Iodosulfuron-methyl-sodium (Ref: AE F115008)

Iodosulfuron-methyl-sodium (Ref: AE F115008)	Last updated: 11/08/2025
(Not known by any other names)

SUMMARY

Iodosulfuron-methyl-sodium is a sulfonylurea herbicide. It is highly soluble in aqueous solution and semi-volatile. It is not persistent in soil but may be in aquatic systems. It is highly toxic to mammals, a neurotoxin and a skin, eye and respiratory tract irritant. It is moderately toxic to birds, most aquatic organisms, honeybees and earthworms.

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: Drainflow: Mobile	Ecotoxicity Moderate alert: Birds chronic ecotoxicity: Moderate; Fish chronic ecotoxicity: Moderate; Daphnia chronic ecotoxicity: Moderate; Bees acute oral ecotoxicity: Moderate; Earthworms chronic ecotoxicity: Moderate	Human health High alert: Neurotoxicant

GENERAL INFORMATION

Description

A post-emergence herbicide used to control weeds in cereals and other crops

Example pests controlled

Grass; Broadleaved weeds

Example applications

Cereals including wheat, barley, corn; Turf; Soybean

Efficacy & activity

Scientifically proven to be selective in cereals, acting against a broad spectrum of grass weeds and a range of dicot weeds.

GB regulatory status

GB COPR regulatory status

Approved

Date COPR inclusion expires

31/03/2032

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

Sweden/Finland

Date EC 1107/2009 inclusion expires

31/03/2032

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

C₁₄H₁₃IN₅NaO₆S

Canonical SMILES

CC1=NC(=NC(=N1)OC)NC(=O)[N-]S(=O)(=O)C2=C(C=CC(=C2)I)C(=O)OC.[Na+]

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

JUJFQMPKBJPSFZ-UHFFFAOYSA-M

International Chemical Identifier (InChI)

InChI=1S/C14H14IN5O6S.Na/c1-7-16-12(19-14(17-7)26-3)18-13(22)20-27(23,24)10-6-8(15)4-5-9(10)11(21)25-2;/h4-6H,1-3H3,(H2,16,17,18,19,20,22);/q;+1/p-1/fC14H13IN5O6S.Na/h20H;/q-1;m

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance groups

Triazinylsulfonylurea herbicide; Sulfonylurea herbicide

Minimum active substance purity

910 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Selective to cereals. Inhibits plant amino acid synthesis - acetohydroxyacid synthase AHAS

CAS RN

144550-36-7

EC number

604-422-1

CIPAC number

634

US EPA chemical code

122021

PubChem CID

16760189

CLP index number

616-108-00-1

Molecular mass

529.24

PIN (Preferred Identification Name)

IUPAC name

sodium ({[5-iodo-2-(methoxycarbonyl)phenyl]sulfonyl}carbamoyl)(4-methoxy-6-methyl-1,3,5-triazin-2-yl)azanide

CAS name

sodium salt of methyl 4-iodo-2-(((((4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino)carbonyl)amino)sulfonyl)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

Many recorded cases, Avena fatua, Phalaris mino, Alopecurus myosuroides, Papaver rhoeas, Sinapis alba

Physical state

Beige coloured crystalline powder

Related substances & organisms

iodosulfuron

Commercial

Property

Value

Availability status

Current

Introduction & key dates

circa 2000, introduced

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

Bayer CropScience
Farmalinx Pty Ltd

Example products using this active

Atlantis WG
Chekkar
Hussar
Othello
Pacifica
Sekator
Farmalinx Winx

Formulation and application details

Often supplied as wettable granules that are mixed with water and used as a spray

Commercial production

Iodosulfuron-methyl-sodium is commercially synthesised through a multi-step process typical of sulfonylurea herbicides. The production begins with the preparation of a substituted triazine ring, which serves as the core scaffold. This is followed by the introduction of a sulfonylurea moiety via condensation reactions involving sulfonamide and isocyanate intermediates. The final step involves iodination and methylation to yield the active compound, which is then converted into its sodium salt form for improved solubility and formulation stability.

