Imazalil (Ref: R 023979)

Imazalil (Ref: R 023979)	Last updated: 16/03/2024
(Also known as: enilconazole; chloramizol)

GENERAL INFORMATION

Description

Topically applied veteriary antifungal agent

Availability status

Current

Introduction & key dates

1977, introduced

Examples of veterinary uses

Active against ringworm fungal infections

Examples of species treated

Cattle; Horses, Dogs

Approval status

VMR 2013/2033 approval status (GB/UK)

Not approved

EU Regulatory approval status

Not approved

Chemical structure

Isomerism

Substance is racemic

Chemical formula

C₁₄H₁₄Cl₂N₂O

Canonical SMILES

C=CCOC(CN1C=CN=C1)C2=C(C=C(C=C2)Cl)Cl

Isomeric SMILES

International Chemical Identifier key (InChIKey)

PZBPKYOVPCNPJY-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C14H14Cl2N2O/c1-2-7-19-14(9-18-6-5-17-10-18)12-4-3-11(15)8-13(12)16/h2-6,8,10,14H,1,7,9H2

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
imazalil	-

General status

Veterinary substance type

Antifungal agent, Antimycotic

Substance groups

Imidazole fungicide; Conazole fungicide

Minimum active substance purity

950 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Systemic with curative and protective properties. Disrupts membrane function.

Molecular targets

[Sterol synthesis, Inhibitor]

CAS RN

35554-44-0

EC number

252-615-0

CIPAC number

335

US EPA chemical code

111901

PubChem CID

37175

CLP index number

613-042-00-5

Therapeutic Class

Dermatologicals: Antifungals for dermatological use

ATCvet Code

QD01AC90

Controlled Drug?

Regulation 37/2010 MRL Classification

Molecular mass

297.18

PIN (Preferred Identification Name)

IUPAC name

(RS)-1-(β-allyloxy-2,4-dichlorophenylethyl)imidazole

CAS name

1-(2-(2,4-dichlorophenyl)-2-(2-propenyloxy)ethyl)-1H-imidazole

Other status information

Relevant Environmental Water Quality Standards

Physical state

Yellow-brown oily solid

Related substances & organisms

imazalil nitrate

imazalil sulfate

Formulations

Property

Product

Manufacturer

Authorisation Route

Legal Class (GB/UK)

Example products (past and present) using this active

Imaverol 100 mg/ml Concentrate for Cutaneous Emulsion

Janssen-Cilag Ltd

Not licensed

Formulation and application details

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

184

Moderate

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

500000

Methanol

500000

Ethyl acetate

19000

n-Hexane

500000

Toluene

Melting point (°C)

51.5

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

260

Flashpoint (°C)

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

3.63 X 10⁰²

Calculated

Log P

2.56

Low

Fat solubility of residues

Solubility

Insoluble

Data type

Regulatory data - imazalil is almost completely metabolised with no accumulation

Density (g ml⁻¹)

1.35

Dissociation constant pKa) at 25 °C

6.49

Weak base

Vapour pressure at 20 °C (mPa)

0.158

Low volatility. If applied directly to plants, drift is a concern & mitigation is advisable

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

0.000108

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

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

At pH4: 265nm = 236, 272nm = 311, 280nm = 255
At pH7: 265nm = 246, 272nm = 325, 280nm = 268. At pH9: 265nm = 246, 272nm = 329, 280nm = 273

Surface tension (mN m⁻¹)

46.6

at 20°C

Refractive Index

1.5609

at 20°C

Environmental release

Degradation

Property

Value

Source; quality score; and other information

Interpretation

Soil degradation (days) (aerobic)

DT₅₀ (typical)

76.3

Moderately persistent

DT₅₀ (lab at 20 °C)

76.3

Moderately persistent

DT₅₀ (field)

6.4

Non-persistent

DT₉₀ (lab at 20 °C)

1311

Very persistent

DT₉₀ (field)

Note

EU dossier lab studies DT₅₀ range 43.9-128 days, DT₉₀ range 202-4366 days; field studies DT₅₀ range 5.7-7.1 days, DT₉₀ range 54-68 days

Manure DT₅₀ (days)

Aqueous photolysis DT₅₀ (days) at pH 7

Value

6.1

Moderately fast

Note

Data for continuous irradiation

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

Value

Relatively stable

Note

Water-sediment DT₅₀ (days)

117

Slow

Water phase only DT₅₀ (days)

7.8

Moderately fast

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.

