Chloroxuron (Ref: C 1983)-Pesticide database

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Chloroxuron (Ref: C 1983)

(Also known as: chloroxyphenidin; chloroxyfenidim )

Chloroxuron is a herbicide used to control annual weeds and grasses. It has a low aqueous solubility and is not volatile. It is moderately persistent in soil systems but is unlikely to persist in aquatic systems. Based on its physico-chemical properties it is not expected to leach to groundwater. It is moderately toxic to birds, fish, aquatic invertebrates, algae and honey bees. Mammalian toxicity is low.

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; Drainflow: Slightly mobile; Potential for particle bound transport: Medium	Ecotoxicity Moderate alert: Birds acute ecotoxicity: Moderate; Fish acute ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate; Bees acute contact ecotoxicity: Moderate	Human health Moderate alert: Possible Carcinogen

GENERAL INFORMATION

An obsolete selective phenylurea herbicide once used to control annual grasses, mosses and broad-leaved weeds

Example pests controlled

Barnyardgrass; Nightshade; Carpetweed; Corn cockle; Dandelion; Goosegrass; Crabgrass; Ragweed; Puslane; Shepherd's purse; Pigweed; Velvetleaf

Example applications

Soybeans; Onions; Strawberries; Celery; Ornamentals; vegetables including onions, carrots, leeks, peas & beans

Efficacy & activity

Availability status

Considered obsolete but may be available in some countries

Introduction & key dates

1961, first reported

UK regulatory status

UK COPR regulatory status

Date COPR inclusion expires

UK LERAP status

No UK approval for use

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Dossier rapporteur/co-rapporteur

Date EC 1107/2009 inclusion expires

EU Candidate for substitution (CfS)

Listed in EU database

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

Chemical structure

Chemical formula

C₁₅H₁₅ClN₂O₂

Canonical SMILES

CN(C)C(=O)NC1=CC=C(C=C1)OC2=CC=C(C=C2)Cl

Isomeric SMILES

International Chemical Identifier key (InChIKey)

IVUXTESCPZUGJC-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C15H15ClN2O2/c1-18(2)15(19)17-12-5-9-14(10-6-12)20-13-7-3-11(16)4-8-13/h3-10H,1-2H3,(H,17,19)

2D structure diagram/image available?

Substance groups

Phenylurea herbicide; Urea herbicide

Minimum active substance purity

Known relevant impurities

Substance origin

Photosynthetic electron transport inhibitor at the photosystem II receptor. Growth inhibition and chlorotic and necrotic effects on foliage

US EPA chemical code

CLP index number

PIN (Preferred Identification Name)

N'-[4-(4-chlorophenoxy)phenyl]-N,N-dimethylurea

3-[4-(4-chlorophenoxy)phenyl]-1,1-dimethylurea

N'-[4-(4-chlorophenoxy)phenyl]-N,N-dimethylurea

Other status information

Relevant Environmental Water Quality Standards

Herbicide Resistance Classification (HRAC)

Herbicide Resistance Classification (WSSA)

Insecticide Resistance Classification (IRAC)

Fungicide Resistance Classification (FRAC)

Examples of recorded resistance

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

Syngenta
Ciba Geigy AG

Example products using this active

Tenoran
Norex
Gesamoos

Formulation and application details

Usually supplied as a wettable powder

ENVIRONMENTAL FATE

Source; quality score; and other information

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

K4 K = Research datasets (e.g. Pandora, Demetra; these datasets no longer available). Norman Ecotoxicology database. (click here )
4 = Verified data

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

V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID )
3 = Unverified data of known source

V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID )
3 = Unverified data of known source

Dichloromethane

V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID )
3 = Unverified data of known source

V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID )
3 = Unverified data of known source

Melting point (°C)

Q3 Q = Miscellaneous data from online sources
3 = Unverified data of known source

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

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

K4 K = Research datasets (e.g. Pandora, Demetra; these datasets no longer available). Norman Ecotoxicology database. (click here )
4 = Verified data

Fat solubility of residues

A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications )
5 = Verified data used for regulatory purposes

Regulatory data - observed in metabolism and farm animal feeding studies

A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications )
5 = Verified data used for regulatory purposes

Density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

K4 K = Research datasets (e.g. Pandora, Demetra; these datasets no longer available). Norman Ecotoxicology database. (click here )
4 = Verified data

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

H4 H = The US ARS pesticide properties database. Dataset is no longer available.
4 = Verified data

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

Surface tension (mN m⁻¹)

Source; quality score; and other information

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

K4 K = Research datasets (e.g. Pandora, Demetra; these datasets no longer available). Norman Ecotoxicology database. (click here )
4 = Verified data

