Fenazaquin (Ref: DE 436)

Fenazaquin (Ref: DE 436)	Last updated: 15/03/2024
(Also known as: XDE 436; XRD 562; EL-436)

SUMMARY

Fenazaquin is a quinazoline acaricide. It has a low aqueous solubility but is highly soluble in many organic solvents. It is not volatile and is not expected to leach to groundwater. It may be persistent in soil and water systems depending on local conditions. Its toxicity to terrestrial and aquatic organisms tends to high to moderate. Fenazaquin is moderately toxic to humans via the oral route and, whilst it may be a respiratory tract irritant no chronic effects have been identified.

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: Moderately persistent; Potential for particle bound transport: Medium	Ecotoxicity High alert: Fish acute ecotoxicity: High; Fish chronic ecotoxicity: High; Daphnia acute ecotoxicity: High; Daphnia chronic ecotoxicity: High	Human health High alert: Genotoxic

GENERAL INFORMATION

Description

An acaricide active against citrus mites, red mites and other mites on fruit, nuts and ornamentals

Example pests controlled

Mites -Eutetranychus, panonychus, Tetranuchus

Example applications

Fruit including applies, pears, citrus; Nuts; Ornamentals

Efficacy & activity

Availability status

Current

Introduction & key dates

1992, first reported; 1993, first introduced

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

31/05/2026

UK LERAP status

Check label - may vary with formulation

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Germany/Poland

Date EC 1107/2009 inclusion expires

31/08/2026

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

Chemical structure

Isomerism

None

Chemical formula

C₂₀H₂₂N₂O

Canonical SMILES

CC(C)(C)C1=CC=C(C=C1)CCOC2=NC=NC3=CC=CC=C32

Isomeric SMILES

International Chemical Identifier key (InChIKey)

DMYHGDXADUDKCQ-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C20H22N2O/c1-20(2,3)16-10-8-15(9-11-16)12-13-23-19-17-6-4-5-7-18(17)21-14-22-19/h4-11,14H,12-13H2,1-3H3

2D structure diagram/image available?

Yes

General status

Pesticide type

Acaricide, Insecticide

Substance groups

Quinazoline acaricide; Quinazoline insecticide

Minimum active substance purity

97.5

Known relevant impurities

EU dossier - none declared

Substance origin

Synthetic

Mode of action

Mitochondrial complex I electron transport inhibitor

CAS RN

120928-09-8

EC number

410-580-0

CIPAC number

693

US EPA chemical code

044501

PubChem CID

86356

CLP index number

613-159-00-1

Molecular mass

306.40

PIN (Preferred Identification Name)

4-[2-(4-tert-butylphenyl)ethoxy]quinazoline

IUPAC name

4-tert-butylphenethyl quinazolin-4-yl ether

CAS name

4-(2-(4-(1,1-dimethylethyl)phenyl)ethoxy)quinazoline

Other status information

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)

21A

Fungicide Resistance Class (FRAC MOA class)

Not applicable

Examples of recorded resistance

Tetranychus urticae

Physical state

Colourless crystals

Formulations

Property

Value

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

Gowan
Pentagon Fine Chemicals

Example products using this active

Magister F
Pride Ultra
Turkoise

Formulation and application details

Usually supplied as a suspension concentrate that is diluted 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)

0.102

Low

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

450000

Acetone

75000

Methanol

500000

Toluene

600000

Dichloromethane

Melting point (°C)

80.5

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

307

Flashpoint (°C)

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

3.24 X 10⁰⁵

Calculated

Log P

5.51

High

Fat solubility of residues

Solubility

Soluble

Data type

Regulatory data - observed in metabolism and farm animal feeding studies

Density (g ml⁻¹)

1.16

Dissociation constant pKa) at 25 °C

2.44

Strong acid

Vapour pressure at 20 °C (mPa)

1.90 X 10^-02

Low volatility

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

5.71 X 10^-02

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

0.04

24 hr

Volatilisation is not considered critical for air pollution

From soil surface

1.0

24 hr

Volatilisation is not considered critical for air pollution

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

215.8nm = 51500, 262.6nm = 12400

Surface tension (mN m⁻¹)

65.7

at 20°C 58µg l⁻¹

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)

54.0

Moderately persistent

DT₅₀ (field)

30.5

Moderately persistent

DT₉₀ (lab at 20 °C)

270

Persistent

DT₉₀ (field)

101.3

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀ range 50-117.5 days, DT₉₀ range 184-299 days, field studies DT₅₀ range 12.9-43.6 days, DT₉₀ range 42.7-160 days; Other studies lab DT₅₀ range 67-115 days, field range 16-22 days (B4)

Dissipation rate RL₅₀ (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

3.1

Note

Published literature RL₅₀ range 1.8-3.8 days, 3 field crops, various matrices, n=3

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Slow

Note

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

Value

130

Persistent

Note

pH sensitive: DT₅₀ 9.6 days at pH 5, 219 days at pH 9 all at 25 °C

Water-sediment DT₅₀ (days)

Water 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.

