Sulfosulfuron (Ref: MON 37500)

Sulfosulfuron (Ref: MON 37500)	Last updated: 14/03/2021
(Also known as: TKM 19)

SUMMARY

A sulfonylurea herbicide approved for use in the European Union and in some other countries. Sulfosulfuron is highly soluble in water, is semi-volatile and is mobile with a high potential for leaching to groundwater based on its physico-chemical properties. It is considered to be moderately persistent in soils and can also be persistent in water systems depending upon conditions. It may bioaccumulate but has a low mammalian toxicity. It is moderately toxic to fish, algae, earthworms and honeybees but less so to birds and aquatic invertebrates.

GENERAL INFORMATION

Description

A herbicide for annual grass and broad-leaved weed control in cereals and other crops

Example pests controlled

Bermudagrass; Buffalograss; Nutsedge; Bromegrass; Mayweed; Wild mustard; Bedstraw; Dandylion; Henbit; Quackgrass; Shepherds purse; Chickweed

Example applications

Cereals including wheat, triticale; Turf

Efficacy & activity

Availability status

Current

Introduction & key dates

1999, USA

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

31/12/2030

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

Sweden/Ireland

Date EC 1107/2009 inclusion expires

31/12/2030

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
✓			✓			✓		✓

Also used in

Australia

Chemical structure

Isomerism

Chemical formula

C₁₆H₁₈N₆O₇S₂

Canonical SMILES

CCS(=O)(=O)C1=C(N2C=CC=CC2=N1)S(=O)(=O)NC(=O)NC3=NC(=CC(=N3)OC)OC

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

RBSXHDIPCIWOMG-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C16H18N6O7S2/c1-4-30(24,25)13-14(22-8-6-5-7-10(22)17-13)31(26,27)21-16(23)20-15-18-11(28-2)9-12(19-15)29-3/h5-9H,4H2,1-3H3,(H2,18,19,20,21,23)

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance group

Sulfonylurea

Minimum active substance purity

980 g kg⁻¹

Known relevant impurities

EU dossier - Phenol < 2g kg⁻¹

Substance origin

Synthetic

Mode of action

Systemic, absorbed by roots and leaves and translocated. Inhibits plant amino acid synthesis - acetohydroxyacid synthase AHAS

CAS RN

141776-32-1

EC number

CIPAC number

601

US EPA chemical code

085601

PubChem CID

86426

Molecular mass

470.48

PIN (Preferred Identification Name)

N-[(4,6-dimethoxypyrimidin-2-yl)carbamoyl]-2-(ethanesulfonyl)imidazo[1,2-a]pyridine-3-sulfonamide

IUPAC name

1-(4,6-dimethoxypyrimidin-2-yl)-3-(2-ethylsulfonylimidazo[1,2-a]pyridin-3-ylsulfonyl)urea

CAS name

N-(((4,6-dimethoxy-2-pyrimidinyl)amino)carbonyl)-2-(ethylsulfonyl)imidazo(1,2-a)pyridine-3-sulfonamide

Other status information

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

Avena fatua, Phalaris minor, Hordeum glaucum

Physical state

White solid

Related substances & organisms

metsulfuron-methyl

Formulations

Property

Value

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

SafeGuard
Certainty
Maverick
Outrider
Arrow

Example products using this active

AgriGuard
DuPont
Monsanto

Formulation and application details

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

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

1627

High

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

Heptane

160

Xylene

330

Methanol

710

Acetone

Melting point (°C)

201.5

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

Not expected to self ignite; Not highly flammable

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

1.70 X 10^-01

Calculated

Log P

-0.77

Low

Bulk density (g ml⁻¹)

1.52

Dissociation constant pKa) at 25 °C

3.51

Weak acid

Vapour pressure at 20 °C (mPa)

3.05 X 10^-05

Low volatility

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

8.83 X 10^-09

Non-volatile

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

pH 10: 208nm=187150
pH 7: 208nm=38019

Surface tension (mN m⁻¹)

72.7

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

63.8

Moderately persistent

DT₅₀ (lab at 20 °C)

63.8

Moderately persistent

DT₅₀ (field)

44.5

Moderately persistent

DT₉₀ (lab at 20 °C)

309

Persistent

DT₉₀ (field)

148

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀ range 12.0-224.4 days, DT₉₀ range 55.4-731 days, field studies DT₅₀ range 28.8-75.1 days, DT₉₀ range 81.9-250 days; Other sources: 50 days (DW4)

Dissipation rate RL₅₀ on plant matrix

Value

Note

Dissipation rate RL₅₀ on and in plant matrix

Value

3.1

Note

Wheat straw, n=1

Aqueous photolysis DT₅₀ (days) at pH 7

Value

1.4

Moderately fast

Note

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

Value

164

Persistent

Note

pH sensitive: DT₅₀ 7 days at pH 4, 48 days at pH 5, 147 days at pH 9, all at 25 °C

Water-sediment DT₅₀ (days)

26.8

Fast

Water phase only DT₅₀ (days)