Moderately persistent

DT₅₀ (lab at 20 °C)

DT₅₀ (field)

F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment )
3 = Unverified data of known source

Moderately persistent

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Literature states DT₅₀ typically ranges from 30 to 60 days, 110 days silt loam aerobic conditions (CA3)

Dissipation rate RL₅₀ on plant matrix

Dissipation rate RL₅₀ on and in plant matrix

Aqueous photolysis DT₅₀ (days) at pH 7

K4 K = Research datasets (e.g. Pandora, Demetra; these datasets no longer available). Norman Ecotoxicology database. (click here )
4 = Verified data

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

K4 K = Research datasets (e.g. Pandora, Demetra; these datasets no longer available). Norman Ecotoxicology database. (click here )
4 = Verified data

Very persistent

Water-sediment DT₅₀ (days)

Water phase only DT₅₀ (days)

K4 K = Research datasets (e.g. Pandora, Demetra; these datasets no longer available). Norman Ecotoxicology database. (click here )
4 = Verified data

Soil adsorption and mobility

Source; quality score; and other information

H3 H = The US ARS pesticide properties database. Dataset is no longer available.
3 = Unverified data of known source

Slightly mobile

Notes and range

Best available data

Notes and range

Source; quality score; and other information

GUS leaching potential index

Low leachability

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

Potential for particle bound transport index

Potential for loss via drain flow

Slightly mobile

Bio-concentration factor

BCF (l kg⁻¹)

Q2 Q = Miscellaneous data from online sources
2 = Unverified data of unknown source

Threshold for concern

CT₅₀ (days)

Known soil metabolites

Major/Minor fraction

Estimated maximum occurrence fraction

N-(4-chlorophenoxy)-phenyl-N-methylurea

N-(4-chlorophenoxy)-phenylurea

4-chlorophenoxy-aniline

Known groundwater metabolites

None

Other known metabolites

None

Terrestrial ecotoxicology

Source; quality score; and other information

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID )
3 = Unverified data of known source

Mammals - Short term dietary NOEL

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

Birds - Acute LD₅₀ (mg kg⁻¹)

F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment )
3 = Unverified data of known source

Anas platyrhynchos

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)

Soil micro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

Honeybees (Apis spp.)

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

K4 K = Research datasets (e.g. Pandora, Demetra; these datasets no longer available). Norman Ecotoxicology database. (click here )
4 = Verified data

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

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

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)

Beneficial insects (Predatory mites)

Beneficial insects (Ground beetles)

Aquatic ecotoxicology

Source; quality score; and other information

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment )
4 = Verified data

Oncorhynchus mykiss

Fish - Chronic 21 day NOEC (mg l⁻¹)

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

F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment )
4 = Verified data

Daphnia magna

Aquatic invertebrates - Chronic 21 day NOEC (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)

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

K3 K = Research datasets (e.g. Pandora, Demetra; these datasets no longer available). Norman Ecotoxicology database. (click here )
3 = Unverified data of known source

Unknown species

Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)

Mesocosm study data

NOEAEC mg l⁻¹

NOEAEC mg l⁻¹

HUMAN HEALTH AND PROTECTION

Source; quality score; and other information

Threshold of Toxicological Concern (Cramer Class)

High (class III)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID )
3 = Unverified data of known source

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

Mammals - Inhalation LC₅₀ (mg l⁻¹)

Other Mammal toxicity endpoints

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

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

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

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

Dermal penetration studies (%)

Dangerous Substances Directive 76/464

Exposure Routes

Occupational exposure may occur through inhalation of dusts and dermal contact

EU MRL pesticide database

GB MRL Register

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

Mammalian dose elimination route and rate

Specific human health issues

Endocrine disruptor

?Possibly, status not identified

A0 A = Chromosome aberration (EFSA database)
0 = No data

B0 B = DNA damage/repair (EFSA database)
0 = No data

C0 C = Gene mutation (EFSA database)
0 = No data

D0 D = Genome mutation (EFSA database)
0 = No data

E0 E = Unspecified genotoxicity type (miscellaneous data source)
0 = No data

XNo, known not to cause a problem

Reproduction / development effects

Acetyl cholinesterase inhibitor

XNo, known not to cause a problem

XNo, known not to cause a problem

Respiratory tract irritant

Skin sensitiser

?Possibly, status not identified

?Possibly, status not identified

?Possibly, status not identified

General human health issues

Harmful by ingestion and inhalation
May be harmful by skin contact
Under certain conditions may form carcinogenic dimethylnitrosamine

Handling issues

Value and interpretation

Fire may produce irritating or poisonous gases

CLP classification 2013

Health: H332
Environment: H400

WHO Classification

U (Unlikely to present an acute hazard)

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

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