8-hydroxyquinoline

8-hydroxyquinoline	Last updated: 21/03/2024
(Also known as: 8-hydroxychinoline; hydroxybenzopyridine; quinophenol; 1-azanaphthalene-8-ol; HQ; oxyquinoline)

SUMMARY

A fungicide with applications mainly in horticulture. It has a high aqueous solubility, moderate volatility and a low risk of leaching to groundwater. It is not persistent in soil systems but may be persistent in aqueous systems under some conditions. It has a moderate oral rat toxicity and may have some negative impacts on human health. it is a potential mutagen and may cause damage to reproduction and development. It is toxic to birds and moderately toxic to most aquatic life, honeybees and earthworms.

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: Potential for particle bound transport: Medium	Ecotoxicity High alert: Fish chronic ecotoxicity: High	Human health High alert: Genotoxic; Reproduction/development effects

GENERAL INFORMATION

Description

A quinoline preventative and curative fungicide used to control various pathogens on vines and other crops

Example pests controlled

Grey mould; Downy mildew; Fusarium; Verticillium

Example applications

Vines; Tomatoes; Hops

Efficacy & activity

Efficiacy evaluated via field trials and extensive use.

Availability status

Current

Introduction & key dates

circa 1940, introduced

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

31/12/2024

UK LERAP status

No data

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Spain/Netherlands

Date EC 1107/2009 inclusion expires

31/12/2024

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

Chemical structure

Isomerism

Isomeric

Chemical formula

C₉H₇NO

Canonical SMILES

C1=CC2=C(C(=C1)O)N=CC=C2

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

MCJGNVYPOGVAJF-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C9H7NO/c11-8-5-1-3-7-4-2-6-10-9(7)8/h1-6,11H

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
8-hydroxyquinoline	-

General status

Pesticide type

Fungicide, Bactericide

Substance groups

Quinoline fungicide; Quinoline biocide

Minimum active substance purity

99%, 990 g/Kg

Known relevant impurities

EU dossier: None declared

Substance origin

Synthetic

Mode of action

Systemic, preventative and curative - chelates various metals required by micro-organisms for their metabolism.

CAS RN

148-24-3

EC number

205-711-1

CIPAC number

677

US EPA chemical code

059803

PubChem CID

1923

CLP index number

613-324-00-8

Molecular mass

145.16

PIN (Preferred Identification Name)

8-quinolinol

IUPAC name

quinolin-8-ol

CAS name

8-quinolinol

Other status information

Potential groundwater pollutant

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)

Not known

Examples of recorded resistance

Physical state

Pure substance (99.9%) is a crystalline solid with characteristic odour and slightly yellowish colour

Formulations

Property

Value

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

Probelte SA

Example products using this active

Beltanol-L

Formulation and application details

Usually supplied as a soluble concentrate and often applied by drip irrigation

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

633

High

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

10000

n-Heptane

250000

1,2-Dichloroethane

250000

Acetone

250000

Ethyl acetate

Melting point (°C)

73.1

Boiling point (°C)

265.6

Degradation point (°C)

Flashpoint (°C)

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

8.22 X 10⁰¹

Calculated

Log P

1.915

at 22 °C

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

1.03

Dissociation constant pKa) at 25 °C

4.88

pKa(2) = 9.45

Vapour pressure at 20 °C (mPa)

6.7

Moderately volatile. If applied directly to plants or soil, drift is a concern & mitigation is advisable

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

1.68 X 10^-03

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

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

pH 1.5: 251.5nm = 41800, 357nm = 1624
pH 6.8: 239.5nm = 33136, 305nm = 2437
pH 10.1: 253nm = 29074, 333.5nm = 2421

Surface tension (mN m⁻¹)

71.2

at 20 °C 99.9%

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Not readily biodegradable

Soil degradation (days) (aerobic)

DT₅₀ (typical)

0.88

Non-persistent

DT₅₀ (lab at 20 °C)

0.3

Non-persistent

DT₅₀ (field)

