Benzobicyclon (Ref: SB 500)

Benzobicyclon (Ref: SB 500)	Last updated: 11/04/2025
(Also known as: SAN 1315H)

SUMMARY

Benzobicyclon is an unclassified herbicide used to control annual and perennial weeds mainly in rice crops. It has a low aqueous solubility and is not volatile. Environmental persistence data is not available. It has a low to moderate level of toxicity to most biodiversity. It has a low oral toxicity to mammals but little else has been published regarding its impacts on human health.

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: Birds chronic ecotoxicity: Moderate; Fish acute ecotoxicity: Moderate; Fish chronic ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate; Daphnia chronic ecotoxicity: Moderate	Human health Moderate alert: Reproduction/development effects

GENERAL INFORMATION

Description

Used to control annual and perennial weeds in rice crops

Example pests controlled

Barnyardgrass; Yellow nutsedge; Ducksalad; Water plantain; Bog pondweed; Rice cutgrass

Example applications

Rice

Efficacy & activity

Efficacy demonstrated via field trials with paddy rice

Availability status

Current

Introduction & key dates

2001, introduced

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

Pending

Dossier rapporteur/co-rapporteur

Malta/Greece

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

Chemical structure

Isomerism

Benzobicyclon is a chiral molecule.Substance is racemic.

Chemical formula

C₂₂H₁₉ClO₄S₂

Canonical SMILES

CS(=O)(=O)C1=CC(=C(C=C1)C(=O)C2=C(C3CCC(C3)C2=O)SC4=CC=CC=C4)Cl

Isomeric SMILES

International Chemical Identifier key (InChIKey)

VIXCLRUCUMWJFF-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C22H19ClO4S2/c1-29(26,27)16-9-10-17(18(23)12-16)21(25)19-20(24)13-7-8-14(11-13)22(19)28-15-5-3-2-4-6-15/h2-6,9-10,12-14H,7-8,11H2,1H3

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
benzobicyclon	-

General status

Pesticide type

Herbicide

Substance groups

Carbobicyclic compound; Cyclic ketone compound

Minimum active substance purity

>980 g kg⁻¹

Known relevant impurities

EU 2023 dossier: None declared

Substance origin

Synthetic

Mode of action

Selective, absorbed through roots and basal stems and translocated. Bleaching inhibition of 4-hydroxyphenyl-pyruvate-dioxygenase.

CAS RN

156963-66-5

EC number

605-078-5

CIPAC number

None allocated

US EPA chemical code

215101

PubChem CID

11236201

CLP index number

No data found

Molecular mass

446.96

PIN (Preferred Identification Name)

rac-(1R,5R)-3-[2-chloro-4-(methanesulfonyl)benzoyl]-4-(phenylsulfanyl)bicyclo[3.2.1]oct-3-en-2-one

IUPAC name

3-(2-chloro-4-mesylbenzoyl)-2-phenylthiobicyclo[3.2.1]oct-2-en-4-one

CAS name

3-[2-chloro-4-(methylsulfonyl)benzoyl]-4-(phenylthio)bicyclo[3.2.1]oct-3-en-2-one

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

Pale yellow crystalline solid

Formulations

Property

Value

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

SDS Biotech K.K.

Example products using this active

Showace
Butte Herbicide
Avanza

Formulation and application details

Usually supplied as granules or suspension concentrates

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

0.052

Low

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

190

Ethanol

390

Methanol

9300

Acetone

2600

Ethyl acetate

Melting point (°C)

187

Boiling point (°C)

Degrades before boiling

Degradation point (°C)

281

Flashpoint (°C)

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

1.26 X 10⁰³

Calculated

Log P

3.1

High

Fat solubility of residues

Solubility

Soluble

Data type

Regulatory data based on LogP

Density (g ml⁻¹)

1.45

Dissociation constant pKa) at 25 °C

No dissociation

Vapour pressure at 20 °C (mPa)

5.0 X 10^-06

Low volatility

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

4.31 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

Methanol: 323nm=18900, 314nm=16400, 304nm=11700, 290nm=8200
1M HCl: 324nm=18900, 314nm=16100, 304nm=11400, 290nm=8100
1M NaOH: 314nm=5200, 304nm=9100, 290nm=16100, ,262nm=36400

Surface tension (mN m⁻¹)

70.6

20 °C 99.3%

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Not readily biodegradable

Soil degradation (days) (aerobic)

DT₅₀ (typical)

56.5

Moderately persistent

DT₅₀ (lab at 20 °C)

56.5

Moderately persistent

DT₅₀ (field)

