Chlorbromuron (Ref: C6313)	Last updated: 22/12/2020
(Also known as: chlorobromuron)

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SUMMARY

Chorbromuron is an obsolete herbicide. It has a low aqueous solubility, low volatility and, under normal conditions, would not be expected to leach to groundwater. Whilst not usually persistent in water bodies it can be persistent in soils. It is not highly toxic to humans if ingested but there is a data gap regarding other health issues. There is also a gap in available ecotoxicity data but based on data does exist it tends to be moderately toxic.

GENERAL INFORMATION

Description	An obsolete pre- and post-emergence herbicide once used for annual grass and for broad-leaved weeds on a wide variety of crops
Example pests controlled	Foxtail; Crabgrass; Goosegrass; Chickweed
Example applications	Potaoes; Tobacco; Peanuts; Soybeans; Sunflowers; Flax; Corn; Potatoes; Cereals
Efficacy & activity	-
Availability status	Obsolete
Introduction & key dates	circa 1967

UK regulatory status

UK COPR regulatory status	Not approved
Date COPR inclusion expires	Expired
UK LERAP status	No UK approval for use

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status	Not approved
Dossier rapporteur/co-rapporteur	Not applicable
Date EC 1107/2009 inclusion expires	Expired
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

Also used in	-

Chemical structure

Isomerism	None
Chemical formula	C₉H₁₀BrClN₂O₂
Canonical SMILES	CN(C(=O)NC1=CC(=C(C=C1)Br)Cl)OC
Isomeric SMILES	No data
International Chemical Identifier key (InChIKey)	NLYNUTMZTCLNOO-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/C9H10BrClN2O2/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
chlorbromuron	-

General status

Pesticide type	Herbicide
Substance group	Urea
Minimum active substance purity	-
Known relevant impurities	-
Substance origin	Synthetic
Mode of action	Photosynthetic electron transport inhibitor at the photosystem II. Sective, absorbed via roots and translocated
CAS RN	13360-45-7
EC number	236-411-9
CIPAC number	186
US EPA chemical code	090701
PubChem CID	25912
Molecular mass	293.5
PIN (Preferred Identification Name)	N'-(4-bromo-3-chlorophenyl)-N-methoxy-N-methylurea
IUPAC name	3-(4-bromo-3-chlorophenyl)-1-methoxy-1-methylurea
CAS name	N'-(4-bromo-3-chlorophenyl)-N-methoxy-N-methylurea
Other status information	Phytotoxic to a variety of crops post-emergence including rice, beet, tomatoes and strawberries
Relevant Environmental Water Quality Standards	-
Herbicide Resistance Classification (HRAC)	C2
Herbicide Resistance Classification (WSSA)	7
Insecticide Resistance Classification (IRAC)	Not applicable
Fungicide Resistance Classification (FRAC)	Not applicable
Examples of recorded resistance	-
Physical state	Colourless powder

Formulations

Property	Value
Example manufacturers & suppliers of products using this active now or historically	Maloran 50WP
Example products using this active	Ciba-Geigy Ltd Syngenta
Formulation and application details	Usually formulated as a wettable powder

ENVIRONMENTAL FATE

Property		Value	Source; quality score; and other information	Interpretation
Solubility - In water at 20 °C (mg l⁻¹)		35	K4 K = Research datasets, e.g. Pandora, Demetra 4 = Verified data	Low
Solubility - In organic solvents at 20 °C (mg l⁻¹)		460000	CA3 CA = Medical and toxicological databases and information systems e.g. TOXNET (click here ) 3 = Unverified data of known source Acetone	-
		170000	CA3 CA = Medical and toxicological databases and information systems e.g. TOXNET (click here ) 3 = Unverified data of known source Dichloromethane	-
		89000	CA3 CA = Medical and toxicological databases and information systems e.g. TOXNET (click here ) 3 = Unverified data of known source Hexane	-
		72000	CA3 CA = Medical and toxicological databases and information systems e.g. TOXNET (click here ) 3 = Unverified data of known source Benzene	-
Melting point (°C)		96	CA3 CA = Medical and toxicological databases and information systems e.g. TOXNET (click here ) 3 = Unverified data of known source	-
Boiling point (°C)		-	-	-
Degradation point (°C)		-	-	-
Flashpoint (°C)		-	-	-
Octanol-water partition coefficient at pH 7, 20 °C	P	1.23 X 1003	Calculated	-
	Log P	3.09	V3 V = ChemID online databases / IPCS INCHEM (ChemID; IPCS INCHEM ) 3 = Unverified data of known source	High
Bulk density (g ml⁻¹)		1.69	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
Dissociation constant pKa) at 25 °C		-	-	-
		-
Vapour pressure at 20 °C (mPa)		0.053	K4 K = Research datasets, e.g. Pandora, Demetra 4 = Verified data	Low volatility
Henry's law constant at 25 °C (Pa m³ mol⁻¹)		2.63 X 10-04	H4 H = The US ARS pesticide properties database (click here ) 4 = Verified data	Non-volatile
Maximum UV-vis absorption L mol⁻¹ cm⁻¹		-	-	-
Surface tension (mN m⁻¹)		-	-	-

