| alpha-cypermethrin (Ref: OMS 3004) |
 |
Environmental Fate - Ecotoxicology - Human Health
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SUMMARY
Alpha-cypermethrin is a widely used pyrethroid insecticide that is approved for use in the EU. It has a low aqueous solubility, in relatively volatile and, based on its chemical properties, is not expected to leach to groundwater. However, it is considered to be a serious water pollutant. It is moderately persistent in soil and has been known to persist in water. It is highly toxic to mammals and a recognised irritant. It is relatively non-toxic to birds but is highly toxic to most aquatic organisms and honeybees. Alpha-cypermethrin is moderately toxic to earthworms. GENERAL INFORMATION 
for alpha-cypermethrin
Description: An insecticide for control of chewing and sucking insects in a wide range of crops and non-crop situations. Also has veterinary treatment applications.
Example pests controlled: Weevils; Moths; Caterpillars; Mites; Bollworm; Budworm; Green mirid; Cutworms; Aphids; Wireworms
Example applications: Asparagus; Brassicas; Cucumber; Leafy crops; Curcubits; OSR; Cereals including barley, wheat, rye, oats, triticale; Ornamentals; Forestry; Public health; Veterinary medicine
Efficacy & activity: Has been shown, via research and field trials, to have a high level of effectiveness for the control of a wide range of insect pests on agricultural crops.
Availability status: Current
Introduction & key dates: 1983, first reported; circa 1985, first introduced
EC Regulation 1107/2009 (repealing 91/414):
| Status | Approved |
| Dossier rapporteur/co-rapporteur | Belgium/Greece |
| Date inclusion expires | 31/10/2026 |
| EU Candidate for substitution (CfS) | No |
| Listed in EU database | Yes |
Approved for use (
) or known to be used (
) in the following European countries: 
AT |
BE |
BG |
CY |
CZ |
DE |
DK |
EE |
EL |
ES |
FI |
FR |
HR |
HU |
IE |
IT |
LT |
LU |
LV |
MT |
NL |
PL |
PT |
RO |
SE |
SI |
SK |
UK |
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Also used in: Australia
Chemical structure:
| Isomerism | Cypermethrin itself is a chiral molecule and consists of eight isomers, four cis and four trans. Alpha-Cypermethrin contains more than 90% of the insecticidally most active enantiomer pair of the four cis isomers of cypermethrin as |
| Chemical formula | C22H19Cl2NO3 |
| Canonical SMILES | CC1(C(C1C(=O)OC(C#N)C2=CC(=CC=C2)OC3=CC=CC=C3)C=C(Cl)Cl)C |
| Isomeric SMILES | CC1([C@@H]([C@@H]1C(=O)O[C@@H](C#N)C2=CC(=CC=C2)OC3=CC=CC=C3)C=C(Cl)Cl)C |
| International Chemical Identifier key (InChIKey) | GUQZCTLEJXHSIH-RZAVTOELSA-N |
| International Chemical Identifier (InChI) | InChI=1S/C22H19Cl2NO3/c1-22(2)17(12-19(23)24)20(22)21(26)28-18(13-25)14-7-6-10-16(11-14)27-15-8-4-3-5-9-15/h3-12,17-18,20H,1-2H3/t17-,18?,20-/m0/s1 |
| 2D structure diagram/image available? | Yes |
General status:
| Pesticide type | Insecticide, Veterinary substance | |
| Substance group | Pyrethroid | |
| Minimum active substance purity | 980 g/kg | |
| Known relevant impurities | EU dossier - None declared | |
| Substance origin | Synthetic | |
| Mode of action | Non-systemic with contact and stomach action. Sodium channel modulator. | |
| CAS RN | 67375-30-8 | |
| EC number | 257-842-9 | |
| CIPAC number | 454 | |
| US EPA chemical code | - | |
| PubChem CID | 3086172 | |
| Molecular mass (g mol-1) | 416.30 | |
| PIN (Preferred Identification Name) | rac-(R)-cyano(3-phenoxyphenyl)methyl (1S,3S)-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropane-1-carboxylate | |
| IUPAC name | racemate comprising (R)-α-cyano-3-phenoxybenzyl (1S)-cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate and (S)-α-cyano-3-phenoxybenzyl (1R)-cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate | |
| CAS name | (R)-cyano(3-phenoxyphenyl)methyl (1S,3S)-rel-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate | |
| Other status information | - | |