Impact on climate of production and use

Iodosulfuron-methyl-sodium synthesis involves multiple chemical steps suggesting that the process is energy-intensive and so will produce significant GHGs. However, precise life cycle emissions are unpublished but Audsley et al. (2009) reported that it takes 691 MJ of energy per kg produced. This is equivalent to approximately 47.7 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)

25000

High

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

n-Heptane

n-Hexane

2100

Toluene

12000

Methanol

Melting point (°C)

152

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

155

Flashpoint (°C)

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

2.00 X 10^-01

Calculated

Log P

-0.70

Low

Fat solubility of residues

Solubility

Insoluble

Data type

Regulatory data

Density (g ml⁻¹)

1.76

Dissociation constant pKa) at 25 °C

3.22

Strong acid

Vapour pressure at 20 °C (mPa)

2.6 X 10^-06

Low volatility

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

2.29 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

In methanol: 291nm = 1471
Methanol:NaOH (9:1): 291nm = 2073

Surface tension (mN m⁻¹)

72.0

at 20 °C 910 g/Kg

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

2.7

Non-persistent

DT₅₀ (lab at 20 °C)

2.7

Non-persistent

DT₅₀ (field)

3.2

Non-persistent

DT₉₀ (lab at 20 °C)

22.5

Non-persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU 2016 dossier Lab studies DT₅₀ range 0.6-20.8 days, DT₉₀ range 2.6-110 days, Soils=15; field studies DT₅₀ 0.8-10.3 days, Soils=5

Dissipation rate RL₅₀ (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

4.8

Note

Wheat, whole plant, n=1

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Slow

Note

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

Value

Stable

Note

pH sensitive: DT₅₀ 4 days at pH 4, 31 days at pH 5, 365 days at pH 6 and pH 7, 362 days at pH 9, all at 20 °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)

0.82

Mobile

K_foc (mL g⁻¹)

¹/_n

0.97

Notes and range

EU dossier K_f range 0.12-2.47 mL g⁻¹, K_foc range 0.8-152 mL g⁻¹, ¹/_n range 0.70-1.85, Soils=10

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

1.19

Calculated

Low leachability

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

Value

2.67 X 10^-03

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

152

Calculated using the Atkinson method. Assumed 0.5E+06 OH/cm³, 24 hr

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

Major fraction

0.409

methyl 2-(3- (4-hydroxy-6-methyl-1,3,5-triazin-2-yl)ureidosulfonyl) benzoate (Ref: AE-F161778)

Major fraction

0.145

metsulfuron-methyl (Ref: DPX T6376)

Major fraction

0.885

Bayer verified

iodosulfuron

Minor fraction

0.087

Bayer verified

2-amino-4-methoxy-6-methyl-1,3,5-triazine (Ref: AE F059411)

Major fraction

0.409

Bayer verified

methyl 4-iodo-2-{[(4-methyl-6-oxo-1,6-dihydro-1,3,5-triazin-2-yl)carbamoyl]sulfamoyl}benzoate (Ref: AE F145741)

Major fraction

0.145

CAS 126312-31-0; Bayer verified

methyl 4-hydroxy-2-({[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)carbamoyl] amino}sulfonyl)benzoate (Ref: AE 0002166)

Minor fraction

0.058

Bayer verified

methyl 2-{[(Ncarbamoylcarbamimidoyl)carbamoylcarbamimidoyl)benzoate (Ref: BCS-CW81253)

Major fraction

0.351

Bayer verified

1-(4-methoxy-6-methyl-1,3,5-triazin-2-yl)urea (Ref: AE 0000119)

Major fraction

0.199

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)

iodosulfuron

Not relevant

methyl 4-iodo-2-{[(4-methyl-6-oxo-1,6-dihydro-1,3,5-triazin-2-yl)carbamoyl]sulfamoyl}benzoate (Ref: AE F145741)

Not relevant

methyl 2-(3- (4-hydroxy-6-methyl-1,3,5-triazin-2-yl)ureidosulfonyl) benzoate (Ref: AE-F161778)

Not relevant

1-(4-methoxy-6-methyl-1,3,5-triazin-2-yl)urea (Ref: AE 0000119)

Not relevant

2-amino-4-methoxy-6-methyl-1,3,5-triazine (Ref: AE F059411)

Not relevant

methyl 2-{[(Ncarbamoylcarbamimidoyl)carbamoylcarbamimidoyl)benzoate (Ref: BCS-CW81253)

Not relevant

methyl 4-hydroxy-2-({[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)carbamoyl] amino}sulfonyl)benzoate (Ref: AE 0002166)

Not relevant

metsulfuron-methyl (Ref: DPX T6376)

Relevant

0.22

1320

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

2-amino-4-methoxy-6-methyl-1,3,5-triazine (Ref: AE-F059411)

Mammal; Plant

methyl 4-hydroxy-2-{[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)carbamoyl]sulfamoyl}benzoate (Ref: AE-0002166)

