Copper II hydroxide

Copper II hydroxide	Last updated: 29/06/2026
(Also known as: cupric hydroxide; copper dihydroxide)

SUMMARY

A widely used copper fungicide. It has a low aqueous solubility and a low volatility. As a heavy metal, copper itself will not degrade in the environment. It is moderately toxic to mammals and most biodiversity.

Hazard alerts

The following Pesticide Hazard Tricolour (PHT) 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. The alerts for Highly Hazardous Pesticides (HHPs) are based on applying the FAO/WHO (Type 1) and the PAN (Type II) criteria to PPDB data. Further details on the HHP indicators are given in the tables below. Neither the PHT nor the HHP hazard alerts take account of usage patterns or exposure, thus they do not represent risk.

PHT: Environmental fate	PHT: Ecotoxicity	PHT: Human health	Highly Hazardous Pesticide
Environmental fate Low alert: Non-persistent; GUS: Low leachability; Drainflow: Non-mobile; Potential for particle bound transport: Low	Ecotoxicity High alert: Birds chronic ecotoxicity: High; Fish acute ecotoxicity: High; Daphnia acute ecotoxicity: High	Human health Moderate alert: Mammals acute toxicity: Moderate; Mammals chronic toxicity: Moderate; Reproduction/development effects	Highly Hazardous Pesticide (HHP) Type II alert

GENERAL INFORMATION

Description

Inorganic copper compound used to protect against a number of fungal and bacterial diseases

Example pests/issues controlled

Wide range of fungal pathogens including mildews and leaf spots

Example applications

Fruit including plums, citrus, litchi, mango, apples, pears, grapes; Beans, Peppers, Brassicas, Lettuce, Onions, Curcubits; Tomatoes

Efficacy & activity

Copper based products have been shown to be affective against many fungal pathogens in field trials.

Appearance and life cycle

Taxonomic classification

GB regulatory status

GB COPR regulatory status

Approved

Date COPR inclusion expires

31/12/2027

GB LERAP status

No data

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

France/Germany

Date EC 1107/2009 inclusion expires

30/06/2029

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; Japan; Mexico; Morocco; USA

Chemical structure

Isomerism

None

Chemical formula

H₂O₂Cu

Canonical SMILES

[Cu+2].[OH-].[OH-]

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

JJLJMEJHUUYSSY-UHFFFAOYSA-L

International Chemical Identifier (InChI)

InChI=1S/Cu.2H2O/h;2*1H2/q+2;;/p-2/rCuH2O2/c2-1-3/h2-3H

2D structure diagram/image available?

Yes

General status

Biopesticide type

Fungicide; Other substance

Other bioactivity & uses

Bactericide

Substance groups

Inorganic compound

Minimum active substance purity

> 583 g kg⁻¹ total copper

Known relevant impurities

EU 2018 dossier: May contain heavy metals including Pb, Cd, As, Ni, CO, Sb & Hg

Substance origin

Natural

Mode of action

Absorbed copper disrupts the enzyme systems of the pathogens. Multi-site activity.

Substance source

Copper hydroxide occurs naturally in the mineral spertinite but this is very rare

Uses

Crop protection

Farming system suitability

CAS RN

20427-59-2

EC number

243-815-9

CIPAC number

44.305

US EPA chemical code

PubChem CID

30154

CLP index number

029-021-00-3

Molecular mass (Da)

97.56

PIN (Preferred Identification Name)

copper II hydroxide

IUPAC name

copper II hydroxide

CAS name

copper hydroxide

Global Governance status: Listed (✓) under

UK Poisons List Order 1972	Rotterdam Convention	Montreal Protocol
XNo The Poisons List Order 1972	XNo Rotterdam Convention	XNo Montreal Protocol
Stockholm Convention	OSPAR	EU Water Framework Directive
XNo Stockholm Convention	XNo OSPAR	XNo EU Water Framework Directive

Relevant Environmental Water Quality Standards

Forever chemical

Highly Hazardous Pesticide (HHP)

Type I

Type II

Yes []

Other status information

PAN listed Highly Hazardous Chemical

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)

M01

Examples of recorded resistance

Physical state

Blue-green powdery solid

Related substances & organisms

bordeaux mixture

Commercial

Property

Value

Availability status

Current

Introduction & key dates

1968, registered USA

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

Bayer CropScience
BOC Sciences
Certis Biologicals
Syngenta AG

Example products using this active

Formulation and application details

Usually supplied as concentrated liquid formulations, particularly as suspension concentrates

Commercial production

Copper II hydroxide is produced industrially by mixing solutions of lye (sodium or potassium hydroxide) and blue vitriol (copper II sulphate)

Impact on climate of production and use

There is no precise figure for copper(II) hydroxide alone, a rough estimate would place its GHG footprint slightly above that of refined copper, probably in the range of 5–6 tonnes CO₂e per tonne of product, depending on the production method and energy source.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

Solubility - In water at 20 °C at pH 7 (mg l⁻¹)

0.506

Low

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

0.007

Heptane

0.016

p-Xylene

0.0016

Isopropanol

0.005

Acetone

Melting point (°C)

Decomposes before melting

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

229

Flashpoint (°C)

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

2.75 X 10⁰⁰

Calculated

Log P

0.44

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

3.37

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

0.000001

Low volatility

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

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

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

Acidic soln: 205nm=3605, 250nm=185, 800nm=13, 290nm=32, 295nm=24

Surface tension (mN m⁻¹)

Not applicable

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Not biodegradable

Soil degradation (days) (Aerobic conditions)

DT₅₀ (typical)

