Fenthion (Ref: OMS 2)

Fenthion (Ref: OMS 2)	Last updated: 21/01/2021
(Also known as: MPP; ENT 25540; Bayer 29493; S-1752; BAY 29493; DMTP)

SUMMARY

Fenthino is an insecticide that is no longer approved for use in the EU. 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.

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

Also used in

Chemical structure

Isomerism

Chemical formula

C₁₀H₁₅O₃PS₂

Canonical SMILES

CC1=C(C=CC(=C1)OP(=S)(OC)OC)SC

Isomeric SMILES

No data

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 group

Organophosphate

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

US EPA chemical code

053301

PubChem CID

3346

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)

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

Formulations

Property

Value

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

Baycid
Baytex
Lebaycid
Queletox
Pilartex

Example products using this active

Bayer CropScience
AgroCare
King Tech Corp
Mobay

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

Low

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

100000

Hexane

250000

Toluene

250000

Dichloromethane

250000

Isopropanol

Melting point (°C)

7.5

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

170

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

6.92 X 10⁰⁴

Calculated

Log P

4.84

High

Bulk density (g ml⁻¹)

1.25

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

0.37

Low volatility

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

2.40 X 10^-02

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)

Non-persistent

DT₅₀ (lab at 20 °C)

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

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

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

Fast

Note

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

Value

Stable

Note

Water-sediment DT₅₀ (days)

Moderately fast

Water phase only DT₅₀ (days)

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

Slightly mobile

K_oc

1500

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

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

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

fenthion sulfoxide (Ref: BAY S 2281)

Soil

fenthion sulfone

Soil

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

154

(Whole body Other literature Log BCF range 1.0-2.3 ())

Threshold for concern

CT₅₀ (days)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

~ 250

Rat

Moderate

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)

7.2

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)

0.8

Oncorhynchus mykiss

Moderate

Fish - Chronic 21 day NOEC (mg l⁻¹)

0.12

Pimephales promelas 30 day

Moderate

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

0.0057

Daphnia magna

High

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

0.000013

Daphnia magna

High

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

0.00018

Americamysis bahia

High

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)

1.79

Scenedemus subspicatus

Moderate

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

> 0.3

Pseudokirchneriella subcapitata 48 hr

Moderate

Honeybees (Apis spp.)

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

> 0.308

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)

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)

375

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

Nitrogen mineralisation: >25% effect
Carbon mineralisation: No significant adverse effect

Dose: 10 uL/kg soil 20°C

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)

~ 250

Rat

Moderate

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

1680

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

1.2

Rat

Other Mammal toxicity endpoints

Intraperitoneal LD₅₀ = 260 mg kg⁻¹

Rat

Intravenous LD₅₀ = 320 mg kg⁻¹

Mouse

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

0.007

JMPR 1995

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

0.01

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

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

; ; ; ;

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

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

EC Risk Classification

T - Toxic: R23, R48/25, R68
Xn - Harmful: R21/22
N - Dangerous for the environment: R50, R53

EC Safety Classification

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

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

Record last updated:	21/01/2021
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