Clofentezine (Ref: NC 21314)

Clofentezine (Ref: NC 21314)	Last updated: 09/04/2025
(Also known as: bisclofentazin)

SUMMARY

Clofentazine is a selective insecticide used to control mites. It has a low aqueous solubility and is not volatile. It is moderately persistent in soil systems but tends not to be in aquatic systems. Based on its physico-chemical properties it is not expected to leach to groundwater. Clofentazine is highly toxic to birds and fish and moderately toxic to aquatic invertebrates, honeybees and earthworms. It has a low mammalian toxicity.

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 High alert: Potential for particle bound transport: High	Ecotoxicity High alert: Birds chronic ecotoxicity: High; Fish acute ecotoxicity: High; Fish chronic ecotoxicity: High	Human health Moderate alert: Mammals chronic toxicity: Moderate; Possible Carcinogen; Reproduction/development effects

GENERAL INFORMATION

Description

A selective ovicidal tetrazine acaricide for use in a range of crops including fruit and ornamentals

Example pests controlled

Spidermites (eggs and adults) including the two-spotted spider mite, European red mite, McDaniel spider mite

Example applications

Fruit including apples, pears, peaches, nectarines, raspberries, strawberries, citrus; Tomatoes; Aubergine; Ornamentals including nursery stock

Efficacy & activity

Efficacy has been established via development trials and commercial use over a number of years,

Availability status

Current

Introduction & key dates

2001, introduced

GB regulatory status

GB COPR regulatory status

Approved

Date COPR inclusion expires

31/12/2027

GB LERAP status

None

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Not approved

Dossier rapporteur/co-rapporteur

Spain/Netherlands

Date EC 1107/2009 inclusion expires

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

Also used in

Australia; USA; Morocco

Chemical structure

Isomerism

None

Chemical formula

C₁₄H₈Cl₂N₄

Canonical SMILES

C1=CC=C(C(=C1)C2=NN=C(N=N2)C3=CC=CC=C3Cl)Cl

Isomeric SMILES

International Chemical Identifier key (InChIKey)

UXADOQPNKNTIHB-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C14H8Cl2N4/c15-11-7-3-1-5-9(11)13-17-19-14(20-18-13)10-6-2-4-8-12(10)16/h1-8H

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
clofentezine	-

General status

Pesticide type

Acaricide; Insecticide

Substance groups

Tetrazine insecticide; Tetrazine acaricide

Minimum active substance purity

780 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Specific with contact action and long residual activity. Mite growth inhibitor affecting CHS1.

CAS RN

74115-24-5

EC number

277-728-2

CIPAC number

418

US EPA chemical code

125501

PubChem CID

73670

CLP index number

No data found

Molecular mass

303.15

PIN (Preferred Identification Name)

3,6-bis(2-chlorophenyl)-1,2,4,5-tetrazine

IUPAC name

3,6-bis(2-chlorophenyl)-1,2,4,5-tetrazine

CAS name

3,6-bis(2-chlorophenyl)-1,2,4,5-tetrazine

Other status information

Has been detected in Swedish air monitoring programmes.

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)

10A

Fungicide Resistance Class (FRAC MOA class)

Not applicable

Examples of recorded resistance

Panonychus ulmi, Tetranychus urticae

Physical state

Magenta crystals

Formulations

Property

Value

Example manufacturers & suppliers of products using this active now or historically

Adama
Makhteshim-Agan
Ypsilon SA
Scotts
FBC

Example products using this active

Apollo 50 SC
Vivaro
Panatac

Formulation and application details

Usually supplied as a soluble concentrate or wettable powder

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

0.0342

Low

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

9300

Acetone

5670

Ethyl acetate

490

Ethanol

5000

Xylene

Melting point (°C)

183

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

190

Flashpoint (°C)

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

1.23 X 10⁰⁴

Calculated

Log P

4.09

High

Fat solubility of residues

Solubility

Soluble

Data type

Regulatory data

Density (g ml⁻¹)

1.52

Dissociation constant pKa) at 25 °C

Unstable- cannot be determined

Vapour pressure at 20 °C (mPa)

6.0 X 10^-04

Low volatility

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

0.00536

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

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

Neutral solution 534.5nm = 465
Acidic solution: 526.3nm=636
Basic solution: 536.2=220

Surface tension (mN m⁻¹)

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Not readily biodegradable

Soil degradation (days) (aerobic)

DT₅₀ (typical)

69.8

Moderately persistent

DT₅₀ (lab at 20 °C)

69.8

Moderately persistent

DT₅₀ (field)

63.0

Moderately persistent

DT₉₀ (lab at 20 °C)

426

Very persistent

DT₉₀ (field)

209.7

DT₅₀ modelling endpoint

67.2

nomalised geometric mean

Note

EU 2018 dossier (not normalised) lab studies DT₅₀ range 16.9-133 days, DT₉₀ range 56->1000 days, field studies DT₅₀ range 52.9-71.3 days, DT₉₀ range 176-237 days, Soils=3

Dissipation rate RL₅₀ (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

Note

Aqueous photolysis DT₅₀ (days) at pH 7

Value

5.88

Moderately fast

Note

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

Value

3.1

Non-persistent

Note

Water-sediment DT₅₀ (days)

9.6

Fast

Water phase only DT₅₀ (days)

2.1

Moderately fast

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.

