Etoxazole (Ref: S 1283)

Etoxazole (Ref: S 1283)	Last updated: 09/04/2025
(Also known as: Yl 5301)

SUMMARY

Etoxazole is a commonly used insecticide. It has a low aqueous solubility, a low volatility and, based on its chemical properties, would not be expected to leach to groundwater. It is non-mobile, not persistent in most soils but may be persistent in some water systems depending upon conditions. It not highly toxic to humans but is toxic to fish and aquatic invertebrates. It has a low toxicity to birds, 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: Daphnia acute ecotoxicity: High; Daphnia chronic ecotoxicity: High	Human health Moderate alert: Mammals chronic toxicity: Moderate; Endocrine disrupter; Reproduction/development effects

GENERAL INFORMATION

Description

An insecticide for use in the field and in the glasshouse, on, for example, pome fruits, cotton and vegetables to control phytophagous mites

Example pests controlled

Phytophagous mites

Example applications

Apples; Pears; Plums; Cherry; Citrus; Cotton; Tomato; Aubergine; Strawberries; Ornamentals

Efficacy & activity

Substance has been on the EU market for sometime and has been successfully evaluated for performance by research and according to the EU's Uniform Principles

Availability status

Current

Introduction & key dates

1994, first reported; 1998, first registered Japan

GB regulatory status

GB COPR regulatory status

Approved

Date COPR inclusion expires

31/07/2028

GB LERAP status

None

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

France/Greece

Date EC 1107/2009 inclusion expires

31/01/2028

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, USA, Morocco

Chemical structure

Isomerism

A chiral molecule existing in the S- and R-forms. Substance is racemic.

Chemical formula

C₂₁H₂₃F₂N₀₂

Canonical SMILES

CCOC1=C(C=CC(=C1)C(C)(C)C)C2COC(=N2)C3=C(C=CC=C3F)F

Isomeric SMILES

International Chemical Identifier key (InChIKey)

IXSZQYVWNJNRAL-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C21H23F2NO2/c1-5-25-18-11-13(21(2,3)4)9-10-14(18)17-12-26-20(24-17)19-15(22)7-6-8-16(19)23/h6-11,17H,5,12H2,1-4H3

2D structure diagram/image available?

Yes

General status

Pesticide type

Acaricide

Substance groups

Diphenyl oxazoline insecticide

Minimum active substance purity

948 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Non-systemic with contact action. A moulting hormone agonist. Mite growth inhibitor affecting CHS1.

CAS RN

153233-91-1

EC number

604-891-2

CIPAC number

623

US EPA chemical code

107091

PubChem CID

153974

CLP index number

603-199-00-8

Molecular mass

359.42

PIN (Preferred Identification Name)

rac-(4R)-2-(2,6-difluorophenyl)-4-(4-tert-butyl-2-ethoxyphenyl)-4,5-dihydro-1,3-oxazole

IUPAC name

(RS)-5-tert-butyl-2-[2-(2,6-difluorophenyl)-4,5-dihydro-1,3-oxazol-4-yl]phenetole

CAS name

2-(2,6-difluorophenyl)-4-(4-(1,1-dimethylethyl)-2-ethoxyphenyl)-4,5-dihydrooxazole

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)

10B

Fungicide Resistance Class (FRAC MOA class)

Not applicable

Examples of recorded resistance

Blattella germanica

Physical state

White crystalline powder

Formulations

Property

Value

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

PCT Holdings Pty Ltd

Example products using this active

Surefire Etoxazole Selective Miticide

Formulation and application details

Foliar application

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

0.07

Low

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

249000

Ethyl acetate

309000

Acetone

104000

Methanol

252000

Xylene

Melting point (°C)

101.5

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

293

Flashpoint (°C)

457

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

3.31 X 10⁰⁵

Calculated

Log P

5.52

High

Fat solubility of residues

Solubility

Soluble

Data type

Regulatory data - total residues higher in fat compared to fat free muscle.

Density (g ml⁻¹)

1.24

Dissociation constant pKa) at 25 °C

Not applicable

Not determinable

Vapour pressure at 20 °C (mPa)

0.007

Low volatility

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

3.60 X 10^-02

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

Negligible

From soil surface

Negligible

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

Neutral solution: 220nm = 17379
Acidic solution: 222.5nm = 16670
Basic solution: 272.5nm = 3993

Surface tension (mN m⁻¹)

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

19.3

Non-persistent

DT₅₀ (lab at 20 °C)

19.31

Non-persistent

DT₅₀ (field)

7.33

Non-persistent

DT₉₀ (lab at 20 °C)

93.0

Moderately persistent

DT₉₀ (field)

36.0

DT₅₀ modelling endpoint

74.1

Worst case

Note

EU 2018 dossier lab studies DT₅₀ range 9.3-74.1 days, DT₉₀ range 19.9-246.2 days, Soils = 8; Field studies DT₅₀ range 0.48-23.2 days, DT₉₀ range 8.4-77.2 days, Soils= 11

Dissipation rate RL₅₀ (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

4.2

Note

Published literature RL₅₀ range 1.6-8.9days, 4 field crops, various matrices, n=6

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Slow

Note

130hrs at pH 9, summer sunlight equivalent

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

Value

161

Persistent

Note

pH sensitive: 9.6 days at pH 5, 165 days at pH 9, all at 20 °C.

