Asulam sodium (Ref: AE F102789)

Asulam sodium (Ref: AE F102789)	Last updated: 20/05/2025
(Also known as: asulam; HOE 102789; sodium asulam; RPA 4143636; Hoe 102789; AE C518360)

SUMMARY

Asulam sodium is a carbamate herbicide. It is highly soluble in water, volatile with a low risk of leaching to groundwater. It is not persistent in soils but may be persistent in water especially under dark conditions. Although it is not highly toxic there is a risk of bioaccumulation. It is a skin, eye and respiratory system irritant and may cause undesirable effects on reproduction. Asulam sodium is moderately toxic to birds, most aquatic organisms, honeybees and earthworms.

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 High alert: Persistent; GUS: High leachability; Drainflow: Mobile	Ecotoxicity Moderate alert: Birds acute ecotoxicity: Moderate; Fish acute ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate; Daphnia chronic ecotoxicity: Moderate	Human health Moderate alert: Endocrine disrupter; Reproduction/development effects

GENERAL INFORMATION

Description

A translocated carbamate herbicide for control of problematic weeds in cropped and non-cropped situations

Example pests controlled

Docks; Bracken; Ragwort

Example applications

Moorland; Amenity vegetation; Forestry; Spinach; Ornamentals including bulb production

Efficacy & activity

Availability status

Current

Introduction & key dates

1965, introduced

GB regulatory status

GB COPR regulatory status

Not approved

Date COPR inclusion expires

Expired

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

France

Date EC 1107/2009 inclusion expires

Not applicable

EU Candidate for substitution (CfS)

Not applicable

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

C₈H₉N₂O₄SNa₂

Canonical SMILES

COC(=O)[N-]S(=O)(=O)C1=CC=C(C=C1)N.[Na+]

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

PEXLHWBDBQUUOG-UHFFFAOYSA-M

International Chemical Identifier (InChI)

InChI=1S/C8H10N2O4S.Na/c1-14-8(11)10-15(12,13)7-4-2-6(9)3-5-7;/h2-5H,9H2,1H3,(H,10,11);/q;+1

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
asulam	Parent

General status

Pesticide type

Herbicide

Substance groups

Carbamate herbicide; Sulphonamide herbicide

Minimum active substance purity

876 g kg⁻¹ as sodium salt

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Selective system action, absorbed by leaves, shoots and roots. Inhibition of dihydropterate synthase causing slow chlorosis.

CAS RN

2302-17-2

EC number

218-953-8

CIPAC number

240

US EPA chemical code

106902

PubChem CID

61292

CLP index number

No data found

Molecular mass

253.23

PIN (Preferred Identification Name)

sodium (4-aminobenzenesulfonyl)(methoxycarbonyl)azanide

IUPAC name

sodium methyl (EZ)-sulfanilylcarbonimidate

CAS name

methyl [(4-aminophenyl)sulfonyl]carbamate monosodium salt

Other status information

Chemical subject to PIC regulations

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

Colourless to white crystals

Related substances & organisms

asulam

Formulations

Property

Value

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

AgriGuard
United Phosphorus
Bayer CropScience

Example products using this active

Asulox
Brack-N
Aceto Asulam 400 Herbicide

Formulation and application details

Often available as a soluble liquid concentrate that is 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)

962000

High

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

0.07

n-Heptane

Xylene

117000

Methanol

1100

Acetone

Melting point (°C)

230

Boiling point (°C)

104

Degradation point (°C)

230

Flashpoint (°C)

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

1.41 X 10⁰⁰

Calculated

Log P

0.15

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

1.53

Dissociation constant pKa) at 25 °C

1.29

Strong acid; pKa(2) 4.68

Vapour pressure at 20 °C (mPa)

5.00 X 10^-04

Low volatility

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

1.31 X 10^-10

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

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

292nm = 2750

Surface tension (mN m⁻¹)

71.5

at 20°C 89.6%

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

4.6

Non-persistent

DT₅₀ (lab at 20 °C)

4.6

Non-persistent

DT₅₀ (field)

356

Persistent

DT₉₀ (lab at 20 °C)

19.5

Non-persistent

DT₉₀ (field)

1000

DT₅₀ modelling endpoint

Note

EU dossier 2006 lab studies DT₅₀ range 2.66-11.1 days, DT₉₀ range 8.0-37.2 days, Soils=12; Field studies, DT₅₀ & DT₉₀ > 365 days; Other studies: DT₅₀ 6-14 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

