Penconazole (Ref: CGA 71818)

Penconazole (Ref: CGA 71818)	Last updated: 13/07/2025
(Not known by any other names)

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 acute ecotoxicity: Moderate; 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	Human health High alert: Endocrine disrupter

GENERAL INFORMATION

Description

A fungicide used to control fungal pathogens, particularly Ascomycetes, Basidiomycetes and Deuteromycetes

Example pests controlled

Powdery mildew; Scab; Ring spot; Rusts

Example applications

Vines; Fruit including apples, pears, peaches, plums, apricots, strawberries; Ornamentals; Hops; Vegetables; Cucumbers; Tomatoes

Efficacy & activity

Availability status

Current

Introduction & key dates

1983, introduced

GB regulatory status

GB COPR regulatory status

Approved

Date COPR inclusion expires

31/12/2028

GB LERAP status

None

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Norway

Date EC 1107/2009 inclusion expires

15/10/2026

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
✓	✓	✓	✓	✓	✓	✓	✓	✓

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; Morocco

Chemical structure

Isomerism

A chiral molecule. The technical material is a racemate comprising equal amounts of (R)- and (S)-penconazole.

Chemical formula

C₁₃H₁₅Cl₂N₃

Canonical SMILES

CCCC(CN1C=NC=N1)C2=C(C=C(C=C2)Cl)Cl

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

WKBPZYKAUNRMKP-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C13H15Cl2N3/c1-2-3-10(7-18-9-16-8-17-18)12-5-4-11(14)6-13(12)15/h4-6,8-10H,2-3,7H2,1H3

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
penconazole	-

General status

Pesticide type

Fungicide

Substance groups

Triazole fungicide; Conazole fungicide

Minimum active substance purity

95%

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Systemic with curative and protective action, acts by interfering with ergosterol biosynthesis

CAS RN

66246-88-6

EC number

266-275-6

CIPAC number

446

US EPA chemical code

128999

PubChem CID

91693

CLP index number

613-317-00-X

Molecular mass

284.18

PIN (Preferred Identification Name)

IUPAC name

(RS)-1-[2-(2,4-dichlorophenyl)pentyl]-1H-1,2,4-triazole

CAS name

1-(2-(2,4-dichlorophenyl)pentyl)-1H-1,2,4-triazole

Other status information

PAN listed Highly Hazardous Chemical

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

White powder

Formulations

Property

Value

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

Agrovista
Syngenta
Globalchem
BOC Sciences

Example products using this active

Topas
Topenco 100EC

Formulation and application details

Often supplied as an emulsifiable 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)

Moderate

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

500000

Acetone

24000

n-Hexane

500000

Toluene

500000

Dichloromethane

Melting point (°C)

60.3

Boiling point (°C)

415.3

Degradation point (°C)

Flashpoint (°C)

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

5.25 X 10⁰³

Calculated

Log P

3.72

High

Fat solubility of residues

Solubility

Soluble

Data type

Regulatory data - observed in metabolism and farm animal feeding studies

Density (g ml⁻¹)

1.27

Dissociation constant pKa) at 25 °C

1.51

Very weak base; 2013 Peer reviewed literature gives pKa=5.2 [R4].

Vapour pressure at 20 °C (mPa)

0.366

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)

6.60 X 10^-04

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

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

Neutral solution: 220nm = 10564, 273nm = 437, 281nm = 401
Acidic solution: 220nm = 10741, 273nm = 410, 281nm = 376
Basic solution: 224nm = 9607, 273nm = 453, 281nm = 417
No absorption maximum above 290nm

Surface tension (mN m⁻¹)

59.7-62.8

at 20°C 0.1g l⁻¹ suspension

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

117

Persistent

DT₅₀ (lab at 20 °C)

117.2

Persistent

DT₅₀ (field)

89.7

Moderately persistent

DT₉₀ (lab at 20 °C)

434.7

Very persistent

DT₉₀ (field)

299.6

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀r ange 55.3-207 days (normalised), DT₉₀ range 184-1620 days, field studies DT₅₀ range 67-115 days, DT₉₀ range 221-380 days

Dissipation rate RL₅₀ (days) on plant matrix

Value

65.6

Note

Tomato fruit, n=1

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

6.28

Note

Published literature RL₅₀ range 1.5-14.0 days, 8 field & undercover grown crops, various matrices, n=15

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Moderately fast

Note

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

Value

Stable

Note

Stable pH 4 to pH 9 at 25 and 50 °C

Water-sediment DT₅₀ (days)

853

Stable

Water phase only DT₅₀ (days)

Moderately fast

Sediment phase only DT₅₀ (days)

