO-HGPRT forward 

mutation

40700949 (1988)

Unacceptable/guideline

Negative with or without activation at 

concentrations ranging from 12.5-200 and 80-100 

μg/mL, respectively; highest concentration tested 

did not produce high level of cytotoxicity.

870.5375 

In vitro Cytogenetics 

(human lymphocytes)

40700953 (1988)

Acceptable with activation; 

Unacceptable without activation

Negative for chromosome aberrations with 

activation (30-300 μg/mL) and without activation 

(10-300 μg/mL); highest dose not cytotoxic 

without activation.

870.5395

Mammalian erythrocyte 

micronucleus

40700951 (1985)

Acceptable/guideline

Negative at all doses up to 2000 mg/kg bw

870.5450

Mouse dominant 

lethality

40700950 (1986)

Unacceptable/guideline

Negative at 2000 mg/kg bw (only dose tested) 

during 12 serial mating periods; positive control 

was not included

870.5500

DNA damage and 

repair (E.coli)

40700955 (1983)

Unacceptable/guideline

Negative with or without activation at 

concentrations ranging from 625-10,000 μg/plate); 

no growth inhibition zone detected
Page 26 of 32

Table A.4.2. Subchronic, Chronic and Other Toxicity Profile for Tebuconazole Technical.

Guideline No.

Study Type

MRID No. (year)

Doses/ Classification Results

870.5550

Unscheduled DNA 

synthesis (rat 

hepatocytes)

40816402 (1988)

Acceptable/guideline

No evidence of an increase in unscheduled DNA 

synthesis at 0.504-25.2 μg/mL

870.5900

Sister chromatid 

exchange (CHO cells in 

vitro)

40700952 (1987)

Acceptable/guideline

Negative with and without activation with S9 at 

concentrations ranging from 4-30 μg/mL and 15-

120 μg/mL, respectively.

870.6200a 

Acute neurotoxicity 

screening battery 

-rat

44449301, 44545701 (1997)

0, 21, 50, 103, 497, 950 mg/kg

Unacceptable/Guideline

(Upgradeable)

NOAEL = 50 mg/kg/day

LOAEL = 100 mg/kg/day based on increased 

motor activity in males and females and decreased 

footsplay in females.

870.6200b 

Subchronic 

neurotoxicity screening 

battery 

-rat

44588001 (1998)

0, 100, 400, or 1600 ppm 

M: 0.00, 7.57, 29.2, 107 

mg/kg/day F: 0.00, 8.81, 34.0, 

122 mg/kg/day

Unacceptable/Guideline

(Not upgradeable)

NOAEL = 107 mg/kg/day

LOAEL = Not determined [>107 mg/kg/day]

870.6300

Developmental 

neurotoxicity 

-rat

45074301 (2000)

0, 100, 300, 1000 ppm 

[GD/LD 0/0, 8.8/16.3, 22/41.3, 

65/125.4 to dams], GD6 to LD11

Acceptable/Guideline

Maternal NOAEL = 22 mg/kg/day

LOAEL = 65 mg/kg/day based on decreased body 

weight, body weight gain, and food consumption; 

prolonged gestation with mortality, increased 

number of dead fetuses.

Offspring NOAEL = <8.8 mg/kg/day

LOAEL = 8.8 mg/kg/day based on decreased body 

weight, decreased absolute brain weights and brain 

measurements, and decreased motor activity.

870.7485

Metabolism

- rat

40995911, 40995912 (1987)

Acceptable/guideline

98.1% of oral dose is absorbed. Over 87% of dose 

excreted in urine & feces within 72 hours after 

dosing. At sacrificed (72 hrs postdosing) total 

residue (minus GI tract) amounted to 0.63% of the 

dose. A total of 10 compounds were identified in 

excreta. A large fraction of the identified 

metabolites corresponded to successive oxidation 

steps of a methyl group of tebuconazole. At higher 

dose 920 mg/kg) changes in detoxification patterns 

may result from metabolic saturation.

870.7600

Dermal penetration

- monkey

46634901 (2003)

132 μg/cm2tebuconazole in 

Folicur EW250, single 8 hr 

administration

Acceptable/nonguideline

Estimated dermal absorption 23.1%. (including the 

fraction of the dose absorbed and the amount of 

dose remaining in the skin after washing).