(a) Water (Hydrolysis); =(b), Air (Photolysis)

a= 0.182; b=0.666

methyl 4-iodo-2-{[(4-methyl-6-oxo-1,6-dihydro-1,3,5-triazin-2-yl)carbamoyl]sulfamoyl}benzoate (Ref: AE F145741)

Plant; Sediment; Surface water

4-amino-6-(hydroxymethyl)-1,3,5-triazin-2-ol (Ref: AE 0031838)

Plant

-(4-methyl-6-oxo-1,6-dihydro-1,3,5-triazin-2-yl)urea (Ref: AE 0034855)

Surface water; Sediment

1,2-benzothiazol-3(2H)-one 1,1-dioxide (Ref: AE F159737)

Surface water; Sediment

2-sulfamoylbenzoic acid (Ref: AE 1234964)

Surface water

methyl 2-(aminosulfonyl)-4-iodobenzoate (Ref: AE F114368)

Mammal

6-iodo-1,2-benzisothiazol-3(2H)-one 1,1-dioxide (Ref: AE F143133)

Mammal

4-amino-6-methyl-1,3,5-triazin-2-ol (Ref: AE F154781)

Surface water; Sediment

1-(4-methoxy-6-methyl-1,3,5-triazin-2-yl)urea (Ref: AE 0000119)

Surface water; Sediment

methyl 2-{[(Ncarbamoylcarbamimidoyl)carbamoylcarbamimidoyl)benzoate (Ref: BCS-CW81253)

Surface water; Sediment

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

2448

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Dog

High

(ppm diet)

200

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

255

Unknown species Reproductive NOAEL

Low

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2000

Colinus virginianus

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)

9.3

Eisenia foetida

Moderate

Soil micro-organisms

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

Dose: 0.05 kg ha⁻¹

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

316

Folsomia candida

Non-target plants

Vegetative vigour ER₅₀ (g ha⁻¹)

0.042

7 plant species tested

Seedling emergence ER₅₀ (g ha⁻¹)

0.567

10 plant species tested

Honeybees (Apis spp.)

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

> 150

Apis mellifera

Low

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

> 80

Apis mellifera

Moderate

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

Chronic as 10-day LDD₅₀ µg bee⁻¹ day⁻¹

> 4.4

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) as Mortality LR₅₀ g ha⁻¹, Std lab test

30.3

Aphidius rhopalosiphi

Moderate

Beneficial insects (Predatory mites) as Mortlity LR₅₀ g ha⁻¹, Std lab test

30.3

Typhlodromus pyri Protonymph

Moderate

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

Lepomis macrochirus

Low

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

Oncorhynchus mykiss

Moderate

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)

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) (ErC₅₀, Semi-static)

0.0004

Lemna gibba 14 day

High

Aquatic plants (rooted, growth rate, fresh) - 14 day (mg l⁻¹) (EyC₅₀ (yield) Shoot length, Static)

0.0025

Myriophyllum spicatum

High

Algae - Acute (growth rate, fresh; mg l⁻¹) (96 hr ErC₅₀, Static)

0.152

Raphidocelis subcapitata

Moderate

Algae - Chronic (growth rate, fresh; mg l⁻¹) (96 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)

2448

Rat

Low

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 2.81

Rat 4 hr (nose only aerosol)

Other Mammal toxicity endpoints

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

0.03

Rat as iodosulfuron

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

3.15

Rat as iodosulfuron

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

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

0.05

Rat as iodosulfuron

Dermal penetration studies (%)

Dangerous Substances Directive 76/464

Exposure Routes

Public

No unacceptable risks to bystanders or residents 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
IMDG Transport Hazard Class 9
Not expected to auto-ignite; Not highly flammable

CLP classification 2013

Environment: H400, H410

WHO Classification

Not listed (Not listed)

UN Number

UN3077

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

Chemically stable under standard ambient conditions

TRANSLATIONS

Language

Name

English

iodosulfuron-methyl-sodium

French

iodosulfuron

German

Iodosulfuron-methyl-Natrium

Danish

iodosulfuron-methyl-natrium

Italian

iodosulfuron-metil-sodio

Spanish

iodosulfuron-metil-sodio

Greek

Polish

jodosulfuron metylosodowy

Swedish

jodsulfuronmetyl-natrium

Hungarian

jodosulphuron-methyl-sodium

Dutch

joodsulfuronmethylnatrium

Norwegian

jodsulfuron-metyl natrium

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