15.1

Non-persistent

DT₉₀ (lab at 20 °C)

0.88

Non-persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

0.88

geometric mean

Note

EU dossier 2024 Lab studies DT₅₀ (normalised) range 0.037-10.3 days, DT₉₀ range 0.14-34.2 days, Soils=4

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

Note

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

Value

Stable

Note

Stable at pH 4 to pH 7

Water-sediment DT₅₀ (days)

230

Slow

Water phase only DT₅₀ (days)

1.0

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

527.6

Non-mobile

K_oc

24784

Notes and range

EU dossier 2024 kd range 314-878 mL g⁻¹, K_oc range 13902-45837 mL g⁻¹, Soils=5

Freundlich

K_f

1105.6

Non-mobile

K_foc

55460

¹/_n

1.06

Notes and range

EU dossier 2021 K_f range 286-2965 mL g⁻¹, K_foc range 12796-111459 mL g⁻¹, ¹/_n range 0.66-1.39, Soils=5

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

-0.88

Calculated

Low leachability

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

Value

5.35 X 10^-03

Calculated

Note

Estimated concentrations of chemicals with Koc values greater than 9995 ml g⁻¹ are beyond the scope of the regression data used in SCI-GROW development. If there are concerns for such chemicals, a higher tier groundwater exposure assessment should be considered, regardless of the concentration returned by SCI-GROW

Potential for particle bound transport index

Medium

Calculated

Potential for loss via drain flow

Non-mobile

Calculated

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

0.647

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)

Low risk

Based on LogP < 3

Low risk

CT₅₀ (days)

Known soil metabolites

None

Known groundwater metabolites

None

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

8-hydroxyquinoline glucuronide

Human; Rat

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

177

Mouse

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

(ppm diet)

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

Birds - Acute LD₅₀ (mg kg⁻¹)

459

Coturnix japonica

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

> 5000 mg kg feed⁻¹

Coturnix japonica

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

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

> 408.6

Eisenia foetida as sulphate

Moderate

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

> 417.3

Eisenia foetida as sulphate

Low

Soil micro-organisms

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

Dose: 43 mg ha⁻¹ 28 Day

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

248.4

Folsomia candida as sulphate

Non-target plants

Honeybees (Apis spp.)

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

> 100

Apis mellifera as HQ-sulphate

Low

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

> 68.6

Apis mellifera as HQ-sulphate

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)

Beneficial insects (Lacewings)

Beneficial insects (Parasitic wasps) as Mortality LR₅₀ L/ha

> 16

Aphidius rhopalosiphi

Beneficial insects (Predatory mites) as LR₅₀ L/ha

> 16

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)

1.96

Oncorhynchus mykiss

Moderate

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

> 0.0082

Oncorhynchus mykiss 28 day

High

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

0.084

Danio rerio

High

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

3.32

Daphnia magna

Moderate

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

0.236

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)

118

Chironomus riparius

Low

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

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

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

0.503

Desmodesmus subspicatus Growth

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)

177

Mouse

Moderate

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

10000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

Other Mammal toxicity endpoints

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

0.05

Rabbit SF=100

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

0.05

Rabbit SF=100

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

0.03

Rabbit SF=100

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

0.05

Dermal penetration studies (%)

0.97-42

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

Negligible if used as prescribed

Occupational

PPE/PPC advised

MRLs

European

EU MRL pesticide database

Great Britain

GB MRL Register

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

Mammalian dose elimination route and rate

Rapid and extensive mainly via the urine

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

No data found

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

Eye irritant

Phototoxicant

No data found

General human health issues

May cause irreversible eye damage
Possible kidney & spleen toxicant
Allergen & skin sensitiser
Genotox potential is inconclusive

Handling issues

Property

Value and interpretation

General

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

CLP classification 2013

Health: H360D, H301, H318, H317
Environment: H400, H410

WHO Classification

Not listed (Not listed)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

8-hydroxyquinoline

French

German

8-Hydroxy-chinolin

Danish

Italian

Spanish

Greek

Polish

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	21/03/2024
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