Mesosulfuron-methyl (Ref: AE F130060)

Mesosulfuron-methyl (Ref: AE F130060)	Last updated: 11/08/2025
(Also known as: mesosulfuron)

SUMMARY

Hazard 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. These hazard alerts do not take account of usage patterns or exposure, thus do not represent risk.

Environmental fate	Ecotoxicity	Human health
Environmental fate High alert: GUS: High leachability	Ecotoxicity Moderate alert: Birds chronic ecotoxicity: Moderate; Daphnia chronic ecotoxicity: Moderate	Human health Moderate alert: Neurotoxicant

GENERAL INFORMATION

Description

A systemic herbicide used for post-emergence control of grasses and other weeds in cereals

Example pests controlled

Grasses including blackgrass; Broadleaved weeds

Example applications

Cereals including spring wheat, winter wheat, durum wheat, winter rye

Efficacy & activity

GB regulatory status

GB COPR regulatory status

Approved

Date COPR inclusion expires

30/06/2032

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

France/Poland

Date EC 1107/2009 inclusion expires

30/06/2032

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; Morocco

Chemical structure

Isomerism

None

Chemical formula

C₁₇H₂₁N₅O₉S₂

Canonical SMILES

COC1=CC(=NC(=N1)NC(=O)NS(=O)(=O)C2=C(C=CC(=C2)CNS(=O)(=O)C)C(=O)OC)OC

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

NIFKBBMCXCMCAO-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C17H21N5O9S2/c1-29-13-8-14(30-2)20-16(19-13)21-17(24)22-33(27,28)12-7-10(9-18-32(4,25)26)5-6-11(12)15(23)31-3/h5-8,18H,9H2,1-4H3,(H2,19,20,21,22,24)/f/h21-22H

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance groups

Sulfonylurea herbicide; Pirimidinylsulfonylurea herbicide

Minimum active substance purity

>955 g kg⁻¹

Known relevant impurities

EU dossier: None disclosed

Substance origin

Synthetic

Mode of action

Inhibits plant amino acid synthesis - acetohydroxyacid synthase AHAS

CAS RN

208465-21-8

EC number

606-653-3

CIPAC number

663.201

US EPA chemical code

122009

PubChem CID

11409499

CLP index number

607-729-00-9

Molecular mass

503.51

PIN (Preferred Identification Name)

methyl 2-[(4,6-dimethoxypyrimidin-2-ylcarbamoyl)sulfamoyl]-a-(methanesulfonamido)-p-toluate

IUPAC name

methyl 2-[(4,6-dimethoxypyrimidin-2-ylcarbamoyl)sulfamoyl]-a-(methanesulfonamido)-p-toluate

CAS name

methyl 2-[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]-4-[[(methylsulfonyl)amino]methyl]benzoate

Forever chemical

Other status information

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

Alopecurus myosuroides

Physical state

Pale yellow crystalline solid

Related substances & organisms

mesosulfuron

Commercial

Property

Value

Availability status

Current

Introduction & key dates

circa 2001, introduced

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

Bayer CropScience
Teliton

Example products using this active

Atlantis WG
Othello
Pacifica
Atlantis
Hussar Plus

Formulation and application details

Often supplied as an oil suspension

Commercial production

Mesosulfuron-methyl is produced through a complex multi-step chemical synthesis starting from 4-chloro-2-aminobenzoic acid and other readily available raw materials. The process involves eleven distinct reactions, including esterification, diazotization, sulfur dioxide introduction, oxychlorination, ammoniation cyclization, nitrogen methylation, cyanidation, reduction, ring opening, mesylation, and final condensation to form the active sulfonylurea compound

Impact on climate of production and use

Precise life cycle emissions are unpublished but Audsley et al. (2009) reported that it takes 659 MJ of energy per kg produced. This is equivalent to approximately 45.5 kg CO₂e. There will also be emissions associated with packaging, transport and application.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

483

Moderate

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

200

Hexane

13660

Acetone

2000

Ethyl acetate

130

Toluene

Melting point (°C)

195.4

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

190

Flashpoint (°C)

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

3.31 X 10^-01

Calculated

Log P

-0.48

Low

Fat solubility of residues

Solubility

Insoluble

Data type

Regulatory data

Density (g ml⁻¹)

1.48

Dissociation constant pKa) at 25 °C

4.35

Vapour pressure at 20 °C (mPa)

3.5 X 10^-09

Low volatility

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

3.65 X 10^-12

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

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

203nm = 53566, 237nm = 22220, 291nm = 904

Surface tension (mN m⁻¹)

61.9

at 20 °C 19.27 mg l⁻¹

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

43.5

Moderately persistent

DT₅₀ (lab at 20 °C)

43.5

Moderately persistent

DT₅₀ (field)

Moderately persistent

DT₉₀ (lab at 20 °C)

345.5

Persistent

DT₉₀ (field)

257

DT₅₀ modelling endpoint

Note

EU 2016 dossier Lab studies DT₅₀ range 7.6-140.1 days, DT₉₀ range 25.3- >1000 days, Soils=9

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

253

Persistent

Note

pH and temperature sensitive: DT₅₀ 7.2 days at pH 5 and 20 °C, 3.5 days at pH 5 and 25 °C, 253 days at pH 7 and 25 °C, 23 days at pH 7 and 40 °C, 318 days at pH 9 and 25 °C, 27 dats at pH 9 and 40 °C

Water-sediment DT₅₀ (days)

48.9

Moderately fast

Water phase only DT₅₀ (days)

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)

1.27

Moderately mobile

K_foc (mL g⁻¹)

