Permethrin (Ref: OMS 1821)	Last updated: 30/09/2021
(Also known as: permethrine)

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SUMMARY

Permethrin is a contact insecticide. It is not highly soluble in water, has a low volatility and is not normally expected to leach to groundwater. It would also not be expected to persist in soil or water systems. It is moderately toxic to humans, is an irritant and may be a CNS toxicant. It is highly toxic to most aquatic species and honey bees but is not highly toxic to birds or 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; Potential for particle bound transport: Medium	Ecotoxicity High alert: Fish acute ecotoxicity: High; Fish chronic ecotoxicity: High; Daphnia acute ecotoxicity: High; Bees acute contact ecotoxicity: High; Bees acute oral ecotoxicity: High	Human health High alert: Carcinogen; Endocrine distrupter; Reproduction/development effects; Neurotoxicant

GENERAL INFORMATION

Description	An insecticide active against a wide range of pests including Lepidoptera and Coleoptera in crops and various animal ectoparasites
Example pests controlled	Cockroaches; Termites; Ticks; Mosquitoes; Aphids; Fleas; Ants
Example applications	Fruit; Vegetables; Cotton; Ornamentals; Potatoes; Cereals
Efficacy & activity	-
Availability status	Current
Introduction & key dates	circa 1973

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	Ireland
Date EC 1107/2009 inclusion expires	Expired
EU Candidate for substitution (CfS)	Not applicable
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

Additional information

Also used in	Australia, USA

Chemical structure

Isomerism	A chiral molecule
Chemical formula	C₂₁H₂₀Cl₂O₃
Canonical SMILES	CC1(C(C1C(=O)OCC2=CC(=CC=C2)OC3=CC=CC=C3)C=C(Cl)Cl)C
Isomeric SMILES	No data
International Chemical Identifier key (InChIKey)	RLLPVAHGXHCWKJ-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/C21H20Cl2O3/c1-21(2)17(12-18(22)23)19(21)20(24)25-13-14-7-6-10-16(11-14)26-15-8-4-3-5-9-15/h3-12,17,19H,13H2,1-2H3/t17-,19-/m0/s1
2D structure diagram/image available?	Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
cispermethrin	Cis-isomer
transpermethrin	Trans-isomer

General status

Pesticide type	Insecticide, Veterinary substance
Substance group	Pyrethroid
Minimum active substance purity	-
Known relevant impurities	-
Substance origin	Synthetic
Mode of action	Broad spectrum with contact and stomach action. Slight repellant effect. Sodium channel modulator.
CAS RN	52645-53-1
EC number	258-067-9
CIPAC number	331
US EPA chemical code	109701
PubChem CID	40326
Molecular mass	391.3
PIN (Preferred Identification Name)	-
IUPAC name	3-phenoxybenzyl (1RS,3RS;1RS,3SR)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate
CAS name	(3-phenoxyphenyl)methyl 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate
Other status information	Chemical subject to PIC regulations
Relevant Environmental Water Quality Standards	UK statutory standard for the protection of aquatic life: freshwater and saltwater: 0.01 µg l⁻¹
Herbicide Resistance Classification (HRAC)	Not applicable
Herbicide Resistance Classification (WSSA)	Not applicable
Insecticide Resistance Classification (IRAC)	3A
Fungicide Resistance Classification (FRAC)	Not applicable
Examples of recorded resistance	Aedes aegypti, Bemisia tabaci, Chrysoperla carnea, Culex pipiens pipiens, Diadegma insulare, Helicoverpa zea, many others
Physical state	Colourless crystalline solid to brown viscous liquid depending upon purity
Related substances & organisms	kaolin

Formulations

Property	Value
Example manufacturers & suppliers of products using this active now or historically	Agropharm ICI Plant Protection Mitchell Cotts FMC
Example products using this active	Fortefog P Fumer Ambush Exmin Kestril Ectiban Pynosect Corsair Arctic
Formulation and application details	Available in a variety of formulations including fumigants, shampoos and spot-on treatments

