Dithianon (Ref: BAS 216F)

Dithianon (Ref: BAS 216F)	Last updated: 15/03/2024
(Also known as: IT 931; CME 107)

SUMMARY

Dithianon is a widely used fungicide. It has a low aqueous solubility and a low volatility. It is not expected to be persistent in soil or water systems. Generally, it has a moderate toxicity to biodiversity. Dithianon has a moderate oral mammalian toxicity and is an irritant.

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: Moderately persistent; Drainflow: Slightly mobile; Potential for particle bound transport: Medium	Ecotoxicity High alert: Fish acute ecotoxicity: High	Human health Moderate alert: Mammals acute toxicity: Moderate; Mammals chronic toxicity: Moderate; Genotoxic; Reproduction/development effects

GENERAL INFORMATION

Description

A dicarbonitrile fungicide for control of scab and other foliar diseases excluding powdery mildew

Example pests controlled

Scab (reduction); Downy mildew

Example applications

Apples; Pears; Grapes (table & wine); Blackcurrants

Efficacy & activity

Availability status

Current

Introduction & key dates

circa 1965, introduced

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

31/08/2029

UK LERAP status

Check label - may vary with formulation

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Austria/Spain

Date EC 1107/2009 inclusion expires

31/08/2024

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

Chemical structure

Isomerism

None

Chemical formula

C₁₄H₄N₂O₂S₂

Canonical SMILES

C1=CC=C2C(=C1)C(=O)C3=C(C2=O)SC(=C(S3)C#N)C#N

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

PYZSVQVRHDXQSL-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C14H4N2O2S2/c15-5-9-10(6-16)20-14-12(18)8-4-2-1-3-7(8)11(17)13(14)19-9/h1-4H

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
dithianon	-

General status

Pesticide type

Fungicide

Substance groups

Quinone fungicide

Minimum active substance purity

930 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Protectant with some curative activity. Multi-site activity.

CAS RN

3347-22-6

EC number

222-098-6

CIPAC number

153

US EPA chemical code

099201

PubChem CID

18771

CLP index number

613-021-00-0

Molecular mass

296.32

PIN (Preferred Identification Name)

5,10-dioxo-5,10-dihydronaphtho[2,3-b][1,4]dithiine-2,3-dicarbonitrile

IUPAC name

5,10-dihydro-5,10-dioxonaphtho[2,3-b]-1,4-dithiine-2,3-dicarbonitrile

CAS name

5,10-dihydro-5,10-dioxonaphtho(2,3-b)-1,4-dithiin-2,3-dicarbonitrile

Other status information

Marine pollutant; PAN listed Highly Hazardous Chemical

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)

M09

Examples of recorded resistance

Physical state

Dark brown fibrous crystals

Formulations

Property

Value

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

BASF
Celamerck

Example products using this active

Dithianon Flowable
Dithianon WG
Delan 70WG

Formulation and application details

Often supplied as a soluble concentrate or wettable granules that are mixed with water and applied as a spray

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

0.22

Low

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

14700

Toluene

22200

Acetone

10600

Ethyl acetate

8.77

Hexane

Melting point (°C)

215

Boiling point (°C)

Degradation point (°C)

222

Flashpoint (°C)

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

1.58 X 10⁰³

Calculated

Log P

3.2

at pH 2.0

High

Fat solubility of residues

Solubility

Soluble

Data type

Regulatory data based on lofP

Density (g ml⁻¹)

1.58

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

Vapour pressure at 20 °C (mPa)

1.0 X 10^-07

Low volatility

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

1.347 X 10^-07

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

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

In CH3CN: 199nm = 35932, 233nm = 20542, 330nm = 5083, 290.5nm = 6535
pH 1.3: 199nm = 18102, 237nm = 15110, 342nm = 4489, 290.5nm = 5100
pH 6.9: 199nm = 22380, 250nm = 15110, 350nm = 7204, 290.5nm = 8724

Surface tension (mN m⁻¹)

72.7

at 20°C

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

10.5

Non-persistent

DT₅₀ (lab at 20 °C)

10.5

Non-persistent

DT₅₀ (field)

Moderately persistent

DT₉₀ (lab at 20 °C)

51.4

Moderately persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀ range 2.6-33.3 days (normalised), DT₉₀ range 8.5-135 days

Dissipation rate RL₅₀ (days) on plant matrix

Value

18.3

Note

Published literature RL₅₀ range 14.9-21.4 days, fruit from 3 field crops, n=3

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

Note

Aqueous photolysis DT₅₀ (days) at pH 7

Value

0.01

Fast

Note

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

Value

0.6

Non-persistent

Note

pH sensitive: DT₅₀ 10.7 days at pH 5, 9.8 minutes at pH 9 all at 20 °C

Water-sediment DT₅₀ (days)

0.05

Fast

Water phase only DT₅₀ (days)

0.05

Fast

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.