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

K_oc

Notes and range

Freundlich

K_f

126.9

Non-mobile

K_foc

4753

¹/_n

0.87

Notes and range

EU dossier kf range 38.2-195.3 mL g⁻¹, K_foc range 2080-8150 mL g⁻¹, ¹/_n range 0.719-0.987, Soils=12

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

0.26

Calculated

Low leachability

Bio-concentration factor

BCF (l kg⁻¹)

56.3

Low potential

CT₅₀ (days)

35.2

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

1-(2,4-dichlorophenyl)2-imidazol-1-ylethanol (Ref: R014821)

Minor fraction

0.096

methyl isothiocyanate (Ref: SN-32866)

Minor fraction

0.096

Known groundwater metabolites

None

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

methyl 2-sulfamoylbenzoate (Ref: IN D5803)

[3-[1-(2,4-dichlorophenyl)-2-(1H-imidazole-1-yl)ethoxyl]-1,2-propanediol] (Ref: R042243)

Animal

Ref: R043449

Animal (Bovine tissue & milk)

Ref: FK284

Animal

Ref: FK772

Animal

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

227

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

2.5

Rat

High

(ppm diet)

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

Unknown species Reproductive NOAEL

Moderate

Birds - Acute LD₅₀ (mg kg⁻¹)

510

Coturnix japonica

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

> 5620 mg kg feed⁻¹

Coturnix japonica

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

Unknown species

Moderate

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

271

Eisenia foetida corr

Moderate

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

Soil micro-organisms

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

Dose: 1 mg kg⁻¹ soil

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

106.6

Soil mite

Non-target plants

Honeybees (Apis spp.)

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

Apis mellifera

Moderate

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

35.1

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)

> 100

Bombus terrestris

Low

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

> 67.7

Bombus terrestris

Moderate

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 14 day

Coccinella septempunctata

Beneficial insects (Lacewings)

Beneficial insects (Parasitic wasps) as % Mortality at dose 30 g ha⁻¹

Encarsia formosa

Beneficial insects (Predatory mites)

Beneficial insects (Ground beetles) as % Mortality st dose 88 h/ha

Poecilus cupreus

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

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

1.48

Oncorhynchus mykiss

Moderate

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

0.043

Oncorhynchus mykiss 28 day LOEC

Moderate

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

19.61

Danio rerio Embryo

Moderate

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

3.5

Daphnia magna

Moderate

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

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

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

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

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

0.181

Chironomus riparius

Moderate

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

27.5

Chironomus riparius

Moderate

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

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

0.87

Raphidocelis subcapitata

Moderate

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

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)

227

Rat

Moderate

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

1.84

Rat

Other Mammal toxicity endpoints

Intraperitoneal LD₅₀ = 155 mg kg⁻¹

Rat

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

0.025

Dog SF=100

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

0.05

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

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

0.05

Rat SF=100

Dermal penetration studies (%)

7-46

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

No unacceptable risk to bystanders identified
Consumers may be exposed via ingestion of contaminated foodstuffs

Occupational

No unacceptable risk for operators or other workers identified

Mammalian dose elimination route and rate

Extensively metabolised and the main excretion routes are urine and faeces.

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

Eye irritant

Phototoxicant

No data found

General human health issues

Possible liver and kidney toxicant
US EPA - likely to be human carcinogen; CLP data - suspected carcingen

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
IMDG Transport Hazard Class 6.1
Not expected to auto-ignite; Not highly flammable
Not compatible with strong oxidising agents

CLP classification 2013

Health: H301, H318, H332. H351
Environment: H410

WHO Classification

II (Moderately hazardous)

UN Number

UN2811

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

Chemically stable under standard ambient conditions

TRANSLATIONS

Language

Name

English

imazalil

French

imazalil

German

Imazalil

Danish

imazalil

Italian

imazalil

Spanish

imazalil

Greek

Polish

imazalil

Swedish

imazalil

Hungarian

imazalil

Dutch

imazalil

Norwegian

imazalil

Record last updated:	16/03/2024
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