ENVIRONMENTAL FATE

Property		Value	Source; quality score; and other information	Interpretation
Solubility - In water at 20 °C (mg l⁻¹)		0.2	G4 G = Extension Toxicology network database EXTOXNET (click here ) 4 = Verified data	Low
Solubility - In organic solvents at 20 °C (mg l⁻¹)		1000000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Hexane	-
		258000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Methanol	-
		1000000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Xylene	-
Melting point (°C)		34.5	E3 E = Manufacturers safety data sheets 3 = Unverified data of known source	-
Boiling point (°C)		200	E3 E = Manufacturers safety data sheets 3 = Unverified data of known source	-
Degradation point (°C)		-	-	-
Flashpoint (°C)		100	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
Octanol-water partition coefficient at pH 7, 20 °C	P	1.26 X 1006	Calculated	-
	Log P	6.1	G4 G = Extension Toxicology network database EXTOXNET (click here ) 4 = Verified data	High
Bulk density (g ml⁻¹)		1.29	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
Dissociation constant pKa) at 25 °C		-	-	-
		-
Vapour pressure at 20 °C (mPa)		0.007	R4 R = Peer reviewed scientific publications 4 = Verified data at 25°C	Low volatility
Henry's law constant at 25 °C (Pa m³ mol⁻¹)		1.89 X 10-01	H4 H = The US ARS pesticide properties database (click here ) 4 = Verified data	Moderately 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)	13	K4 K = Research datasets, e.g. Pandora, Demetra 4 = Verified data	Non-persistent
	DT₅₀ (lab at 20 °C)	13	K4 K = Research datasets, e.g. Pandora, Demetra 4 = Verified data	Non-persistent
	DT₅₀ (field)	42	H4 H = The US ARS pesticide properties database (click here ) 4 = Verified data	Moderately persistent
	DT₉₀ (lab at 20 °C)	-	-	-
	DT₉₀ (field)	-	-	-
	DT₅₀ modelling endpoint	-	-	-
	Note	-
Dissipation rate RL₅₀ on plant matrix	Value	6.7	R4 R = Peer reviewed scientific publications 4 = Verified data	-
	Note	Published literature RL₅₀ range 2.5-20.0 days, 8 field & undercover grown crops, various matrices, n=9
Dissipation rate RL₅₀ on and in plant matrix	Value	11.1	R4 R = Peer reviewed scientific publications 4 = Verified data	-
	Note	Published literature RL₅₀ range 9.5-13.9 days, 3 field & undercover grown crops, various matrices, n=3
Aqueous photolysis DT₅₀ (days) at pH 7	Value	1	K4 K = Research datasets, e.g. Pandora, Demetra 4 = Verified data	Moderately fast
	Note	-
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7	Value	31	K4 K = Research datasets, e.g. Pandora, Demetra 4 = Verified data	Moderately persistent
	Note	-
Water-sediment DT₅₀ (days)		40	K4 K = Research datasets, e.g. Pandora, Demetra 4 = Verified data	Moderately fast
Water phase only DT₅₀ (days)		23	K4 K = Research datasets, e.g. Pandora, Demetra 4 = Verified data	Slow

Soil adsorption and mobility

Property		Value	Source; quality score; and other information	Interpretation
Linear	Kd	-	G4 G = Extension Toxicology network database EXTOXNET (click here ) 4 = Verified data	Non-mobile
	Koc	100000
	Notes and range	-
Freundlich	Kf	1.87	R4 R = Peer reviewed scientific publications 4 = Verified data	-
	Kfoc	-
	1/n	0.99
	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		-1.62	Calculated	Low leachability
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate	Value	5.35 X 10-03	Calculated	-
	Note	Estimated concentrations of chemicals with Koc values greater than 9995 ml g⁻¹ are beyond the scope of the regression data used in SCI-GROW development. If there are concerns for such chemicals, a higher tier groundwater exposure assessment should be considered, regardless of the concentration returned by SCI-GROW
Potential for particle bound transport index		Medium	Calculated	-
Potential for loss via drain flow		Non-mobile	Calculated	-

