Allethrin (Ref: FMC 249)

Allethrin (Ref: FMC 249)	Last updated: 24/08/2024
(Also known as: palléthrine; S-bioallethrin; toluen-disocianato; esdepallethrine; d-allethrolone chrysanthemumate)

SUMMARY

Allethrin is a pyrethroid insecticide mostly used in amenity and domestic situations. It has a low aqueous solubility, is volatile and, based on its chemical properties, would not be expected to leach to groundwater. It tends to be moderately persistent in most soil systems. Allethrin is moderately toxic to mammals and a recognised irritant. Whilst it is not highly toxic to birds it is moderately toxic to fish, honeybees and earthworms.

GENERAL INFORMATION

Description

A pyrethroid insecticide used in veterinary medicine to control parasites

Availability status

Current

Introduction & key dates

1949, first introduced; circa 1954, first registered Japan

Examples of veterinary uses

Used to control general livestock insect pests as well as fleas and ticks in domestic animals

Examples of species treated

Cattle; Cats; Dogs

Approval status

VMR 2013/2033 approval status (GB/UK)

Not approved

EU Regulatory approval status

Not approved

Chemical structure

Isomerism

A chiral molecule. Allethrin is a isomeric mixture of 8 stereoisomers.

Chemical formula

C₁₉H₂₆O₃

Canonical SMILES

CC1=C(C(=O)CC1OC(=O)C2C(C2(C)C)C=C(C)C)CC=C

Isomeric SMILES

International Chemical Identifier key (InChIKey)

ZCVAOQKBXKSDMS-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C19H26O3/c1-7-8-13-12(4)16(10-15(13)20)22-18(21)17-14(9-11(2)3)19(17,5)6/h7,9,14,16-17H,1,8,10H2,2-6H3

2D structure diagram/image available?

Yes

General status

Veterinary substance type

Antiparasitic

Substance groups

Pyrethroid insecticide

Minimum active substance purity

93%

Known relevant impurities

Substance origin

Synthetic

Mode of action

Stomach and respiratory action, non-systemic, paralyses insects before killing them.

Molecular targets

[Sodium & Chloride channels, Blocker]

CAS RN

584-79-2

EC number

209-542-4

CIPAC number

267

US EPA chemical code

004001/004003

PubChem CID

11442

CLP index number

006-025-00-3

Therapeutic Class

Antiparasitic products, insecticides & repellents: Pyrethrins & pyrethroids

ATCvet Code

QP53AC

Controlled Drug?

Regulation 37/2010 MRL Classification

Molecular mass

302.41

PIN (Preferred Identification Name)

(1E)-2-methyl-4-oxo-3-(prop-2-en-1-yl)cyclopent-2-en-1-yl (1?,3?)-2,2-dimethyl-3-(2-methylprop-1-en-1-yl)cyclopropane-1-carboxylate

IUPAC name

1RS)-3-allyl-2-methyl-4-oxocyclopent-2-enyl (1RS,3RS;1RS,3SR)-2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropanecarboxylate

CAS name

2-methyl-4-oxo-3-(2-propenyl)-2-cyclopenten-1-yl 2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropanecarboxylate

Other status information

Relevant Environmental Water Quality Standards

Physical state

Viscous amber liquid

Related substances & organisms

bioallethrin

S-bioallethrin

Formulations

Property

Product

Manufacturer

Authorisation Route

Legal Class (GB/UK)

Example products (past and present) using this active

Formulation and application details

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

0.0001

Low

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

Miscible

Acetone

Miscible

Ethanol

655000

Hexane

Melting point (°C)

Boiling point (°C)

281.5

Degradation point (°C)

Flashpoint (°C)

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

9.12 X 10⁰⁴

Calculated

Log P

4.96

High

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

1.01

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

0.78

at 25°C

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)

6.20 X 10^-07

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)

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

Note

Manure DT₅₀ (days)

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Note

Decomposes rapidly in UV light

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

Value

Note

Hydrolysis occurs only under alkaline conditions

Water-sediment DT₅₀ (days)

Water 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

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d (mL g⁻¹)

Slightly mobile

K_oc (mL g⁻¹)

1400

Notes and range

Other sources: 9500 mL g⁻¹ (CB2)

Freundlich

K_f (mL g⁻¹)

K_foc (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

1.52

Calculated

Low leachability

Bio-concentration factor

BCF (l kg⁻¹)

200

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)

685

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

(ppm diet)

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

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2030

Colinus virginianus

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)

> 1000

Unknown species

Low

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)

> 3.4

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)

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

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

> 0.019

Oncorhynchus mykiss

High

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

0.005

Cyprinus carpio

High

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

> 1.99

Danio rerio

Moderate

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

> 0.021

Daphnia magna

High

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

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 - Acute 7 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

HUMAN HEALTH AND PROTECTION

General

Property

Value

Source; quality score; and other information

Interpretation

Threshold of Toxicological Concern (Cramer Class)

Intermediate (class II)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

685

Rat

Moderate

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

2660

Rabbit

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 3.88

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

Exposure Routes

Public

Low risk to Europeans as no longer approved for use

Occupational

Exposure may occur via skin contact or inhalation - PPE/PPC advised

Mammalian dose elimination route and rate

Urinary (25 - 50%) and faecal (50-70%) in around 3 days

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

No data found

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

Moderately toxic
Potential mutagen
Kidney and liver toxicant
Inhalation may cause asthma, coughing, wheezing, running nose and eyes

Handling issues

Property

Value and interpretation

General

Incompatible with alkalis
Sensitive to light

CLP classification 2013

Health: H302, H332
Environment: H400, H410

WHO Classification

II (Moderately hazardous)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

allethrin

French

allethrine

German

Allethrin

Danish

d-trans-allethrin

Italian

alletrina

Spanish

aletrina

Greek

allethrin bioallethrin

Polish

aletryna

Swedish

Hungarian

Dutch

allethrin

Norwegian

Record last updated:	24/08/2024
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