Chlorsulfuron (Ref: DPX 4189)

Chlorsulfuron (Ref: DPX 4189)	Last updated: 25/08/2024
(Also known as: W 4189)

SUMMARY

Chlorsulfuron is a sulfonylurea herbicide used to control broad-leaved weeds mainly in cereals. It is highly soluble in water and non-volatile, and hence has a low drift potential. It tends to be moderately persistent in soil systems and can also be persistent in aquatic systems depending on conditions. Its physico-chemical properties suggest it has potential to leach to groundwater. For most fauna and flora species it has a low to moderate toxicity. Chlorsulfuron also has a low mammalian toxicity and no data has been found that suggests it may cause serious adverse health impacts unless exposure is high.

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 High alert: GUS: High leachability; Drainflow: Mobile	Ecotoxicity Moderate alert: Earthworms acute ecotoxicity: Moderate	Human health Moderate alert: Endocrine disrupter; Reproduction/development effects

GENERAL INFORMATION

Description

A herbicide used to control most broad-leaved and some grass weeds

Example pests controlled

Velvetleaf; Shepherd's purse; Paradoxa grass; Canada thistle; Pidgweed; Henbit; Plantain; Docks; Cocklebur; Hogweed; Rough poppy

Example applications

Cereals including wheat, barley, triticale, oats; Flax

Efficacy & activity

Availability status

Current

Introduction & key dates

1982, introduced

GB regulatory status

GB COPR regulatory status

Not approved

Date COPR inclusion expires

Expired

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

Greece

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
			✓		✓			✓

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

Australia, USA

Chemical structure

Isomerism

None

Chemical formula

C₁₂H₁₂ClN₅O₄S

Canonical SMILES

CC1=NC(=NC(=N1)OC)NC(=O)NS(=O)(=O)C2=CC=CC=C2Cl

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

VJYIFXVZLXQVHO-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C12H12ClN5O4S/c1-7-14-10(17-12(15-7)22-2)16-11(19)18-23(20,21)9-6-4-3-5-8(9)13/h3-6H,1-2H3,(H2,14,15,16,17,18,19)

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
chlorsulfuron	-

General status

Pesticide type

Herbicide

Substance groups

Sulfonylurea herbicide; Triazinylsulfonylurea herbicide

Minimum active substance purity

950 g kg⁻¹

Known relevant impurities

EU dossier - 2-chlorobenzenesulfonamide, 4-methoxy-6-methyl-1,3,5-triazin-2-amine

Substance origin

Synthetic

Mode of action

Selective, systemic, absorbed by roots and foliage, acts by inhibiting cell division. Inhibits plant amino acid synthesis - acetohydroxyacid synthase AHAS

CAS RN

64902-72-3

EC number

265-268-5

CIPAC number

391

US EPA chemical code

118601

PubChem CID

47491

CLP index number

613-121-00-4

Molecular mass

357.77

PIN (Preferred Identification Name)

2-chloro-N-[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)carbamoyl]benzene-1-sulfonamide

IUPAC name

1-(2-chlorophenylsulfonyl)-3-(4-methoxy-6-methyl-1,3,5-triazin-2-yl)urea

CAS name

2-chloro-N-(((4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino)carbonyl)benzenesulfonamide

Other status information

Potential groundwater contaminant; PAN Bad Actor Chemical;[ Marine pollutan

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

Lolium perenne, Lolium rigidum, Alopecurus myosuroides, Kochia scoparia

Physical state

White crystalline solid

Formulations

Property

Value

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

DuPont
King Tech
Pacific Agriscience Pte. Ltd
Nufarm
Cheminova

Example products using this active

Master
Trisufron
Lasher
Pilargreen
Glean
Chisum
Chlormmet
Alligare Chlorsulfuron 75

Formulation and application details

Usually supplied as a dry flowable concentrate

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

12500

High

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

37000

Acetone

140000

Dichloromethane

15000

Methanol

2800

Toluene

Melting point (°C)

173

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

150

Flashpoint (°C)

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

1.02 X 10^-01

Calculated

Log P

-0.99

Low

Fat solubility of residues

Solubility

Not relevant - no significant residues in livestock feed

Data type

Regulatory data

Density (g ml⁻¹)

1.48

Dissociation constant pKa) at 25 °C

3.4

Weak acid

Vapour pressure at 20 °C (mPa)

3.07 X 10^-06

Low volatility

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

3.50 X 10^-11

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 solution: 236nm = 26399, 204nm = 31320, 236nm = 26284
Acidic solution pH2: 202nm = 42552, 205nm = 32941, 222nm = 23968
Basic solution pH10: 203nm = 33752, 236nm = 26399

Surface tension (mN m⁻¹)

73.1

at 20.5°C

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

160

Persistent

DT₅₀ (lab at 20 °C)

51.4

Moderately persistent

DT₅₀ (field)

36.2

Moderately persistent

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

120.3

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀ range 10.4-187.4 days, field studies DT₅₀ range 11.2-70.1 days, DT₉₀ range 8.3-232.9 days; Other sources: field studies DT₅₀ range 10-185 days

Dissipation rate RL₅₀ (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

0.4

Note

Published literature RL₅₀ range 0.2-0.5 days, ryegrass, various matrices, n=2

Aqueous photolysis DT₅₀ (days) at pH 7

Value

18.8

Slow

Note

Not a major degradation route. DT₅₀ 18.8 days at pH 5 in light, 100 days discounting hydrolytic degradation