Water-sediment DT₅₀ (days)

79.5

Moderately fast

Water phase only DT₅₀ (days)

1.45

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

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)

92.0

Non-mobile

K_foc (mL g⁻¹)

6650

¹/_n

0.93

Notes and range

EU 2018 dossier K_f range 66-131 mL g⁻¹, K_foc range 4910-11000 mL g⁻¹, OC 0.6-2.4%, pH 4.3-7.4, Soils=4

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

0.15

Calculated

Low leachability

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

Value

5.61 X 10^-03

Calculated

Note

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

1.7

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)

2900

Whole fish

Threshold for concern

CT₅₀ (days)

Not available

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

N-(2,6-difluorobenzoyl)-4-tert-butyl-2-ethoxybenzamine

Major fraction

0.104

2 amino-2-(4-tert-butyl-2-ethoxyphenyl)ethyl 2',6'-difluorobenzoate hydrochloride

Major fraction

0.240

2 amino-2-(4-tert-butyl-2-ethoxyphenyl)ethanol

Major fraction

0.448

4-(4-tert-butyl-2-ethoxyphenyl)-2-(2,6-difluorophenyl)oxazole

Major fraction

0.231

N-[(1RS)-1-(4-tert-butyl-2-ethoxyphenyl)-2-hydroxyethyl]-2,6-difluorobenzamide (Ref: R-04)

Major fraction

0.124

4-tert-butyl-2-ethoxybenzoic acid (Ref: R-12)

Minor fraction

0.085

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)

> 5000

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

(ppm diet)

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

> 140

Rat Reproductive NOAEL

Moderate

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2000

Anas platyrhynchos

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

> 5200 mg kg feed⁻¹

Colinus virginianus

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

28.6

Colinus virginianus NOEC

Moderate

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

> 1000

Eisenia foetida

Low

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

5.0

Eisenia foetida 56 day

Moderate

Soil micro-organisms

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

Dose: 0.07 mg kg⁻¹ soil

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Folsomia candida

Non-target plants

> 67.2

Lactuca sativa Cucumis sativus Brassica oleracea Brassica oleracea Zea mays
Vegetative vigour, ER₅₀
as g ha⁻¹

> 67.2

Lactuca sativa Cucumis sativus Brassica oleracea Brassica oleracea Zea mays
Seedling emergence, ER₅₀
as g ha⁻¹

Honeybees (Apis spp.)

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

> 200

Apis mellifera

Low

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

> 200

Apis mellifera

Low

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

Chronic as 10-day LDD₅₀ µg bee⁻¹ day⁻¹

> 32.9

Apis mellifera

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)

4.4

Bombus terrestris LC₅₀ mg l⁻¹

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)

Beneficial insects (Lacewings)

8% Mortality at dose 55 g ha⁻¹

Chrysoperla carnea

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

> 55.0

Aphidius rhopalosiphi

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

> 55

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)

2.8

Oncorhynchus mykiss

Moderate

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

0.015

Oncorhynchus mykiss

Moderate

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

0.62

Danio rerio EC₅₀ Embryo

Moderate

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

0.0071

Daphnia magna

High

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

0.0002

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)

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

Chironomus Spp.

Moderate

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

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

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

> 10

Raphidocelis subcapitata

Low

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)

> 5000

Rat

Low

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 1.09

Rat (whole body)

Other Mammal toxicity endpoints

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

0.04

Rat 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)

0.03

Dog SF=100

Dermal penetration studies (%)

default

Dangerous Substances Directive 76/464

List II

Exposure Routes

Public

Risk low for consumers, bystanders and residents

Occupational

Operator use of appropriate PPE/PPC is 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

Extensively metabolised and rapidly excreted within 48 hours, mainly via 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

General human health issues

Possible liver toxicant

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising

CLP classification 2013

Environment: H400, H410

WHO Classification

III (Slightly hazardous)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

etoxazole

French

etoxazole

German

Etoxazol

Danish

etoxazole

Italian

etoxazole

Spanish

etoxazol

Greek

etoxazol

Polish

etoksazol

Swedish

Hungarian

Dutch

etoxazol

Norwegian

Record last updated:	09/04/2025
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