Fenthion (Ref: OMS 2)	Last updated: 03/02/2023
(Also known as: MPP; ENT 25540; Bayer 29493; S-1752; BAY 29493; DMTP)

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SUMMARY

Fenthino is an insecticide for sucking and chewing pests. It has a low water solubility but is generally highly soluble in organic solvents. It is volatile and is not expected to leach to groundwater. Its persistence in soil and water systems depends on local conditions. It is moderately toxic to mammals and a cholinesterase inhibitor. Fenthion is highly toxic to birds and honeybees and has a high to moderate toxicity to most aquatic species and earthworms.

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

GENERAL INFORMATION

Description	A broad spectrum insecticide used to control various sucking and biting insect pests in a range of agricultural, commercial and domestic situations. It is also used in veterinary medicine and for bird control
Example pests controlled	Fruit flies, Leafhoppers, Leaf miners, Stem borers, Codling moth, Mosquitoes, Pigeons, Weaver birds
Example applications	Fruit including apples, pears, avocadoes, grapes, stone fruit; Peppers; Ornamental trees, flowers and shrubs
Efficacy & activity	-
Availability status	Current
Introduction & key dates	1960, first reported & introduced

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	Greece
Date EC 1107/2009 inclusion expires	Expired
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
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	-

Chemical structure

Isomerism	None
Chemical formula	C₁₀H₁₅O₃PS₂
Canonical SMILES	CC1=C(C=CC(=C1)OP(=S)(OC)OC)SC
Isomeric SMILES	-
International Chemical Identifier key (InChIKey)	PNVJTZOFSHSLTO-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/C10H15O3PS2/c1-8-7-9(5-6-10(8)16-4)13-14(15,11-2)12-3/h5-7H,1-4H3
2D structure diagram/image available?	Yes

General status

Pesticide type	Insecticide, Veterinary substance, Avicide
Substance groups	Organophosphate insecticide
Minimum active substance purity	-
Known relevant impurities	-
Substance origin	Synthetic
Mode of action	Contact, stomach and respiratory action. Cholinesterase inhibitor.
CAS RN	55-38-9
EC number	200-231-9
CIPAC number	79
US EPA chemical code	053301
PubChem CID	3346
CLP index number	015-048-00-8
Molecular mass	278.33
PIN (Preferred Identification Name)	O,O-dimethyl O-[3-methyl-4-(methylsulfanyl)phenyl] phosphorothioate
IUPAC name	O,O-dimethyl O-4-methylthio-m-tolyl phosphorothioate
CAS name	O,O-dimethyl O-(3-methyl-4-(methylthio)phenyl) phosphorothioate
Other status information	Severe Marine Pollutant; Evidence of use in third world countries; Chemical subject to PIC regulations; Highly toxic to birds
Relevant Environmental Water Quality Standards	-
Herbicide Resistance Classification (HRAC)	Not applicable
Herbicide Resistance Classification (WSSA)	Not applicable
Insecticide Resistance Classification (IRAC)	1B
Fungicide Resistance Classification (FRAC)	Not applicable
Examples of recorded resistance	Many recorded cases, mosquitoes, Bactrocera dorsalis, Myzus persicae, Panonychus ulmi, Rhizoglyphus robini
Physical state	Colourless oily liquid
Related substances & organisms	fenthion-ethyl fenthion sulfone fenthion sulfoxide

Formulations

Property	Value
Example manufacturers & suppliers of products using this active now or historically	Bayer CropScience AgroCare King Tech Corp Mobay
Example products using this active	Baycid Baytex Lebaycid Queletox Pilartex Spotton
Formulation and application details	Available in a wide range of formulations including dustable powders, emulsifiable concentrates, granules, concentrates, ULV liquids and wettable powders.

