Pyrethrins (pyrethrin I)

Pyrethrins (pyrethrin I)	Last updated: 31/10/2024
(Also known as: pyrethum)

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: Potential for particle bound transport: Medium	Ecotoxicity High alert: Fish acute ecotoxicity: High; Daphnia acute ecotoxicity: High; Bees acute contact ecotoxicity: High	Human health Moderate alert: Mammals acute toxicity: Moderate; Endocrine disrupter; Reproduction/development effects

GENERAL INFORMATION

Description

A non-persistent insecticide extracted from Pyrethrum, used to control a variety of pests on crops, in domestic and public health situations

Example pests controlled

A wide range of insects including mites

Example applications

A wide range of crops including vegetables, fruit, protected crops and ornamentals

Efficacy & activity

Appearance and life cycle

Availability status

Current

Introduction & key dates

circa 1930, introduced

Taxonomic classification

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

31/08/2026

UK LERAP status

None

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Italy/Germany

Date EC 1107/2009 inclusion expires

15/06/2026

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

Known to be also used in the following countries

USA, East Africa, Australia

Chemical structure

Isomerism

Pyrethrin-I is a complex molecule with three chiral centres.

Chemical formula

C₂₁H₂₈O₃

Canonical SMILES

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

Isomeric SMILES

CC1=C(C(=O)C[C@@H]1OC(=O)[C@@H]2[C@H](C2(C)C)C=C(C)C)C/C=C\C=C

International Chemical Identifier key (InChIKey)

ROVGZAWFACYCSP-WIURDZCKSA-N

International Chemical Identifier (InChI)

InChI=1S/C21H28O3/c1-7-8-9-10-15-14(4)18(12-17(15)22)24-20(23)19-16(11-13(2)3)21(19,5)6/h7-9,11,16,18-19H,1,10,12H2,2-6H3/b9-8+/t16-,18+,19+/m1/s1

2D structure diagram/image available?

Yes

General status

Biopesticide type

Insecticide, Acaricide, Veterinary substance

Substance groups

Plant-derived substance

Minimum active substance purity

Known relevant impurities

Substance origin

Natural

Mode of action

Contact acting neurotoxins with repellent properties. Sodium channel modulator.

Substance source

Orignially pertains to the dried powdered flower of the plant genus Chrysanthemum but optained rom the genus Tanacetum

Substance production

Extracted from the flowers of Tanacetum cineriaefolium

Uses

Crop protection; Public health

Target pests

A wide range of insects including mites

Target host

A wide range of crops including vegetables, fruit, protected crops and ornamentals

Farming system suitability

Suitable for use in all farming systems where approved for use in that country

CAS RN

121-21-1

Alternative/old CAS RN

8003-34-7

EC number

204-455-8

CIPAC number

US EPA chemical code

069001

PubChem CID

Molecular mass

328.4

PIN (Preferred Identification Name)

IUPAC name

(Z)-(S)-2-methyl-4-oxo-3-(penta-2,4-dienyl)cyclopent-2-enyl(1R)-trans-2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropanecarboxylate

CAS name

(1R-(1α(S(Z),3β)))-2-methyl-4-oxo-3-(2,4-pantadienyl)cyclopenten-1-yl 2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropanecarboxylate

Other status information

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)

Fungicide Resistance Class (FRAC MOA class)

Not applicable

Examples of recorded resistance

Blattella germanica, Boophilus decoloratus, Myzus persicae, Plodia interpunctella, Spodoptera litura, many others

Physical state

Viscous amber coloured liquid

Related substances & organisms

pyrethrins (cinerin I)

pyrethrins (jasmolin I)

pyrethrins (pyrethrin II)

pyrethrins (cinerin II)

pyrethrins (jasmolin II)

pyrethrins (mix)

Formulations

Property

Product

Manufacturer

Example products

Evergreen Crop Protetction 60-6

MGK

Diatect II

Diatect International

Pyrethrum 5EC concentrate

Agropharm Ltd

Formulation and application details

Available in a variety of formulations including ultra low-volume liquids and ready-to-use sprays for crop and public health applications and as powders, shampoos and impregnated collars for animals.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