14.65

Non-persistent

DT₉₀ (lab at 20 °C)

202.5

Persistent

DT₉₀ (field)

55.5

DT₅₀ modelling endpoint

Note

EU 2023 Dossier Lab studies DT₅₀ (normalised) range 33.7-88.6 days, DT₉₀ (measured) range 119-288 days, Soils=3; Field studies DT₅₀ (normalised) range 4.3-49.3 days, DT₉₀ (measured) range 11.0-103 days, Soils=2

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

26.9

at pH5

Slow

Note

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

Value

0.7

at 25 °C

Non-persistent

Note

pH4: 0.6 days; pH9: 0.5 days all at 25 °C

Water-sediment DT₅₀ (days)

Water phase only DT₅₀ (days)

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)

Slightly mobile

K_oc (mL g⁻¹)

1104

Notes and range

Estimated

Freundlich

K_f (mL g⁻¹)

83.4

Non-mobile

K_foc (mL g⁻¹)

8439

¹/_n

0.826

Notes and range

EU dossier 2023 kf range 28.22-215.7 mL g⁻¹, K_foc range 4351-24797 mL g⁻¹, ¹/_n ramge 0.77-0.88, Soils=5

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

0.09

Calculated

Low leachability

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

Value

5.67 X 10^-03

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

2.2

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)

1.26

Low potential

CT₅₀ (days)

10.0

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

3-(2-chloro-4- methylsulfonylbenzoyl) bicyclo[3.2.1]octane-2,4- dione (Ref: 1315P-070)

Major fraction

0.401

Flooded soil

4-amino-3-[2-chloro-4-(methylsulfonyl)benzoyl]bicyclo[3.2.1]oct-3-en-2-one (Ref: 1315P-570)

Majpr fraction

0.567

Flooded soil

(4-(carboxymethyl)amino)- 3-(2-chloro-4-methylsulfonylbenzoyl)- bicyclo [3.2.1]oct-3-en-2- one (Ref: 1315P-960)

Major fraction

0.136

Flooded soil

2-chloro-4-methylsulfonyl-benzoic acid

Major fraction

0.208

Non-flooded soil

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-chloro-4-methylsulfonyl-benzoic acid

Not relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

4-amino-3-[2-chloro-4-(methylsulfonyl)benzoyl]bicyclo[3.2.1]oct-3-en-2-one (Ref: 1315P-570)

Surface water; Sediment

3596

(4-(carboxymethyl)amino)- 3-(2-chloro-4-methylsulfonylbenzoyl)- bicyclo [3.2.1]oct-3-en-2- one (Ref: 1315P-960)

Surface water; Sediment

3597

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)

> 2250

Colinus virginianus

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

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

36.2

Colinus virginianus NOED

Moderate

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

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

500

Eisenia foetida corr

Low

Soil micro-organisms

Nitrogen mineralisation: No significant adverse effect

Dose 2.0 mg kg⁻¹ soil 28 Day

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

> 300

Bean Radish
Vegetative vigour, ER₅₀
as g ha⁻¹

> 300

Bean Radish
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)

> 200

Apis mellifera

Low

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

> 200

Apis mellifera

Low

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

Chronic 10 day NOED

>= 62

Apis mellifera

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) as LR₅₀ g ha⁻¹

> 600

Chrysoperla carnea Larvae

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

< 37.5

Aphidius rhopalosiphi

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

< 37.5

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)

> 0.489

Oncorhynchus mykiss

Moderate

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

0.1

Oncorhynchus mykiss 28 days

Moderate

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

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

> 0.368

Daphnia magna

Moderate

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

0.279

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)

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

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

0.00619

Lemna gibba

High

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

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

> 0.450

Raphidocelis subcapitata

Moderate

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

0.450

Raphidocelis subcapitata

Moderate

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)

> 2.72

Rat 4 hr (whole body)

Other Mammal toxicity endpoints

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

0.034

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)

None allocated

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

0.06

Rat SF=1000

Dermal penetration studies (%)

0.66-16.0

concentration dependent

Dangerous Substances Directive 76/464

Not listed

Exposure Routes

Public

Low risk for public and consumers

Occupational

PPE/PPC recommended

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

Rapid and extensive excretion as metabolites mainly via 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

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

Possible renal and liver toxicant

Handling issues

Property

Value and interpretation

General

Not expected to auto-ignite; Not highly flammable
Npt explosive

CLP classification 2013

Environment: H400, H410

WHO Classification

Not listed (Not listed)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

benzobicyclon

French

German

Danish

Italian

Spanish

Greek

Polish

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	11/04/2025
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