Metobromuron (Ref: C 3216)

Metobromuron (Ref: C 3216)	Last updated: 12/01/2021
(Also known as: monobromuron; metbromuron; metobromurone)

SUMMARY

Metobromuron is a herbicide currently approved for use in the EU. It is moderately soluble in water, is quite volatile and there is a moderate risk that it may leach to groundwater. It is moderately persistent in soil systems and may also be persistent in water bodies, depending upon conditions. It has a low mammalian toxicity but has a high potential to bioaccumulate. It is classified as an irritant. It is moderately toxic to birds and most aquatic organisms and earthworms but it is not considered toxic to honeybees.

GENERAL INFORMATION

Description

A herbicide used pre-emergence and applied to soil surface for the control weeds and grasses

Example pests controlled

Broad-leaved weeds including chickweed, black bindweed, charlock, fat hen, knotgrass, field pansy; Grasses including annual meadow grass, coskspur grass, foxtails

Example applications

Sunflowers; Potatoes; Tomatoes; Soybeans; Tobacco

Efficacy & activity

Availability status

Current

Introduction & key dates

circa 1965

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

31/12/2024

UK LERAP status

None

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

France

Date EC 1107/2009 inclusion expires

31/12/2024

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
	✓	✓	✓	✓	✓	✓	✓

Also used in

Chemical structure

Isomerism

Chemical formula

C₉H₁₁BrN₂O₂

Canonical SMILES

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

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

WLFDQEVORAMCIM-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C9H11BrN2O2/c1-12(14-2)9(13)11-8-5-3-7(10)4-6-8/h3-6H,1-2H3,(H,11,13)

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
metobromuron	-

General status

Pesticide type

Herbicide

Substance group

Urea

Minimum active substance purity

978 g kg⁻¹

Known relevant impurities

EU dossier - none declared

Substance origin

Synthetic

Mode of action

Photosynthetic electron transport inhibitor at the photosystem II.

CAS RN

3060-89-7

EC number

221-301-5

CIPAC number

168

US EPA chemical code

035901

PubChem CID

18290

Molecular mass

259.10

PIN (Preferred Identification Name)

IUPAC name

3-(4-bromophenyl)-1-methoxy-1-methylurea

CAS name

N'-(4-bromophenyl)-N-methoxy-N-methylurea

Other status information

Possible groundwater pollutant; PAN listed Highly Hazardous Chemical

Relevant Environmental Water Quality Standards

Herbicide Resistance Classification (HRAC)

Herbicide Resistance Classification (WSSA)

Insecticide Resistance Classification (IRAC)

Not applicable

Fungicide Resistance Classification (FRAC)

Not applicable

Examples of recorded resistance

Physical state

Colourless to pale yellow crystals with a musty odour

Formulations

Property

Value

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

Metobromuron 500 SC
Patoran
Pattonex
Praxim

Example products using this active

Belchim
Ciba-Geigy
BASF
Makhteshim Agan

Formulation and application details

Usually supplied as a wettable powder or suspension concentrate

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

328

Moderate

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

500000

Acetone

10000

Hexane

250000

Methanol

250000

Ethyl acetate

Melting point (°C)

95.6

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

173.2

Flashpoint (°C)

Not expected to self ignite; Not highly flammable

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

3.02 X 10⁰²

Calculated

Log P

2.48

Low

Bulk density (g ml⁻¹)

1.52

Dissociation constant pKa) at 25 °C

12.0

Vapour pressure at 20 °C (mPa)

0.219

Low volatility

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

1.1 X 10^-04

Non-volatile

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

Surface tension (mN m⁻¹)

72.2

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

34.3

Moderately persistent

DT₅₀ (lab at 20 °C)

34.3

Moderately persistent

DT₅₀ (field)

22.4

Non-persistent

DT₉₀ (lab at 20 °C)

112

Persistent

DT₉₀ (field)

141

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀ range 24.6-49.7 days, DT₉₀ range 81.3-165.1 days; Field studies DT₅₀ range 5.4-64.5 days; Other sources: DT₅₀ 24-43 days (R3)

Dissipation rate RL₅₀ on plant matrix

Value

Note

Dissipation rate RL₅₀ 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

170

Persistent

Note

Water-sediment DT₅₀ (days)

33.8

Moderately fast

Water phase only DT₅₀ (days)

