Imidacloprid (Ref: BAY NTN 33893)

Imidacloprid (Ref: BAY NTN 33893)	Last updated: 24/10/2024
(Not known by any other names)

SUMMARY

Imidacloprid is a neonicotinoid insecticide. It is highly soluble, non-volatile and persistent in soil. It is moderately mobile. It has a low risk of bioaccumulating. It is highly toxic to birds and honeybees. Moderately toxic to mammals and earthworms. It is non-toxic to fish.

GENERAL INFORMATION

Description

A veterinary insecticide used as an antiparasitic agent

Availability status

Current

Introduction & key dates

1990, first reported; 1991, introduced

Examples of veterinary uses

Used as a flea treatment for domestic pets but also effective against ticks, mosquitoes, chewing lice, heartworms, hookworms, roundworms, whipworms, scabies, cheyletiellosis, demodex, or ear mites

Examples of species treated

Domestic pets including cats and dogs

Approval status

VMR 2013/2033 approval status (GB/UK)

Approved

EU Regulatory approval status

Approved

Chemical structure

Isomerism

Isomeric - existing as both the E- and Z- forms however many commerical products are comprised of almost entirely the (E)-isomer

Chemical formula

C₉H₁₀ClN₅O₂

Canonical SMILES

C1CN(C(=N1)N[N+](=O)[O-])CC2=CN=C(C=C2)Cl

Isomeric SMILES

International Chemical Identifier key (InChIKey)

YWTYJOPNNQFBPC-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C9H10ClN5O2/c10-8-2-1-7(5-12-8)6-14-4-3-11-9(14)13-15(16)17/h1-2,5H,3-4,6H2,(H,11,13)

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
imidacloprid	-

General status

Veterinary substance type

Insecticide, Antiparastic

Substance groups

Neonicotinoid insecticide; Guanidine insecticide

Minimum active substance purity

970 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Systemic with contact and stomach action. Nicotinic acetylcholine receptor (nAChR) channel blocker.

Molecular targets

CAS RN

138261-41-3

EC number

428-040-8

CIPAC number

582

US EPA chemical code

129099

PubChem CID

86418

CLP index number

612-252-00-4

Therapeutic Class

Antiparasitic products, insecticides & repellents: Ecoparasiticides, insecticides & repellents

ATCvet Code

QP53AX17

Controlled Drug?

Regulation 37/2010 MRL Classification

Molecular mass

255.66

PIN (Preferred Identification Name)

IUPAC name

(E)-1-(6-chloro-3-pyridylmethyl)-N-nitroimidazolidin-2-ylideneamine

CAS name

(2E)-1-((6-chloro-3-pyridinyl)methyl)-N-nitro-2-imidazolidinimine

Other status information

Some applications may be approved under GB Biocides Products Regulations; A ban or usage restriction may be in place for use on flowering crops in some EU Member States

Relevant Environmental Water Quality Standards

Physical state

Colourless to cream crystalline powder depending on purity

Formulations

Property

Product

Manufacturer

Authorisation Route

Legal Class (GB/UK)

Example products (past and present) using this active

Advantage Spot On solution for dogs

Elanco Europe Ltd

GB National authorisation

For non-food animal use and may be supplied without a prescription by a suitable qualified person (NFA-VPS)

Advantix Spot-on Solution

Elanco Europe Ltd

GB National authorisation

Prescription only medicine to be authorised by a veterinarian (POM-V)

Moxiclear Spot-on Solution

Norbrook Laboratories Spot-on Solution

GB National authorisation

Prescription only medicine to be authorised by a veterinarian (POM-V)

Ridaflea Solution

EU Pharmaceuticals Ltd

UK National authorisation

Authorised veterinary medicine for general sale (AVM-GSL)

Formulation and application details

Often formuated as spot-on products for topically application

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

610

High

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

67000

Dichloromethane

690

Toluene

100

n-Hexane

2300

2-Propanol

Melting point (°C)

144

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

230

Flashpoint (°C)

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

3.72 X 10⁰⁰

Calculated

Log P

0.57

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

1.54

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

Vapour pressure at 20 °C (mPa)

4.0 X 10^-07

Low volatility

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

1.7 X 10^-10

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

Negligible

24 hr

From soil surface

Negligible

24 hr

Maximum UV-vis absorption L mol⁻¹ cm⁻¹

212nm = 13346, 270nm = 22054

Surface tension (mN m⁻¹)

72.2

at 20°C

Refractive Index

Environmental release

Degradation

Property

Value

Source; quality score; and other information

Interpretation

Soil degradation (days) (aerobic)

DT₅₀ (typical)

191

Persistent

DT₅₀ (lab at 20 °C)

187

Persistent

DT₅₀ (field)

174

Persistent

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

577.9

Note

EU dossier lab studies DT₅₀ range 77-425 days, field studies DT₅₀ range 104-228 days, DT₉₀ range 345-717 days

Manure DT₅₀ (days)

Aqueous photolysis DT₅₀ (days) at pH 7

Value

0.2

Fast

Note

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

Value

Stable

Note

Stable pH 5 to pH 7, DT₅₀ approx 1 year at pH 9, all at 25 °C

Water-sediment DT₅₀ (days)

129

Slow

Water phase only DT₅₀ (days)

Stable

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

[Clementine: No residue decay after 32 days of cold storage; Field study]

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d (mL g⁻¹)

K_oc (mL g⁻¹)

Notes and range

Freundlich

K_f (mL g⁻¹)

2.23

Moderately mobile

K_foc (mL g⁻¹)

225

¹/_n

0.802

Notes and range

EU dossier K_f range 0.956-4.18, K_foc range 109-411 mL g⁻¹, ¹/_n range 0.744-0.888, Soils=12

