Endosulfan (Ref: OMS 570)

Endosulfan (Ref: OMS 570)	Last updated: 18/01/2021
(Also known as: thiodan; benzoepin; FMC 5462; ENT 23979; thiosulfan)

SUMMARY

Endosulfan is an insecticide and acaricide that is not approved for use in the EU. It has a low aqueous solubility and is volatile. Based on its chemical properties it may have a tendency to leach to groundwater. Endosulfan is moderately persistent in soil but does not tend to persist in water systems. It is highly toxic to mammals, a neurotoxin and possibly a mutagen. It is moderately toxic to birds, honeybees and earthworms but slightly more toxic to aquatic organisms.

GENERAL INFORMATION

Description

An isomer mixture of alpha- and beta-endosulfan which is an insecticide and acaricide used to control sucking, chewing and boring insects

Example pests controlled

Whiteflies; Aphids; Leafhoppers; Colorado beetle; Cabbage worms; Ticks; Mites; Tstetse flies.

Example applications

Vegetable crops; Cotton; Potatoes; Tomatoes; Apples

Efficacy & activity

Availability status

Current

Introduction & key dates

circa 1956

UK regulatory status

UK COPR regulatory status

Not approved

Date COPR inclusion expires

Expired

UK LERAP status

No UK approval for use

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Not approved

Dossier rapporteur/co-rapporteur

Spain

Date EC 1107/2009 inclusion expires

Expired

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

Also used in

Australia, USA

Chemical structure

Isomerism

A molecule with 4 chiral centres, endosulfan is is a mixture of the alpha- and beta-forms.

Chemical formula

C₉H₆Cl₆O₃S

Canonical SMILES

C1C2C(COS(=O)O1)C3(C(=C(C2(C3(Cl)Cl)Cl)Cl)Cl)Cl

Isomeric SMILES

C1[C@@H]2[C@H](COS(=O)O1)[C@@]3(C(=C([C@]2(C3(Cl)Cl)Cl)Cl)Cl)Cl

International Chemical Identifier key (InChIKey)

RDYMFSUJUZBWLH-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C9H6Cl6O3S/c10-5-6(11)8(13)4-2-18-19(16)17-1-3(4)7(5,12)9(8,14)15/h3-4H,1-2H2

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
endosulfan	Beta-isomer

General status

Pesticide type

Insecticide, Acaricide

Substance group

Organochlorine

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Non-systemic with contact and stomach action, acts as a non-competitive GABA antagonist

CAS RN

115-29-7

EC number

204-079-4

CIPAC number

US EPA chemical code

079401

PubChem CID

3224

Molecular mass

406.93

PIN (Preferred Identification Name)

(5aE,6E,9E,9aE)-6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin-3-one

IUPAC name

1,4,5,6,7,7-hexachloro-8,9,10-trinorborn-5-en-2,3-ylenebismethylene sulfite

CAS name

6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin 3-oxide

Other status information

POP - regulated by Stockholm Convention; OSPAR pfa/soc; WFD priority substance; Severe Marine Pollutant; Global ban (2011); Chemical subject to PIC regulation

Relevant Environmental Water Quality Standards

EU Directive 2008/105/EC EQS surface waters: annual average 0.005 µg l⁻¹; max measured 0.01 µg l⁻¹
UK Statutory standard for the protection of aquatic life in inland waters, coastal and territorial waters: 0.003 µg l⁻¹ as annual average

Herbicide Resistance Classification (HRAC)

Not applicable

Herbicide Resistance Classification (WSSA)

Not applicable

Insecticide Resistance Classification (IRAC)

Fungicide Resistance Classification (FRAC)

Not applicable

Examples of recorded resistance

Many recorded cases, Aphis gossypii, Bemisia tabaci, Dasineura tetensi, Leptinotarsa decemlineata, Myzus persicae, many others

Physical state

Colourless to brown coloured crystals

Formulations

Property

Value

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

Thiodan
Benzoepin

Example products using this active

Bayer CropScience
Hoechst
FMC
Velsicol
Makhteshim-Agan

Formulation and application details

Supplied in a variety of formulations including emulsifiable concentrates, wettable powders, granules and dusts

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

0.32

Low

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

200000

Ethyl acetate

65000

Ethanol

24000

Hexane

200000

Toluene

Melting point (°C)