Moderately fast

Note

DT₅₀ 0.78 days at pH 4, 1.56 days at pH 9

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

Value

Stable

Note

Stable at pH 5 to pH 9

Water-sediment DT₅₀ (days)

Moderately fast

Water phase only DT₅₀ (days)

Stable

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)

0.949

Mobile

K_foc (mL g⁻¹)

25.4

¹/_n

0.75

Notes and range

EU dossier kf range 0.150-3.28 mL g⁻¹, K_foc range 15.4-149.7 mL g⁻¹, ¹/_n range 0.66-0.87, Soils=10

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

6.62

Calculated

High leachability

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

Value

4.15 X 10⁰¹

Calculated

Note

Potential for particle bound transport index

Medium

Calculated

Potential for loss via drain flow

Mobile

Calculated

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

8.93

Calculated using the Atkinson method. Assumed 1.5E+06 OH/cm³, 12 hr

Below the level of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

0.75

Whole fish

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

acetyl-asulam

Minor fraction

acetylsulphanilamide

Minor fraction

aminobenzenesulphonic acid

Minor fraction

N-(4-aminophenyl)formamide

Minor fraction

methyl phenylsulphonylcarbamate

Minor fraction

benzenesulphonamide

Minor fraction

sulphanilamide

Major fraction

0.139

Known groundwater metabolites

None

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

sulphanilamide

Animal

formyl asulam

Plant

aminobenzenesulphonic acid

Surface water

N-(4-aminophenyl)formamide

Water

malonyl-asulam

Plant

acetyl-asulam

Animal (Urine); Plant

malonyl-sulphanilamide

Processing

asulam glucosides

Plant

methyl phenylsulphonylcarbamate

desamino asulam; MBSC

Plant

4-acetylbenzenesulphonamide

Plant

acetylsulphanilamide

Animal (Urine)

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)

Rat

High

(ppm diet)

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

Birds - Acute LD₅₀ (mg kg⁻¹)

> 1826

Colinus virginianus as asulam

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

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

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

1004

Eisenia foetida as asulam

Low

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

180.7

Eisenia foetida as asulam Reproduction

Low

Soil micro-organisms

Nitrogen mineralisation: Up to -26% effect
Carbon mineralisation: No significant adverse effect

Dose: 0.16 g asulam/kg soil 56 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 as asulam

Low

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

> 123.7

Apis mellifera as asulam

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)

4.8% Mortality at dose 22.4 g ha⁻¹

Chrysoperla carnea Larva

Beneficial insects (Parasitic wasps) as Mortality LR₅₀ g ha⁻¹ 48 hr

1.35

Aphidius rhopalosiphi

Beneficial insects (Predatory mites) as Mortality LR₅₀ g ha⁻¹ 7 day

3.31

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)

> 91.3

Lepomis macrochirus as asulam

Moderate

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

119.1

Oncorhynchus mykiss as asulam

Low

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

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

57.87

Daphnia magna as asulam

Moderate

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

6.4

Daphnia magna as asulam

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)

100

Chironomus riparius as asulam

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)

0.27

Lemna gibba as asulam

Moderate

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

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

> 0.66

Anabaena flos-aquae as asulam

Moderate

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)

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 5.46

Rat

Other Mammal toxicity endpoints

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

0.36

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

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

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

0.046

Dermal penetration studies (%)

0.5-3

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

Low risk of dietary exposure and accidental exposure of residents or bystanders

Occupational

Risk of exposure acceptable under label recommendations for use for personal protection clothing and equipment

MRLs

European

EU MRL pesticide database

Great Britain

GB MRL Register

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

0.1

EU Dir 89/778/EC limit; Calc MAC=1080 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

No data found

General human health issues

Possible blood, thyroid and kidney toxicant

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
Not expected to auto-ignite; Not highly flammable
IMDG Transport Hazard Class 6,1

CLP classification 2013

Health: H317

WHO Classification

U (Unlikely to present an acute hazard)

UN Number

UN2757

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

asulam sodium

French

asulame

German

Asulam

Danish

asulam

Italian

asulame

Spanish

asulame

Greek

Polish

asulam sodowy

Swedish

Hungarian

aszulam

Dutch

asulam

Norwegian

Record last updated:	20/05/2025
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