Fenvalerate (Ref: OMS 2000)

Fenvalerate (Ref: OMS 2000)	Last updated: 04/09/2025
(Not known by any other names)

SUMMARY

Fenvalerate is a pyrethroid, non-systemic acaricide. It has a low aqueous solubility and has a low volatility. Evidence suggests it is moderately persistent in both soil and water systems. Based on its physico-chemical properties it is not expected to leach to groundwater. It is highly toxic to most aquatic organisms and to bees. It has a moderate mammalian oral toxicity and is a recognised irritant.

GENERAL INFORMATION

Description

A pyrethroid insecticideonce used in veterinary medicine for parasite management

Examples of veterinary uses

Used to control external parasites such as flies and ticks on livestock and in stables

Examples of species treated

Cattle; Horses; Pigs; Dogs

Approval status

VMR 2013/2033 approval status (GB/UK)

Not approved

EU Regulatory approval status

Not approved

Chemical structure

Isomerism

A molecule with 2 chiral centres, fenvalerate is a mixture of four optical isomers which have different insecticidal activities. The 2-S alpha (or SS) configuration is the most insecticidally active isomer.

Chemical formula

C₂₅H₂₂ClNO₃

Canonical SMILES

CC(C)C(C1=CC=C(C=C1)Cl)C(=O)OC(C#N)C2=CC(=CC=C2)OC3=CC=CC=C3

Isomeric SMILES

International Chemical Identifier key (InChIKey)

NYPJDWWKZLNGGM-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C25H22ClNO3/c1-17(2)24(18-11-13-20(26)14-12-18)25(28)30-23(16-27)19-7-6-10-22(15-19)29-21-8-4-3-5-9-21/h3-15,17,23-24H,1-2H3

2D structure diagram/image available?

Yes

General status

Veterinary substance type

Insecticide

Substance groups

Pyrethroid insecticide; Pyrthroid acaricide; Pyrethroid ester insecticide; Pyrethroid ester acaricide

Minimum active substance purity

92%

Known relevant impurities

Substance origin

Synthetic

Mode of action

Non-systemic with contact and stomach action. Sodium channel modulator.

Molecular targets

[Sodium channel, Modulator]

CAS RN

51630-58-1

EC number

257-326-3

CIPAC number

334

US EPA chemical code

109301

PubChem CID

3347

CLP index number

No data found

Therapeutic Class

Antiparasitic products, insecticides & repellents: Pyrethrins & pyrethroids / Other ectoparasiticides for topical use

ATCvet Code

QP53AC14 / QP53AX02

Controlled Drug?

Regulation 37/2010 MRL Classification

Molecular mass

419.90

PIN (Preferred Identification Name)

(E)-cyano(3-phenoxyphenyl)methyl (2E)-2-(4-chlorophenyl)-3-methylbutanoate

IUPAC name

(RS)-α-cyano-3-phenoxybenzyl (RS)-2-(4-chlorophenyl)-3-methylbutyrate

CAS name

cyano(3-phenoxyphenyl)methyl 4-chloro-α-(1-methylethyl)benzeneacetate

Forever chemical

Other status information

Chemical subject to PIC regulations

Relevant Environmental Water Quality Standards

Physical state

Viscous yellow-brown liquid

Related substances & organisms

esfenvalerate

brofenvalerate

Commercial

Property

Value

Availability status

Current

Introduction & key dates

1976, introduced

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

Sumitomo
Shell
SDS Biotech
BOC Sciences

Example products using this active

Sumicidin
Pydrin
Belmark
Ectrin
Tirade
Sumifly

Formulation and application details

Supplied in a variety of formulations including emulsifiable concentrates, ULV, wettable powders & granules

Commercial production

Fenvalerate is synthesised commercially through a multi-step process involving esterification and cyanohydrin formation. First, 2-(4-chlorophenyl)-3-methylbutyric acid is reacted with thionyl chloride in the presence of a catalytic amount of N,N-dimethylformamide to produce the corresponding acid chloride. Separately, 3-phenoxybenzaldehyde is treated with sodium cyanide and triethylamine in a mixture of water and an organic solvent like toluene, forming a cyanohydrin intermediate. This intermediate is then acylated by the acid chloride under mild stirring conditions at room temperature, yielding fenvalerate.

