Captan (Ref: SR 406)

Captan (Ref: SR 406)	Last updated: 14/08/2025
(Also known as: captane; captab; ENT 26538)

SUMMARY

Captan is a dicarboximide fungicide used on fruit and other crops. It has a low aqueous solubility, is not volatile and is not generally expected to leach to groundwater considering its chemical properties. It is not usually persistent in soil or water systems. It has a low mammalian toxicity but is considered to be an eye and skin irritant. Some data sources also suggest captan is carcinogenic and may also cause endocrine issues. It has a low to moderate ecotoxicity for most aquatic and terrestrial species.

Hazard 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. These hazard alerts do not take account of usage patterns or exposure, thus do not represent risk.

Environmental fate	Ecotoxicity	Human health
Environmental fate Moderate alert: Drainflow: Moderately mobile	Ecotoxicity Moderate alert: Birds chronic ecotoxicity: Moderate; 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: Genotoxic; Endocrine disrupter

GENERAL INFORMATION

Description

A dicarboximide fungicide widely used on fruit and other crops

Example pests controlled

Seed rot; Damping-off; Grey mold; Berry rot; Spur blight; Brown rot; Leaf spot; Downy mildew; Bunch rot; Scab

Example applications

Fruit including apples, apricots, blueberries, blackberries, cherries, grapes, raspberries, nectarines, plums, peaches; Almonds; Grasses; Roses

Efficacy & activity

GB regulatory status

GB COPR regulatory status

Approved

Date COPR inclusion expires

31/07/2029

GB 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

Italy

Date EC 1107/2009 inclusion expires

31/10/2039

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

Captan exhibits limited isomerism. It is considered isomeric in the sense that it can exist in different stereoisomeric forms however, these forms are mostly theoretical and not a major factor in its commercial or biological behavior

Chemical formula

C₉H₈Cl₃NO₂S

Canonical SMILES

C1C=CCC2C1C(=O)N(C2=O)SC(Cl)(Cl)Cl

Isomeric SMILES

International Chemical Identifier key (InChIKey)

LDVVMCZRFWMZSG-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C9H8Cl3NO2S/c10-9(11,12)16-13-7(14)5-3-1-2-4-6(5)8(13)15/h1-2,5-6H,3-4H2

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
captan	Unstated isomer

General status

Pesticide type

Fungicide; Other substance

Other bioactivity & uses

Bactericide; Biocide; Preservative

Substance groups

Phthalimide fungicide

Minimum active substance purity

910-930 g kg⁻¹

Known relevant impurities

Substance origin

Synthetic

Mode of action

Non-systemic with protective and curative action. Multi-site activity.

CAS RN

133-06-2

EC number

205-087-0

CIPAC number

US EPA chemical code

081301

PubChem CID

8606

CLP index number

613-044-00-6

Molecular mass

300.61

PIN (Preferred Identification Name)

2-[(trichloromethyl)sulfanyl]-3a,4,7,7a-tetrahydro-1H-isoindole-1,3(2H)-dione

IUPAC name

N-(trichloromethylthio)cyclohex-4-ene-1,2-dicarboximide

CAS name

3a,4,7,7a-tetrahydro-2-[(trichloromethyl)thio]-1H-isoindole-1,3(2H)-dione

Forever chemical

Other status information

PAN Bad Actor

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)

M04

Examples of recorded resistance

Physical state

Dirty white powder

Commercial

Property

Value

Availability status

Current

Introduction & key dates

1952, first reported

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

Adama
Makhteshim-Agan
Bonide Products
Chemtura Corp
Chevron
Stauffer
Pillar International
Imtrade Australia Pty Ltd

Example products using this active

Alpha Captan
Orthocide 406
Hexacap
Aacaptan
Merpan
Malvin
Pillarcap
Imtrade Captan 800 WG

Formulation and application details

Usually supplied as wettable granules or powders that are mixed with water and applied as a spray

Commercial production

Captan is commercially produced through a multi-step chemical synthesis involving phthalimide derivatives. The process typically begins with the reaction of phthalic anhydride with ammonia to form phthalimide. This intermediate is then chlorinated and reacted with trichloromethylthiol compounds to yield captan.

Impact on climate of production and use

Information relating to the life-cycle GHG emissions from captan are not readily available. However, one study showed that fungicides can have emissions ranging from 11.9 to 29.2 kg CO₂-eq/kg.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

5.2

Low

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

Hexane

4000

Methanol

9000

Xylene

38000

Acetone

Melting point (°C)

174

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

173

Flashpoint (°C)

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

3.16 X 10⁰²

Calculated

Log P

2.5

Low

Fat solubility of residues

Solubility

Insoluble

Data type

Regulatory data

Density (g ml⁻¹)

1.68

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

Vapour pressure at 20 °C (mPa)

0.41

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)

3.00 X 10^-04

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 solution: 243nm = 312
Acidic solution: 243nm = 330
Basic solution: 286nm = 195, 343nm = 12.6

Surface tension (mN m⁻¹)

72.4

at 20°C

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

0.8

Non-persistent

DT₅₀ (lab at 20 °C)

0.8

Non-persistent

DT₅₀ (field)

3.7

Non-persistent

DT₉₀ (lab at 20 °C)