Degradation

Property		Value	Source; quality score; and other information	Interpretation
General biodegradability		-
Soil degradation (days) (aerobic)	DT₅₀ (typical)	39	K4 K = Research datasets, e.g. Pandora, Demetra 4 = Verified data	Moderately persistent
	DT₅₀ (lab at 20 °C)	40	Q2 Q = Miscellaneous internet resources 2 = Unverified data of unknown source	Moderately persistent
	DT₅₀ (field)	36.5	R4 R = Peer reviewed scientific publications 4 = Verified data	Moderately persistent
	DT₉₀ (lab at 20 °C)	-	-	-
	DT₉₀ (field)	-	-	-
	DT₅₀ modelling endpoint	-	-	-
	Note	Best available data: persists for more than 8 days (CA2)
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	-	-	-
	Note	-
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7	Value	-	-	-
	Note	-
Water-sediment DT₅₀ (days)		52	K4 K = Research datasets, e.g. Pandora, Demetra 4 = Verified data	Moderately fast
Water phase only DT₅₀ (days)		-	-	-

Soil adsorption and mobility

Property		Value	Source; quality score; and other information	Interpretation
Linear	Kd	-	H3 H = The US ARS pesticide properties database (click here ) 3 = Unverified data of known source	Moderately mobile
	Koc	470
	Notes and range	Other sources: Koc range 217 to 3262 mL g⁻¹ (R3)
Freundlich	Kf	-	-	-
	Kfoc	-
	1/n	-
	Notes and range	-
pH sensitivity		-

Fate indices

Property		Value	Source; quality score; and other information	Interpretation
GUS leaching potential index		2.07	Calculated	Transition state
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate	Value	8.30 X 10-02	Calculated	-
	Note	-
Potential for particle bound transport index		Low	Calculated	-
Potential for loss via drain flow		Moderately mobile	Calculated	-

ECOTOXICOLOGY

Property		Value	Source; quality score; and other information	Interpretation
Bio-concentration factor	BCF (l kg⁻¹)	68	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source (whole fish)	Low potential
	CT₅₀ (days)	Not available		-
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		> 2150	V3 V = ChemID online databases / IPCS INCHEM (ChemID; IPCS INCHEM ) 3 = Unverified data of known source 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)		> 10250	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Anas platyrhynchos	Low
Birds - Short term dietary (LC₅₀/LD₅₀)		-	-	-
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Fish - Acute 96 hour LC₅₀ (mg l⁻¹)		5	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data Oncorhynchus mykiss	Moderate
Fish - Chronic 21 day NOEC (mg l⁻¹)		-	-	-
Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		5.8	K3 K = Research datasets, e.g. Pandora, Demetra 3 = Unverified data of known source Unknown species	Moderate
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)		-	-	-
Non-target plants		-	-	-
		-	-	-
Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)		0.017	K2 K = Research datasets, e.g. Pandora, Demetra 2 = Unverified data of unknown source Unknown species	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)	16	K4 K = Research datasets, e.g. Pandora, Demetra 4 = Verified data	Moderate
	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 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)		-	-	-
Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)		-	-	-
Other soil macro-organisms	Acute LC₅₀ (mg kg⁻¹)	-	-	-
	Chronic NOEC (mg kg⁻¹)	-	-	-
Other arthropod (1)	LR₅₀ g ha⁻¹	-	-	-
	% Effect	-	-	-
Other arthropod (2)	LR₅₀ g ha⁻¹	-	-	-
	% Effect	-	-	-
Soil micro-organisms		-	-	-
Mesocosm study data	NOEAEC mg l⁻¹	-	-	-
	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)		> 2150	V3 V = ChemID online databases / IPCS INCHEM (ChemID; IPCS INCHEM ) 3 = Unverified data of known source Rat	Low
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)		2000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Rat	-
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	Public	Consumers may be exposed through the ingestion of contaminated food
	Occupational	Occupational exposure may be through inhalation or dermal contact
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 XNo, known not to cause a problem 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 No data found Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant No data found XNo, known not to cause a problem XNo, known not to cause a problem Respiratory tract irritant Skin irritant Skin sensitiser No data found ?Possibly, status not identified No data found Eye irritant Phototoxicant   ?Possibly, status not identified No data found
General human health issues		Chronic exposure may cause protein metabolism disturbances, emphysema, and weight loss

Handling issues

Property	Value and interpretation
General	No information available
CLP classification 2013	Health: H315, H319, H332
EC Risk Classification	Not classified: Obsolete
EC Safety Classification	Not classified: Obsolete
WHO Classification	O (Obsolete substance)
UN Number	-
Waste disposal & packaging	-

TRANSLATIONS

Language	Name
English	chlorbromuron
French	chlorbromuron
German	Chlorbromuron
Danish	chlorbromuron
Italian	clorbromuron
Spanish	clorbromuron
Greek	-
Polish	chlorbromuron
Swedish	-
Hungarian	-
Dutch	chloorbromuron

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Record last updated:	22/12/2020
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