Orthosulfamuron (Ref: IR5878)

Orthosulfamuron (Ref: IR5878)	Last updated: 23/01/2025
(Not known by any other names)

SUMMARY

A herbicide used to control weeds, especially sedges, in rice. It is moderately soluble in water, volatile and, based on its chemical properties, there is a high risk of of leaching to groundwater. It tends not to be persistent in either soil or aquatic systems. It has a low mammalian toxicity and not thought to bioaccumulate. However, there are some concerns that it may be neurotoxic and be a reproduction/development toxin. It has a low to moderate toxicity to most biodiversity.

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: Drainflow: Moderately mobile	Ecotoxicity Moderate alert: Fish chronic ecotoxicity: Moderate; Daphnia chronic ecotoxicity: Moderate	Human health High alert: Neurotoxicant

GENERAL INFORMATION

Description

Pre- and post-emergence rice herbicide active against grasses and some broadleaved weeds

Example pests controlled

Sedges including flatsedge; Grass weeds including Barnyardgrass; Velvetleaf; Water-plantain; Mud-plantain; Sagittaria; False pimpernel

Example applications

Rice

Efficacy & activity

Availability status

Current

Introduction & key dates

circa 1998 introduced; 2007, registered USA

GB regulatory status

GB COPR regulatory status

Not approved

Date COPR inclusion expires

Not applicable

GB LERAP status

No UK approval for use as a plant protection agent

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Not approved

Dossier rapporteur/co-rapporteur

Italy

Date EC 1107/2009 inclusion expires

Not applicable

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

USA

Chemical structure

Isomerism

None

Chemical formula

C₁₆H₂₀N₆O₆S

Canonical SMILES

CN(C)C(=O)C1=CC=CC=C1NS(=O)(=O)NC(=O)NC2=NC(=CC(=N2)OC)OC

Isomeric SMILES

International Chemical Identifier key (InChIKey)

UCDPMNSCCRBWIC-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C16H20N6O6S/c1-22(2)14(23)10-7-5-6-8-11(10)20-29(25,26)21-16(24)19-15-17-12(27-3)9-13(18-15)28-4/h5-9,20H,1-4H3,(H2,17,18,19,21,24)

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance groups

Pyrimidinylsulfonylurea herbicide; Sulfonylurea herbicide

Minimum active substance purity

985mg kg⁻¹

Known relevant impurities

EU dossier: Dichloromethane, maximum content 1 g kg⁻¹

Substance origin

Synthetic

Mode of action

Systemic, systemic absorbed by foliage and roots and translocated, acetohydroxy acid synthase

CAS RN

213464-77-8

EC number

606-744-8

CIPAC number

781

US EPA chemical code

108209

PubChem CID

11091168

CLP index number

No data found

Molecular mass

424.44

PIN (Preferred Identification Name)

2-({[(4,6-dimethoxypyrimidin-2-yl)carbamoyl]sulfamoyl}amino)-N,N-dimethylbenzamide

IUPAC name

1-(4,6-dimethoxypyrimidin-2-yl)-3-[2-(dimethylcarbamoyl)phenylsulfamoyl]urea

CAS name

2-[[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]amino]-N,N-dimethylbenzamide

Other status information

Chemical subject to PIC regulations: GB Part 2

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, odourless powder

Formulations

Property

Value

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

Isagro USA

Example products using this active

Strada
Kelion
Percutio

Formulation and application details

Usually supplied as a water-dispersible granular formulation

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

629

Moderate

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

19500

Acetone

3300

Ethyl acetate

8300

Methanol

56000

1,2-Dichloromethane

Melting point (°C)

157

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

185

Flashpoint (°C)

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

2.04 X 10⁰¹

Calculated

Log P

1.31

Low

Fat solubility of residues

Solubility

Insoluble

Data type

Regulatory data - Low to negligible residues found in goat milk, muscle and fat

Density (g ml⁻¹)

1.48

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

0.112

Low volatility. If applied directly to plants, drift is a concern & mitigation is advisable

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

7.6 X 10^-05

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.: 238nm=21100
Acidic soln.: 236nm=19500
Basic soln.: 241.0nm=27900

Surface tension (mN m⁻¹)

71.4

at 22°C

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

12.5

Non-persistent

DT₅₀ (lab at 20 °C)

12.5

Non-persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

41.5

Moderately persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU dossier (DAR) lab studies DT₅₀ range 1.9-25 days, DT₉₀ range 6.4-83 days; Isagro datasheet gives DT₅₀ 20-80 days; Other literature DT₅₀ ranges 10-21 days

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

Not considered to be a significant route of degradation

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

Value

24.4

Non-persistent

Note

pH and temperature sensitive: DT₅₀ 8 hours at pH 5, 228 days at pH 9, all at 25 °C; 0.4 hours at pH 4, 1.5 days at pH 7, 8 days at pH 9 all at 50 °C.

