Fenbuconazole (Ref: RH 7592)

Fenbuconazole (Ref: RH 7592)	Last updated: 19/01/2021
(Also known as: fenethanil; RH 57592)

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 High alert: Potential for particle bound transport: High	Ecotoxicity Moderate alert: Birds chronic ecotoxicity: Moderate; Fish acute ecotoxicity: Moderate; Fish chronic ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate; Daphnia chronic ecotoxicity: Moderate; Bees acute contact ecotoxicity: Moderate; Bees acute oral ecotoxicity: Moderate; Earthworms acute ecotoxicity: Moderate; Earthworms chronic ecotoxicity: Moderate	Human health High alert: Mammals chronic toxicity: High

GENERAL INFORMATION

Description

A fungicide used to control a range of diseases including powdery mildew, black rot and scab

Example pests controlled

Powdery mildew, Black rot, Scab, Rusts, Smuts, Leaf spots

Example applications

Cereals; Vines; Top fruit; Stone fruit; Bananas; Pecans; Rice

Efficacy & activity

Availability status

Current

Introduction & key dates

1992, Europe

UK regulatory status

UK COPR regulatory status

Not approved

Date COPR inclusion expires

Not applicable

UK LERAP status

None

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Sovenia/UK

Date EC 1107/2009 inclusion expires

30/04/2021

EU Candidate for substitution (CfS)

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
	✓		✓	✓

Also used in

Australia, USA, Latin America, Asia, Africa

Chemical structure

Isomerism

A chiral molecule, fenbuconazole is a racemate of the R- and S-forms

Chemical formula

C₁₉H₁₇ClN₄

Canonical SMILES

C1=CC=C(C=C1)C(CCC2=CC=C(C=C2)Cl)(CN3C=NC=N3)C#N

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

RQDJADAKIFFEKQ-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C19H17ClN4/c20-18-8-6-16(7-9-18)10-11-19(12-21,13-24-15-22-14-23-24)17-4-2-1-3-5-17/h1-9,14-15H,10-11,13H2

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
fenbuconazole	Unstated isomer

General status

Pesticide type

Fungicide

Substance group

Triazole

Minimum active substance purity

965 g kg⁻¹ (50:50 racemic mixture)

Known relevant impurities

EU dossier: none declared

Substance origin

Synthetic

Mode of action

Systemic protectant and curative, acts by inhibiting sterol biosynthesis in fungi.

CAS RN

114369-43-6

EC number

406-140-2

CIPAC number

694

US EPA chemical code

129011

PubChem CID

86138

Molecular mass

336.82

PIN (Preferred Identification Name)

rac-(2R)-4-(4-chlorophenyl)-2-phenyl-2-(1H-1,2,4-triazol-1-ylmethyl)butanenitrile

IUPAC name

4-(4-chlorophenyl)-2-phenyl-2-(1H-1,2,4-triazol-1-ylmethyl)butyronitrile

CAS name

α-(2-(4-chlorophenyl)ethyl)-a-phenyl-1H-1,2,4-triazole-1-propanenitrile

Other status information

Relevant Environmental Water Quality Standards

Herbicide Resistance Classification (HRAC)

Not applicable

Herbicide Resistance Classification (WSSA)

Not applicable

Insecticide Resistance Classification (IRAC)

Not applicable

Fungicide Resistance Classification (FRAC)

Examples of recorded resistance

Physical state

Colourless to off-white crystalline powder

Related substances & organisms

dinocap

Formulations

Property

Value

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

Indar 5EW
Enable
Impala
Agrovista Radni

Example products using this active

Dow AgroSciences
Landseer
Agrovista

Formulation and application details

Often supplied as a oil emulsion which is mixed with water and applied as a spray

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

2.47

Low

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

132000

Ethyl acetate

250000

Acetone

680

n-Heptane

26000

Xylene

Melting point (°C)

126.5

Boiling point (°C)

Degradation point (°C)

360

exothermic decomposition above this temperature

Flashpoint (°C)

Not expected to self ignite; Not highly flammable

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

6.17 X 10⁰³

Calculated

Log P

3.79

High

Bulk density (g ml⁻¹)

1.28

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

Vapour pressure at 20 °C (mPa)

3.4 X 10^-04

Low volatility

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

3.01 X 10^-05

Non-volatile

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

Neutral solution 195nm = 35600
Acidic solution 200nm = 20600
Basic solution 217nm = 12100

Surface tension (mN m⁻¹)

69.5

at 22°C

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)

152

Persistent

DT₅₀ (field)

Moderately persistent

DT₉₀ (lab at 20 °C)

659

Very persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀ range 33-590 days, DT₉₀ range 109-1219 days, field studies DT₅₀ range 6-98 days ; Other studies DT₅₀ (1) lab data - no degradation after 363 days, field study range 28-84 days (B3), (2) 247 days (DW4)

Dissipation rate RL₅₀ on plant matrix

Value

Note

Dissipation rate RL₅₀ on and in plant matrix

Value

10.2

Note

Published literature RL₅₀ range 5.7-14.7 days, 2 field & undercover grown fruit, n=2

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Stable

Note

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

Value

Stable

Note

Stable pH 5 to pH 9

Water-sediment DT₅₀ (days)