0.1

Non-persistent

DT₅₀ (lab at 20 °C)

0.1

Non-persistent

DT₅₀ (field)

0.1

Non-persistent

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU 2018 dossier: Copper ion rapidly released in soil. Copper is a naturally occurring element and, as such, does not then degrade further. DT₅₀ of Cu >10,000 days

Soil mineralisation

Aerobic (at 20 °C)

Anaerobic (at 20 °C)

Dissipation rate RL₅₀ (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

Note

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Stable

Note

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

Value

Stable

Note

Water-sediment DT₅₀ (days)

Water phase only DT₅₀ (days)

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

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d (mL g⁻¹)

Non-mobile

K_oc (mL g⁻¹)

12000

Notes and range

General literature: K_oc range 4000-20000 mL g⁻¹ (US3)

Freundlich

K_f (mL g⁻¹)

K_foc (mL g⁻¹)

¹/_n

Notes and range

pH sensitivity

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

Copper

1.00

Known groundwater metabolites

None

Other known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 489

Rat

Moderate

Mammals - Short Term Oral NOAEL (mg kg⁻¹ bw d⁻¹)

Mammals - Long Term (Chronic) Oral NOAEL (mg kg⁻¹ bw d⁻¹)

4.0

Rat 2-yr as copper

Moderate

Birds - Acute LD₅₀ (mg kg⁻¹)

223

Colinus virginianus as copper

Moderate

Birds - Short term dietary LC₅₀ (mg kg⁻¹ bw d⁻¹)

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

5.0

Colinus virginianus

High

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

> 677

Eisenia foetida

Moderate

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

< 15

Eisenia foetida as Cu 56 day

Moderate

Soil micro-organisms

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

Dose: 12.5 kg Cu/ha

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)

> 44.46

Apis mellifera

Moderate

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

49.0

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)

55.6% Mortality at dose 0.56 kg Cu/ha

Chrysoperla carnea Adult

Beneficial insects (Parasitic wasps) as Mortality LR₅₀ g Cu/ha, Std lab test

Aphidius rhopalosiphi

Moderate

Beneficial insects (Predatory mites) as Mortality LR₅₀ g Cu/ha, Std lab test

> 14880

Typhlodromus pyri

Low

Beneficial insects (Ground beetles)

Beneficial insects (Butterflies)

Contact

Notes

Oral

Notes

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

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

0.017

Oncorhynchus mykiss

High

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

0.027

Oncorhynchus mykiss

Moderate

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

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

0.038

Daphnia magna

High

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

0.03

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)

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

59.5

Chironomus riparius as mg Cu/kg

Moderate

Aquatic Plants (free-floating, fonds growth, fresh) - 7 day (mg l⁻¹)

Aquatic plants (rooted, growth rate, fresh) - 14 day (mg l⁻¹)

Algae - Acute (growth rate, fresh; mg l⁻¹) (72 hr ErC₅₀, Static)

> 0.0223

Raphidocelis subcapitata

Moderate

Algae - Chronic (growth rate, fresh; mg l⁻¹)

Mesocosm study data

NOEAEC mg l⁻¹

0.003

NOEAEC mg l⁻¹

Marine bivalves

Regulatory Threshold Levels (RTLs)

Note: These RTLs have been calculated using the regulatory approach used in the European Union and based on ecotoxocity values in the PPDB.

Species group

RTL

Notes

Mammals

0.8

Worst case of acute and chronic mammals

Birds

Worst case of acute and chronic birds

Soil organisms

Worst case of acute and chronic earthworms

Terrestrial plants

No data

No data for non-target plants vegetative vigour and seedling emergence

Pollinators

0.8892

Worst case of contact and oral honeybees

Arthropods

Worst case of parasitic wasps and predatory mites

Fish

0.00017

Worst case of temperate acute and chronic fish

Aquatic invertebrates

0.00038

Worst case of temperate acute and chronic aquatic invertebrates

Aquatic plants

0.00223

Worst case of free-floating plants, rooted plants, acute and chronic algae

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)

> 489

Rat

Moderate

Mammals - Short Term Oral NOAEL (mg kg⁻¹ bw d⁻¹)

Mammals - Long Term (Chronic) Oral NOAEL (mg kg⁻¹ bw d⁻¹)

4.0

Rat 2-yr as copper

Moderate

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

> 2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

0.45

Rat 4 hr (whole body)

Other Mammal toxicity endpoints

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

0.15

Dog SF=100

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

None allocated

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

None allocated

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

0.072

Dermal penetration studies (%)

1-9

concentration dependent

Dangerous Substances Directive 76/464

List II

Exposure Routes

Public

Negligible risk to bystanders for proposed uses

Occupational

Acceptable risk to operators and workers for proposed uses with PPE/PPC

Mammalian dose elimination route and rate

Health issues

Specific human health issues (hazard-based)

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

Potential heavy metal poisoning

Handling issues

Property

Value and interpretation

General

Prevent generation of dust
Corrosive
Not explosive or oxidising
Not expected to auto-ignite; Not highly flammable

CLP classification 2013

Health: H301, H332

WHO Classification

II (Moderately hazardous)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

Limited shelf-life. Store at 0-6 DegC

TRANSLATIONS

Language

Name

English

copper II hydroxide

French

hydroxyde de cuivre

German

Kupferhydroxid

Danish

kobberhydroxid

Italian

idrossido di rame

Spanish

hidróxido de cobre

Greek

Polish

wodorotlenek miedzi (II)

Swedish

kopparhydroxid

Hungarian

réz(II)-hidroxid

Dutch

Norwegian

Record last updated:	29/06/2026
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

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