Tebuconazole (Ref: HWG 1608)

Tebuconazole (Ref: HWG 1608)	Last updated: 24/10/2024
(Also known as: fenetrazole; terbuconazole; terbutrazole; ethyltrianol)

SUMMARY

Data alerts

The following alerts are based on the data in the tables below. An absence of an alert does not imply the substance has no implications for human health, biodiversity or the environment but just that we do not have the data to form a judgement.

Environmental fate	Ecotoxicity	Human health
Environmental fate Moderate alert: Moderately persistent; GUS: Transition state; Drainflow: Slightly mobile; Potential for particle bound transport: Medium	Ecotoxicity High alert: Birds chronic ecotoxicity: High	Human health High alert: Endocrine disrupter

GENERAL INFORMATION

Description

A fungicide effective against various foliar diseases in cereals and other field crops

Example pests controlled

Smut; Bunt; Stripe rust; Yellow leaf spot; Powdery mildew; Scelerotinia rot; Black spot; Net blotch

Example applications

Cereals including wheat, barley, oat, rye; Grapes; Peanuts; Vegetables including onions, peas, pepper; Bananas; Sugarcane

Efficacy & activity

Wheat/Mildew=Low; Wheat/Septoria=Low; Wheat/Rust=High; Wheat/Ear blight=Moderate; Barley/Rhynchosporium=Low; Barley/Net blotch=Low; Barley/Ramularia=Low; Corn/Northern leaf blight=High; Corn/Rust=Low

Availability status

Current

Introduction & key dates

1986, first reported; 1988, first introduced South Africa

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

31/08/2028

UK LERAP status

Probably - see product label

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Denmark

Date EC 1107/2009 inclusion expires

15/08/2026

EU Candidate for substitution (CfS)

Yes - two 'Persistent-Bioaccumulative-Toxic' criteria

Listed in EU database

Yes

Approved for use (✓) under EC 1107/2009 in the following EU Member States

ATAustria	BEBelgium	BGBulgaria	CYCyprus	CZCzech Republic	DEGermany	DKDenmark	EEEstonia	ELGreece
✓	✓	✓	✓	✓	✓	✓	✓	✓
ESSpain	FIFinland	FRFrance	HRCroatia	HUHungary	IEIreland	ITItaly	LTLithuania	LULuxembourg
✓	✓	✓	✓	✓	✓	✓	✓	✓
LVLatvia	MTMalta	NLNetherlands	PLPoland	PTPortugal	RORomania	SESweden	SISlovenia	SKSlovakia
✓	✓	✓	✓	✓	✓	✓	✓	✓

Approved for use (✓) under EC 1107/2009 by Mutual Recognition of Authorisation and/or national regulations in the following EEA countries

ISIceland	NONorway
	✓

Additional information

Also used in

Australia, Egypt, Morocco

Chemical structure

Isomerism

A chiral molecule. The technical material is an isomeric mixture of the (S-) and (R-) isomers. The R-form is more biologically active than the S-form.

Chemical formula

C₁₆H₂₂ClN₃O

Canonical SMILES

CC(C)(C)C(CCC1=CC=C(C=C1)Cl)(CN2C=NC=N2)O

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

PXMNMQRDXWABCY-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C16H22ClN3O/c1-15(2,3)16(21,10-20-12-18-11-19-20)9-8-13-4-6-14(17)7-5-13/h4-7,11-12,21H,8-10H2,1-3H3

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
tebuconazole	Unstated isomer

General status

Pesticide type

Fungicide, Plant Growth Regulator, Other substance

Other bioactivity & uses

Biocide, Wood preservative, Construction material preservative

Substance groups

Triazole fungicide; Conazole fungicide

Minimum active substance purity

905 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Systemic with protective, curative and eradicant action. Disrupts membrane function. Sterol biosynthesis inhibitor.

CAS RN

107534-96-3

EC number

403-640-2

CIPAC number

494

US EPA chemical code

128997

PubChem CID

86102

CLP index number

603-197-00-7

Molecular mass

307.82

PIN (Preferred Identification Name)

rac-(3R)-1-(4-chlorophenyl)-4,4-dimethyl-3-(1H-1,2,4-triazol-1-ylmethyl)pentan-3-ol

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

Other status information

Some applications may be approved under GB Biocides Products Regulations

Relevant Environmental Water Quality Standards

Herbicide Resistance Class (HRAC MoA class)

Not applicable

Herbicide Resistance Class (WSSA MoA class)

Not applicable

Insecticide Resistance Class (IRAC MoA class)

Not applicable

Fungicide Resistance Class (FRAC MOA class)

Examples of recorded resistance

Physical state

Colourless crystals

Formulations

Property

Value

Example manufacturers & suppliers of products using this active now or historically

AgriGuard
Bayer CropScience
Headland
Makhteshim-Agan
Nufarm
Syngenta

Example products using this active

Alpha Tebuconazole
Bezel
Cello
Coronet
Folicur
Grail
Kestrel
Mystique
Nativo
Riza
Sage
Silvacur
Raxil S
Seedron

Formulation and application details

Often supplied as an oil in water emulsion or concentrate that is mixed with water and used as a spray