3.4

Fast

Water phase only DT₅₀ (days)

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

K_oc

Notes and range

Freundlich

K_f

Non-mobile

K_foc

4425

¹/_n

1.00

Notes and range

EU dossier: K_f range 5.1-115.4 mL g⁻¹, K_foc range 2185-9043 mL g⁻¹, ¹/_n range 0.845-1.222, Soils=5

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

0.63

Calculated

Low leachability

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

Value

1.22 X 10^-02

Calculated

Note

Potential for particle bound transport index

High

Calculated

Potential for loss via drain flow

Non-mobile

Calculated

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

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

Soil

0.124

Major fraction, Relevant

cis-5-(4-chlorophenyl)-dihydro-3-phenyl-3-(1H-1,2,4-triazole-1-ylmethyl)-2-3H-furanone (Ref: RH-9129)

Soil

0.097

Minor fraction, Relevant

4-(4-chlorophenyl)-2-(methyl-1H-1,2,4-triazole)-4-oxo-2-phenylbutanenitrile (Ref: RH-6467)

Soil

0.056

Minor fraction, Relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

(2RS)-4-(4-chloro-3-hydroxyphenyl)-2-phenyl-2-(1H-1,2,4-triazol-1-ylmethyl)butanenitrile (Ref: RH 4911)
Note: Toxicologically relevant

hydroxy phenol fenbuconazole

Plant

(2RS)-4-(4-chlorophenyl)-2-(hydroxymethyl)-2-phenylbutanenitrile (Ref: RH 7968)

Animal

(2RS)-4-(4-chlorophenyl)-2-(4-hydroxyphenyl)-2-(1H-1,2,4-triazol-1-hydroxyphenyl)-2-(1H-1,2,4-triazol-1- (Ref: RH 1311)

4-phenol fenbuconazole

Animal

3-(1H-1,2,4-triazol-1-yl)-DL-alanine (Ref: RH 3968)
Note: Toxicologically relevant

triazole alanine

Plant

1H-1,2,4-triazol-1-ylacetic acid (Ref: RH 4098)
Note: Toxicologically relevant

TAA; Triazole acetic acid

Rat

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

160

Whole fish

Threshold for concern

CT₅₀ (days)

1.4

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 2000

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

> 1.4

Rat

High

(ppm diet)

> 20

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

Rat Reproductive NOAEL

High

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2150

Colinus virginianus

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

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

Anas platyrhynchos

Moderate

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

1.5

Oncorhynchus mykiss

Moderate

Fish - Chronic 21 day NOEC (mg l⁻¹)

0.32

Oncorhynchus mykiss

Moderate

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

2.3

Daphnia magna

Moderate

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

0.078

Daphnia magna

Moderate

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

0.75

Americamysis bahia

Moderate

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

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

1.73

Chironomus riparius

Moderate

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

8.0

Chironomus riparius

Moderate

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

Non-target plants

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

0.33

Pseudokirchneriella subcapitata

Moderate

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

0.18

Unknown species

Moderate

Honeybees (Apis spp.)

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

> 5.5

Moderate

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

> 5.2

Moderate

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

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 pollinators (1)

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

Mode of exposure

Other pollinators (2)

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

Mode of exposure

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

> 100

Eisenia foetida corr

Moderate

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

Eisenia foetida corr

Moderate

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Other arthropod (1)

LR₅₀ g ha⁻¹

% Effect

0.0

Mortality [Dose: 0.136 kg ha⁻¹]
Aphidius rhopalosiphi

Other arthropod (2)

LR₅₀ g ha⁻¹

% Effect

0.0

Mortality [Dose: 0.063 kg ha⁻¹]
Typhlodromus pyri

Soil micro-organisms

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

Dose: 1.49 mg kg⁻¹ 28days

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)

> 2000

Rat

Low

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

5000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 2.1

Rat 4 hr (nose only)

Other Mammal toxicity endpoints

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

0.006

Dog SF=100 Proposed

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

0.3

Rat SF=100 Proposed

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

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

0.02

Rat SF=300 Proposed

Dermal penetration studies (%)

4-30

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

Vapour drift unlikley to be a concern to bystanders

Occupational

Acceptable risk for registered applications - PPE/PPC advised

MRLs

European

EU MRL pesticide database

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

0.1

EU Dir 89/778/EC limit; Calc MAC=18.0 µg l⁻¹

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

Possible liver & kidney toxicant
USEPA - possible human carcinogen
Endocrine issues - Inhibition of thyroid hormones production

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
IMDG Transport Code is usually 9

CLP classification 2013

Environment: H400, H410

EC Risk Classification

Xn - Harmful: R63
N - Dangerous for the environment: R50, R53

EC Safety Classification

S60, S61

WHO Classification

III (Slightly hazardous)

UN Number

Usually 1993 or 3077

Waste disposal & packaging

Packaging Group III (minor danger)

TRANSLATIONS

Language

Name

English

fenbuconazole

French

fenbuconazole

German

Fenbuconazol

Danish

fenbuconazol

Italian

fenbuconazolo

Spanish

fenbuconazol

Greek

Polish

fenbukonazol

Swedish

Hungarian

Dutch

Record last updated:	19/01/2021
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