Captan (Ref: SR 406)

Captan (Ref: SR 406)	Last updated: 12/01/2021
(Also known as: captane; captab; ENT 26538)

SUMMARY

Captan is a dicarboximide fungicide used on fruit and other crops that may be used within the EU subject to local MS approval. 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.

GENERAL INFORMATION

Description

A dicarboximide fungicide widely used on fruit and other crops

Example pests controlled

Seed rot; Damping-off; Grey mould; 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

Availability status

Current

Introduction & key dates

1952, first reported

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

31/07/2024

UK LERAP status

None

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Italy

Date EC 1107/2009 inclusion expires

31/07/2021

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
✓		✓	✓	✓	✓		✓	✓

Also used in

Australia, USA

Chemical structure

Isomerism

A chiral molecule

Chemical formula

C₉H₈Cl₃NO₂S

Canonical SMILES

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

Isomeric SMILES

No data

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, Bactericide

Substance group

Phthalimide

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

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

Other status information

Relevant Environmental Water Quality Standards

Herbicide Resistance Classification (HRAC)

Not applicable

Herbicide Resistance Classification (WSSA)

Not applicable

Insecticide Resistance Classification (IRAC)

Not applicable

Fungicide Resistance Classification (FRAC)

M04

Examples of recorded resistance

Physical state

Dirty white powder

Formulations

Property

Value

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

Alpha Captan
Orthocide 406
Hexacap
Aacaptan
Merpan
Malvin
Pillarcap

Example products using this active

Makhteshim-Agan
Bonide Products
Chemtura Corp
Chevron
Stauffer
Pillar International

Formulation and application details

Usually supplied as wettable granules or powders 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)

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)

Not expected to self ignite; Not highly flammable

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

3.16 X 10⁰²

Calculated

Log P

2.5

Low

Bulk density (g ml⁻¹)

1.68

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

Vapour pressure at 20 °C (mPa)

0.0042

Low volatility

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

3.00 X 10^-04

Non-volatile

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 on plant matrix

Value

6.9

Note

Published literature RL₅₀ range 1.0-12.8 days, 8 field and undercover grown crops, various matrices, n=13

Dissipation rate RL₅₀ 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

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

Moderately mobile

K_oc

200

Notes and range

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

Freundlich

K_f

K_foc

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

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

tetrahydrophthalimide

Soil

0.464

Major fraction, Relevant

tetrahydrophthalamic acid

Soil

0.168

Major fraction, Relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

2-cyanocyclohex-4-ene carboxylic acid

THCY

Soil (Anaerobic)

0.210

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

tetrahydrophthalic acid
Note: Minor metabolite

Soil

0.032

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

140

Whole fish

Threshold for concern

CT₅₀ (days)

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

Quail

Moderate

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

0.186

Oncorhynchus mykiss

Moderate

Fish - Chronic 21 day NOEC (mg l⁻¹)

0.18

Oncorhynchus mykiss 3 day

Moderate

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

7.1

Daphnia magna

Moderate

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

0.56

Daphnia magna

Moderate

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 - Acute 7 day EC₅₀, biomass (mg l⁻¹)

12.7

Lemna gibba 7 day

Low

Non-target plants

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

1.18

Raphidocelis subcapitata

Moderate

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

> 10

Green algae population

Low

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)

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 pollinators (1)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

Other pollinators (2)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

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

> 519

Eisenia foetida

Moderate

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

12.2

Eisenia foetida

Moderate

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Other arthropod (1)

LR₅₀ g ha⁻¹

% Effect

100

Mortality [Dose: 0.6 kg ha⁻¹]
Aphidius rhopalosiphi adult

Other arthropod (2)

LR₅₀ g ha⁻¹

% Effect

7.2

Mortality [Dose: 1.49 kg ha⁻¹]
Typhlodromus pyri protonymph

Soil micro-organisms

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

Dose: Not stated

Mesocosm study data

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)

> 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)

0.1

SF=100

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

0.3

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

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

0.1

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

European MRLs

EU MRL pesticide database

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

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
Endocrine issues - Inhibition of estrogen action

Handling issues

Property

Value and interpretation

General

Not explosive
IMDG Transport Code is variable depending upon product, often either 6.1 or 9

CLP classification 2013

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

EC Risk Classification

Carcinogen category 3: R40
T - Toxic: R23
Xn - Harmful: R43, R41
N - Dangerous for the environment: R50

EC Safety Classification

S1/2, S26, S29, S36/37/39, S45, S61

WHO Classification

U (Unlikely to present an acute hazard)

UN Number

Variable with product, usually 2588 or 3077

Waste disposal & packaging

Packaging Group III (minor danger)

TRANSLATIONS

Language

Name

English

captan

French

captane

German

Captan

Danish

captan

Italian

captano

Spanish

captan

Greek

captan

Polish

kaptan

Swedish

Hungarian

kaptan

Dutch

captan

Record last updated:	12/01/2021
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