Metsulfuron-methyl (Ref: DPX T6376)

Metsulfuron-methyl (Ref: DPX T6376)	Last updated: 12/01/2021
(Also known as: metsulfuron; IN T6376)

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

Broad-leaved 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

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

31/03/2026

UK LERAP status

Buffer probably required in UK - see product label

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

31/03/2023

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
✓		✓	✓	✓	✓	✓	✓	✓

Also used in

Australia

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 group

Sulfonylurea

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

CIPAC number

441.201

US EPA chemical code

122010

PubChem CID

52999

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 Classification (HRAC)

Herbicide Resistance Classification (WSSA)

Insecticide Resistance Classification (IRAC)

Not applicable

Fungicide Resistance Classification (FRAC)

Not applicable

Examples of recorded resistance

Lolium rigidum, Bacopa rotundifolia

Physical state

White to pale yellow solid with charcateristic odour

Related substances & organisms

carfentrazone-ethyl

thifensulfuron-methyl

tribenuron-methyl

metsulfuron

Can be a metabolite of:

Parent

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

iodosulfuron-methyl-sodium

Soil

0.885

Major fraction, Relevany unknown

iodosulfuron

Soil

0.885

Major fraction; Relevany unknown

Formulations

Property

Value

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

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

Example products using this active

AgriGuard
Clayton
DuPont
Headland
Nufarm

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)

Not expected to self ignite; Not highly flammable

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

1.35 X 10^-02

Calculated

Log P

-1.87

Low

Bulk density (g ml⁻¹)

1.45

Dissociation constant pKa) at 25 °C

3.75

Weak acid

Vapour pressure at 20 °C (mPa)

1.40 X 10^-08

Low volatility

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

2.87 X 10^-06

Non-volatile

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 on plant matrix

Value

Note

Dissipation rate RL₅₀ 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

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

K_oc

Notes and range

Freundlich

K_f

0.77

Very mobile

K_foc

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

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

methyl 2-(aminosulfonyl)benzoate (Ref: IN-D5803)

Soil

0.487

Major fraction, Relevant

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

Soil

0.059

Major fraction, Relevant

phenylurea (Ref: IN-B5685)

Soil

0.170

Major fraction, Relevant

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

Soil

0.087

Major fraction, Relevant

2-amino-4-methoxy-6-methyl-1,3,5-triazine (Ref: IN-A4098)

Soil

0.423

Major fraction, Relevant

metsulfuron

Soil

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

metsulfuron

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

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

Low potential

CT₅₀ (days)

Not available

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 5000

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat 2 year

(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 Colinus virginianus

Moderate

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

> 110

Poecilia reticulata

Low

Fish - Chronic 21 day NOEC (mg l⁻¹)

68.0

Salmo gairdneri

Low

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

> 43.1

Daphnia magna

Moderate

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

3.13

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)

0.00036

Lemna gibba

High

Non-target plants

0.054

White mustard
Vegetative vigour, ER₅₀
as g ha⁻¹

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

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)

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)

> 1000

Eisenia foetida

Low

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

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

>= 250

Folsomia candida

Other arthropod (1)

LR₅₀ g ha⁻¹

76.8

>
Aphidius rhopalosiphi

% Effect

19.3

Beneficial capacity
Aphidius rhopalosiphi

Other arthropod (2)

LR₅₀ g ha⁻¹

30.7

Typhlodromus pyri

% Effect

-1.2

Beneficial capacity
Typhlodromus pyri

Soil micro-organisms

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

Dose: 0.2 mg kg⁻¹ soil

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)

> 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)

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)

0.7

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

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

; ; ; ;

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 Code is usually 9

CLP classification 2013

Environment: H400, H410

EC Risk Classification

N - Dangerous for the environment: R50, R53

EC Safety Classification

S60, S61

WHO Classification

U (Unlikely to present an acute hazard)

UN Number

Usually 3077

Waste disposal & packaging

Packaging Group III (minor danger)

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

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