Ethion (Ref: ENT 24105)	Last updated: 13/02/2025
(Also known as: diethion; diéthion; dietion; FMC 1240; NIA 1240 )

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SUMMARY

Ethion is an organophosphate insecticide and acaricide which is not approved for use in the UK nor the EU. It has a low water solubility but is miscible with most organic solvents. It is moderately persistent in soils but can be persistent in water bodies under certain conditions. It is not mobile. Based on its physico-chemical parameters, ethion is not expected to leach to groundwater. It demonstrates a moderate to high level of toxicity for most species. There are concerns regarding its toxicity to humans being moderately toxic via the oral route, an acetyl cholinesterase inhibitor and neurotoxin.

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 High alert: Persistent; Potential for particle bound transport: High	Ecotoxicity High alert: Daphnia acute ecotoxicity: High; Daphnia chronic ecotoxicity: High	Human health High alert: Acetyl cholinesterase inhibitor; Neurotoxicant

GENERAL INFORMATION

Description	An insecticide and acaricide used to control a range of pests. Can also be a pesticide transformation product
Example pests controlled	Red spidermite (Tetranychus urticae); Planthoppers; Aphids; Scale insects; Codling moth
Example applications	Fruit including apples, pears, citrus; Onions; Cotton; Cereals
Efficacy & activity	-
Availability status	Current
Introduction & key dates	1957, first reported; 2002, withdrawn UK

GB regulatory status

GB COPR regulatory status	Not approved
Date COPR inclusion expires	Expired
GB LERAP status	No UK approval for use as a pesticide

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status	Not approved
Dossier rapporteur/co-rapporteur	France
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
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

Chemical structure

Isomerism	None
Chemical formula	C₉H₂₂O₄P₂S₄
Canonical SMILES	CCOP(=S)(OCC)SCSP(=S)(OCC)OCC
Isomeric SMILES	No data
International Chemical Identifier key (InChIKey)	RIZMRRKBZQXFOY-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/C9H22O4P2S4/c1-5-10-14(16,11-6-2)18-9-19-15(17,12-7-3)13-8-4/h5-9H2,1-4H3
2D structure diagram/image available?	Yes

General status

Pesticide type	Insecticide, Acaricide, Metabolite
Metabolite Type	Soil
Substance groups	Organophosphate insecticide; Organophosphate acaricide; Organothiophosphate insecticide; Organothiophosphate acaricide
Minimum active substance purity	-
Known relevant impurities	-
Substance origin	Synthetic
Mode of action	Non-systemic with a predominate contact action. Acetylcholinesterase (AChE) inhibitor.
CAS RN	563-12-2
EC number	209-242-3
CIPAC number	102
US EPA chemical code	058401
PubChem CID	3286
CLP index number	015-047-00-2
Molecular mass	384.48
PIN (Preferred Identification Name)	O,O,O',O'-tetraethyl S,S'-methylene bis(phosphorodithioate)
IUPAC name	O,O,O',O'-tetraethyl S,S'-methylene bis(phosphorodithioate)
CAS name	S,S'-methylene bis(O,O-diethyl phosphorodithioate)
Other status information	Severe Marine Pollutant; Chemical subject to PIC regulations
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)	1B
Fungicide Resistance Class (FRAC MOA class)	Not applicable
Examples of recorded resistance	Amblyseius fallacis, Delia antiqua, Musca domestica, Phytoseiulus persimilis, Boophilus microplus, many others
Physical state	Amber liquid

Can be a metabolite of:

Parent	Formation medium	Estimated maximum occurrence fraction	1107/2009 relevancy
chlormephos	Soil	-	-

Formulations

Property	Value
Example manufacturers & suppliers of products using this active now or historically	Bayer CropScience Cheminova King Tech Corp Hikal Ltd.
Example products using this active	Rhodocide Ethio Tefethion Ethiomobeed Nialate Hylemox
Formulation and application details	Available in a variety of formulations including dusts, emulsifiable concentrates and solutions, granules and wettable powders.

ENVIRONMENTAL FATE

Property		Value	Source; quality score; and other information	Interpretation
Solubility - In water at 20 °C (mg l⁻¹)		2	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	Low
Solubility - In organic solvents at 20 °C (mg l⁻¹)		Miscible	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Acetone	-
		Miscible	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Ethanol	-
		Miscible	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Xylene	-
		Miscible	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Methanol	-
Melting point (°C)		-12	Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source	-
Boiling point (°C)		165	F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source	-
Degradation point (°C)		-	-	-
Flashpoint (°C)		176	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source (closed cup)	-
Octanol-water partition coefficient at pH 7, 20 °C	P	1.17 X 1005	Calculated	-
	Log P	5.07	G4 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 4 = Verified data	High
Fat solubility of residues	Solubility	-	-	-
	Data type	-	-	-
Density (g ml⁻¹)		1.22	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
Dissociation constant pKa) at 25 °C		-	-	-
		-
Vapour pressure at 20 °C (mPa)		0.2	G4 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 4 = Verified data	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)		3.85 X 10-02	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	Non-volatile
Volatilisation as max % of applied dose lost	From plant surface	-	-	-
	From soil surface	-	-	-
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)	90	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	Moderately persistent
	DT₅₀ (lab at 20 °C)	150	Q2 Q = Miscellaneous data from online sources 2 = Unverified data of unknown source	Persistent
	DT₅₀ (field)	-	-	-
	DT₉₀ (lab at 20 °C)	-	-	-
	DT₉₀ (field)	-	-	-
	DT₅₀ modelling endpoint	-	-	-
	Note	Tropical soils DT₅₀ range 9-16 days, temperate sandy soils DT₅₀ 49-56 day, 168 days organic soils
Dissipation rate RL₅₀ (days) on plant matrix	Value	5.5	R4 R = Peer reviewed scientific publications 4 = Verified data	-
	Note	Published literature RL₅₀ range 3.0-10.5 days, 5 field crops, various matrices, n=6
Dissipation rate RL₅₀ (days) on and in plant matrix	Value	4.4	R4 R = Peer reviewed scientific publications 4 = Verified data	-
	Note	Published literature RL₅₀ range 2.0-9.4 days, 10 field crops, various matrices, n=11
Aqueous photolysis DT₅₀ (days) at pH 7	Value	-	-	-
	Note	-
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7	Value	146	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data	Persistent
	Note	-
Water-sediment DT₅₀ (days)		-	-	-
Water phase only DT₅₀ (days)		-	-	-
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		[Grapes: 6.3 days @ 25 DegC; Field study], [Grapes: 10.4 days @ 4 DegC; Field study]