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

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

5.62 X 10⁰⁴

Calculated

Log P

4.75

High

Bulk density (g ml⁻¹)

1.8

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

0.83

Low volatility

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

1.48

Moderately volatile

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

Surface tension (mN m⁻¹)

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

Moderately persistent

DT₅₀ (lab at 20 °C)

Moderately persistent

DT₅₀ (field)

Moderately persistent

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀ range 28-50 days, field studies DT₅₀ range 62-126 days for summer applications, 68-87 days for autumn applications (UK); FAO state DT₅₀ 60-800 days

Dissipation rate RL₅₀ on plant matrix

Value

3.7

Note

Published literature RL₅₀ range 0.1-5.5 days, 19 field crops, various matrices, n=23

Dissipation rate RL₅₀ on and in plant matrix

Value

4.3

Note

Published literature RL₅₀ range 0.4-14.5 days, 19 field & undercover grown crops, various matrices, n=41

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Note

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

Value

Non-persistent

Note

Water-sediment DT₅₀ (days)

Water phase only DT₅₀ (days)

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

Non-mobile

K_oc

11500

Notes and range

Freundlich

K_f

0.28

Mobile

K_foc

18.6

¹/_n

0.558

Notes and range

Literature data K_f range 0.08-0.52 mL g⁻¹, K_foc range 5.7-38.5 mL g⁻¹, ¹/_n range 0.500-0.648, soils=4

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

5.28

Calculated

High leachability

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

Value

5.86 X 10⁰⁰

Calculated

Note

Potential for particle bound transport index

Medium

Calculated

Potential for loss via drain flow

Non-mobile

Calculated

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

endosulfan sulfate

Soil

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

2755

(Whole fish Literature values log BCF range 1.0-3.7 (R3))

Threshold for concern

CT₅₀ (days)

Not available

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

Rat

High

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat 2 year

(ppm diet)

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

Birds - Acute LD₅₀ (mg kg⁻¹)

> 111

Anas platyrhynchos

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

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

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

0.002

Oncorhynchus mykiss

High

Fish - Chronic 21 day NOEC (mg l⁻¹)

0.0000005

Cyprinodon variegatus 28 day

High

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

0.44

Daphnia magna

Moderate

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

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

0.24

Americamysis bahia

Moderate

Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)

0.1

Chironomus riparius 2 day

Moderate

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)

Non-target plants

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

2.15

Anabaena doliolum

Moderate

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

Honeybees (Apis spp.)

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

> 7.81

Apis mellifera

Moderate

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

> 15.6

Apis mellifera 24hr

Moderate

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)

> 1.72

Bombus terrestris

Moderate

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 pollinators (1)

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

0.210

Trigona spinipes

High

Mode of exposure

Contact

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)

> 14

Eisenia foetida

Moderate

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

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Other arthropod (1)

LR₅₀ g ha⁻¹

% Effect

Harmless

Chrysoperla carnea

Other arthropod (2)

LR₅₀ g ha⁻¹

% Effect

Soil micro-organisms

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)

Rat

High

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

500

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

0.013

Rat

Other Mammal toxicity endpoints

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

0.006

JMPR 1998

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

0.02

JMPR 1998

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

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

Dermal penetration studies (%)

Dangerous Substances Directive 76/464

List II

Exposure Routes

Public

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

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

Mutagenic potential
Highly toxic
Research shows that endosulfan interferes with the spermatogenic & steroidogenic cycles in rats
Endocrine issues - Competitive binding to androgen receptors

Handling issues

Property

Value and interpretation

General

Corrosive
IMDG Transport Code is usually 6.1

CLP classification 2013

Health: H300, H312, H330
Environment: H400, H410

EC Risk Classification

T+ - Very toxic: R26/28
Xn - Harmful: R21
N - Dangerous for the environment: R50, R53

EC Safety Classification

S1/2, S28, S36/37, S45, S60, S61, S63

WHO Classification

II (Moderately hazardous)

UN Number

2761

Waste disposal & packaging

Packaging Group II (medium danger)

TRANSLATIONS

Language

Name

English

endosulfan

French

endosulfan

German

Endosulfan

Danish

endosulfan

Italian

endosulfan

Spanish

endosulfan

Greek

endosulphan

Polish

endosulfan

Swedish

Hungarian

endoszulfan

Dutch

endosulfan

Record last updated:	18/01/2021
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