Fenquinotrione (Ref: KIH-3653)

Fenquinotrione (Ref: KIH-3653)	Last updated: 09/01/2025
(Also known as: KUH-110)

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 Moderate alert: Moderately persistent; GUS: Transition state; Drainflow: Moderately mobile	Ecotoxicity Moderate alert: Daphnia acute ecotoxicity: Moderate; Bees acute contact ecotoxicity: Moderate; Earthworms chronic ecotoxicity: Moderate	Human health Low alert

GENERAL INFORMATION

Description

A herbicide for weed control in paddy fields

Example pests controlled

ALS-resistant broad-leaf weeds; Annual dicotyledonous weeds

Example applications

Rice; Winter and spring cereals

Efficacy & activity

Efficacy established from development and experimental trials

Availability status

Introduction & key dates

2013, introduced

GB regulatory status

GB COPR regulatory status

Pending

Date COPR inclusion expires

GB LERAP status

No UK approval for use as a pesticide

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Pending

Dossier rapporteur/co-rapporteur

Austria/Malta

Date EC 1107/2009 inclusion expires

Not applicable

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

C₂₂H₁₇ClN₂O₅

Canonical SMILES

COC1=CC=C(C=C1)N2C3=C(C(=CC=C3)Cl)N=C(C2=O)C(=O)C4C(=O)CCCC4=O

Isomeric SMILES

International Chemical Identifier key (InChIKey)

KPSTXQYTZBZXMM-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C22H17ClN2O5/c1-30-13-10-8-12(9-11-13)25-15-5-2-4-14(23)19(15)24-20(22(25)29)21(28)18-16(26)6-3-7-17(18)27/h2,4-5,8-11,18H,3,6-7H2,1H3

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance groups

Benzoylcyclohexanedione

Minimum active substance purity

980 g kg⁻¹

Known relevant impurities

GB HSE 2023: None declared

Substance origin

Synthetic

Mode of action

Inhibits the biosynthesis of synthesis of 4-hydroxyphenyl-pyruvate dioxygenase (HPPD)

CAS RN

1342891-70-6

EC number

861-589-5

CIPAC number

None allocated

US EPA chemical code

PubChem CID

71463595

CLP index number

No data found

Molecular mass

424.83

PIN (Preferred Identification Name)

2-[8-chloro-4-(4-methoxyphenyl)-3-oxo-3,4-dihydroquinoxaline-2-carbonyl]cyclohexane-1,3-dione

IUPAC name

2-(8-chloro-3,4-dihydro-4-(4-methoxyphenyl)-3-oxoquinoxalin-2-ylcarbonyl)cyclohexane-1,3-dione

CAS name

2-((8-chloro-3,4-dihydro-4-(4-methoxyphenyl)-3-oxo-2-quinoxalinyl)carbonyl)-1,3-cyclohexanedione

Other status information

Relevant Environmental Water Quality Standards

Herbicide Resistance Class (HRAC MoA class)

Herbicide Resistance Class (WSSA MoA class)

Insecticide Resistance Class (IRAC MoA class)

Not applicable

Fungicide Resistance Class (FRAC MOA class)

Not applicable

Examples of recorded resistance

Physical state

Pale yellow powdery solid

Formulations

Property

Value

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

Kumiai Chemicals
K-I Chemical Europe

Example products using this active

Formulation and application details

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

3835

High

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

734

Methanol

0.553

n-Hexane

5622

Toluene

9270

Acetone

Melting point (°C)

251.3

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

260

Flashpoint (°C)

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

4.68 X 10^-01

Calculated

Log P

-0.33

at 25 °C

Low

Fat solubility of residues

Solubility

Insoluble

Data type

Regulatory data

Density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

2.72

Vapour pressure at 20 °C (mPa)

3.42 X 10^-04

Low volatility

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

8.40 X 10^-06

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 soln: 240.5nm=29149
Alkaline soln: 240nm=29226
Acidic soln: 260nm=16939

Surface tension (mN m⁻¹)

72.4

at 20 °C 98.8%

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Not readily biodegradable

Soil degradation (days) (aerobic)

DT₅₀ (typical)

143

Persistent

DT₅₀ (lab at 20 °C)

143

Persistent

DT₅₀ (field)

38.6

Moderately persistent

DT₉₀ (lab at 20 °C)

596

Very persistent

DT₉₀ (field)

340

DT₅₀ modelling endpoint

455

Note

GB HSE 2023 dossier Lab studies: DT₅₀ (normalised) range 32.5-350 days, DT₉₀ (measured) range 143->1000 days, Soils=8; Field studies DT₅₀ (normalised) range 16.0-226 days, DT₉₀ (measured) range 71.7-1170 days; Soils=6

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

Stable at all relevant pH valeus at 25 °C

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)

K_oc (mL g⁻¹)

Notes and range

Freundlich

K_f (mL g⁻¹)

3.817

Moderately mobile

K_foc (mL g⁻¹)

242

¹/_n

0.881

Notes and range

GB HSE 2023 K_f range 1.234-10.74 mL g⁻¹, K_foc range 200-275 mL g⁻¹, ¹/_n range 0.877-0.886, Soils=4

pH sensitivity

None

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

2.56

Calculated

Transition state

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

Value

1.61 X 10^-01

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Moderately mobile

Calculated

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

6.610

Calculated using the Atkinson method

Below the level of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

1.08

Low potential

CT₅₀ (days)