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

K_oc

Notes and range

Freundlich

K_f

247

Non-mobile

K_foc

26499

¹/_n

0.899

Notes and range

EU dossier K_f range 54-512 mL g⁻¹, K_foc range 16020-42695 mL g⁻¹, ¹/_n range 0.887-0.917, Soils=4

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

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

3.321

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)

699

Threshold for concern

CT₅₀ (days)

98% 14days

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

4-tert-butylphenylethyl alcohol

Minor fraction

2-oxyfenazaquin

Minor fraction

0.091

Known groundwater metabolites

None

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

4-(2-hydroxy-1,1dimethylethyl)phenylacetic acid

fenazaquin AN-1

Rat (Urine)

2,2-dimethyl-2-(4-((4-quinazolinyl)oxy)-1-hydroxyethyl)phenyl ethanol

fenazaquin F-1A

Rat (Faecal)

2,2-dimethyl-2-(4-((4-quinazolinyl)oxy)ethyl)phenyl ethanol

fenazaquin F-1

Rat (Faecal); Plant (Grapes)

2,2-dimethyl-2-(4-((2-((6-hydroxy-4-quinazolinyl)oxy)ethyl)phenyl acetic acid

fenazaquin F-3; fenazquin M29

Rat (Faecal); Animal

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

134

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

> 10

Rat

High

(ppm diet)

> 150

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

Birds - Acute LD₅₀ (mg kg⁻¹)

1747

Colinus virginianus

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

> 1169 mg kg bw⁻¹ day⁻¹

Colinus virginianus

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

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

> 13.25

Eisenia foetida corr

Moderate

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

0.6

Eisenia foetida 56 day corr

Moderate

Soil micro-organisms

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

Dose: 0.75 kg ha⁻¹

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

125

Folsomia candida

Non-target plants

> 897

range of tested species
Seedling emergence, ER₅₀
as g ha⁻¹

> 897

range of tested species
Vegetative vigour, ER₅₀
as g ha⁻¹

Honeybees (Apis spp.)

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

1.21

Apis mellifera

Moderate

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

4.29

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)

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) as Mortality LR₅₀ g ha⁻¹

< 21.9

Coccinella septempunctata

Beneficial insects (Lacewings)

Beneficial insects (Parasitic wasps) as Mortality LR₅₀ g ha⁻¹

< 187.25

Aphidius rhopalosiphi

Beneficial insects (Predatory mites) as Mortality LR₅₀ g ha⁻¹

< 2.0

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)

0.0038

Oncorhynchus mykiss

High

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

0.00096

Oncorhynchus mykiss

High

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

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

0.0041

Daphnia magna

High

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

0.0021

Daphnia magna

High

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)

0.16

Chironomus riparius

Moderate

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)

> 0.208

Pseudokirchneriella 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)

134

Rat

Moderate

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

5000

Rabbit

Mammals - Inhalation LC₅₀ (mg l⁻¹)

1.9

Rat

Other Mammal toxicity endpoints

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

0.005

Rat SF=100

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

0.1

Rat 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)

0.01

Dog SF=100

Dermal penetration studies (%)

2-14

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

Acceptable for the registered uses

Occupational

Acceptable for the registered uses

MRLs

European

EU MRL pesticide database

Great Britain

GB MRL Register

Notes

GB MRL levels for some commodities subject to change in late 2021

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

Mammalian dose elimination route and rate

Rapidly and extensively eliminated in faeces (up to 89%) and urine (up to 21%)

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

No data found

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

Moderately toxic
Harmful by inhalation
Possible liver toxicant

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
IMDG Transport Hazard Class 6.1
Not explected to auto-ignite, Not highly flammable

CLP classification 2013

Health: H301, H332
Environment: H400, H410

WHO Classification

II (Moderately hazardous)

UN Number

UN2811

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

fenazaquin

French

fenazaquin

German

Fenazaquin

Danish

fenazaquin

Italian

fenazaquin

Spanish

fenazaquin

Greek

Polish

fenazachina

Swedish

Hungarian

fanarquin

Dutch

Norwegian

Record last updated:	15/03/2024
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