Metsulfuron-methyl (Ref: DPX T6376)

Metsulfuron-methyl (Ref: DPX T6376)	Last updated: 09/05/2025
(Also known as: metsulfuron; IN T6376)

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 High alert: GUS: High leachability; Drainflow: Very mobile	Ecotoxicity Moderate alert: Birds chronic ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate; Daphnia chronic ecotoxicity: Moderate; Bees acute contact ecotoxicity: Moderate; Bees acute oral ecotoxicity: Moderate; Earthworms chronic ecotoxicity: Moderate	Human health Moderate alert: Reproduction/development effects

GENERAL INFORMATION

Description

A herbicide used to control weeds mainly in cereals and land temporarily removed from production. It is also be a pesticide transformation product.

Example pests controlled

Broadleaved weeds; Some annual grasses

Example applications

Spring & winter cereals; Land removed from production

Efficacy & activity

Availability status

Current

Introduction & key dates

1983, first reported; 1984, first approvals

GB regulatory status

GB COPR regulatory status

Approved

Date COPR inclusion expires

30/09/2027

GB LERAP status

Check label - may vary with formulation

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Slovenia/Sweden

Date EC 1107/2009 inclusion expires

31/08/2026

EU Candidate for substitution (CfS)

Yes - two 'Persistent-Bioaccumulative-Toxic' criteria

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; Morocco

Chemical structure

Isomerism

None

Chemical formula

C₁₄H₁₅N₅O₆S

Canonical SMILES

CC1=NC(=NC(=N1)OC)NC(=O)NS(=O)(=O)C2=CC=CC=C2C(=O)OC

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

RSMUVYRMZCOLBH-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C14H15N5O6S/c1-8-15-12(18-14(16-8)25-3)17-13(21)19-26(22,23)10-7-5-4-6-9(10)11(20)24-2/h4-7H,1-3H3,(H2,15,16,17,18,19,21)

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Metabolite Type

Soil

Substance groups

Sulfonylurea Herbicide; Triazinylsulfonylurea herbicide

Minimum active substance purity

967 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Selective, systemic with contact and residual action. Inhibits plant amino acid synthesis - acetohydroxyacid synthase AHAS

CAS RN

74223-64-6

EC number

616-063-8

CIPAC number

441.201

US EPA chemical code

122010

PubChem CID

52999

CLP index number

613-139-00-2

Molecular mass

381.36

PIN (Preferred Identification Name)

IUPAC name

methyl 2-(4-methoxy-6-methyl-1,3,5-triazin-2-ylcarbamoylsulfamoyl)benzoate

CAS name

methyl 2-(((((4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino)carbonyl)amino)sulfonyl)benzoate

Other status information

PAN listed Highly Hazardous Chemical

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 rigidum, Bacopa rotundifolia

Physical state

White to pale yellow solid with charcateristic odour

Related substances & organisms

metsulfuron

Can be a metabolite of:

Parent

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

iodosulfuron-methyl-sodium

Soil

0.885

Major fraction

iodosulfuron-methyl-sodium

Groundwater

Relevant

iodosulfuron

Soil

0.885

Major fraction

iodosulfuron

Groundwater

Relevant

Formulations

Property

Value

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

AgriGuard
Clayton
DuPont
Headland
Nufarm

Example products using this active

Ally Express
Ally Max
Ally 20 SG
Cimarron
Concert
Finish
Minx PX
Pike
Nufarm Associate

Formulation and application details

Often supplied as wettable or water soluble granules or as a dry flowable formulation

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

2790

at 25 °C

High

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

0.058

n-Hexane

37000

Acetone

763

Methanol

124

Toluene

Melting point (°C)

162

Boiling point (°C)

Degradation point (°C)

164

Flashpoint (°C)

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

1.35 X 10^-02

Calculated

Log P

-1.87

Low

Fat solubility of residues

Solubility

Insoluble

Data type

Regulatory data based on LogP

Density (g ml⁻¹)

1.45

Dissociation constant pKa) at 25 °C

3.75

Weak acid

Vapour pressure at 20 °C (mPa)

1.0 X 10^-06

Low volatility

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

2.87 X 10^-06

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

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

pH 1.8: 235nm=15752
pH 7.0: 235nm=16032
pH 10: 235nm=14658

Surface tension (mN m⁻¹)

71.7

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

Non-persistent

DT₅₀ (lab at 20 °C)

23.2

Non-persistent

DT₅₀ (field)

13.3

Non-persistent

DT₉₀ (lab at 20 °C)

102.4

Persistent

DT₉₀ (field)

54.8

DT₅₀ modelling endpoint

Note

EU dossier (2015) lab studies DT₅₀ range 6.4-48.8 days 8 soils, DT₉₀ range 48-175 days; field studies DT₅₀ range 7.3-37.1 days, DT₉₀ range 24.3-123 days Soils =4

Dissipation rate RL₅₀ (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

5.2

Note

Published literature RL₅₀ range 4.8-5.6 days, 2 cereal crops, whole plant, n=2

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Stable

Note

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

Value

Stable

Note

DT₅₀ 22 days at pH 5, stable at pH 7 and pH 9, all at 25 °C

Water-sediment DT₅₀ (days)

224.3

Slow

Water phase only DT₅₀ (days)

