Alpha-endosulfan

Alpha-endosulfan	Last updated: 16/12/2020
(Also known as: endosulfan I)

SUMMARY

Alpha-endosulfan is an insecticide that is not generally approved for use in the developed world. It has some potential for bio-concentration, highly toxic to mammals and a neurotoxin. Alpha-endosulfan has a low aqueous solubility and moderately. It is moderately persistent in the soil but has a low mobility. It is moderately toxic to birds and most aquatic species.

GENERAL INFORMATION

Description

An insecticide and acaricide used to control sucking, chewing and boring insects

Example pests controlled

Mites; Ticks; Tstetse fly; Colorado beetle; Aphids; White flies; Leaf hoppers

Example applications

Cotton; Potatoes; Tomatoes; Apples

Efficacy & activity

Availability status

Unknown

Introduction & key dates

circa 1956

UK regulatory status

UK COPR regulatory status

Not approved

Date COPR inclusion expires

Not applicable

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

Not applicable

Date EC 1107/2009 inclusion expires

Not applicable

EU Candidate for substitution (CfS)

Not applicable

Listed in EU database

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

Chemical structure

Isomerism

This is one of two isomers, endo and exo (also known as I and II)

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-AZVNHNRSSA-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
enosulfan	Unstated 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

959-98-8

EC number

CIPAC number

US EPA chemical code

PubChem CID

12309460

Molecular mass

406.93

PIN (Preferred Identification Name)

an equimolar mixture of 2 asymmetric, twisted-chair conformers of (5aR,6S,9R,9aS)-6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepine 3-oxide

IUPAC name

equimolar mixture of 2 asymmetric, conformers of (5aR,6S,9R,9aS)-6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepine 3-oxide

CAS name

(3α,5αβ,6α,9α,9αβ)-6,7,8,9,10,10-hexachloro-1,5,5α,6,9,9α-hexahydro-6,9-methano-2,4,3-benzodioxathiepin 3-oxide

Other status information

POP candidate; OSPAR pfa/soc; WFD priority substance; Chemical subject to PIC regulations

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

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

None identified

Physical state

Brown crystals

Formulations

Property

Value

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

Example products using this active

Bayer CropScience

Formulation and application details

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

6500

Ethanol

24000

Hexane

200000

Toluene

Melting point (°C)

109.2

Boiling point (°C)

401.28

Degradation point (°C)

Flashpoint (°C)

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

5.50 X 10⁰⁴

Calculated

Log P

4.74

High

Bulk density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

8.3

Moderately volatile

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

Dissipation rate RL₅₀ on plant matrix

Value

1.5

Note

Published data RL₅₀ range 0.7-2.2 days, 4 field grown crops inc. peppers & tomatoes, various matrices, n=6

Dissipation rate RL₅₀ on and in plant matrix

Value

1.4

Note

Published data RL₅₀ range 0.2-2.7 days, 3 field grown crops inc. peppers & tea, various matrices, n=4

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

K_foc

¹/_n

Notes and range

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

-0.12

Calculated

Low leachability

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

Value

5.35 X 10^-03

Calculated

Note

Estimated concentrations of chemicals with Koc values greater than 9995 ml g⁻¹ are beyond the scope of the regression data used in SCI-GROW development. If there are concerns for such chemicals, a higher tier groundwater exposure assessment should be considered, regardless of the concentration returned by SCI-GROW

Potential for particle bound transport index

High

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

Threshold for concern

CT₅₀ (days)

Not available

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

Rat

High

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)

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)

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

Moderate

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

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)

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)

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)

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

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)

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

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 I

Exposure Routes

Public

Occupational

Can be absorbed following ingestion, inhalation and skin contact

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

Mutagenic potential
Highly toxic
Endocrine toxicant

Handling issues

Property

Value and interpretation

General

Corrosive

CLP classification 2013

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

Waste disposal & packaging

TRANSLATIONS

Language

Name

English

alpha-endosulfan

French

alphaendosulfan

German

alpha-Endosulfan

Danish

alpha-endosulfan

Italian

alfaendosulfan

Spanish

alfaendosulfan

Greek

alfa endosulphan

Polish

alfa-endosulfan

Swedish

Hungarian

alpha endoszulfan

Dutch

alfa-endosulfan

Record last updated:	16/12/2020
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