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

3.69

Calculated

High leachability

Bio-concentration factor

BCF (l kg⁻¹)

0.61

Estimated

Low potential

CT₅₀ (days)

Not available

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

1-((6-chloro-3-pyridinyl)methyl)N-nitro-1H-imidazol-2-amine

Minor fraction

0.018

6-chloronicotinic acid (Ref: IC-0)

Minor fraction

Known groundwater metabolites

None

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

1-[(6-chloropyridin-3-yl)methyl]imidazolidin-2-imine

imidaclopric metabolite M09; NTN33893-desnitro

Plant; Animal

6-chloropyridine-3-carboxylic acid

imidaclopric metabolite M14

Plant

1[(6-Chloro-3-pyridinyl)methyl]-4,5-dihydro-2-(nitroamino)-1H-imidazol-4-ol

imidaclopric metabolite M02

Animal

[(6-Chloro-3-pyridinyl)methyl]-4,5-dihydro-2-(nitroamino)-1H-imidazol-5-ol

imidaclopric metabolite M01

Rat; Water; Plant

1-[(6-chloro-3-pyridinyl)methyl]-, oxohydrazone

imidaclopric metabolite M07; NTN33893-nitrosimine

Plant; Animal

1-[(6-chloropyridin-3-yl)methyl]imidazolidin-2-one

imidaclopric metabolite M12; NTN33893-urea

Plant; Animal

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

131

Mouse LD₅₀ (Rat) = 424 (F4)

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

> 13

Rat

High

(ppm diet)

> 120

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

> 50

Rat Reproductive NOAEL

Moderate

Birds - Acute LD₅₀ (mg kg⁻¹)

Coturnix japonica

High

Birds - Short term dietary (LC₅₀/LD₅₀)

Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)

9.3

Colinus virginianus NOAEL

High

Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)

10.7

Eisenia foetida

Moderate

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

>= 0.178

Eisenia foetida

Moderate

Soil micro-organisms

Nitrogen mineralisation: No significant adverse effect
Carbon mineralisation: No significant adverse effect

Dose: 2.25 kg ha⁻¹ 28 Day

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

> 100

Avena sativa Brassica rapa
Seedling emergence, ER₅₀
as mg kg⁻¹ soil

> 100

Avena sativa Brassica rapa
Vegetative vigour, ER₅₀
as mg kg⁻¹ soil

Honeybees (Apis spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

0.081

Apis mellifera

High

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

0.0037

Apis mellifera

High

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)

0.218

Bombus terrestris 72 hr

High

Literature DT₅₀ values range 0.014-0.554 µg bee⁻¹

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

0.038

Bombus terrestris 72 hr

High

Literature DT₅₀ values range 0.006-0.23 µg bee⁻¹

Mason bees (Osmia spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

0.031

Osmia bicornis

High

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)

0.17

Megachile rotundata

High

Mode of exposure

Contact

Other bee species (2)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

24.5

Scaptotrigona postica

Moderate

Mode of exposure

Oral

Beneficial insects (Ladybirds) as Mortlity LR₅₀ g ha⁻¹

11.38

Coccinella septempunctata Adult

Beneficial insects (Lacewings) as Mortality LR₅₀ g ha⁻¹

10.51

Chrysoperla carnea

Beneficial insects (Parasitic wasps) as Mortality LR₅₀ g ha⁻¹

0.022

Aphidius rhopalosiphi

Beneficial insects (Predatory mites) as Mortality LR₅₀ g ha⁻¹

4.23

Typhlodromus pyri

Beneficial insects (Ground beetles) as Mortality LR₅₀ g ha⁻¹

497

Poecilus cupreus

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

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

> 83

Oncorhynchus mykiss

Moderate

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

9.02

Oncorhynchus mykiss

Moderate

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

> 19.04

Danio rerio Juvenile

Moderate

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

Daphnia magna

Moderate

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

1.8

Daphnia magna

Moderate

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

72.1

Ceriodaphnia dubia

Moderate

Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)

0.034

Americamysis bahia

High

Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)

0.055

Chironomus riparius

High

Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l⁻¹)

> 0.0021

Chironomus riparius

High

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)

> 10

Scenedesmus subspicatus

Low

Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)

Scenedesmus subspicatus

Low

Mesocosm study data

NOEAEC mg l⁻¹

0.0006

Chironomids Batidae

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)

131

Mouse LD₅₀ (Rat) = 424 (F4)

Moderate

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

5000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 0.069

Rat 4 hr (aerosol)

Other Mammal toxicity endpoints

Intraperitoneal LD₅₀ = 35 mg kg⁻¹

Mouse

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

0.06

Rat SF=100

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

0.08

Dog 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)

0.08

Dog SF=100

Dermal penetration studies (%)

0.3-8.0

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

Acceptable for proposed uses

Occupational

Acceptable for proposed uses
Occupational exposure may occur through dermal contact

Mammalian dose elimination route and rate

In rats the major excretion route is via the urine, over 90% of dose eliminated in 24hrs.

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

No data found

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

Moderately toxic
Potential liver, kidney, thyroid, heart and spleen toxicant

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
IMDG Transport Hazard Class 6.1
Not expected to auto-ignite; Not highly flammable

CLP classification 2013

Health: H302
Environment: H400, H410

WHO Classification

II (Moderately hazardous)

UN Number

UN2588

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

imidacloprid

French

imidaclopride

German

Imidacloprid

Danish

imidacloprid

Italian

imidacloprid

Spanish

imidacloprid

Greek

Polish

imidachlopryd

Swedish

imidakloprid

Hungarian

imidaklorid

Dutch

imidacloprid

Norwegian

Record last updated:	24/10/2024
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