Acibenzolar-S-methyl (Ref: CGA 245704)

Acibenzolar-S-methyl (Ref: CGA 245704)	Last updated: 20/05/2025
(Also known as: benzothiadiazole; 1,2,3-benzothiadiazole-7-carbothioic acid; azibenzolar-S-methyl; ASM)

SUMMARY

Acibenzolar-S-methyl is a preventative fungicide. It is not highly soluble in water but is highly soluble in most organic solvents. It is quite volatile. It is not expected to leach to groundwater. It is slightly mobile but tends not to be persistence in soil or aquatic systems. It has a moderate mammalian toxicity and there is some concern regarding its potential for bioaccumulation. Acibenzolar-S-methyl is moderately toxic to birds, honeybees, earthworms and most aquatic organisms.

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: Slightly mobile; Potential for particle bound transport: Medium	Ecotoxicity Moderate alert: Fish acute ecotoxicity: Moderate; Fish chronic ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate; Daphnia chronic ecotoxicity: Moderate; Earthworms acute ecotoxicity: Moderate; Earthworms chronic ecotoxicity: Moderate	Human health High alert: Reproduction/development effects

GENERAL INFORMATION

Description

A preventative fungicide used to control various fungi, bacteria and viruses but also has some insecticide activity

Example pests controlled

Downy mildew; White rust; Bacteria spot; Bacteria speck; Blue mold

Example applications

Leafy vegetables; Tobacco; Tomatoes; Cotton

Efficacy & activity

Availability status

Current

Introduction & key dates

1996, first introduced Germany

GB regulatory status

GB COPR regulatory status

Approved

Date COPR inclusion expires

31/03/2031

GB LERAP status

No data

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Not approved

Dossier rapporteur/co-rapporteur

Spain/Belgium

Date EC 1107/2009 inclusion expires

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; USA; Morocco

Chemical structure

Isomerism

None

Chemical formula

C₈H₆N₂OS₂

Canonical SMILES

CSC(=O)C1=C2C(=CC=C1)N=NS2

Isomeric SMILES

International Chemical Identifier key (InChIKey)

UELITFHSCLAHKR-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C8H6N2OS2/c1-12-8(11)5-3-2-4-6-7(5)13-10-9-6/h2-4H,1H3

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
acibenzolar-S-methyl	-

General status

Pesticide type

Fungicide; Other substance

Other bioactivity & uses

Plant activator

Substance groups

Benzothiadiazole pesticide; Plant activator

Minimum active substance purity

970 g kg⁻¹

Known relevant impurities

EU dossier - Toluene < 5g kg⁻¹

Substance origin

Synthetic

Mode of action

Systemic Activated Resistance (SAR). Induces host plant defence.

CAS RN

135158-54-2

EC number

420-050-0

CIPAC number

597

US EPA chemical code

061402

PubChem CID

86412

CLP index number

016-083-00-1

Molecular mass

210.3

PIN (Preferred Identification Name)

S-methyl 1,2,3-benzothiadiazole-7-carbothioate

IUPAC name

S-methyl benzo[1,2,3]thiadiazole-7-carbothioate

CAS name

1,2,3-benzothiadiazole-7-carbothioic acid, S-methyl ester

Other status information

Relevant Environmental Water Quality Standards

Herbicide Resistance Class (HRAC MoA class)

Not applicable

Herbicide Resistance Class (WSSA MoA class)

Not applicable

Insecticide Resistance Class (IRAC MoA class)

Not applicable

Fungicide Resistance Class (FRAC MOA class)

P01

Examples of recorded resistance

Physical state

White to beige crystalline powder

Related substances & organisms

acibenzolar

Formulations

Property

Value

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

Novartis
Syngenta

Example products using this active

Actigard
Bion 50WG
Blockade
Boost
Daconil Action

Formulation and application details

Usually supplied as water dispersible granules for foliar application or as a seed treatment.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

7.7

Low

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

28000

Acetone

36000

Toluene

1300

Hexane

4200

Methanol

Melting point (°C)

133

Boiling point (°C)

267

Degradation point (°C)

Flashpoint (°C)

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

1.26 X 10⁰³

Calculated

Log P

3.1

at 25 °C

High

Fat solubility of residues

Solubility

Insoluble

Data type

Regulatory data

Density (g ml⁻¹)

1.54

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

Vapour pressure at 20 °C (mPa)

0.46

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)