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

Value

Stable

Note

pH sensitive: DT₅₀ 2.23 days at pH 5, stable pH 7 to pH 9, all at 25 °C

Water-sediment DT₅₀ (days)

Fast

Water phase only DT₅₀ (days)

Slow

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)

0.42

Mobile

K_foc (mL g⁻¹)

36.3

¹/_n

0.89

Notes and range

EU dossier kf range 0.09-0.91 mL g⁻¹, K_foc range 14.1-60.2 mL g⁻¹, ¹/_n range 0.85-0.91, Soils=4; Literature mean: K_f = 1.6 mL g⁻¹, K_foc = 456 mL g⁻¹, 1.n = 0.78, Soils = 4

pH sensitivity

Greater adsoption at lower pH. Organic Carbon content also increases adsoprtion.

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

3.80

Calculated

High leachability

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

Value

7.63 X 10^-01

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Mobile

Calculated

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

Bio-concentration factor

BCF (l kg⁻¹)

Low potential

CT₅₀ (days)

Not available

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

2-chlorobenzenesulfonamide (Ref: IN A4097)

Major fraction

0.775

2-amino-4-methoxy-6-methyl-1,3,5-triazine (Ref: CGA 150829)

Major fraction

0.659

N-((N-carbamoylcarbamimidoyl)carbamoyl)-2-chlorobenzenesulfonamide (Ref: IN JJ998)

Major fraction

0.267

1-(4-methoxy-6-methyl-1,3,5-triazine-2-yl)urea (Ref: IN-V7160)

2-chloro-N-[(4-hydroxy-6-methyl-1,3,5-triazin-2-yl)carbamoyl]benzenesulfonamide (Ref: IN-M6957)

2-chlorophenylsulfonylurea (Ref: IN-D5293)

4-amino-6-methyl-1,3,5-triazin-2-ol (Ref: IN-B5528)

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)

2-chlorobenzenesulfonamide (Ref: IN A4097)

Relevant

0.009

2-amino-4-methoxy-6-methyl-1,3,5-triazine (Ref: CGA 150829)

Relevant

0.20

1200

N-((N-carbamoylcarbamimidoyl)carbamoyl)-2-chlorobenzenesulfonamide (Ref: IN JJ998)

Relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

2-chloro-5-hydroxy-N-[[(4-methoxy-6-methyl-1,3,5-trazi-2yl)amino]-carbonyl]benzenesulfonamide (Ref: IN-N5754)

Plant

2-chloro-N-[(4-hydroxy-6-methyl-1,3,5-triazin-2-yl)carbamoyl]benzenesulfonamide (Ref: IN-M6957)
Note: Highly mobile

Plant

2-chloro-5-hydroxybenzenesulfonamide (Ref: IN-A5760)

Animal

2-chloro-5-(beta-D-glucopyranosyloxy)-N-[[(4-methoxy-6-methyl-1,3,5-trazi-2-yl)amino]-carbonyl]benzenesulfonamide (Ref: IN-69182)

Plant

2-chloro-5-(â-D-glucopyranosyloxy)-benzenesulfonamide

chlorsulfuron metabolite B

Plant

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 5000

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat 2 yr

(ppm diet)

> 100

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

Birds - Acute LD₅₀ (mg kg⁻¹)

> 5000

Anas platyrhynchos

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

> 634 mg kg bw⁻¹ day⁻¹

Anas platyrhynchos

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

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

> 750

Eisenia foetida

Moderate

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

187.5

Eisenia foetida

Low

Soil micro-organisms

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

Dose: 0.025 mg kg⁻¹ soil

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

0.09

Sugarbeet
Vegetative vigour, ER₅₀
as g ha⁻¹

1.09

Pea
Seedling emergence, ER₅₀
as g ha⁻¹

Honeybees (Apis spp.)

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

> 100

Apis mellifera

Low

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

> 130

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) as Mortality LR₅₀ g ha⁻¹

> 56.25

Aphidius rhopalosiphi

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

> 56.25

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)

> 122

Oncorhynchus mykiss

Low

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

Oncorhynchus mykiss

Low

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

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

> 112

Daphnia magna

Low

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

Daphnia magna

Low

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

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

71.0

Americamysis bahia

Moderate

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)

0.00035

Lemna gibba

High

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

0.068

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)

> 5000

Rat

Low

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

3400

Rabbit

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 5.5

Rat 4 hr (nose only aerosol)

Other Mammal toxicity endpoints

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

0.2

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)

0.43

Dermal penetration studies (%)

100

default

Dangerous Substances Directive 76/464

Exposure Routes

Public

Negligible risk to bystanders

Occupational

Acceptable risks for operators and other workers

MRLs

European

EU MRL pesticide database

Great Britain

GB MRL Register

Notes

GB MRL expected to deviate from the EU MRL in mid-2023

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

No further information available

Handling issues

Property

Value and interpretation

General

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

CLP classification 2013

Environment: H400, H410

WHO Classification

U (Unlikely to present an acute hazard)

UN Number

UN3077

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

chlorsulfuron

French

chlorsulfuron

German

Chlorsulfuron

Danish

chlorsulfuron

Italian

clorsulfuron

Spanish

clorsulfuron

Greek

Polish

chlorosulfuron

Swedish

klorsulfuron

Hungarian

klorszulfuron

Dutch

Norwegian

Record last updated:	25/08/2024
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