¹/_n

0.91

Notes and range

EU dossier K_f 0.24-3.71 ml/g; K_foc range 26-345 mL g⁻¹; ¹/_n range 0.85-0.93; Soils=9

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

3.85

Calculated

High leachability

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

Value

9.95 X 10^-01

Calculated

Note

Potential for particle bound transport index

Medium

Calculated

Potential for loss via drain flow

Moderately mobile

Calculated

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

1.2

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 risk

Based on LogP < 3

Low risk

CT₅₀ (days)

No data

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

2-amino-4,6-dimethoxypyrimidine (Ref: AE-F092944)

Major fraction

0.101

Bayer verified

4,6-dimethoxypyrimidine-2-yl-urea (Ref: AE-F099095)

Major fraction

0.292

Bayer verified

mesosulfuron (Ref: AE F154851)

Major fraction

0.162

Bayer verified

O-desmethyl mesosulfuron (Ref: AE F160459)

Minor fraction

0.089

Anaerobic; Bayer verified

2-[({[(4-hydroxy-6-methoxypyrimidin-2-yl)amino]carbonyl}amino)sulfonyl]-4-{[(methylsulfonyl)amino]methyl}benzoic acid (Ref: AE F160460)

Minor fraction

0.086

Bayer verified

methyl 2-(aminosulfonyl)-4-{[(methylsulfonyl)amino]methyl} benzoate (Ref: AE F140584)

Minor fraction

0.051

Bayer verified

N-[(1,1-dioxido-3-oxo-2,3-dihydro-1,2-benzisothiazol-6-yl)methyl]methane sulfonamide (Ref: AE F147447)

Minor fraction

0.065

Bayer verified

2-[(amidinocarbamoyl)sulfamoyl]-4-[(methanesulfonamido)methyl]benzoic acid (Ref: BCS-CV14885)

Major fraction

0.259

Bayer verified

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)

O-desmethyl mesosulfuron (Ref: AE F160459)

Not relevant

1.0

6000

4,6-dimethoxypyrimidine-2-yl-urea (Ref: AE-F099095)

Not relevant

0.22

1320

2-amino-4,6-dimethoxypyrimidine (Ref: AE-F092944)

Not relevant

2-[({[(4-hydroxy-6-methoxypyrimidin-2-yl)amino]carbonyl}amino)sulfonyl]-4-{[(methylsulfonyl)amino]methyl}benzoic acid (Ref: AE F160460)

Not relevant

mesosulfuron (Ref: AE F154851)

Not relevant

methyl 2-(aminosulfonyl)-4-{[(methylsulfonyl)amino]methyl} benzoate (Ref: AE F140584)

Not relevant

N-[(1,1-dioxido-3-oxo-2,3-dihydro-1,2-benzisothiazol-6-yl)methyl]methane sulfonamide (Ref: AE F147447)

Not relevant

2-[(amidinocarbamoyl)sulfamoyl]-4-[(methanesulfonamido)methyl]benzoic acid (Ref: BCS-CV14885)

Not relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

O-desmethyl mesosulfuron (Ref: AE F160459)

Water/sediment

benzisothiazole (Ref: AE F147447)

Water (Hydrolysis); Water/sediment

0.374

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)

(ppm diet)

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

> 840

Rat Reproductive NOAEL

Low

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2000

Anas platyrhynchos

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

> 5000 mg kg feed⁻¹

Colinus virginianus

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

Colinus virginianus NOEL

Moderate

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

> 1000

Eisenia foetida

Low

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

125

Eisenia foetida 56 day

Low

Soil micro-organisms

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

Dose: 0.075 kg ha⁻¹

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

>= 1000

Folsomia candida

Non-target plants

Vegetative vigour ER₅₀ (g ha⁻¹)

Seedling emergence ER₅₀ (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)

> 105.6

Apis mellifera

Low

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

Chronic as 10-day LC₅₀ µg bee⁻¹ day⁻¹

> 4.85

Apis mellifera

Notes

Bumblebees (Bombus spp.)

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

> 100

Bombus terrestris

Low

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)

Beneficial insects (Predatory mites)

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)

> 100

Oncorhynchus mykiss

Low

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

32.0

Oncorhynchus mykiss

Low

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

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

> 100

Daphnia magna

Low

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

1.8

Daphnia magna

Moderate

Tropical Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (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 (free-floating, fonds growth, fresh) - 7 day (mg l⁻¹) (EC₅₀)

0.00062

Lemna gibba

High

Aquatic plants (rooted, growth rate, fresh) - 14 day (mg l⁻¹)

Algae - Acute (growth rate, fresh; mg l⁻¹) (72 hr ErC₅₀, Static)

> 0.25

Raphidocelis subcapitata

Moderate

Algae - Chronic (growth rate, fresh; mg l⁻¹) (72 hr NOEC, Static)

0.018

Raphidocelis subcapitata

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)

5000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 1.33

Rat 4 hr (nose only)

Other Mammal toxicity endpoints

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

1.0

Rat as mesosulfuron

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

None allocated

Rat

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

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

0.13

Rat as mesosulfuron

Dermal penetration studies (%)

9.3-13.9

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

Eye irritant

Phototoxicant

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

CLP classification 2013

Environment: H400

WHO Classification

Not listed (Not listed)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

mesosulfuron-methyl

French

mesosulfuron-methyle

German

Mesosulfuron

Danish

mesosulfuron

Italian

mesosulfuron-metile

Spanish

mesosulfuron-metil

Greek

Polish

mezosulfuron metylowy

Swedish

mesosulfuronmetyl

Hungarian

Dutch

Norwegian

mesosulfuron-metyl

Record last updated:	11/08/2025
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