Literature study: 

Developmental 

neurotoxicity 

/immunotoxicity

45486901 (2001), 45591701 

(2002), 46146701 (2003)

0, 6, 20, 60 mg/kg (gavage) 

GD14-PND7 to dams, PND7-42 

to offspring

Study evaluated reproductive, immuno-, and 

neurotoxicity in offspring. Identified one effect of 

concern: learning deficits in high dose offspring, 

evaluated starting on PND74. Neuropathological 

effects identified in the original study were 

retracted based on a pathology peer-review.
Page 27 of 32

Table A.4.2. Subchronic, Chronic and Other Toxicity Profile for Tebuconazole Technical.

Guideline No.

Study Type

MRID No. (year)

Doses/ Classification Results

870.7800

Immunotoxicity

48769501 (2012)

Acceptable/Guideline

Doses: 0, 100, 300, 1000 ppm

0, 8.1, 24.3, 78.4 mg/kg/day

Systemic: NOAEL = 78.4 mg/kg/day

 LOAEL > 78.4 mg/kg/day

Immunotoxicity: NOAEL = 78.4 mg/kg/day

 LOAEL = 78.4 mg/kg/day
Page 28 of 32

Attachment 5

Toxicology Data Requirements

The requirements (40 CFR §158.340) for food and non-food uses for Tebuconazole are in Table 

1. Use of the new guideline numbers does not imply that the new (1998) guideline protocols 

were used.

Table A.5.1 Toxicology Data Requirements for Tebuconazole

Test 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

CR

yes

yes

yes

yes

no

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 ...................................................

no

yes

no

yes

yes

no

yes

—

yes

yes

870.5100 Mutagenicity—Gene Mutation - bacterial.....................

870.5300 Mutagenicity—Gene Mutation - mammalian ...............

870.5xxx Mutagenicity—Structural Chromosomal Aberrations...

870.5xxx Mutagenicity—Other Genotoxic Effects.......................

yes

yes

yes

yes

yes

yes

870.6100a Acute Delayed Neurotox. (hen).....................................

870.6100b 90-Day Neurotoxicity (hen) ..........................................

870.6200a Acute Neurotox. Screening Battery (rat).......................

870.6200b 90-Day Neuro. Screening Battery (rat) .........................

870.6300 Develop. Neuro .............................................................

no

no

yes

yes

yes

—

—

yes

yes

yes

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

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

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

yes

no

yes

yes

yes

yes

Special Studies for Ocular Effects

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

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

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

no

no

no

no

no

no

 

+

: 21-day inhalation toxicity study is available.
Page 29 of 32

Attachment 6

Tolerance/MRL Table

International Residue Limits 

Summary of US and International Tolerances and Maximum Residue Limits 

Residue Definition:

US Canada Mexico1 Codex2

40 CFR §180.474(a) General. (1) 

Compliance with the tolerance levels 

specified below is to be determined by 

measuring only tebuconazole [α-[2-(4-

chlorophenyl)ethyl]-α-(1,1-

dimethylethyl)-1H-1,2,4-triazole-1-

ethanol]

α-[2-(4-

chlorophenyl)ethyl]-

α-(1,1-

dimethylethyl)-1H1,2,4-triazole-1-

ethanol

Tebuconazole

The residue is fat-soluble.

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

US Canada Mexico1 Codex2

Almond, hulls 6.0

Apple, wet pomace 0.1

Asparagus 0.05

Banana 0.05 0.03 0.05

Barley, grain 0.3 0.3 2

Barley, hay 7.0

Barley, straw 3.5 40

Bean, dry seed 0.1 0.3

Bean, succulent 0.1

Beet, garden, roots 0.70

Beet, garden, tops 7.0

Brassica, leafy greens, 

subgroup 5B

2.5

Cherry, sweet, pre- and postharvest5.0 3 cherry 4 cherries

Cherry, tart, pre- and postharvest5.0

Coffee, green bean1 0.15 0.1 coffee beans

Coffee, roasted bean1 0.3

Corn, field, forage 4.0

Corn, field, grain 0.05 0.05

Corn, field, stover 3.5

Corn, pop, grain 0.05

Corn, pop, stover 3.5

Corn, sweet, forage 7.0

Corn, sweet, kernel plus cob 

with husks removed

0.5 0.5 0.6

Corn, sweet, stover 6.0

Cotton, gin byproducts 25.0

Cotton, undelinted seed 2.0 2

Fruit, pome, group 11 0.05 1 apple, pear, 

Fruit, stone, group 12, except 

cherry

1.0 1 nectarines, peaches 2 apricot, nectarine, peach, 

1 plums (except prunes) 

3 prunes
Page 30 of 32

Summary of US and International Tolerances and Maximum Residue Limits 

Residue Definition:

US Canada Mexico1 Codex2

Grain, aspirated fractions 16.0

Grape 5.0 5 6

7 dried grapes (=currants, 

raisins and sultanas)

Grass, forage 8.0

Grass, hay 25.0

Grass, seed screenings 55.0

Grass, straw 30.0

Hop, dried cones 35.0 40

Lychee 1.6

Mango, postharvest 0.15 0.05 mango

Nut, tree, group 14 0.05 0.05 0.05 (*)

Oat, forage 0.10

Oat, grain 0.15 0.15 2

Oat, hay 0.10

Oat, straw 0.10

Onion, bulb, subgroup 3-07A 0.2 0.1 garlic, onion bulb

Onion, green, subgroup 3-

07B

1.3 0.7 leek

Orange1 1.0

Orange, oil1 10

Peach 1.0 1 2

Peanut 0.1 0.15

40 peanut fodder

Pistachio 0.05 0.05 0.05 (*) tree nuts

Plum, pre- and post-harvest 1.0 1 (except prunes)

Soybean, forage 25

Soybean, hay 50

Soybean, seed 0.08 0.08 0.15

Sunflower, seed 0.05

Sunflower, meal 0.2

Sunflower, refined oil 0.2

Vegetable, cucurbit, group 9 0.4 0.4 0.15 cucumber, melons 

(except watermelon), 

0.2 squash summer

0.1 watermelon (proposed)

Vegetable, fruiting, group 8-

10

1.3 0.1 Eggplant

10 peppers, chili, dried

1 peppers sweet (including 

pimento or pimiento)

0.7 tomato

Wheat, forage 3.0

Wheat, germ 0.20

Wheat, grain 0.15 0.15 0.15 wheat, triticale

Wheat, hay 7.0

Wheat, shorts 0.20

Wheat, straw 1.5 40

MRLs with NO US Equivalent

Artichoke 0.6

Broccoli 0.2
Page 31 of 32

Summary of US and International Tolerances and Maximum Residue Limits 

Residue Definition:

US Canada Mexico1 Codex2

Brussels sprouts 0.3

Cabbages, head 1

Carrot 0.4

Cauliflower 0.05 (*)

Common bean (pods and/or 

immature seeds) (proposed)

2 (proposed)

Elderberries 1.5

Lettuce, head 5

Olives 0.05 (*)

Papaya 2

Passion fruit 0.1

Rapeseed 0.3

Rice 1.5

Rye 0.15

Rye straw and fodder, dry 40

(2) Compliance with the tolerance levels 

specified in the following table is to be 

determined by measuring only the sum of 

tebuconazole (alpha-[2-(4-

chlorophenyl)ethyl]-alpha-(1,1-

dimethylethyl)-1H-1,2,4-triazole-1-

ethanol) and its diol metabolite (1-(4-

chlorophenyl)-4,4-dimethyl-3-(1H-1,2,4-

triazole-1-yl-methyl)-pentane-3,5-diol), 

calculated as the stoichiometric 

equivalent of tebuconazole

α-[2-(4-

chlorophenyl)ethyl]-

α-(1,1-

dimethylethyl)-1H1,2,4-triazole-1-

ethanol, including the 

metabolite 5-(4-

chlorophenyl)-2,2-

dimethyl-3-(1H1,2,4-triazol-1-

ylmethyl)-1,3-

pentanediol

Tebuconazole

The residue is fat-soluble.

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

US Canada Mexico1 Codex2

Cattle, meat byproducts 0.2 0.2 0.05 (*)

Goat, meat byproducts 0.2 0.2 0.05 (*)

Horse, meat byproducts 0.2 0.2 0.05 (*)

Milk 0.1 0.1 0.01 (*)

Sheep, meat byproducts 0.2 0.2 0.2

MRLs with NO US Equivalent

Eggs 0.1 0.05 (*)

Meat byproducts of hogs 0.2 0.2

Meat byproducts of poultry 0.1 0.05 (*)

Meat of (cattle, goats, hogs, 

horses, sheep)

0.2 0.05 (*)

Meat of poultry 0.1 0.05 (*)

M. Negussie; 10/08/15

1There are no U.S. registrations.

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

3* = 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.

(c) Tolerances with regional registrations. Tolerances are established for residues of the fungicide tebuconazole, 

including its metabolites and degradates, in or on the commodities in the following table. Compliance with the 
Page 32 of 32

tolerance levels specified below is to be determined by measuring only tebuconazole, alpha-[2-(4-

chlorophenyl)ethyl]-alpha-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol, in or on the commodity.

Commodity Parts per million

Turnip, roots 0.5

Turnip, tops 7.0