| Relevant Environmental Water Quality Standards | UK Environment Agency non-statutory standard for the protection of aquatic life in freshwater and saltwater annual average 0.0002 ug/L, max acceptable conc 0.002 ug/L UK statutory standard for water quality: ‘Good’ for fresh, transitional & saltwater: 0.1 ng/L as annual mean conc, 0.4 ng/L 95th percentile |
|
| Herbicide Resistance Classification (HRAC) | Not applicable | |
| Herbicide Resistance Classification (WSSA) | Not applicable | |
| Insecticide Resistance Classification (IRAC) | 3 | |
| Fungicide Resistance Classification (FRAC) | Not applicable | |
| Examples of recorded resistance | Aphis gossypii Bemisia tabaci Helicoverpa armigera Meligethes aeneus Bactrocera oleae Chrysoperla carnea Halotydeus destructor Thrips tabaci |
|
| Physical state | Colourless crystals | |
| Related substances & organisms | ||
Formulations:
| Property |
Value | |||
| Example manufacturers & suppliers of products using this active now or historically |
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| Example products using this active |
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| UK LERAP status | Buffer probably required in UK - see product label | |||
| Formulation and application details | Available in various formulations including crops sprays and livestock pour-ons . | |||
ENVIRONMENTAL FATE
for alpha-cypermethrin
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Solubility - In water at 20oC (mg l-1) | 0.004 | A5 | Low | |
| Solubility - In organic solvents at 20oC (mg l-1) | 596000 | A5 - Toluene | - | |
| 21300 | A5 - Methanol | - | ||
| 584000 | A5 - Ethyl acetate | - | ||
| Melting point (oC) | 82.1 | A5 | - | |
| Boiling point (oC) | Decomposes before boiling | A5 | - | |
| Degradation point (oC) | 248 | A5 | - | |
| Flashpoint (oC) | Not expected to self ignite; Not highly flammable | A5 | - | |
| Octanol-water partition coefficient at pH 7, 20oC | P | 6.31 X 1005 | Calculated | - |
| Log P | 5.8 | A4 | High | |
| Bulk density (g ml-1)/Specific gravity | - | A5 | - | |
| Dissociation constant (pKa) at 25oC | Not applicable | A5 | - | |
| Note: No dissociation | ||||
| Vapour pressure at 20oC (mPa) | 0.00038 | A5 | Low volatility | |
| Henry's law constant at 25oC (Pa m3 mol-1) | 5.30 X 10-02 | A5 | Non-volatile | |
GUS leaching potential index  |
-2.38 | 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 |
- | Calculated | Medium | |
| Maximum UV-vis absorption L mol-1 cm-1 | 276nm = 2073, 300nm = 38.64 | A4 | - | |
| Surface tension (mN m-1) | Not applicable | A4 | - | |
Degradation:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
General biodegradability | Not readily biodegradable |
| Soil degradation (days) (aerobic) | DT50 (typical) | 23.0 | A4 | Non-persistent |
| DT50 (lab at 20oC) | 23.4 | A4 | Non-persistent | |
| DT50 (field) | 42.6 | A5 | Moderately persistent | |
| DT90 (lab at 20oC) | 166 | A5 | - | |
| DT90 (field) | 120.2 | A5 | - | |
| DT50 modelling endpoint | 36.2 | A5 normalised, geometric mean | - | |
| Note | EU 2017 dossier Lab studies DT50 range 3.1-48.1 days - not normalised, DT90 range 4.5-329.4 days, Soils=7, Field studies DT50 range 11.7-114.1 days, DT90 range 38.7-250.5 days, Soils = 6; EU 2004 dossier Lab studies DT50 range 25-125 days, DT90 range 102-792 days, Field studies DT50 range 14-112 day (UK conditions), DT90 range 35-385 days; Other sources:DT50 77 days (DW4) | |||
| Dissipation rate RL50 on plant matrix | Value | - | - | - |
| Note | - | |||
| Dissipation rate RL50 on and in plant matrix | Value | 4.8 | R4 | - |
| Note | Published literature RL50 range 3.7-7.3 days, 3 field & undercover grown crops, various matrices, n=5 | |||
| Aqueous photolysis DT50 (days) at pH 7 | Value | 6.3 | A5 | Moderately fast |
| Note | - | |||
| Aqueous hydrolysis DT50 (days) at 20oC and pH 7 | Value | 70 | A - @ 25deg C | Moderately persistent |
| Note | DT50 sensitive to pH: stable at pH 4, 3.3 days at pH 9 & 25 degC | |||