2.5

Non-persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀ range 0.44-1.09 days, DT₉₀ range 1.46-3.62 days, field studies DT₅₀ range 0.33-7.04 days USA

Dissipation rate RL₅₀ (days) on plant matrix

Value

6.9

Note

Published literature RL₅₀ range 1.0-14.0 days, 8 field and undercover grown crops, various matrices, n=14

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

1.9

Note

Published literature RL₅₀ range 0.9-2.5 days, 3 field and undercover grown crops, various matrices, n=3

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Stable

Note

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

Value

0.6

Non-persistent

Note

pH sensitive: 0.15 days at pH 5, 6 minutes at pH 9

Water-sediment DT₅₀ (days)

Fast

Water phase only DT₅₀ (days)

0.6

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)

Moderately mobile

K_oc (mL g⁻¹)

200

Notes and range

Measurement difficulties - EU dossier quotes literature values between 33-600 mL g⁻¹

Freundlich

K_f (mL g⁻¹)

K_foc (mL g⁻¹)

¹/_n

Notes and range

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

0.97

Calculated

Low leachability

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

Value

2.59 X 10^-03

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

1.5

Calculated using the Atkinson method, 12 hr

Below the level of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

140

Whole fish

Threshold for concern

CT₅₀ (days)

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

tetrahydrophthalimide

Major fraction

0.251

Adama verified

tetrahydrophthalamic acid

Major fraction

0.145

Adama verified

2-cyanocyclohex-4-ene carboxylic acid

Major fraction (anaerobic)

0.288

Anaerobic; Adama verified

tetrahydrophthalamic acid

Major fraction (anaerobic)

0.216

Anaerobic; Adama verified

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)

tetrahydrophthalimide

Not relevant

tetrahydrophthalamic acid

Not relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

cyclohex-4-ene-1,2-dicarboxylic acid

Water

3-hydroxy-4,5-cyclohexene-1,2-dicarboximide

3-OH THPI

Animal

5-hydroxy-4,5-cyclohexene-1,2-dicarboximide

5-OH THPI

Animal

4,5-epoxy-1,2-dicarboximide

THPI-epoxide

Animal; Plant

4,5-dihydroxy-1,2-dicarboximide

4,5-diOH THPI

Animal

6-hydroxy-1-amido-2-carboxy-4,5-cyclohexene

3-OH THP-amic acid).

Animal

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

High

(ppm diet)

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

100

Rabbit Reproductive NOAEL

Moderate

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2000

Anas platyrhynchos

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

> 1040 mg kg bw⁻¹ day⁻¹

Anas platyrhynchos

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

> 74.4

Coturnix coturnix

Moderate

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

> 259.7

Eisenia foetida corr

Moderate

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

6.1

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

Vegetative vigour ER₅₀ (g ha⁻¹)

Seedling emergence ER₅₀ (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)

> 100

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)

269.7

Osmia lignaria

Low

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

100.45

Osmia lignaria

Low

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)

7.0% Mortality at dose 0.56 kg ha⁻¹

Chrysoperla carnea Larva

Beneficial insects (Parasitic wasps)

100% Mortality at dose 0.6 kg ha⁻¹

Aphidius rhopalosiphi Adult

Beneficial insects (Predatory mites)

7.2% Mortality at dose 1.49 kg ha⁻¹

Typhlodromus pyri Protonymph

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)

0.186

Oncorhynchus mykiss

Moderate

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

0.18

Oncorhynchus mykiss 3 day

Moderate

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

0.67

Danio rerio

Moderate

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

7.1

Daphnia magna

Moderate

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

0.56

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, fonds growth, fresh) - 7 day (mg l⁻¹) (EC₅₀)

12.7

Lemna gibba

Low

Aquatic plants (rooted, growth rate, fresh) - 14 day (mg l⁻¹)

Algae - Acute (growth rate, fresh; mg l⁻¹) (96 hr EbC50 (biomass), Static)

1.6

Raphidocelis subcapitata

Moderate

Algae - Chronic (growth rate, fresh; mg l⁻¹) (NOEC, Population study)

> 10

Raphidocelis subcapitata

Low

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)

0.67

Rat

Other Mammal toxicity endpoints

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

0.25

Rat SF=100

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

0.9

Rat SF=100

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

0.9

Rat SF=100

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

0.25

Rat SF=100

Dermal penetration studies (%)

Dangerous Substances Directive 76/464

Exposure Routes

Public

Acute risk to consumer identified from top fruit but established MRLs will mitigate this risk

Occupational

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

Metabolised and excreted in the urine (~50%) and faeces (~33%)

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

No data found

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

May cause contact dermatitis
IARC Group 3 carcinogen - not classifiable; CLP data - suspected carcinogen; US EPA - probable human carcinogen
Endocrine issues - Inhibition of estrogen action

Handling issues

Property

Value and interpretation

General

Not explosive
IMDG Transport Hazard Class 9
Not expected to auto-ignite; Not highly flammable

CLP classification 2013

Health: H317, H318, H331, H351
Environment: H400

WHO Classification

U (Unlikely to present an acute hazard)

UN Number

UN3077

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

captan

French

captane

German

Captan

Danish

captan

Italian

captano

Spanish

captan

Greek

captan

Polish

kaptan

Swedish

Hungarian

kaptan

Dutch

captan

Norwegian

Record last updated:	14/08/2025
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