Soil adsorption and mobility

Property		Value	Source; quality score; and other information	Interpretation
Linear	Kd (mL g⁻¹)	-	G3 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 3 = Unverified data of known source	Non-mobile
	Koc (mL g⁻¹)	10000
	Notes and range	-
Freundlich	Kf (mL g⁻¹)	-	-	-
	Kfoc (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		0.00	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	-
Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk		-	-	-
Bio-concentration factor	BCF (l kg⁻¹)	586	F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source	Threshold for concern
	CT₅₀ (days)	Not available		-

Known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property		Value	Source; quality score; and other information	Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		208	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data Rat	Moderate
Mammals - Short term dietary NOEL	(mg kg⁻¹)	0.3	L2 L = Pesticide manuals and hard copy reference books / other sources 2 = Unverified data of unknown source Rat 2 yr	High
	(ppm diet)	6		-
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Birds - Acute LD₅₀ (mg kg⁻¹)		128	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Phasianidae	Moderate
Birds - Short term dietary (LC₅₀/LD₅₀)		-	-	-
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)		-	-	-
Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)		-	-	-
Soil micro-organisms		-	-	-
Collembola	Acute LC₅₀ (mg kg⁻¹)	-	-	-
	Chronic NOEC (mg kg⁻¹)	-	-	-
Non-target plants		-	-	-
		-	-	-
Honeybees (Apis spp.)	Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	11	K3 K = Research datasets (e.g. Pandora, Demetra; these datasets no longer available). Norman Ecotoxicology database. (click here ) 3 = Unverified data of known source Apis mellifera	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)	20.6	G3 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 3 = Unverified data of known source	Moderate
	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)	-	-	-
	Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
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)		-	-	-
Beneficial insects (Parasitic wasps)		-	-	-
Beneficial insects (Predatory mites)		Harmful	Q2 Q = Miscellaneous data from online sources 2 = Unverified data of unknown source Typhlodromus pyri	-
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)		0.5	G4 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 4 = Verified data Salmonidae spp.	Moderate
Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)		0.013	P3 P = Other non-EU, UK or US Governments and Regulators 3 = Unverified data of known source Pimephales promelas 33 day	Moderate
Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)		-	-	-
Temperate Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		0.000056	G3 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 3 = Unverified data of known source Unknown species	High
Temperate Freshwater Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)		0.000025	P3 P = Other non-EU, UK or US Governments and Regulators 3 = Unverified data of known source Daphnia magna	High
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, growth) - Acute 7 day EC₅₀, biomass (mg l⁻¹)		-	-	-
Aquatic plants (rooted, growth) - Acute 14 day EC₅₀, biomass (mg l⁻¹)		-	-	-
Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)		-	-	-
Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)		-	-	-
Mesocosm study data	NOEAEC mg l⁻¹	-	-	-
	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)		208	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data Rat	Moderate
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)		838	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Rabbit	-
Mammals - Inhalation LC₅₀ (mg l⁻¹)		0.45	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source 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; List II	-	-
Exposure Routes	Public	-
	Occupational	May be 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)		-	-	-
Mammalian dose elimination route and rate		-	-	-

Health issues

Specific human health issues		Carcinogen Genotoxic Endocrine disruptor XNo, known not to cause a problem A3 A = Chromosome aberration (EFSA database) 3 = Negative ; B0 B = DNA damage/repair (EFSA database) 0 = No data ; C0 C = Gene mutation (EFSA database) 0 = No data ; D0 D = Genome mutation (EFSA database) 0 = No data ; E3 E = Unspecified genotoxicity type (miscellaneous data source) 3 = Negative No data found Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant ?Possibly, status not identified ✓Yes, known to cause a problem ✓Yes, known to cause a problem Respiratory tract irritant Skin irritant Skin sensitiser No data found No data found No data found Eye irritant Phototoxicant   No data found No data found
General human health issues		Bioaccumulates

Handling issues

Property	Value and interpretation
General	Prevent generation of mists Use foam, carbon dioxide or dry chemicals to tackle fires May produce toxic gases in a fire IMDG Transport Hazard Class 6.1
CLP classification 2013	Health: H301, H312 Environment: H400, H410
WHO Classification	II (Moderately hazardous)
UN Number	UN3018
Waste disposal & packaging	-
Shelf-life, storage, stability and reactivity	-

TRANSLATIONS

Language	Name
English	ethion
French	ethion
German	Ethion
Danish	ethion
Italian	etion
Spanish	etion
Greek	ethion
Polish	etion
Swedish	-
Hungarian	-
Dutch	ethion
Norwegian	-

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Record last updated:	13/02/2025
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