Disulfoton (Ref: ENT 23347)

Disulfoton (Ref: ENT 23347)	Last updated: 15/09/2021
(Also known as: M 74; ethylthiodemeton; thiodemeton; dithiodemeton; dithiosystox)

SUMMARY

Disulfoton is an organothiophosphate insecticide and acaricide that is not approved for use in the EU. It has a low aqueous solubility, is moderately volatile and, based on its chemical properties it would not normally be expected to leach to groundwater. It can be persistent in some soil systems but would not normally be persistent in water bodies. It is highly toxic to mammals, a cholinesterase inhibitor, a neurotoxicant and there are some concerns regarding its carcinogenity. It is moderately or highly toxic to most fauna.

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: Drainflow: Slightly mobile; Potential for particle bound transport: Medium	Ecotoxicity High alert: Birds acute ecotoxicity: High; Fish acute ecotoxicity: High; Daphnia acute ecotoxicity: High; Daphnia chronic ecotoxicity: High; Bees acute contact ecotoxicity: High	Human health High alert: Mammals acute toxicity: High; Acetyl cholinesterase inhibitor; Neurotoxicant

GENERAL INFORMATION

Description

An organophosphate aphicide and insecticide used to sucking insects on agricultural crops

Example pests controlled

Aphids; Thrips; Mealybugs; Spider mites; Leaf miners; Leaf hoppers; Beet flies

Example applications

Cotton; Tobacco; Sugarbeet; Cole crops; Peanuts; Corn; Wheat; Ornamentals; Cereals grains; Potatoes

Efficacy & activity

Availability status

Current

Introduction & key dates

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

Not applicable

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

Additional information

Also used in

Australia, USA

Chemical structure

Isomerism

None

Chemical formula

C₈H₁₉O₂PS₃

Canonical SMILES

CCOP(=S)(OCC)SCCSCC

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

SYJFEGQWDCRVNX-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C8H19O2PS3/c1-4-9-11(12,10-5-2)14-8-7-13-6-3/h4-8H2,1-3H3

2D structure diagram/image available?

Yes

General status

Pesticide type

Insecticide, Acaricide

Substance group

Organophosphate

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Systemic absorbed via roots. Acetylcholinesterase (AChE) inhibitor.

CAS RN

298-04-4

EC number

206-054-3

CIPAC number

152

US EPA chemical code

032501

PubChem CID

3118

Molecular mass

274.40

PIN (Preferred Identification Name)

O,O-diethyl S-[2-(ethylsulfanyl)ethyl] phosphorodithioate

IUPAC name

O,O-diethyl S-2-ethylthioethyl phosphorodithioate

CAS name

O,O-diethyl S-[2-(ethylthio)ethyl] phosphorodithioate

Other status information

Potential groundwater contaminant; Marine Pollutant

Relevant Environmental Water Quality Standards

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

Myzus persicae, Phorodon humuli, Rhizoglyphus robini, Tetranychus kanzawai, Leucoptera coffeella, many others

Physical state

Yellow oil

Formulations

Property

Value

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

Bayer
Sandoz
Mobay

Example products using this active

Disyston
Frumin AL
Solvirex

Formulation and application details

Available in a variety of formulations includign emulsifiable concentrates, dry seed dressings and granules

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

Low

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

Miscible

n-Hexane

Miscible

Dichloromethane

Miscible

Isopropanol

Miscible

Toluene

Melting point (°C)

-25

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

133

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

8.91 X 10⁰³

Calculated

Log P

3.95

High

Bulk density (g ml⁻¹)

1.14

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

7.2

Moderately volatile

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

1.60 X 10^-01

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)

Non-persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

Best available data

Dissipation rate RL₅₀ on plant matrix

Value

Note

Dissipation rate RL₅₀ on and in plant matrix

Value

Note

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Moderately fast

Note

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

Value

300

Persistent

Note

Water-sediment DT₅₀ (days)

Fast

Water phase only DT₅₀ (days)

Slow

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

Slightly mobile

K_oc

1345

Notes and range

Other sources: 600 mL g⁻¹ (DW3)

Freundlich

K_f

39.5

K_foc

¹/_n

1.09

Notes and range

General literature data: K_f range 15.5-24.3 mL g⁻¹, mean of 8 values for 2 loam soils.

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

0.26

Calculated

Low leachability

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

Value

6.29 X 10^-04

Calculated

Note

Potential for particle bound transport index

Medium

Calculated

Potential for loss via drain flow

Slightly mobile

Calculated

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

disulfoton sulfoxide

Soil

0.05

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

460

Whole fish

Threshold for concern

CT₅₀ (days)

Not available

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

2.6

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)

Colinus virginianus

High

Birds - Short term dietary (LC₅₀/LD₅₀)

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

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

0.039

Lepomis macrochirus

High

Fish - Chronic 21 day NOEC (mg l⁻¹)

0.22

Oncorhynchus mykiss 35 day LOEC

Moderate

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

0.013

Daphnia magna

High

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

0.00004

Daphnia magna

High

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

0.1

Americamysis bahia

Moderate

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)

Non-target plants

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

0.036

Unknown species

Moderate

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

0.01

Unknown species

Moderate

Honeybees (Apis spp.)

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

0.96

Apis mellifera

High

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

4.1

Apis mellifera

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)

> 1.0

Bombus spp.

Moderate

Literature values range 1.0-6.0 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)

180

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)

2.6

Rat

High

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

3.6

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

0.015

Rat

Other Mammal toxicity endpoints

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

0.0003

JMPR 1996

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

0.003

JMPR 1996

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; List II

Exposure Routes

Public

Occupational

Rapidly absorbed through the skin

MRLs

European

EU MRL pesticide database

Great Britain

GB MRL Register

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

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

No further information available

Handling issues

Property

Value and interpretation

General

No information available

CLP classification 2013

Health: H300, H310
Environment: H400, H410

EC Risk Classification

T+ - Very toxic: R27/28
N - Dangerous for the environment: R50, R53

EC Safety Classification

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

WHO Classification

Ia (Extremely hazardous)

UN Number

3018

Waste disposal & packaging

TRANSLATIONS

Language

Name

English

disulfoton

French

disulfoton

German

Disulfoton

Danish

disulfoton

Italian

disulfoton

Spanish

disulfoton

Greek

disulfoton

Polish

disulfoton

Swedish

Hungarian

Dutch

disulfoton

Record last updated:	15/09/2021
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