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 honeybees but is not highly toxic to birds or earthworms.
Hazard 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. These hazard alerts do not take account of usage patterns or exposure, thus do not represent risk.
Environmental fate
Ecotoxicity
Human health
Environmental fate High alert: Potential for particle bound transport: High
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: Endocrine disrupter; 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
No UK approval for use as a plant protection agent
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
 
 
 
 
 
 
 
 
 
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
Also used in
Australia; USA
Chemical structure
Isomerism
Permethrin exhibits stereoisomerism, specifically diastereomerism and enantiomerism, due to the presence of two adjacent chiral centres on its cyclopropane ring. This structural feature gives rise to four distinct stereoisomers: two pairs of enantiomers that are also diastereomers of each other. These are commonly referred to as cis- and trans-permethrin, based on the relative positioning of substituents around the cyclopropane ring. Commercial formulations of permethrin are typically mixtures of these isomers, often in ratios like 25:75 or 40:60 cis to trans. The cis-isomers tend to be more biologically active but also more toxic than the trans forms.
Colourless crystalline solid to brown viscous liquid depending upon purity
Commercial
Property
Value
Availability status
Current
Introduction & key dates
circa 1973, introduced; 2002, phase out began GB
Example manufacturers & suppliers of products using this active now or historically
Agropharm
ICI Plant Protection
Mitchell Cotts
FMC
BOC Sciences
Sundew Solutions Pty Ltd
Example products using this active
Fortefog P Fumer
Ambush
Exmin
Kestril
Ectiban
Pynosect
Corsair
Arctic
Starrdust Pro Insecticide
Formulation and application details
Available in a variety of formulations including fumigants, shampoos and spot-on treatments
Commercial production
The production of permethrin involves a multi-step chemical synthesis starting with 1,1-dichloro-4-methyl-1,3-pentadiene, which reacts with ethyl diazoacetate in the presence of a copper catalyst to form a cyclopropane intermediate: ethyl (±)-cis,trans-2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropane carboxylate. This intermediate is then hydrolysed to yield the corresponding carboxylic acid, which contains both cis- and trans-isomers. To separate these, the mixture is treated with n-hexane, where the cis-isomer dissolves and the trans-isomer precipitates. The trans-isomer is then filtered and esterified with 3-phenoxybenzyl alcohol, producing permethrin as the final product.
Impact on climate of production and use
Data for the amount of life cycle GHGs produced by permethrin 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)
0.011
E4 E = Manufacturers safety data sheets 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
E4 E = Manufacturers safety data sheets 4 = Verified data
-
Boiling point (°C)
465.9
E4 E = Manufacturers safety data sheets 4 = Verified data
-
Degradation point (°C)
-
-
-
Flashpoint (°C)
159.4
E4 E = Manufacturers safety data sheets 4 = Verified data
-
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. Available online but no longer updated. (click here ) 4 = Verified data
High
Fat solubility of residues
Solubility
Soluble
A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes
-
Data type
Regulatory data - observed in metabolism and farm animal feeding studies
A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes
-
Density (g ml⁻¹)
1.19
E3 E = Manufacturers safety data sheets 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. Dataset is no longer available. 4 = Verified data
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)
-
-
-
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; these datasets no longer available). Norman Ecotoxicology database. (click here ) 4 = Verified data
Non-persistent
DT₅₀ (lab at 20 °C)
13
K4 K = Research datasets (e.g. Pandora, Demetra; these datasets no longer available). Norman Ecotoxicology database. (click here ) 4 = Verified data
Non-persistent
DT₅₀ (field)
42
H4 H = The US ARS pesticide properties database. Dataset is no longer available. 4 = Verified data
Moderately persistent
DT₉₀ (lab at 20 °C)
-
-
-
DT₉₀ (field)
-
-
-
DT₅₀ modelling endpoint
-
-
-
Note
-
Dissipation rate RL₅₀ (days) 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 (days) 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; these datasets no longer available). Norman Ecotoxicology database. (click here ) 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; these datasets no longer available). Norman Ecotoxicology database. (click here ) 4 = Verified data
Moderately persistent
Note
-
Water-sediment DT₅₀ (days)
40
K4 K = Research datasets (e.g. Pandora, Demetra; these datasets no longer available). Norman Ecotoxicology database. (click here ) 4 = Verified data
Moderately fast
Water phase only DT₅₀ (days)
23
K4 K = Research datasets (e.g. Pandora, Demetra; these datasets no longer available). Norman Ecotoxicology database. (click here ) 4 = Verified data
Slow
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.
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
High
Calculated
-
Potential for loss via drain flow
Non-mobile
Calculated
-
Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk
-
-
-
Bio-concentration factor
BCF (l kg⁻¹)
300
P4 P = Other non-EU, UK or US Governments and Regulators 4 = Verified data
(Other literature Log BCF range 1.4-3.3 (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)
> 430
G4 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (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 yr
-
(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. Available online but no longer updated. (click here ) 4 = Verified data
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)
1440
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
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
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)
R3 R = Peer reviewed scientific publications 3 = Unverified data of known source
Ceriodaphnia dubia
High
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 / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source
K3 K = Research datasets (e.g. Pandora, Demetra; these datasets no longer available). Norman Ecotoxicology database. (click here ) 3 = Unverified data of known source
Non-statutory WHO drinking water guideline 0.3 mg l⁻¹
B5 B = UK CRD and ACP Evaluation Documents / and other DEFRA (UK) documents; Also Chemicals Regulation Division, Health and Safety Executive (HSE), UK (click here ) 5 = Verified data used for regulatory purposes
UK EA QS database 2018
-
Drinking Water MAC (μg l⁻¹)
-
-
-
Mammalian dose elimination route and rate
Rapidly metabolised by ester hydrolysis to inactive metabolites which are excreted primarily in the urine
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
-
Health issues
Specific human health issues
Carcinogen
Genotoxic
Endocrine disruptor
XNo, known not 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
?Possibly, status not identified
✓Yes, known to cause a problem
✓Yes, known to cause a problem
Eye irritant
Phototoxicant
 
✓Yes, known to cause a problem
No data found
 
General human health issues
Harmful Estrogenic IARC Group 3 carcinogen - not classifiable; US EPA - weak evidence to suggest human carcinogen 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: H302, H332, H335 Environment: H400, H410
WHO Classification
II (Moderately hazardous)
UN Number
UN3077
Waste disposal & packaging
Packaging Group III (minor danger)
Shelf-life, storage, stability and reactivity
Chemically stable under standard ambient conditions. Shelf-life of 2 yrs. Store -20 DegC in an inert atmosphere
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