Linuron (Ref: HOE 02810)

Linuron (Ref: HOE 02810)	Last updated: 22/08/2024
(Also known as: DPX Z0326; AE F002810)

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: Slightly mobile; Potential for particle bound transport: Medium	Ecotoxicity Moderate alert: Birds acute ecotoxicity: Moderate; Birds chronic ecotoxicity: Moderate; Fish acute ecotoxicity: Moderate; Fish chronic ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate; Daphnia chronic ecotoxicity: Moderate; Bees acute contact ecotoxicity: Moderate; Earthworms acute ecotoxicity: Moderate; Earthworms chronic ecotoxicity: Moderate	Human health High alert: Mammals chronic toxicity: High; Reproduction/development effects

GENERAL INFORMATION

Description

A herbicide for the pre- and post-emergence control of annual grass and broad-leaved weeds

Example pests controlled

Chickweed; Prickly lettuce; Lambsquarter; Crabgrass; Goosegrass

Example applications

Wide variety of crops including asparagus, carrots, parsnips, beans, cereals; Cotton; Coffee; Tea; Rice; Ornamentals

Efficacy & activity

Availability status

Current

Introduction & key dates

circa 1965, introduced

GB regulatory status

GB COPR regulatory status

Not approved

Date COPR inclusion expires

Not applicable

GB LERAP status

No UK approval for use as a pesticide

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Not approved

Dossier rapporteur/co-rapporteur

Italy/Germany

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

C₉H₁₀Cl₂N₂O₂

Canonical SMILES

CN(C(=O)NC1=CC(=C(C=C1)Cl)Cl)OC

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

XKJMBINCVNINCA-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C9H10Cl2N2O2/c1-13(15-2)9(14)12-6-3-4-7(10)8(11)5-6/h3-5H,1-2H3,(H,12,14)

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
linuron	-

General status

Pesticide type

Herbicide

Substance groups

Urea herbicide; Phenylurea herbicide

Minimum active substance purity

950 g kg⁻¹

Known relevant impurities

EU dossier - TCB 1 mg kg⁻¹ max; TCAB 1 mg kg⁻¹ max; TCAOB 1 mg kg⁻¹ max

Substance origin

Synthetic

Mode of action

Selective, systemic with contact and residual action. Inhibits photosynthesis (photosystem II)

CAS RN

330-55-2

EC number

206-356-5

CIPAC number

US EPA chemical code

035506

PubChem CID

9502

CLP index number

006-021-00-1

Molecular mass

249.09

PIN (Preferred Identification Name)

IUPAC name

3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea

CAS name

N'-(3,4-dichlorophenyl)-N-methoxy-N-methylurea

Other status information

OSPAR candidate; Potential groundwater contaminant; Marine Pollutant; Chemical subject to PIC regulations: GB Part 2

Relevant Environmental Water Quality Standards

UK statutory standard for the protection of aquatic life in inland, coastal and territorial waters: 2 µg l⁻¹

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

White crystalline solid

Formulations

Property

Value

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

AgriGuard
DAPT
Nufarm UK
Makhteshim-Agan
United Phosphorus

Example products using this active

Afalon 450 SC
Linuron 50SC
Blios
Uranus
Lorox

Formulation and application details

Available in a variety of formulations including wettable powders, emulsifiable concentrates and suspension concentrates

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

63.8

Moderate

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

395000

Acetone

292000

Ethyl acetate

170000

Methanol

75000

Toluene

Melting point (°C)

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

220

Flashpoint (°C)

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

1.00 X 10⁰³

Calculated

Log P

3.0

Moderate

Fat solubility of residues

Solubility

Insoluble

Data type

Regulatory data

Density (g ml⁻¹)

1.49

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

Vapour pressure at 20 °C (mPa)

0.051

Low volatility

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

2.00 X 10^-04

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

Negligible

24 hr

From soil surface

Negligible

24 hr

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

211nm

Surface tension (mN m⁻¹)

70.2

at 20 °C 97.4%

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

57.6

Moderately persistent

DT₅₀ (lab at 20 °C)

57.6

Moderately persistent

DT₅₀ (field)

Moderately persistent

DT₉₀ (lab at 20 °C)

210

Persistent

DT₉₀ (field)

218

DT₅₀ modelling endpoint

Note

EU 2016 dossier lab studies DT₅₀ (actual0 range 10.1-168.4 days, DT₉₀ range 70.3-559 days; EU 2012 dossier Lab studies DT₅₀ range 38-135 days, field studies DT₅₀ range 13-82 days, DT₉₀ range 70-365 days

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

1460

Very persistent

Note

Stable pH 5 to pH 9 at 22 °C

Water-sediment DT₅₀ (days)

24.1

Fast

Water phase only DT₅₀ (days)

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.