Water-sediment DT₅₀ (days)

30.3

Moderately fast

Water phase only DT₅₀ (days)

19.8

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)

6.73

Moderately mobile

K_oc (mL g⁻¹)

352.5

Notes and range

EU dossier K_d range 6.003-8.568 mL g⁻¹, K_oc range 249-550 mL g⁻¹, soil=4

Freundlich

K_f (mL g⁻¹)

5.41

K_foc (mL g⁻¹)

¹/_n

0.871

Notes and range

EU dossier K_f range 3.763-6.662mL g⁻¹, K_foc not calculated, ¹/_n range 0.749-0.920, soils=4

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

1.59

Calculated

Low leachability

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

Value

3.03 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

1.76

Calculated using the Atkinson method

Below the level of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

1.0

Low potential

CT₅₀ (days)

Not available

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

2-((dimethylamino)carbonyl)phenyl sulfamic acid (Ref: IR7863)

Major fraction

0.545

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

Major fraction

0.570

1-(4-methoxy-6-hydroxypyrimidin-2-yl)-3-(2,(2-dimethylcarbomyl)phenylsulfomoyl)urea (Ref: IR 8181)

Major fraction

0.224

1-(4-hydroxy-6-methoxypyrimidin-2-yl)urea (Ref: IR9512)

Minor fraction

0.090

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)

2-((dimethylamino)carbonyl)phenyl sulfamic acid (Ref: IR7863)

Relevant

1-(4,6-dimethoxypyrimidin-2-yl)urea (Ref: IR7825)

Relevant

1-(4-methoxy-6-hydroxypyrimidin-2-yl)-3-(2,(2-dimethylcarbomyl)phenylsulfomoyl)urea (Ref: IR8181)

Relevant

1-(4-hydroxy-6-methoxypyrimidin-2-yl)urea (Ref: IR9512)

Relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

1,-(4-methoxy-6-hydroxypyrimidin-2-yl)-3-(2-(methylcarbomoyl)phenylsulfomoyl)urea

N-desm-O-desm IR5878

Rat; Animal

2-amino-N,N-dimethylbenzamide

DB amine

Rat; Plant (Rice, Crop); Animal

2-sulfamoylamino-N,N-dimethylbenzamide

DBS amide

Rat; Plant (Rice, Crop)

Pyr-O-Glucur IR5878

Rat

N-desmethyl IR5878

Rat; Animal

Pyr-O-Glucur DOP urea

Rat

(4,6-dimethoxy-5-sulfate pyrimidin-2-yl)urea

Pyr-O-Sulf DOP Urea

Rat; Animal

2-amino-N-methylbenzamide

N-desmethyl DB amine

Animal

Pyr-OH DOP urea

Animal

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)

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2000

Colinus virginianus

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

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)

> 1000

Eisenia foetida

Low

Soil micro-organisms

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

Dose: 0.507mg/Kg soil 42 Day

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

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)

> 109.4

Apis mellifera

Low

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

Chronic

Notes

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

> 225

Aphidius rhopalosiphi

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

89.5

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)

> 122

Oncorhynchus mykiss

Low

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

6.1

Pimephales promelas

Moderate

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

> 100

Danio rerio

Low

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)

66.9

Chironomus riparius

Low

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

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

0.00033

Lemna gibba Fronds

High

Aquatic plants (rooted, growth) - Acute 14 day EC₅₀, biomass (mg l⁻¹)

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

Anabaena flos-aquae

Low

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

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)

> 2.19

Rat 4 hr (nose only)

Other Mammal toxicity endpoints

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

None allocated

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)

None allocated

Dermal penetration studies (%)

0.54-2.63

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

Acceptable for proposed uses

Occupational

Acceptable for proposed 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

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 be absorbed through skin or inhalation
Possible liver, spleen and kideny toxicant
US EPA - weak evidence to suggest possible human carcinogen

Handling issues

Property

Value and interpretation

General

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

CLP classification 2013

Health: H361d
Environment: H400

WHO Classification

Not listed (Not listed)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

orthosulfamuron

French

German

Danish

Italian

Spanish

ortosulfamuron

Greek

Polish

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	23/01/2025
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