| Water-sediment DT50 (days) | 21 | A5 | Fast | |
| Water phase only DT50 (days) | 1.3 | A5 | Moderately fast | |
Soil adsorption and mobility:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Linear | Kd | 3308 | A5 | Non-mobile |
| Koc | 288735 | |||
| Notes and range | EU 2017 dossier Kd range 2366-4362 mL/g, Koc range 228622-353100 mL/g, Soils =5 | |||
| Freundlich | Kf | - | - | - |
| Kfoc | - | |||
| 1/n | - | |||
| Notes and range | - | |||
| pH sensitivity | No | |||
Key metabolites:
| Metabolite | Formation medium | Estimated maximum occurrence fraction | 1107/2009 relevancy |
|
| 3-phenoxybenzoic acid | Soil | 0.054 | Major fraction, Relevant | |
| 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid |
Soil | 0.136 | Major fraction, Relevant | |
| 4-hydroxy-alpha-cypermethrin (Ref: CL 194198) | Soil | 0.08 | Major fraction, Relevant | |
ECOTOXICOLOGY
for alpha-cypermethrin
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Bio-concentration factor | BCF (l kg-1) | 910 | A5 | Threshold for concern |
| CT50 (days) | 7.8 | - | ||
| Mammals - Acute oral LD50 (mg kg-1) | 40 | A5 Rat | High | |
| Mammals - Short term dietary NOEL | (mg kg-1) | 5 | A5 Rat | High |
| (ppm diet) | 200 | - | ||
| Birds - Acute LD50 (mg kg-1) | > 2025 | A5 Colinus virginianus | Low | |
| Birds - Short term dietary (LC50/LD50) | - | - | - | |
| Fish - Acute 96 hour LC50 (mg l-1) | 0.0018 | A5 Oncorhynchus mykiss | High | |
| Fish - Chronic 21 day NOEC (mg l-1) | 0.00003 | A5 Pimephales promelas | High | |
| Aquatic invertebrates - Acute 48 hour EC50 (mg l-1) | 0.00022 | A5 Daphnia magna | High | |
| Aquatic invertebrates - Chronic 21 day NOEC (mg l-1) | 0.00003 | A5 Daphnia magna | High | |
| Aquatic crustaceans - Acute 96 hour LC50 (mg l-1) | - | - | - | |
| Sediment dwelling organisms - Acute 96 hour LC50 (mg l-1) | 0.000013 | A5 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) | > 0.00139 | A5 Lemna gibba | High | |
| Non-target plants | > 100.0 | A5 Onion, Oats, Pea, Rapseed Vegetative vigour, ER50 as g/ha |
- | |
| > 100 | A5 Onion, Oats, Pea, Rapseed Seedling emergence, ER50 as g/ha |
- | ||
| Algae - Acute 72 hour EC50, growth (mg l-1) | 0.084 | A5 Pseudokirchneriella subcapitata | Moderate | |
| Algae - Chronic 96 hour NOEC, growth (mg l-1) | - | - | - | |
| Honeybees (Apis spp.) | Contact acute LD50 (worst case from 24 , 48 and 72 hour values - μg bee-1) | 0.033 | A5 Apis mellifera | High |
| Oral acute LD50 (worst case from 24 , 48 and 72 hour values - μg bee-1) | 0.059 | A5 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) | > 0.29 | A5 Bombus terrestris | High |
| Literature values DT50 24hr = 0.17 ug/bee; 72hr = 0.15 ug/bee | ||||
| Oral acute LD50 (worst case from 24 , 48 and 72 hour values - μg bee-1) | > 0.54 | A5 Bombus terrestris | High | |
| Literature values DT50 24hr = 0.52 ug/bee; 72hr = 0.36 ug/bee | ||||
| Mason bees (Osmia spp.) | Contact acute LD50 (worst case from 24 , 48 and 72 hour values - μg bee-1) | 0.25 | R4 Osmia bicornis | High |
| 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) | - | - | - |
| Mode of exposure | - | |||
| Other pollinators (2) | Acute LD50 (worst case from 24 , 48 and 72 hour values - μg insect-1) | - | - | - |
| Mode of exposure | - | |||
| Earthworms - Acute 14 day LC50 (mg kg-1) | > 100 | A5 Eisenia foetida | Moderate | |
| Earthworms - Chronic NOEC, reproduction (mg kg-1) | > 2.00 | A5 Eisenia foetida, corr | Moderate | |
| Other soil macro-organisms | Acute LC50 (mg kg-1) | > 129 | A5 Folsomia candida, 28d corr | - | Chronic NOEC (mg kg-1) | 4.22 | A5 Folsomia candida, 28d corr | - |
| Other arthropod (1) | LR50 g ha-1 | 0.031 | Mortality A5 Aphidius rhopalosiphi |
- |
| % Effect | - | - | - | |
| Other arthropod (2) | LR50 g ha-1 | 0.0019 | Mortality A5 Typhlodromus pyri |
- |
| % Effect | 85 | Mortality Dose: 15 g ha-1 L3 Typhlodromus pyri |
- | |