Impact on climate of production and use

Data for the amount of life cycle GHGs produced by fenvalerate are not available in the public domain. However, whilst estimates vary, more general data suggests that between 14 and 19 kilograms of CO₂e is emitted per kilogram of insecticide produced.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

0.001

Low

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

53000

n-Hexane

200000

Xylene

84000

Methanol

Melting point (°C)

39.5

Boiling point (°C)

Decomposes on distillation

Degradation point (°C)

Flashpoint (°C)

230

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

1.02 X 10⁰⁵

Calculated

Log P

5.01

High

Fat solubility of residues

Solubility

Soluble

Data type

Regulatory data - observed in metabolism and farm animal feeding studies

Density (g ml⁻¹)

1.175

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

0.0192

Low volatility

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

4.20 X 10^-02

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)

Refractive Index

Environmental release

Degradation

Property

Value

Source; quality score; and other information

Interpretation

Soil degradation (days) (aerobic)

DT₅₀ (typical)

Moderately persistent

DT₅₀ (lab at 20 °C)

Moderately persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

Note

Other sources: DT₅₀ 35 days (DW4)

Manure DT₅₀ (days)

Aqueous photolysis DT₅₀ (days) at pH 7

Value

9.2

Moderately fast

Note

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

Value

115

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

[Wheat grain: >50 wks @ 30 DegC, 50% RH; Modelled data]

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d (mL g⁻¹)

Non-mobile

K_oc (mL g⁻¹)

5273

Notes and range

Freundlich

K_f (mL g⁻¹)

13.11

K_foc (mL g⁻¹)

¹/_n

0.96

Notes and range

Soil with 68% loam, 24% silt, 8% clay, pH 6.5, OC=2.1%

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

0.52

Calculated

Low leachability

Bio-concentration factor

BCF (l kg⁻¹)

1664

(Other literature log BCF range 2.6-3.6 (R3))

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)

451

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat 2 yr

(ppm diet)

250

Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)

Birds - Acute LD₅₀ (mg kg⁻¹)

9932

Anas platyrhynchos

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

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

Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)

Moderate

Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)

Soil micro-organisms

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

Vegetative vigour ER₅₀ (g ha⁻¹)

Seedling emergence ER₅₀ (g ha⁻¹)

Honeybees (Apis spp.)

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

0.23

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

Notes

[The residual time to 25% mortality (RT25) value for honeybees is 8 hrs - USEPA data]

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)

1.09

Trigona spinipes

Moderate

Mode of exposure

Contact

Other bee species (2)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

Beneficial insects (Ladybirds) as Mortality LC₅₀ mg l⁻¹

> 5.84

Coccinella septempunctata Adult

Beneficial insects (Lacewings) as Mortality, Contact LC₅₀ ppm

> 30.2

Chrysoperla carnea Larva

Beneficial insects (Parasitic wasps)

Beneficial insects (Predatory mites)

Harmful

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)

0.0036

Oncorhynchus mykiss

High

Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)

0.002

Clarias batrachus 14 day

High

Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

> 0.005

Danio rerio Larva

High

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

0.001

Daphnia magna

High

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

> 0.00003

Daphnia magna

High

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

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

0.000005

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 (free-floating, fonds growth, fresh) - 7 day (mg l⁻¹)

Aquatic plants (rooted, growth rate, fresh) - 14 day (mg l⁻¹)

Algae - Acute (growth rate, fresh; mg l⁻¹) (EC₅₀)

Unknown species

Low

Algae - Chronic (growth rate, fresh; mg l⁻¹) (14 day NOEC)

5.0

Synechococcus elongatus

Low

Mesocosm study data

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)

451

Rat

Moderate

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

1000

Rabbit

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 0.101

Rat

Other Mammal toxicity endpoints

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

0.0125

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

Exposure Routes

Public

Occupational

Mammalian dose elimination route and rate

Slow elimination (6-8 days). Partial elimination in faeces with minimal excretion in urine

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

No data found

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

No data found

Respiratory tract irritant

Skin irritant

Skin sensitiser

Eye irritant

Phototoxicant

No data found

General human health issues

May cause abdominal pain, convulsions and vomiting if ingested
Cardiovascular and blood toxicant
IARC Group 3 carcinogen - not classifiable
Endocrine issues - Inhibition of estrogen-sensitive cells proliferation

Handling issues

Property

Value and interpretation

General

IMDG Transport Hazard Class 6.1

CLP classification 2013

Health: H301, H315, H319, H332, H335
Environment: H400, H410

WHO Classification

II (Moderately hazardous)

UN Number

UN2811

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

Limited shelf-life

TRANSLATIONS

Language

Name

English

fenvalerate

French

fenvalérate

German

Fenvalerat

Danish

fenvalerat

Italian

fenvalerate

Spanish

fenvalerato

Greek

Polish

fenwalerat

Swedish

Hungarian

Dutch

fenvaleraat

Norwegian

Record last updated:	04/09/2025
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