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

86.4

Slightly mobile

K_oc

3627

Notes and range

EU dossier K_d range 9-157 mL g⁻¹, K_oc range 1167-6004 mL g⁻¹, Soils=5

Freundlich

K_f

K_foc

¹/_n

Notes and range

pH sensitivity

Not stable under wet conditions pH > 4

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

0.68

Calculated

Low leachability

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

Value

1.28 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

6.3

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)

Whole fish

Low potential

CT₅₀ (days)

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

phthalic acid

Photolysis, Anaerobic

1,4-naphthoquinone (Ref: CL 1025)

Anaerobic

Ref: CL 902200

Anaerobic

Ref: CL 153880

Minor fraction

0.046

Anaerobic

4,9-dioxo-4,9-dihydronaphtho(2,3-b)thiophene-2,3-dicarbonitrile (Ref: CL 902198)

Minor fraction

0.039

Aerobic

Known groundwater metabolites

None

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

2-amino-1,4-naphthoquinone

dithianon metabolite D33

Rat (Faeces)

phthalic acid
Note: Not genotoxic

Plant

phthadialdehdye

Water (Hydrolysis, Photolysis)

1,2-benzenedimethanol

Water (Hydrolysis, Photolysis)

Ref: CL 902200

dithianon metabolite D15

Plant

Ref: CL 231509

Plant

Ref: CL 1017911

Water (Hydrolysis)

4,9-dioxo-4,9-dihydronaphtho(2,3-b)thiophene-2,3-dicarbonitrile (Ref: CL 902198)

dithianon metabolite D8

Rat (Faeces)

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

300

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat 2 yr

(ppm diet)

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

27.6

Rat Reproductive NOAEL

Moderate

Birds - Acute LD₅₀ (mg kg⁻¹)

309

Colinus virginianus

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

> 1198.5 mg kg bw⁻¹ day⁻¹

Colinus virginianus

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

22.8

Colinus virginianus NOEC

Moderate

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

578

Eisenia foetida

Moderate

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

22.3

Eisenia foetida

Moderate

Soil micro-organisms

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

Dose: 14 kg ha⁻¹ 28 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)

> 25.4

Apis mellifera

Moderate

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

Chronic

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

> 4500

Aphidius rhopalosiphi

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

720

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)

0.07

Oncorhynchus mykiss

High

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

0.02

Oncorhynchus mykiss

Moderate

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

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

0.26

Daphnia magna

Moderate

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

0.05

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)

> 0.5

Chironomus riparius

Moderate

Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l⁻¹)

> 0.125

Chironomus riparius

Moderate

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

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

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

0.09

Pseudokirchneriella subcapitata

Moderate

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

0.025

Pseudokirchneriella subcapitata

Moderate

Mesocosm study data

NOEAEC mg l⁻¹

0.004

Fish

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)

300

Rat

Moderate

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

0.31

Rat

Other Mammal toxicity endpoints

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

0.01

Rat SF=100

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

0.12

Rat SF=100

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

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

0.0135

Dog SF=100

Dermal penetration studies (%)

0.26-3.1

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

No unacceptable risks to bystanders identified

Occupational

Possible risk to operators identified even with PPE
Minimal risk to other workers with PPE

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

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

Toxic
Possible liver and kidney toxicant
May cause nausea, vomiting and diarrhoea if ingested

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: H302
Environment: H400, H410

WHO Classification

II (Moderately hazardous)

UN Number

UN3077

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

Chemically stable under standard ambient conditions

TRANSLATIONS

Language

Name

English

dithianon

French

dithianon

German

Dithianon

Danish

dithianon

Italian

ditianon

Spanish

ditianona

Greek

dithianon

Polish

ditianon

Swedish

ditianon

Hungarian

ditianon

Dutch

dithianon

Norwegian

ditianon

Record last updated:	15/03/2024
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