1.30 X 10^-02

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

Volatilisation is not considered critical for air pollution

From soil surface

Negligible

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

253nm = 14700, 288nm = 5400, 324nm = 7200

Surface tension (mN m⁻¹)

70.7

at 20.5 °C

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

0.138

Non-persistent

DT₅₀ (lab at 20 °C)

0.131

Non-persistent

DT₅₀ (field)

17.1

Non-persistent

DT₉₀ (lab at 20 °C)

0.986

Non-persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU dossier Lab studies DT₅₀ range 0.031-0.441 days, DT₉₀ range 0.36-3.3 days; Field studies DT₅₀ range 0.1-30 days; Other sources: 16.0 days (DW3)

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

0.1

Fast

Note

DT₅₀: 0.75 hrs at pH 5, 25 °C

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

Value

162

Persistent

Note

pH sensitive: 1400 days at pH 5, <1 day at pH 9

Water-sediment DT₅₀ (days)

Fast

Water phase only DT₅₀ (days)

Moderately fast

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)

19.0

Slightly mobile

K_foc (mL g⁻¹)

1650

¹/_n

0.83

Notes and range

EU dossier K_f range 3.6-58.0 mL g⁻¹, K_foc range 493-3288 mL g⁻¹, ¹/_n range 0.75-1.00, Soils=10

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

0.96

Calculated

Low leachability

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

Value

1.68 X 10^-02

Calculated

Note

Potential for particle bound transport index

Medium

Calculated

Potential for loss via drain flow

Slightly mobile

Calculated

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

Derived from Atkinson nethod

Below the level of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

117

Whole fish

Threshold for concern

CT₅₀ (days)

0.35

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

benzo(1,2,3)thiadiazole-7-carboxylic acid (Ref: CGA 210007)

Major fraction

0.961

6-hydroxy-benzo(1,2,3)thiadiazole-7-carboxylic acid (Ref: SYN 546642)

Major fraction

0.390

acibenzolar

Major fraction

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)

benzo(1,2,3)thiadiazole-7-carboxylic acid (Ref: CGA 210007)

Relevant

6-hydroxy-benzo(1,2,3)thiadiazole-7-carboxylic acid (Ref: SYN 546642)

Relevancy unknown

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

benzo(1,2,3)thiadiazole-7-carboxylic acid (Ref: CGA 210007)

Plant

4-hydroxy acibenzolar (Ref: CGA 324041)
Note: Not toxicologically relevant

Plant

5-hydroxy acibenzolar (Ref: CGA 323060)
Note: Not toxicologically relevant

Plant

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 2000

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat

(ppm diet)

200

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)

> 5200 ppm

Colinus virginianus

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

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

> 500

Eisenia foetida corr

Moderate

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

1.34

Eisenia foetida corr

Moderate

Soil micro-organisms

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

Dose: Not stated

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

> 250

Unknown species
Vegetative vigour, ER₅₀
as g ha⁻¹

> 250

Unknown species
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)

> 128

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

> 200

Aphidius rhopalosiphi

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

> 200

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)

0.4

Oncorhynchus mykiss

Moderate

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

0.026

Oncorhynchus mykiss

Moderate

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

> 1.69

Danio rerio

Moderate

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

2.4

Daphnia magna

Moderate

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

0.044

Daphnia magna

Moderate

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

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

0.88

Mysidopsis bahia

Moderate

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

0.31

Lemna gibba

Moderate

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

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

0.5

Scenedesmus subspicatus

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)

> 2000

Rat

Low

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 5.0

Rat 4 hr (nose only)

Other Mammal toxicity endpoints

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

0.03

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

0.03

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

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

0.03

Dermal penetration studies (%)

0.1-33

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

Minimal risk of dietary exposure
Negligible risk to bystanders

Occupational

No unacceptable risks to operators or other workers identified considering intended 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

Almost totally eliminated via the urine as metabolite CGA 210007 in 24hrs

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

Eye irritant

Phototoxicant

No data found

General human health issues

Possible skin sensitiser
Weak evidence of clastogenicity

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

Health: H315, H317, H319, H335
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

TRANSLATIONS

Language

Name

English

acibenzolar-S-methyl

French

acibenzolar-S-methyl

German

Acibenzolar-S-methyl

Danish

acibenzolar-S-methyl

Italian

acibenzolar-S-metile

Spanish

acibenzolar-S-metil

Greek

Polish

acybenzolar-S metylowy

Swedish

Hungarian

acibenzolar S-metil

Dutch

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