ECOTOXICOLOGY

Property		Value	Source; quality score; and other information	Interpretation
Bio-concentration factor	BCF (l kg⁻¹)	300	P4 P = Other governments and regulators 4 = Verified data (Other literature Log BCF range 1.4-3.3 (R3))	Threshold for concern
	CT₅₀ (days)	Not available		-
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		> 430	G4 G = Extension Toxicology network database EXTOXNET (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)	100		-
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Birds - Acute LD₅₀ (mg kg⁻¹)		> 9800	G4 G = Extension Toxicology network database EXTOXNET (click here ) 4 = Verified data Anas platyrhynchos	Low
Birds - Short term dietary (LC₅₀/LD₅₀)		-	-	-
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Fish - Acute 96 hour LC₅₀ (mg l⁻¹)		0.0125	G4 G = Extension Toxicology network database EXTOXNET (click here ) 4 = Verified data Oncorhynchus mykiss	High
Fish - Chronic 21 day NOEC (mg l⁻¹)		0.000093	P3 P = Other governments and regulators 3 = Unverified data of known source Anabas testudineus	High
Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		0.0006	E3 E = Manufacturers safety data sheets 3 = Unverified data of known source Daphnia magna	High
Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)		-	-	-
Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)		0.00002	F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source Americamysis bahia	High
Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)		0.0029	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data Chironomus riparius	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)		-	-	-
Non-target plants		-	-	-
		-	-	-
Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)		0.0125	K3 K = Research datasets, e.g. Pandora, Demetra 3 = Unverified data of known source Unknown species	Moderate
Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)		0.0009	Q2 Q = Miscellaneous internet resources 2 = Unverified data of unknown source Unknown species	High
Honeybees (Apis spp.)	Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	0.024	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data Apis mellifera	High
	Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	0.13	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data Apis mellifera	High
	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)	> 0.22	R3 R = Peer reviewed scientific publications 3 = Unverified data of known source Bomus terrestris	High
		Literature DT₅₀ values range 0.22-0.82 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)	0.0157	R4 R = Peer reviewed scientific publications 4 = Verified data Megachile rotundata	High
	Mode of exposure	Contact
Other pollinators (2)	Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)	0.07	R4 R = Peer reviewed scientific publications 4 = Verified data Trigona spinipes	High
	Mode of exposure	Contact
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)		1440	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source	Low
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	Harmful	Q2 Q = Miscellaneous internet resources 2 = Unverified data of unknown source Parasitoids	-
Other arthropod (2)	LR₅₀ g ha⁻¹	-	-	-
	% Effect	Harmful	AA2 AA = IOBC Database on classification of side effects to beneficial organisms, 2005 2 = Unverified data of unknown source Typhlodromus pyri	-
Soil micro-organisms		-	-	-
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)		> 430	G4 G = Extension Toxicology network database EXTOXNET (click here ) 4 = Verified data Rat	Moderate
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)		2000	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data Rabbit	-
Mammals - Inhalation LC₅₀ (mg l⁻¹)		> 0.685	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Rat	-
Other Mammal toxicity endpoints		Intraperitoneal LD₅₀ = 429 mg kg⁻¹	V3 V = ChemID online databases / IPCS INCHEM (ChemID; IPCS INCHEM ) 3 = Unverified data of known source Mouse	-
		Intravenous LD₅₀ = 31.0 mg kg⁻¹	V3 V = ChemID online databases / IPCS INCHEM (ChemID; IPCS INCHEM ) 3 = Unverified data of known source Mouse	-
ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)		0.05	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data JMPR 1999	-
ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)		1.5	F5 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 5 = Verified data used for regulatory purposes JMPR 2003	-
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	-
MRLs	European	EU MRL pesticide database
	Great Britain	GB MRL Register
	Notes	-
Drinking Water Standards		Non-statutory WHO drinking water guideline 0.3 mg l⁻¹	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes UK EA QS database 2018	-
Drinking Water MAC (μg l⁻¹)		-	-	-

Health issues

Specific human health issues		Carcinogen Genotoxic Endocrine disruptor ✓Yes, known 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 ; E3 E = Unspecified genotoxicity type (miscellaneous data source) 3 = Negative ✓Yes, known to cause a problem Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant ✓Yes, known to cause a problem ?Possibly, status not identified ✓Yes, known to cause a problem Respiratory tract irritant Skin irritant Skin sensitiser No data found ✓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 Estrogenic IARC Group 3 carcinogen; USEPA - probable human carcinogen Endocrine issues - Inhibition of estrogen-sensitive cells proliferation

Handling issues

Property	Value and interpretation
General	IMDG Transport Code is usually 6.1
CLP classification 2013	Health: H302, H332, H335 Environment: H400, H410
EC Risk Classification	Xn - Harmful: R20/22, R43 N - Dangerous for the environment: R50, R53
EC Safety Classification	S2, S13, S24, S36/37/39, S60, S61
WHO Classification	II (Moderately hazardous)
UN Number	3352 for active, products usually 1230
Waste disposal & packaging	Packaging Group III (medium danger)

TRANSLATIONS

Language	Name
English	permethrin
French	permethrine
German	Permethrin
Danish	permethrin
Italian	permetrina
Spanish	permetrin
Greek	permethrin
Polish	permetryna
Swedish	permetrin
Hungarian	permetrin
Dutch	permethrin

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Record last updated:	30/09/2021
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