ENVIRONMENTAL FATE

Property		Value	Source; quality score; and other information	Interpretation
Solubility - In water at 20 °C (mg l⁻¹)		4.2	H4 H = The US ARS pesticide properties database. Dataset is no longer available. 4 = Verified data	Low
Solubility - In organic solvents at 20 °C (mg l⁻¹)		100000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Hexane	-
		250000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Toluene	-
		250000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Dichloromethane	-
		250000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Isopropanol	-
Melting point (°C)		7.5	AC4 AC = EC Joint Research Centre ESIS European Chemical Substance Information Systems including EINECS, now integrated with the database provided by the European Chemicals Agency (ECHA) (click here ) 4 = Verified data	-
Boiling point (°C)		90	E3 E = Manufacturers safety data sheets 3 = Unverified data of known source	-
Degradation point (°C)		-	-	-
Flashpoint (°C)		170	E3 E = Manufacturers safety data sheets 3 = Unverified data of known source	-
Octanol-water partition coefficient at pH 7, 20 °C	P	6.92 X 1004	Calculated	-
	Log P	4.84	H4 H = The US ARS pesticide properties database. Dataset is no longer available. 4 = Verified data	High
Fat solubility of residues	Solubility	Soluble	A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes	-
	Data type	Observed in metabolism and farm animal feeding studies	A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes	-
Density (g ml⁻¹)		1.25	AC4 AC = EC Joint Research Centre ESIS European Chemical Substance Information Systems including EINECS, now integrated with the database provided by the European Chemicals Agency (ECHA) (click here ) 4 = Verified data	-
Dissociation constant pKa) at 25 °C		-	-	-
		-
Vapour pressure at 20 °C (mPa)		0.37	H4 H = The US ARS pesticide properties database. Dataset is no longer available. 4 = Verified data	Low volatility
Henry's law constant at 25 °C (Pa m³ mol⁻¹)		2.40 X 10-02	H4 H = The US ARS pesticide properties database. Dataset is no longer available. 4 = Verified data	Non-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)	22	W4 W = French database provided by ARVALIS-Institut du Végétal. Dataset no longer available. 4 = Verified data	Non-persistent
	DT₅₀ (lab at 20 °C)	34	DW4 DW = Don Wauchope personal database for Pka data: Wauchope, R. D. and Edwards, J. Dissociation constants for pesticide active ingredients: a database and comparison with predicted values. Dataset is no longer available. 4 = Verified data	Moderately persistent
	DT₅₀ (field)	-	-	-
	DT₉₀ (lab at 20 °C)	-	-	-
	DT₉₀ (field)	-	-	-
	DT₅₀ modelling endpoint	-	-	-
	Note	Data variable DT₅₀ ranges 1(aerobic) - 34 days
Dissipation rate RL₅₀ on plant matrix	Value	6.6	R4 R = Peer reviewed scientific publications 4 = Verified data	-
	Note	Published literature RL₅₀ range 5.6-7.6 days, grape berries, n=2; Grape berries in cold storage RL₅₀ range 42-45 days, n=2
Dissipation rate RL₅₀ on and in plant matrix	Value	4.4	R4 R = Peer reviewed scientific publications 4 = Verified data	-
	Note	Published literature RL₅₀ range 1.0-8.0 days, 6 field crops, various matrices, n=12
Aqueous photolysis DT₅₀ (days) at pH 7	Value	0.4	AC4 AC = EC Joint Research Centre ESIS European Chemical Substance Information Systems including EINECS, now integrated with the database provided by the European Chemicals Agency (ECHA) (click here ) 4 = Verified data	Fast
	Note	-
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7	Value	Stable	W4 W = French database provided by ARVALIS-Institut du Végétal. Dataset no longer available. 4 = Verified data	Stable
	Note	-
Water-sediment DT₅₀ (days)		92	Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source	Moderately fast
Water phase only DT₅₀ (days)		-	-	-

Soil adsorption and mobility

Property		Value	Source; quality score; and other information	Interpretation
Linear	Kd	-	G3 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 3 = Unverified data of known source	Slightly mobile
	Koc	1500
	Notes and range	-
Freundlich	Kf	-	-	-
	Kfoc	-
	1/n	-
	Notes and range	-
pH sensitivity		-

Fate indices

Property		Value	Source; quality score; and other information	Interpretation
GUS leaching potential index		1.26	Calculated	Low leachability
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate	Value	2.77 X 10-02	Calculated	-
	Note	-
Potential for particle bound transport index		Medium	Calculated	-
Potential for loss via drain flow		Slightly mobile	Calculated	-
Bio-concentration factor	BCF (l kg⁻¹)	154	R3 R = Peer reviewed scientific publications 3 = Unverified data of known source Whole body (Other literature Log BCF range 1.0-2.3 ( R3 R = Peer reviewed scientific publications 3 = Unverified data of known source ))	Threshold for concern
	CT₅₀ (days)	5		-

Known soil metabolites

Metabolite	Major/Minor fraction	Estimated maximum occurrence fraction	Notes
fenthion sulfoxide (Ref: BAY S 2281)	-	-	-
fenthion sulfone	-	-	-