| Soil micro-organisms | Nitrogen mineralisation: No significant adverse effect Carbon mineralisation: No significant adverse effect |
A5 Dose: 0.3 kg ha-1, 28 days |
- | |
| Mesocosm study data | NOEAEC mg l-1 | 0.000015 | A5 Aquatic invertebrates and algae | - |
| NOEAEC mg l-1 | - | - | - | |
HUMAN HEALTH AND PROTECTION
for alpha-cypermethrin
General:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Threshold of Toxicological Concern (Cramer Class) |
High (class III) | - | - | |
| Mammals - Acute oral LD50 (mg kg-1) | 40 | A5 Rat | High | |
| Mammals - Dermal LD50 (mg kg-1 body weight) | > 2000 | A5 Rat | - | |
| Mammals - Inhalation LC50 (mg l-1) | 1.33 | A5 Rat, 4 hr (nose only) | - | |
| Other Mammal toxicity endpoints | - | - | ||
| ADI - Acceptable Daily Intake (mg kg-1bw day-1) | 0.015 | A5 | - | |
| ARfD - Acute Reference Dose (mg kg-1bw day-1) | 0.04 | A5 Rat, SF=100 | - | |
| AAOEL - Acute Acceptable Operator Exposure Level (mg kg-1 bw day-1) | - | - | - | |
| AOEL - Acceptable Operator Exposure Level - Systemic (mg kg-1bw day-1) | 0.01 | A5 Dog, 90 day, SF=100 | - | |
| Dermal penetration studies (%) | 0.7-3.0 | A5 Concentration dependent | - | |
| Dangerous Substances Directive 76/464 | - | - | - | |
| Exposure Routes | Public | No unacceptable risks identified for the general public, bystanders and residents | ||
| Occupational | No unacceptable risks identified for operators or other farm workers | |||
| European MRLs | Click here for the EU MRL pesticide database | |||
| Drinking Water Standards | - | - | - | |
| Drinking Water MAC (μg l-1) | - | - | - | |
Health issues:
| Carcinogen | Genotoxic | Endocrine disrupter | Reproduction / development effects | Cholinesterase inhibitor | Neurotoxicant | |||
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A3; B0; C3; D0; E3 |
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| Respiratory tract irritant | Skin irritant | Skin sensitiser | Eye irritant | Phototoxicant | ||||
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| General human health issues | Highly toxic by ingestion USEPA - possible human carcinogen dy |
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| Key: Genotoxicity A: Chromosome aberration (EFSA database) B: DNA damage/repair (EFSA database) C: Gene mutation (EFSA database) D: Genome mutation (EFSA database) E: Unspecified genotoxicity type (miscellaneous data source) 0: No data 1: Positive 2: Mixed/ambiguous results 3: Negative |
Key: Other : Yes, known to cause a problem  : No, known not to cause a problem  : Possibly, status not identified - : No data found |
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Handling issues:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
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| General |
IMDG Transport Code is product specific and usually a 6.1 or 3 Not explosive or oxidising |
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| CLP classification 2013 | Health: H301, H335, H373 Environment: H400, H410 |
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| EC Risk Classification |
T - Toxic: R25 Xn - Harmful: R48/22 Xi - Irritant: R37 N - Dangerous for the environment: R50, R53 |
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| EC Safety Classification |
S2, S36/37/39, S45, S61, S60 | |||
| WHO Classification | II | - | Moderately hazardous | |
| UN Number | 3349 for active, variable with product, usually 1993, 3077 or 3082 | |||
| Waste disposal & packaging |
Packaging Group III (minor danger) | |||
TRANSLATIONS
for alpha-cypermethrin
| Language | Name |
| English | alpha-cypermethrin |
| French | alphacypermethrine |
| German | alpha-Cypermethrin |
| Danish | alpha-cypermethrin |
| Italian | alfametrina |
| Spanish | alfacipermetrina |
| Greek | - |
| Slovenian | alfa-cipermetrin |
| Polish | alfa-cypermetryna |
| Swedish | alfacypermetrin |
| Hungarian | alphamethrin / alpha cypremethrin |
| Dutch | alfa-cypermethrin |
Record last updated: Friday 01 May 2020
Contact: aeru@herts.ac.uk