16.2

Slow

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

Moderately mobile

K_oc

197

Notes and range

Freundlich

K_f

3.87

Moderately mobile

K_foc

160

¹/_n

0.89

Notes and range

EU dossier K_f range 2.30-7.82 mL g⁻¹, K_foc range 122-199 mL g⁻¹, ¹/_n range 0.84-0.93, soils=5

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

2.42

Calculated

Transition state

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

Value

1.14 X 10^-01

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Moderately mobile

Calculated

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

desmethoxy-metobromuron (Ref: CGA 18236)

Soil

0.051

Minor fraction, Relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

4-bromophenylurea (Ref: CGA 18237)

metobromuron metabolite R3

Plant

1-methoxy-1-methyl-3-phenylurea (Ref: HHAC-022)

metobromuron metabolite R6

3-(4-hydroxyphenul)-1-methoxy-1-methylurea (Ref: HHAC-063)

metobromuron metabolite R10

1-(4-hydroxyphenyl)-3-methylurea (Ref: HHAC-065)

metobromuron metabolite R11

1-methyl-3-phenylurea

metobromuron metabolite R9

3-hydroxy-4-bromoaniline (Ref: CGA 14118)

4-hydroxy-5-bromoaniline (Ref: CGA 14120)

3-(4-hydroxyphenyl)-1-hydroxy-1-methylurea (Ref: CGA 14652)

4-bromoaniline

metobromuron metabolite R4

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

Low risk

Based on LogP < 3

Low risk

CT₅₀ (days)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 10000

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat 2 year

(ppm diet)

250

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

> 16.03

Rat Reproductive NOAEL

Moderate

Birds - Acute LD₅₀ (mg kg⁻¹)

1429

Coturnix japonica

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

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

21.6

Colinus virginianus NOEL

Moderate

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

43.0

Oncorhynchus mykiss

Moderate

Fish - Chronic 21 day NOEC (mg l⁻¹)

0.25

Pimephales promelas

Moderate

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

44.1

Daphnia magna

Moderate

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

>= 10

Daphnia magna

Moderate

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)

0.31

Lemna gibba

Moderate

Non-target plants

0.77

Lycopersicon esculentum
Vegetative vigour, mortality, EC₅₀
as L product ha⁻¹

> 7.5

Allium cepa
Seedling emergence, EC₅₀
as L product ha⁻¹

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

0.63

Scenedemus subspicatus

Moderate

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

119.1

Apis mellifera

Low

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 pollinators (1)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

Other pollinators (2)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

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

233

Eisenia foetida corr

Moderate

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

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

23.66

Folsomia candida corr

Other arthropod (1)

LR₅₀ g ha⁻¹

51.2

Mortality
Typhlodromus pyri

% Effect

Other arthropod (2)

LR₅₀ g ha⁻¹

4098

>, Mortality
Aphidius rhopalosiphi

% Effect

Soil micro-organisms

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

Dose: 65.9mg kg⁻¹ soil 84days

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)

> 10000

Rat

Low

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

3000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 1.6

Rat 4 hr (nose only)

Other Mammal toxicity endpoints

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

0.008

Mouse SF=100

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

0.3

Rat SF=300

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

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

0.016

Dog SF=100

Dermal penetration studies (%)

0.5-6.3

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

Very low risk for proposed uses

Occupational

Low risk for proposed uses

European MRLs

EU MRL pesticide database

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

No data found

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

No data found

Respiratory tract irritant

Skin irritant

Skin sensitiser

Eye irritant

Phototoxicant

No data found

General human health issues

Possible blood, spleen and bone marrow toxicant
Possible allergen

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising

CLP classification 2013

Health: H302, H332, H317, H373
Environment: H410

EC Risk Classification

Carcinogen category 3: R40
Xn - Harmful: R22, R43, R48
N - Dangerous for thE environment: R50/53

EC Safety Classification

S36/37, S60, S61

WHO Classification

III/O (Slightly hazardous / Obsolete substance)

UN Number

Waste disposal & packaging

TRANSLATIONS

Language

Name

English

metobromuron

French

metobromuron

German

Metobromuron

Danish

metobromuron

Italian

bromuro di metile

Spanish

bromuro de metilo

Greek

Polish

metobromuron

Swedish

Hungarian

Dutch

Record last updated:	12/01/2021
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