0.96

Low

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

250000

n-Heptane

250000

p-Xylene

250000

Methane

250000

Acetone

Melting point (°C)

142

Boiling point (°C)

Degradation point (°C)

200

Flashpoint (°C)

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

3.89 X 10⁰⁵

Calculated

Log P

5.59

High

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

0.85

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

Vapour pressure at 20 °C (mPa)

3.13 X 10^-02

Low volatility

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

2.96 X 10^-01

Moderately 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)

52.8

as pyrethrins

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

3.3

Non-persistent

DT₅₀ (lab at 20 °C)

3.3

Non-persistent

DT₅₀ (field)

Non-persistent

DT₉₀ (lab at 20 °C)

12.92

Non-persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU 2021 dossier lab studies DT₅₀ (normalised) range 2.5-4.69 days, DT₉₀ (measured) range 6.25-22.1 days, Soils=5

Dissipation rate RL₅₀ (days) on plant matrix

Value

0.5

Note

Published literature RL₅₀ range 0.02-2.5 days, 4 field crops, various matrices, n=6

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

Note

Aqueous photolysis DT₅₀ (days) at pH 7

Value

0.5

Fast

Note

Rapid

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

Value

528

Very persistent

Note

Water-sediment DT₅₀ (days)

3.7

Fast

Water phase only DT₅₀ (days)

1.0

Moderately fast

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)

Non-mobile

K_oc (mL g⁻¹)

100000

Notes and range

Literature data

Freundlich

K_f (mL g⁻¹)

298

Non-mobile

K_foc (mL g⁻¹)

24809

¹/_n

0.952

Notes and range

EU dossier data for pyrethrins K_f range 198-430 mL g⁻¹, kfoc range 12472-74175 mL g⁻¹, ¹/_n range 0.907-1.10, Soils=4

pH sensitivity

Known soil metabolites

Metabolite

Major/Minor fraction

$Click here for further information on Major/Minor fraction$

Estimated maximum occurrence fraction

Notes

chrysanthemic acid

Minor fraction

0.05

Known groundwater metabolites

None

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

hydroxy-chrysanthenic acid

Plant

dihydroxy-chrysanthenic acid

Plant

dicarboxylic-chrysanthenic acid

Plant; Humans (Urine)

aldehyde-chrysanthenic acid

Plant

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

700

Rat as pyrethrins

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)

> 51151

Anas platyrhynchos as pyrethrins

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)

23.7

Eisenia foetida corr

Moderate

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

0.25

Eisenia foetida corr

Moderate

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)

0.013

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)

Harmful

Parasitic wasp

Beneficial insects (Predatory mites)

Harmless

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)

0.005

Oncorhynchus mykiss as pyrethrins

High

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

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

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

0.061

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)

0.0014

Americamysis bahia as pyrethrins

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)

Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)

320

Unknown species

Low

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)

700

Rat as pyrethrins

Moderate

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

2000

Rat as Pyrethrins

Mammals - Inhalation LC₅₀ (mg l⁻¹)

3.4

Rat 4 hr as Pyrethrins

Other Mammal toxicity endpoints

Intraperitoneal LD₅₀ = 200 mg kg⁻¹

Rat as Pyrethrins

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

0.04

Rat SF=100

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

0.2

Rat SF=100

AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)

AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)

None allocated

Dermal penetration studies (%)

default

Dangerous Substances Directive 76/464

Exposure Routes

Public

Occupational

Mammalian dose elimination route and rate

Almost completely excreted within 72hrs

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

May cause dermatitis
May cause gastointestinal problems
Possible thyroid and liver toxicant

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
IMDG Transport Hazard Class 9
Not expected to auto-ignite; Not highly flammable

CLP classification 2013

Health: H332, H312, H302
Environment: H400, H410

WHO Classification

II (Moderately hazardous)

UN Number

UN3082

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

pyrethrins (pyrethrin I)

French

pyrethrines

German

Pyrethrine

Danish

pyrethrin

Italian

piretrine

Spanish

piretrina

Greek

Polish

pyretryny

Swedish

pyretriner

Hungarian

Dutch

pyrethrinen

Norwegian

Record last updated:	31/10/2024
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