Known groundwater metabolites

None

Other known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property		Value	Source; quality score; and other information	Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		~ 250	AC4 AC = EC Joint Research Centre ESIS European Chemical Substance Information Systems including EINECS, now integrated with the database provided by the European Chemicals Agency (ECHA) (click here ) 4 = Verified data Rat	Moderate
Mammals - Short term dietary NOEL	(mg kg⁻¹)	-	L2 L = Pesticide manuals and hard copy reference books / other sources 2 = Unverified data of unknown source Rat 2 year	-
	(ppm diet)	5		-
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Birds - Acute LD₅₀ (mg kg⁻¹)		7.2	E3 E = Manufacturers safety data sheets 3 = Unverified data of known source Colinus virginianus	High
Birds - Short term dietary (LC₅₀/LD₅₀)		-	-	-
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)		375	E3 E = Manufacturers safety data sheets 3 = Unverified data of known source Eisenia foetida	Moderate
Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)		-	-	-
Soil micro-organisms		Nitrogen mineralisation: >25% effect Carbon mineralisation: No significant adverse effect	AC4 AC = EC Joint Research Centre ESIS European Chemical Substance Information Systems including EINECS, now integrated with the database provided by the European Chemicals Agency (ECHA) (click here ) 4 = Verified data Dose: 10 uL/kg soil 20°C	-
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)	> 0.308	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 Apis mellifera	High
	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)	-	-	-
	Chronic	-	-	-
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)		-	-	-
Beneficial insects (Ground beetles)		-	-	-

Aquatic ecotoxicology

Property		Value	Source; quality score; and other information	Interpretation
Fish - Acute 96 hour LC₅₀ (mg l⁻¹)		0.8	E3 E = Manufacturers safety data sheets 3 = Unverified data of known source Oncorhynchus mykiss	Moderate
Fish - Chronic 21 day NOEC (mg l⁻¹)		0.12	P3 P = Other non-EU, UK or US Governments and Regulators 3 = Unverified data of known source Pimephales promelas 30 day	Moderate
Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		0.0057	E3 E = Manufacturers safety data sheets 3 = Unverified data of known source Daphnia magna	High
Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)		0.000013	P4 P = Other non-EU, UK or US Governments and Regulators 4 = Verified data Daphnia magna	High
Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)		0.00018	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 Americamysis bahia	High
Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)		0.0078	R4 R = Peer reviewed scientific publications 4 = Verified data Chironomus salinarius 24 hr	High
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)		-	-	-
Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)		1.79	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Scenedesmus subspicatus	Moderate
Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)		> 0.3	P3 P = Other non-EU, UK or US Governments and Regulators 3 = Unverified data of known source Pseudokirchneriella subcapitata 48 hr	Moderate
Mesocosm study data	NOEAEC mg l⁻¹	-	-	-
	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)		~ 250	AC4 AC = EC Joint Research Centre ESIS European Chemical Substance Information Systems including EINECS, now integrated with the database provided by the European Chemicals Agency (ECHA) (click here ) 4 = Verified data Rat	Moderate
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)		1680	AC4 AC = EC Joint Research Centre ESIS European Chemical Substance Information Systems including EINECS, now integrated with the database provided by the European Chemicals Agency (ECHA) (click here ) 4 = Verified data Rat	-
Mammals - Inhalation LC₅₀ (mg l⁻¹)		1.2	AC4 AC = EC Joint Research Centre ESIS European Chemical Substance Information Systems including EINECS, now integrated with the database provided by the European Chemicals Agency (ECHA) (click here ) 4 = Verified data Rat	-
Other Mammal toxicity endpoints		Intraperitoneal LD₅₀ = 260 mg kg⁻¹	V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source Rat	-
		Intravenous LD₅₀ = 320 mg kg⁻¹	V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source Mouse	-
ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)		0.007	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 JMPR 1995	-
ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)		0.01	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 JMPR 1997	-
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	Ingestion main poisoning route
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		Excreted in the faeces and urine almost completely after 3days	Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source	-

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 ; E2 E = Unspecified genotoxicity type (miscellaneous data source) 2 = Mixed/ambiguous results No data found Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant XNo, known not to cause a problem ✓Yes, known to cause a problem ?Possibly, status not identified Respiratory tract irritant Skin irritant Skin sensitiser ✓Yes, known to cause a problem ✓Yes, known to cause a problem No data found Eye irritant Phototoxicant   ✓Yes, known to cause a problem No data found
General human health issues		Harmful in contact with skin or if inhaled or swallowed May harm central nervous, cardiovascular, and respiratory systems

Handling issues

Property	Value and interpretation
General	No information available
CLP classification 2013	Health: H302, H312, H331, H341 Environment: H400, H410
WHO Classification	II (Moderately hazardous)
UN Number	3018
Waste disposal & packaging	-

TRANSLATIONS

Language	Name
English	fenthion
French	fenthion
German	Fenthion
Danish	fenthion
Italian	fention
Spanish	fention
Greek	fenthion
Polish	fention
Swedish	-
Hungarian	fention
Dutch	fenthion
Norwegian	-

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Record last updated:	03/02/2023
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