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

Solubility - In water at 20 °C (mg l⁻¹)

Low

Solubility - In organic solvents at 20 °C (mg l⁻¹)

200000

Dichloromethane

n-Hexane

57000

Toluene

96000

Octanol

Melting point (°C)

105

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

350

Flashpoint (°C)

Octanol-water partition coefficient at pH 7, 20 °C

5.01 X 10⁰³

Calculated

Log P

3.7

High

Fat solubility of residues

Solubility

Likely to be soluble

Data type

Based on chemical group

Density (g ml⁻¹)

1.25

Dissociation constant pKa) at 25 °C

5.0

2013 Peer reviewed literature 5.0

Vapour pressure at 20 °C (mPa)

1.30 X 10^-03

Low volatility

Henry's law constant at 25 °C (Pa m³ mol⁻¹)

1.00 X 10^-05

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

24 hr

From soil surface

Negligible

24 hr

Maximum UV-vis absorption L mol⁻¹ cm⁻¹

Neutral solution: 221.4nm = 11980, 262.0nm = 304, 268.5nm = 408, 276.5nm = 368, 290.0nm <10

Surface tension (mN m⁻¹)

64.26

at 20°C 28.8mg l⁻¹

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

Moderately persistent

DT₅₀ (lab at 20 °C)

365

Very persistent

DT₅₀ (field)

47.1

Moderately persistent

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

177

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀ >365 days, Field studies DT₅₀ range 25.8-91.6 days, DT₉₀ range 66-304 days; Other sources: DT₅₀ 610 days (DW4)

Dissipation rate RL₅₀ (days) on plant matrix

Value

2.7

Note

Published literature RL₅₀ range 1.4-3.3 days, fruit from 2 field grown crops, n=2

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

9.9

Note

Published literature RL₅₀ range 1.0-59.4 days, 18 field & undercover grown crops, various matrices, n=28; Outlier - RL₅₀ peppers in cold storage = 106 days

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Stable

Note

No significant photolytic degradation

Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7

Value

Stable

Note

Stable pH 5 to pH 9, at 25 °C, 28 days

Water-sediment DT₅₀ (days)

365

Stable

Water phase only DT₅₀ (days)

42.6

Stable

Air degradation

As this parameter is not normally measured directly, a surrogate measure is used: ‘Photochemical oxidative DT₅₀’. Where data is available, this can be found in the Fate Indices section below.

Decay in stored produce DT₅₀

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d (mL g⁻¹)

K_oc (mL g⁻¹)

Notes and range

Freundlich

K_f (mL g⁻¹)

12.69

Slightly mobile

K_foc (mL g⁻¹)

769

¹/_n

0.84

Notes and range

EU dossier K_f range 7.67-15.86 mL g⁻¹, K_foc range 102-1249 mL g⁻¹, ¹/_n range 0.711-1.179; Other literature: Mean of 4 soils. Sandy loam - Sand 67% Silt 27% Clay 6% OC=1.4% pH=5.2 K_f=12.7; Silt - Sand 2% Silt 89% Clay 9% OC=1.8% pH=5.3 K_f=16.4; Sand - Sand 87.8% Silt 8.7% Clay 3.5% OC=0.75% pH=5.6 K_f=7.69; Sandy loam - Sand 58.6% Silt 28.1% Clay 13.2% OC=1.27% p

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

1.86

Calculated

Transition state

SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate

Value

6.46 X 10^-02

Calculated

Note

Potential for particle bound transport index

Medium

Calculated

Potential for loss via drain flow

Slightly mobile

Calculated

Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk

62.4

Calculated using the Atkinson method. Assumed 0.5E+06 OH/cm³, 24 hr

Substance of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

Whole fish

Low potential

CT₅₀ (days)

Known soil metabolites

Metabolite

Major/Minor fraction

$Click here for further information on Major/Minor fraction$

Estimated maximum occurrence fraction

Notes

1,2,4-triazole (Ref: CGA 71019)

Minor fraction

0.09

Bayer verified

Known groundwater metabolites

Metabolite

EC SANCO/221/2000 relevancy

ADI (mg kg⁻¹ bodyweight day⁻¹)

WHO drinking water guidance value (μg L⁻¹ day⁻¹)

1,2,4-triazole (Ref: CGA 71019)

Relevant

0.023

138

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

5-(4-chlorophenyl)-2,2-dimethyl-3-(1H-1,2,4-triazol-1-ylmethyl)pentane-1,3-diol

hydroxy-tebuconazole

Plant

2-chloro-5-[4-hydroxy-5,5-dimethyl-3-(1H-1,2,4-triazol-1-yl)hexyl]phenol

tebuconazole-m-hydroxy

Plant

(R,S)-2-amino-3-(1H-1,2,4-triazol-1-yl)propanoic acid, or 3-(1H-1,2,4-triazol-1-yl)-D,L-alanine

triazole alanine

Plant

2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propanoic acid

triazole lactic acid

Plant

1H-1,2,4-triazol-1-ylacetic acid

triazole acetic acid

Plant

5-(4-chlorophenyl)-3-hydroxy-2,2-dimethyl-3-(1H-1,2,4-triazol-1-ylmethyl)pentanoic acid