Decay in stored produce DT₅₀

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d (mL g⁻¹)

15.7

Slightly mobile

K_oc (mL g⁻¹)

842.8

Notes and range

EU 2016 dossier: K_d range 11.48-21.89 mL g⁻¹, K_oc range 547-1159 mL g⁻¹, Soils=4; Literature data: K_d range 0.50-41.2 mL g⁻¹, K_oc range 92.0-2839 mL g⁻¹, soils=39, mostly irrigated soils (R4)

Freundlich

K_f (mL g⁻¹)

10.43

Slightly mobile

K_foc (mL g⁻¹)

559

¹/_n

0.87

Notes and range

EU 2016 dossier: K_f range 6.28-19.37 mL g⁻¹, K_foc range 484-654 mL g⁻¹, ¹/_n range 0.80-0.91, Soils =4; EU 2002 dossier kf range 3-12 mL g⁻¹, K_foc range 410-463 mL g⁻¹, Soils=3; Literature data: K_f range 0.01-51.3 mL g⁻¹, K_foc range 2.0-2156 mL g⁻¹, ¹/_n range 0.70-3.03, soils=39, mostly irrigarted soils (R4)

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

2.11

Calculated

Transition state

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

Value

8.99 X 10^-02

Calculated

Note

Potential for particle bound transport index

Medium

Calculated

Potential for loss via drain flow

Slightly mobile

Calculated

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

24.82

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 potential

CT₅₀ (days)

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

3,4-dichloroaniline

desmethoxy linuron

Major fraction

0.613

N-(3,4-dichlorophenyl)-N'-methylurea

Major fraction

0.550

Anaerobic

desmethyl linuron

Photolysis

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)

3,4-dichloroaniline

Relevancy unknown

desmethyl linuron

Relevancy unknown

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

norlinuron

Water (Anaerobic)

desmethoxy linuron

Water (Anaerobic)

demethoxymonolinuron

Water (Anaerobic)

3,4-dichlorobenzeneamine

DCA

desmethoxy monlinuron

Water (Anaerobic)

(3,4-dichlorophenyl)urea

DCPU

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

1146

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat

High

(ppm diet)

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

Rat Reproductive NOAEL

High

Birds - Acute LD₅₀ (mg kg⁻¹)

314

Colinus virginianus

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

1250 mg kg feed⁻¹

Colinus virginianus

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

13.9

Anas platyrhynchos NOAEL

Moderate

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

> 500

Eisenia foetida corr

Moderate

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

6.78

Eisenia foetida corr

Moderate

Soil micro-organisms

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

Dose: 1.9 kg ha⁻¹ 100 Day

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

57.06

Folsomia candida corr

Non-target plants

Honeybees (Apis spp.)

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

> 97.8

Apis mellifera

Moderate

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

> 112.1

Apis mellifera

Low

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

Chronic as 10-day LDD₅₀ ug/ber/day

41.5

Apis mellifera

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 g ha⁻¹

> 950

Aphidius rhopalosiphi

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

42.66

Typhlodromus pyri

Beneficial insects (Ground beetles) as Mortality LR₅₀ g ha⁻¹

927

Poecilus cupreus

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

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

3.15

Oncorhynchus mykiss

Moderate

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

0.1

Oncorhynchus mykiss

Moderate

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

> 3.31

Danio rerio Embryo

Moderate

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

0.31

Daphnia magna 24 hr

Moderate

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

0.18

Daphnia magna

Moderate

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

Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)

2.9

Americamysis bahia

Moderate

Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)

10.0

Chironomus riparius 1 day

Moderate

Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l⁻¹)

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

9.5

Chironomus riparius

Moderate

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

0.017

Lemna gibba

Moderate

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

0.016

Raphidocelis subcapitata 72 hr

Moderate

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

0.01

Unknown species

Moderate

Mesocosm study data

NOEAEC mg l⁻¹

Marine bivalves – Acute EC₅₀ development (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)

1146

Rat

Moderate

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 0.85

Rat 4 hr (nose only aerosol)

Other Mammal toxicity endpoints

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

0.003

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

None allocated

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

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

0.0063

Dermal penetration studies (%)

0.5-3.0

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

Minimal risk from dietary exposure
Risk assessment indicates ARfD would not normally be execeeded

Occupational

Occupational exposure may occur through inhalation and dermal contact

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

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

May cause nausea, vomiting, and diarrhoea if ingested
US EPA - possible human carcinogen; CLP data - suspected carcingen
Endocrine issues - Competitive binding to androgen receptor, thyroid receptor agonist

Handling issues

Property

Value and interpretation

General

IMDG Transport Hazard Class 9
Not explosive or oxidising
Not expected to auto-ignite; Not highly flammable

CLP classification 2013

Health: H302, H351, H360Df, H373
Environment: H400, H410

WHO Classification

III (Slightly hazardous)

UN Number

UN3077

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

linuron

French

linuron

German

Linuron

Danish

linuron

Italian

linuron

Spanish

linuron

Greek

linuron

Polish

linuron

Swedish

Hungarian

linuron

Dutch

linuron

Norwegian

Record last updated:	22/08/2024
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