17.8

Slow

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

K_oc

Notes and range

Freundlich

K_f

0.29

Mobile

K_foc

33.0

¹/_n

0.930

Notes and range

EU dossier K_f range 0.076-0.710 mL g⁻¹, K_oc range 5.3 – 89.0 mL g⁻¹, ¹/_n range 0.737-1.20, Soils=5

pH sensitivity

Adsorption increases with decreasing soil pH

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

4.09

Calculated

High leachability

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

Value

1.17 X 10⁰⁰

Calculated

Note

Potential for particle bound transport index

Medium

Calculated

Potential for loss via drain flow

Mobile

Calculated

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

sulfosulfuron sulfonamide (Ref: MON 52729)

Soil

0.547

Major fraction, Relevant

desmethyl sulfosulfuron (Ref: MON 52756)

Soil

0.335

Major fraction, Relevant

sulfosulfuron aminopyrimidine (Ref: CP 017477)

Soil

0.399

Minor fraction, Relevant

sulfosulfuron guanidine (Ref: MON 52726)

Soil

0.188

Major fraction, Relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

N-(carbamoylcarbamoyl)-2-(ethylsulfonyl)imidazo[1,2-alpha]pyridine-3-sulfonamide (Ref: MON 52727)

sulfonyl biuret

Groundwater; Soil

N-carbamoyl-2-(ethylsulfonyl)imidazo[1,2-a]pyridine-3-sulfonamide (Ref: MON 37500)

sulfosulfuron sulfonylurea

Groundwater; Soil

2-(ethylsulfonyl)imidazo[1,2-alpha]pyridine (Ref: CP 180425)

sulfosulfuron sulfone

Surface water; Groundwater

(2-imino-1(2H)-pyridinyl)(oxo)acetic acid (Ref: CP 240488)

sulfosulfuron oxamic acid

Surface water; Groundwater

[(4,6-dimethoxy-2-pyrimidinyl)carbamoyl]sulfamic acid (Ref: MON 52728)

sulfosulfuron sulfamic acid

Surface water; Water (Photolysis)

1-(4,6-dimethoxy-2-pyrimidinyl)-3-hydroxyurea (Ref: -)

sulfosulfuron N-hydroxy urea

Groundwater; Surface water (Photolysis)

2-(ethylsulfonyl)imidazo[1,2-alpha]pyridine-3-sulfonic acid (Ref: CP 180421)

sulfosulfuron sulfonic acid

Surface water(Photolysis); Groundwater

1-(4,6-dimethoxy-2-pyrimidinyl)urea (Ref: CP 240483)

sulfosulfuron urea

Surface water; Groundwater

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

Low risk

Based on LogP < 3

Low risk

CT₅₀ (days)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 5000

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

> 370

Rat

Moderate

(ppm diet)

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

> 1313

Unknown species Reproductive NOAEL

Low

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2250

Anas platyrhynchos

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

> 5310 mg kg feed⁻¹

Anas platyrhynchos

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

33.7

Anas platyrhynchos NOEL

Moderate

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

> 91

Oncorhynchus mykiss

Moderate

Fish - Chronic 21 day NOEC (mg l⁻¹)

100

Oncorhynchus mykiss

Low

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

> 96

Unknown species

Moderate

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

102

Daphnia magna

Low

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

106.0

Americamysis bahia

Low

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)

0.00096

Lemna gibba

High

Non-target plants

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

0.221

Unknown species 72 hour

Moderate

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

Honeybees (Apis spp.)

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

> 25

Apis mellifera

Moderate

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

> 30

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)

> 848

Eisenia foetida

Moderate

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

>= 0.13

Eisenia foetida 56 day

Moderate

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Other arthropod (1)

LR₅₀ g ha⁻¹

% Effect

Fecundity [Dose: 0.03 kg ha⁻¹]
Aphidius rhopalosiphi adult

Other arthropod (2)

LR₅₀ g ha⁻¹

% Effect

Mortality [Dose: 0.03 kg ha⁻¹]
Typhlodromus pyri protonymph

Soil micro-organisms

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

Dose: 5.76 x field rate 100 days

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)

5000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 3.0

Rat 4hr (head-nose only)

Other Mammal toxicity endpoints

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

0.24

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)

0.4

Dog 90 day SF=250

Dermal penetration studies (%)

25-75

concentration dependent default

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

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

No data found

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

May caused weight loss, renal and bladder problems
Possible kidney, bladder, urinary system toxicant
USEPA - possible human carcinogen at high doses

Handling issues

Property

Value and interpretation

General

Risk of explosion - prevent generation of dusts
Not 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

NL (Not listed)

UN Number

Usually 3077

Waste disposal & packaging

Packaging Group III (minor danger)

TRANSLATIONS

Language

Name

English

sulfosulfuron

French

sulfosulfuron

German

Sulfosulfuron

Danish

sulfosulfuron

Italian

sulfosulfuron

Spanish

sulfosulfuron

Greek

sulfosulfuron

Polish

sulfosulfuron

Swedish

sulfosulfuron

Hungarian

szulfoszulfuron

Dutch

sulfosulfuron

Record last updated:	14/03/2021
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