tebuconazole-carboxylic acid

Animal

5-tert-butyl-5-(1H-1,2,4-triazol-1-ylmethyl)dihydrofuran-2(3H)-one

HWG 1608-lactone

Surface water (Photolysis); Surface water/sediment

4-hydroxy-5,5-dimethyl-4-(1H-1,2,4-triazol-1-ylmethyl)hexanoic acid

HWG 1608-pentanoic acid

Surface water (Photolysis); Surface water/sediment

sodium 5-(4-chlorophenyl)-3-hydroxy-2,2-dimethyl-3-(1H-1,2,4-triazol-1-ylmethyl)pentyl sulfate

hydroxy-tebuconazole-sulphate

Animal

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

1700

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

> 10.8

Rat

High

(ppm diet)

> 100

Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)

72.3

Unknown species Reproduction

Moderate

Birds - Acute LD₅₀ (mg kg⁻¹)

1988

Colinus virginianus

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

> 703 mg kg bw⁻¹ day⁻¹

Colinus virginianus

Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)

5.8

Colinus virginianus

High

Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)

1381

Eisenia foetida

Low

Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)

Eisenia foetida 56 day

Moderate

Soil micro-organisms

Nitrogen mineralisation: No significant adverse effect
Carbon mineralisation: No significant adverse effect

Dose: 6.25 kg ha⁻¹

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

250

Folsomia candida

Non-target plants

> 750

Lepidium sativum
Seedling emergence, ER₅₀
as kg ha⁻¹

> 10.5

Lepidium sativum
Vegetative vigour, ER₅₀
as kg ha⁻¹

Honeybees (Apis spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

> 200

Apis mellifera

Low

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

> 83.05

Apis mellifera

Moderate

Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Chronic

Bumblebees (Bombus spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Mason bees (Osmia spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Other bee species (1)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

Other bee species (2)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

Beneficial insects (Ladybirds) as Mortality LD₅₀ g ha⁻¹

158

Coccinella septempunctata Larva

Beneficial insects (Lacewings)

Beneficial insects (Parasitic wasps) as Mortality LR₅₀ g ha⁻¹

62.5

Aphidius rhopalosiphi

Beneficial insects (Predatory mites) as Mortality LR₅₀ g ha⁻¹

58.0

Typhlodromus pyri

Beneficial insects (Ground beetles)

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Temperate Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

4.4

Oncorhynchus mykiss

Moderate

Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)

0.010

Oncorhynchus mykiss

Moderate

Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

> 18.41

Danio rerio

Moderate

Temperate Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)

2.79

Daphnia magna

Moderate

Temperate Freshwater Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)

0.01

Daphnia magna

Moderate

Tropical Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)

Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)

0.46

Mysidopsis bahia

Moderate

Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)

1.899

Chironomus dilutus

Moderate

Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l⁻¹)

2.51

Chironomus riparius EC15

Moderate

Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg⁻¹)

42.9

Chironomus riparius EC15

Moderate

Aquatic plants - Acute 7 day EC₅₀, biomass (mg l⁻¹)

0.144

Lemna gibba

Moderate

Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)

1.96

Scenedesmus subspicatus

Moderate

Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)

0.1

Unknown species

Moderate

Mesocosm study data

NOEAEC mg l⁻¹

HUMAN HEALTH AND PROTECTION

General

Property

Value

Source; quality score; and other information

Interpretation

Threshold of Toxicological Concern (Cramer Class)

High (class III)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

1700

Rat

Moderate

Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 5.09

Rat 4 hr (nose only)

Other Mammal toxicity endpoints

ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)

0.03

Dog SF=100

ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)

0.03

Mouse SF=300

AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)

AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)

0.03

Dog SF=100

Dermal penetration studies (%)

Dangerous Substances Directive 76/464

Exposure Routes

Public

Acceptable risk for bystanders

Occupational

Operator and other worker exposure acceptable for proposed uses

MRLs

European

EU MRL pesticide database

Great Britain

GB MRL Register

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

0.1

EU Dir 89/778/EC limit

Mammalian dose elimination route and rate

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

Targets liver/blood system
US EPA - possible human carcinogen

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
IMDG Transport Hazard Class 9
Not expected to auto-ignite; Not highly flammable

CLP classification 2013

Health: H302, H361d
Environment: H411

WHO Classification

II (Moderately hazardous)

UN Number

UN3077

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

tebuconazole

French

tebuconazole

German

Tebuconazol

Danish

tebuconazol

Italian

tebuconazolo

Spanish

tebuconazol

Greek

Polish

tebukonazol

Swedish

tebukonazol

Hungarian

tebukonazol

Dutch

tebuconazool

Norwegian

tebukonazol

Record last updated:	24/10/2024
Contact:	aeru@herts.ac.uk
Please cite as:	Lewis, K.A., Tzilivakis, J., Warner, D. and Green, A. (2016) An international database for pesticide risk assessments and management. Human and Ecological Risk Assessment: An International Journal, 22(4), 1050-1064. DOI: 10.1080/10807039.2015.1133242