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

[Grapes: 8.7 days @ 25 DegC; Field study], [Grapes: 9.6 days @ 4 DegC; Field study]

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)

27.9

Slightly mobile

K_foc (mL g⁻¹)

2205

¹/_n

0.816

Notes and range

EU dossier kf range 7.2-69.8 mL g⁻¹, kfoc range 786-4120 mL g⁻¹, ¹/_n range 0.75-0.89, Soils=8

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

1.28

Calculated

Low leachability

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

Value

3.02 X 10^-02

Calculated

Note

Potential for particle bound transport index

High

Calculated

Potential for loss via drain flow

Slightly mobile

Calculated

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

15.9

Calculated using the Atkinson method. Assumed 1.5E+06 OH/cm³, 12 hr

Below the level of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

320

Threshold for concern

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)

Major fraction

0.386

2-(2,4-dichlorophenyl)-3-(1H-1,2,4-triazol-1-yl)propanoic acid (Ref: CGA 179944)

Major fraction

0.189

1H-1,2,4-triazol-1-ylacetic acid (Ref: CGA 142856)

Minor fraction

0.05

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)

Relevancy unknown

2-(2,4-dichlorophenyl)-3-(1H-1,2,4-triazol-1-yl)propanoic acid (Ref: CGA 179944)

Relevancy unknown

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

2-hydroxy-3-[1,2,4]triazol-1-yl-propionic acid (Ref: CGA 205369)

Rat

4-(2,4-Dichloro-phenyl)-5-[1,2,4]triazol-1-yl-pentan-2-ol (Ref: CGA 132465)

Plant; Rat (Urine)

2-(2,4-Dichloro-phenyl)-1-[1,2,4]triazol-1-yl-pentan-3-ol (Ref: CGA 190503)

Plant; Rat

4-(2,4-Dichloro-phenyl)-5-[1,2,4]triazol-1-yl-pentan-1-ol (Ref: CGA 127841)

Plant; Rat

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 2000

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

3.8

Rat 2 yr

High

(ppm diet)

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

Rat Reproductive NOAEL

Moderate

Birds - Acute LD₅₀ (mg kg⁻¹)

> 1590

Anas platyrhynchos

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

> 1845 mg kg bw⁻¹ day⁻¹

Anas platyrhynchos

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

28.6

Anas platyrhynchos NOEL

Moderate

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

> 331.5

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; 240 mg ha⁻¹ 28 Day

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

Vegetative vigour ER₅₀ (g ha⁻¹)

Seedling emergence ER₅₀ (g ha⁻¹)

Honeybees (Apis spp.)

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

> 3.0

Apis mellifera

Moderate

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

> 11.2

Apis mellifera

Moderate

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

Chronic

Notes

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)

Beneficial insects (Lacewings)

Beneficial insects (Parasitic wasps) as Mortality LR₅₀ g ha⁻¹, Std lab test

> 50

Aphidius rhopalosiphi

Beneficial insects (Predatory mites) as Mortality LR₅₀ g ha⁻¹, Std lab test

> 10

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)

1.13

Oncorhynchus mykiss

Moderate

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

0.36

Pimephales promelas

Moderate

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

> 2.63

Danio rerio Embryo

Moderate

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

6.75

Daphnia magna

Moderate

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

0.06

Daphnia magna

Moderate

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)

2.0

Chironomus riparius

Moderate

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

25.2

Chironomus riparius

Moderate

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

0.19

Lemna gibba

Moderate

Aquatic plants (rooted, growth) - Acute 14 day EC₅₀, biomass (mg l⁻¹)

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

4.9

Pseudokirchneriella subcapitata Growth

Moderate

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

Mesocosm study data

NOEAEC mg l⁻¹

Marine bivalves

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)

3000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 4.05

Rat 4 hr (nose only dust)

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)

0.5

Rabbit SF=100

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 (%)

1.0-5.0

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

No unacceptable risks to bystanders identified

Occupational

No unacceptable risks to operators or other workers identified for intended 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 Directive 98/778/EEC

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

Potential liver toxicant
Endocrine issues - Weak estrogenic effect

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: H400, H410

WHO Classification

III (Slightly hazardous)

UN Number

UN3077

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

Chemically stable under standard ambient conditions. Limited shelf-life. Store at 2-8 DegC

TRANSLATIONS

Language

Name

English

penconazole

French

penconazole

German

Penconazol

Danish

penconazol

Italian

penconazolo

Spanish

penconazol

Greek

Polish

penkonazol

Swedish

penkonazol

Hungarian

penkonazol

Dutch

penconazool

Norwegian

penkonazol

Record last updated:	13/07/2025
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