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

8-chloro-4-(4-methoxyphenyl)-3-oxo-3,4-dihydroquinoxaline-2-carboxylic acid

Major fraction

0.378

5-chloro-1-(4-methoxyphenyl)quinoxaline-2,3(1H,4H)-dione

Major fraction

0.255

5-chloro-1-(4-hydroxyphenyl)quinoxaline-2,3(1H,4H)-dione

Minor fraction

0.064

5-chloro-1,2-dihydro-1-(4-methoxyphenyl)-2-oxoquinoxaline

Minor fraction

0.057

2-[8-chloro-4-(4-hydroxyphenyl)-3-oxo-3,4-dihydroquinoxaline-2-carbonyl]cyclohexane-1,3-dione

Minor fraction

0.039

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)

8-chloro-4-(4-methoxyphenyl)-3-oxo-3,4-dihydroquinoxaline-2-carboxylic acid

Not relevant

5-chloro-1-(4-methoxyphenyl)quinoxaline-2,3(1H,4H)-dione

Not relevant

5-chloro-1-(4-hydroxyphenyl)quinoxaline-2,3(1H,4H)-dione

Not relevant

5-chloro-1,2-dihydro-1-(4-methoxyphenyl)-2-oxoquinoxaline

Not relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

2-[8-chloro-4-(4-hydroxyphenyl)-3-oxo-3,4-dihydroquinoxaline-2-carbonyl]cyclohexane-1,3-dione
Note: GB HSE 2023

KIH-3653-M-1

Surface water; Sediment; Plant; Rat; Animal

8-chloro-4-(4-methoxyphenyl)-3-oxo-3,4-dihydroquinoxaline-2-carboxylic acid
Note: GB HSE 2023

KIH-3653-M-2

Surface water; Sediment; Plant; Rat

8-chloro-4-(4-hydroxyphenyl)-3-oxo-3,4-dihydroquinoxaline-2-carboxylic acid
Note: GB HSE 2023

Desmethyl-M2

Rat

5-chloro-1-(4-methoxyphenyl)quinoxaline-2,3(1H,4H)-dione
Note: GB HSE 2023

KIH-3653-M-3

Surface water; Sediment; Plant; Rat

1,3-cychlohexanedione
Note: GB HSE 2023

KIH-3653-M-4

Surface water; Rat

5-chloro-1-(4-hydroxyphenyl)quinoxaline-2,3(1H,4H)-dione
Note: GB HSE 2023

KIH-3653-M-5

Surface water; Sediment; Plant; Rat

(RS)-1-chloro-6a-hydroxy-5-(4-methoxyphenyl)-10,11-dihydro-9Hindolo[1,2-a]quinoxaline-6,7,8-trione
Note: GB HSE 2023

KIH-3653-M-7

Surface water; Sediment; Plant; Animal

(RS)-1-chloro-6a-hydroxy-5-(4-hydroxyphenyl)-10,11-dihydroindolo[1,2-a]quinoxaline-6,7,8-trione
Note: GB HSE 2023

Desmethyl-M7

Rat

5-chloro-1,2-dihydro-1-(4-methoxyphenyl)-2-oxoquinoxaline
Note: GB HSE 2023

KIH-3653-M-8

Plant; Rat

5-chloro-1-(4-hydroxyphenyl)-3-(6-oxocyclohex-2-ene-1-carbonyl)quinoxalin-2(1H)-one
Note: GB HSE 2023

U-34/35

Rat

5-chloro-1-(4-methoxyphenyl)-3-(6-oxocyclohex-2-ene-1-carbonyl)quinoxalin-2(1H)-one
Note: GBHSE 2023

U-40

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)

(ppm diet)

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

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2250

Colinus virginianus

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

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

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

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

>= 10.18

Eisenia andrei

Moderate

Soil micro-organisms

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

>= 103

Folsomia candida

Non-target plants

104.5

10 species
Seedling emergence, ER₅₀
as g ha⁻¹

2.18

10 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)

> 17.5

Apis mellifera

Moderate

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

> 100

Apis mellifera

Low

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) Mortality, LR₅₀

> 150

Aphidius rhopalosiphi

Beneficial insects (Predatory mites) Mortality, LR₅₀

> 1000

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)

> 100

Oncorhynchus mykiss

Low

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

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

>= 4.93

Danio rerio

Moderate

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

> 75.0

Daphnia magna

Moderate

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

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)

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

0.0334

Lemna gibba

Moderate

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

1.3

Pseudokirchneriella subcapitata

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)

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 2.0

Rat 4 hrs

Other Mammal toxicity endpoints

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

0.008

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)

0.008

Rat SF=100

Dermal penetration studies (%)

Dangerous Substances Directive 76/464

Exposure Routes

Public

Low risk for residents and bystanders but exposure should be avoided

Occupational

Acceptable risk with PPE/PPC

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: >80% eliminated in 24 hrs mainly in faeces.

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

Eye irritant

Phototoxicant

General human health issues

Probable liver and spleen toxicant

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
Not flammable

CLP classification 2013

Health: H317, H373

WHO Classification

Not listed (Not listed)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

fenquinotrione

French

fenquinotrione

German

Danish

Italian

Spanish

Greek

Polish

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	09/01/2025
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