Halosulfuron-methyl (Ref: CGA 288239)

Halosulfuron-methyl (Ref: CGA 288239)	Last updated: 21/08/2024
(Also known as: MON 12000; MON 12037; A-841101)

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 Moderate alert: GUS: Transition state; Drainflow: Moderately mobile	Ecotoxicity Moderate alert: Daphnia chronic ecotoxicity: Moderate	Human health High alert: Reproduction/development effects

GENERAL INFORMATION

Description

Sulfonylurea post-emergence herbicide used to control annual broad-leaved weeds and sedges in a range of crops, particularly rice

Example pests controlled

Sedges, Broad-leaved weeds

Example applications

Rice; Turf; Ornamental lawns; Woody ornamentals; Landscaped areas; Corn; Fallow ground; Sugarcane

Efficacy & activity

Field studies have demonstrated the efficacy of halosulfuron-methyl for sedge and other target weed control in rice.

Availability status

Current

Introduction & key dates

1991, first reported; 1994, first registered USA

GB regulatory status

GB COPR regulatory status

Approved

Date COPR inclusion expires

30/09/2026

GB LERAP status

No data

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Italy/Poland

Date EC 1107/2009 inclusion expires

30/03/2025

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

Chemical structure

Isomerism

None

Chemical formula

C₁₃H₁₅ClN₆O₇S

Canonical SMILES

CN1C(=C(C(=N1)Cl)C(=O)OC)S(=O)(=O)NC(=O)NC2=NC(=CC(=N2)OC)OC

Isomeric SMILES

International Chemical Identifier key (InChIKey)

FMGZEUWROYGLAY-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C13H15ClN6O7S/c1-20-10(8(9(14)18-20)11(21)27-4)28(23,24)19-13(22)17-12-15-6(25-2)5-7(16-12)26-3/h5H,1-4H3,(H2,15,16,17,19,22)

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance groups

Pyrazole herbicide; Sulfonylurea herbicide; Urea herbicide; Pyrimidinylsulfonylurea herbicide

Minimum active substance purity

790 g kg⁻¹

Known relevant impurities

EU dossier - commercially confidential, not disclosed publically

Substance origin

Synthetic

Mode of action

Systemic, selective, acts by inhibiting biosynthesis of essential amino acids valine and isoleucine restricting plant growth. Inhibits plant amino acid synthesis - acetohydroxyacid synthase AHAS

CAS RN

100784-20-1

EC number

600-130-3

CIPAC number

785.201

US EPA chemical code

128721

PubChem CID

91763

CLP index number

No data found

Molecular mass

434.82

PIN (Preferred Identification Name)

methyl 3-chloro-5-{[(4,6-dimethoxypyrimidin-2-yl)carbamoyl]sulfamoyl}-1-methyl-1H-pyrazole-4-carboxylate

IUPAC name

methyl 3-chloro-5-(4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl)-1-methylpyrazole-4-carboxylate

CAS name

methyl 3-chloro-5-(((((4,6-dimethoxy-2-pyrimidinyl)amino)carbonyl)amino)sulfonyl)-1-methyl-1H-pyrazole-4-carboxylate

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

Physical state

Fine white powder that is slightly crystalline in appearance

Formulations

Property

Value

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

Nissan Chemical Industries Ltd.
Gowan Co
Fertiagro Pte. Ltd.
Syngenta Crop Protection

Example products using this active

Fermit
Yukon
Battalion
NC-31975 WG
Manage

Formulation and application details

Available as a dry flowable formulation and as premeasured amounts in water soluble bags. Also available as wettable granules.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

10.2

Low

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

1616

Methanol

127.8

Hexane

3640

Toluene

15260

Ethyl acetate

Melting point (°C)

175.5

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

181.6

Flashpoint (°C)

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

9.57 X 10^-01

Calculated

Log P

-0.019

Low

Fat solubility of residues

Solubility

Insoluble

Data type

Regulatory data

Density (g ml⁻¹)

1.62

Dissociation constant pKa) at 25 °C

3.44

Weak acid

Vapour pressure at 20 °C (mPa)

1.33 X 10^-02

Low volatility

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

3.5 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

Neutral soln: 245nm=20347, 203nm=34896
Acidic soln: 244nm=19570, 203nm=39329
Basic soln: 260nm=11492, 233nm=15312, 215.5nm=14869

Surface tension (mN m⁻¹)

70.5

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

26.7

Non-persistent

DT₅₀ (lab at 20 °C)

13.9

Non-persistent

DT₅₀ (field)

Non-persistent

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU 2023 dossier lab studies data for dark aerobic soil Lab studies DT₅₀ (normalised) range 4.8-33.1 days, Soils=4; Lab studies flodded paddy field soil-water system DT₅₀ (normalised) 14.2-32.5 days, Soils=2

Dissipation rate RL₅₀ (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

3.0

Note

Published literature RL₅₀ range 0.9-5.3 days, maize & wheat, 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