115

Stable

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)

0.77

Very mobile

K_foc (mL g⁻¹)

12.0

¹/_n

0.98

Notes and range

EU 2015 dossier K_f range 0.1-4.9 mL g⁻¹, K_foc range 4-207 mL g⁻¹, Soils=16

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

3.28

Calculated

High leachability

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

Value

1.83 X 10^-01

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Very mobile

Calculated

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

49.79

Calculated using the Atkinson method. Assumed 1.5E+06 OH/cm³, 12 hr

Substance of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

(Other literature Log BCF range 0.0-1.6 (R3))

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

methyl 2-sulfamoylbenzoate (Ref: IN D5803)

Major fraction

0.487

2-(aminosulfonyl) benzoic acid (Ref: IN D5119)

Major fraction

0.059

phenylurea (Ref: IN B5685)

Major fraction

Formed from IN-D5803

1,2-benzisothiazol-3(2H)-one,1,1-dioxide (Ref: IN 00581)

Minor fraction

0.087

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

Major fraction

0.423

metsulfuron (Ref: IN F5438)

Major fraction

0.156

methyl 2-{[(4-hydroxy-6-methyl-1,3,5-triazin-2-yl)carbamoyl]sulfamoyl}benzoate (Ref: IN-B5067)

Major fraction

0.162

methyl 2-{[(Ncarbamoylcarbamimidoyl)sulfamoyl}benzoate (Ref: IN-NC148)

Major fraction

0.230

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

Minor fraction,

0.092

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

Major fraction

0.128

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

Relevancy unknown

1,2-benzisothiazol-3(2H)-one,1,1-dioxide (Ref: IN 00581)

Not relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

metsulfuron (Ref: IN F5438)

Surface water; Sediment

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

Surface water; Sediment

methyl 2-sulfamoylbenzoate (Ref: IN D5803)

Surface water; Sediment

1,2-benzisothiazol-3(2H)-one,1,1-dioxide (Ref: IN 00581)

saccharin

Surface water; Sediment

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

Surface water; Sediment

methyl 2-{[(Ncarbamoylcarbamimidoyl)sulfamoyl}benzoate (Ref: IN-NC148)

Surface water; Sediment

methyl 2-{[(4-hydroxy-6-methyl-1,3,5-triazin-2-yl)carbamoyl]sulfamoyl}benzoate (Ref: IN-B5067)

Surface water; Sediment

2-{[(4-hydroxy-6-methyl-1,3,5-triazin-2-yl)carbamoyl]sulfamoyl}benzoic acid (Ref: IN-JX909)

Surface water

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)

> 500

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

> 342

Rat Reproductive NOAEL

Low

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2510

Anas platyrhynchos

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

> 5620 mg kg feed⁻¹

Anas platyrhynchos

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

100

Anas platyrhynchos

Moderate

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

> 1000

Eisenia foetida

Low

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

>= 0.83

Eisenia foetida

Moderate

Soil micro-organisms

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

Dose: 0.2 mg kg⁻¹ soil

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

>= 250

Folsomia candida

Non-target plants

0.054

White mustard
Vegetative vigour, ER₅₀
as g ha⁻¹

Honeybees (Apis spp.)

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

> 50

Apis mellifera

Moderate

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

> 44.3

Apis mellifera

Moderate

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) as Mortality LR₅₀ g ha⁻¹

> 8.0

Chrysoperla carnea

Beneficial insects (Parasitic wasps) as Mortality LR₅₀ g ha⁻¹

> 76.8

Aphidius rhopalosiphi

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

30.7

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)

> 113

Oncorhynchus mykiss

Low

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

68.0

Salmo gairdneri

Low

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

> 110

Poecilia reticulata

Low

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

> 43.1

Daphnia magna

Moderate

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

3.13

Daphnia magna

Moderate

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

> 0.2

Ceriodaphnia dubia LC₅₀

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 (free-floating, growth) - Acute 7 day EC₅₀, biomass (mg l⁻¹)

0.00036

Lemna gibba

High

Aquatic plants (rooted, growth) - Acute 14 day EC₅₀, biomass (mg l⁻¹)

0.0003

Myriophyllum spicatum

High

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

0.113

Anabaena flos-aquae

Moderate

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

0.02

Unknown species

Moderate

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)

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 6.2

Rat 4 hr (nose only)

Other Mammal toxicity endpoints

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

0.22

Rat SF=100

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

0.25

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

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

0.25

Dermal penetration studies (%)

25-75

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

No unacceptable risks to bystanders identified

Occupational

No unacceptable risks to operators or other workers identified

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

No further information available

Handling issues

Property

Value and interpretation

General

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

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

Chemically stable under standard ambient condiions

TRANSLATIONS

Language

Name

English

metsulfuron-methyl

French

metsulfuron-methyle

German

Metsulfuron-methyl

Danish

metsulfuron-methyl

Italian

metsulfuron-metile

Spanish

metsulfuron-metil

Greek

metsulfuron-methyl

Polish

metsulfuron metylu

Swedish

metsulfuronmetyl

Hungarian

metsulphuron-methyl

Dutch

metsulfuron methyl

Norwegian

metsulfuron-metyl

Record last updated:	09/05/2025
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