14.4

at 25°C

Non-persistent

Note

DT₅₀ pH sensitive: 26.9 days at pH5; 18.6 hrs at pH9 all at 25°C

Water-sediment DT₅₀ (days)

10.4

Fast

Water phase only DT₅₀ (days)

8.1

Moderately fast

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)

1.67

Moderately mobile

K_oc (mL g⁻¹)

109

Notes and range

EU dossier K_d range 0.36-3.98 mL g⁻¹, K_oc range 31.1-199.22 mL g⁻¹, soils=4; Other literature values range 31-199 mL g⁻¹; Manufacturer safety sheet 75 mL g⁻¹ (Q3)

Freundlich

K_f (mL g⁻¹)

1.51

Not calculated

K_foc (mL g⁻¹)

Not calculated

¹/_n

0.825

Notes and range

EU dossier K_f range 0.32-3.56 mL g⁻¹, K_foc - not determined in dossier, ¹/_n range 0.61-1.08, Soils=4.Treat data with caution.

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

2.25

Calculated

Transition state

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

Value

6.93 X 10^-02

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Moderately mobile

Calculated

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

0.63

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

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

3-chlorosulfonamide

Major fraction

0.119

Aerobic soil

chlorosulfonamide acid (Ref: MON 5783)

Major fraction

0.115

Aerobic soil

O-demethyl halosulfuron methyl

Minor fracton

0.058

Aerobic soil

halosulfuron

Major fraction

0.222

Aerobic soil

Component Pd3

Unstable; Anaerobic

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)

halosulfuron

Relevancy unknown

halosulfuron rearrangement

Relevancy unknown

3-chlorosulfonamide

Relevancy unknown

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

O-demethyl halosulfuron methyl

ODHSM

Water; Sediment; Plant; Animal

4,6-dihydroxy halosulfuron methyl

Animal

5-hydroxy halosulfuron methyl

5-hydroxy NC-319

Animal

5-hydroxy-demethyl-halosulfuron methyl

5-hydroxy demthyl NC-319

Animal

aminopyrimidine

Surface water; Sediment; Plant

2-pyrimidinamine

demethyl aminopyrimidine

Animal

N-demethyl chlorosulfonamide

Plant

N-demethyl chlorosulfonamide acid

Plant

hydroxymethyl chlorosulfonamide acid

Plant

chlorosulfonamide glycerate

Plant

chlorosulfonamide acid glycerate

Plant

N-demethyl chlorosulfonamide glycerate

Plant

N-conjugate chlorosulfonamide

Plant

N-conjugate chlorosulfonamide acid

Plant

N-demethyl halosulfuron-methyl

Animal

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

9295

Mouse

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

(ppm diet)

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

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2250

Colinus virginianus

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

> 5620 mg kg feed⁻¹

Colinus virginianus

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

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

> 1000

Eisenia foetida

Low

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

Soil micro-organisms

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

Dose: 0.2 kg ha⁻¹ 28 Day

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

0.22

Radish
Vegetative vigour, ER₅₀
as g ha⁻¹

0.12

Lettuce
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)

> 100

Apis mellifera

Low

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

Chronic

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

> 300

Aphidius rhopalosiphi

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

> 300

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)

> 118

Lepomis macrochirus

Low

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

Colinus virginianus 87 day

Low

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

14.8

Danio rerio EC₅₀ Embryo

Moderate

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

> 107

Daphnia magna

Low

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

> 6.9

Daphnia magna

Moderate

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

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

109.0

Mysidopsis bahia

Low

Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)

Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l⁻¹)

Chironomus riparius

Moderate

Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg⁻¹)

Chironomus riparius

Moderate

Aquatic plants - Acute 7 day EC₅₀, biomass (mg l⁻¹)

0.0002

Lemna gibba

High

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

0.0053

Pseudokirchneriella subcapitata

High

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

Mesocosm study data

NOEAEC mg l⁻¹

Marine bivalves – Acute EC₅₀ development (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)

9295

Mouse

Low

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 6.0

Rat 4 hr (whole body)

Other Mammal toxicity endpoints

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

0.063

Rat SF=100

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

0.5

Rabbit SF=100

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

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

0.063

Rat SF=100

Dermal penetration studies (%)

0.22-0.34

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

Negligible risk to consumers from food residues

Occupational

Acceptable for intedned uses

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

Rapidly and extensively metabolised and eliminated in the urine and faeces.

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

May cause lethagy
Harmful if swallowed
May cause haematological changes

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
Not expected to auto-ignite; Not highly flammable

CLP classification 2013

Health: H360D
Environment: H400, H410

WHO Classification

Not listed (Not listed)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

halosulfuron-methyl

French

German

Danish

Italian

Spanish

halosulfuron metil

Greek

Polish

halosulfuron metylowy

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	21/08/2024
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