Decay in stored produce DT₅₀

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)

75.7

Non-mobile

K_foc (mL g⁻¹)

6303

¹/_n

0.87

Notes and range

EU 2018 dossier K_f range 40.2-245.9 mL g⁻¹. K_foc range 3753.7-17318.6 mL g⁻¹, ¹/_n range 079-0.97, Soils=4

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

0.36

Calculated

Low leachability

SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate

Value

8.41 X 10^-03

Calculated

Note

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

122.4

Calculated using the Atkinson method. Assumed 1.5E+06 OH/cm³, 12 hr

Substance of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

248

Threshold for concern

CT₅₀ (days)

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

2-chlorobenzoic acid (Ref: AE-C500233)

Major fraction

0.109

Adama verified data

hydrazide-hydrazone (Ref: AE C593600)

Major fraction

0.130

Adama verified data

1,2-di(2-chlorobenzylidene)hydrazine; 1,2-DCBH

Minor fraction

0.070

Adama verified data

1,2-di(2-chlorobenzylidene)hydrazine; 1,2-DCBH

Minor fraction (anaerobic)

0.076

Anaerobic; Adama verified data

2-chlorobenzoic acid (Ref: AE-C500233)

Major fraction (anaerobic)

0.153

Anaerobic; Adama verified data

2-chlorobenzonitrile

Major fraction (photolysis)

0.174

Photolysis; Adama verified data

Known groundwater metabolites

Metabolite

EC SANCO/221/2000 relevancy

ADI (mg kg⁻¹ bodyweight day⁻¹)

WHO drinking water guidance value (μg L⁻¹ day⁻¹)

2-chlorobenzonitrile

Relevancy unknown

hydrazide-hydrazone (Ref: AE C593600)

Relevancy unknown

2-chlorobenzoic acid (Ref: AE-C500233)

Relevancy unknown

1,2-di(2-chlorobenzylidene)hydrazine; 1,2-DCBH

Relevancy unknown

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

2-chlorobenzonitrile (Ref: AE F023666)

Plants

2-chlorobenzamide (Ref: AE F092117)

Plants

2-chlorobenzyl alcohol

Plant

4-hydroxy-clofentazine

Animal

3-hydroxy-clofentazine

Animal

5-hydroxy-clofentazine

Animal

di-hydro-clofentazine

NC 22505

Plant

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 5200

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat 2 yr

(ppm diet)

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

> 27.8

Unknown species Reproductive NOAEL

Moderate

Birds - Acute LD₅₀ (mg kg⁻¹)

> 6501

Anas platyrhynchos

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

> 4000 mg kg bw⁻¹ day⁻¹

Anas platyrhynchos

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

7.62

Colinus virginianus NOEC

High

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

> 215

Eisenia foetida corr

Moderate

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

2.0

Eisenia foetida

Moderate

Soil micro-organisms

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

Dose: 2.39 mg kg⁻¹ 28 Day

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

> 80

Folsomia candida corr

Non-target plants

Honeybees (Apis spp.)

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

> 84.5

Apis mellifera

Moderate

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

> 252.6

Apis mellifera

Low

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

Chronic

Notes

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)

41.7% Mortality at dose 100 g ha⁻¹

Coccinella septempunctata Larva

Beneficial insects (Lacewings)

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

36.2

Aphidius rhopalosiphi

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

> 300

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)

> 0.01

Oncorhynchus mykiss

High

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

0.007

Oncorhynchus mykiss 97 day

High

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

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

> 71.6

Daphnia magna

Moderate

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

0.05

Daphnia magna

Moderate

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

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

0.003

Americamysis bahia as 28 day NOEC

High

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

> 76.4

Chironomus riparius 48 hr

Moderate

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

0.37

Chironomus riparius

Moderate

Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg⁻¹)

0.5

Chironomus riparius

Moderate

Aquatic plants (free-floating, growth) - Acute 7 day EC₅₀, biomass (mg l⁻¹)

Aquatic plants (rooted, growth) - Acute 14 day EC₅₀, biomass (mg l⁻¹)

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

34.0

Selenastrum capricornutum

Low

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

Mesocosm study data

NOEAEC mg l⁻¹

Marine bivalves

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)

> 5200

Rat

Low

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

2100

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 5.2

Rat 4 hr (nose only)

Other Mammal toxicity endpoints

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

0.02

Rat SF=100

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

None allocated

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

None allocated

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

0.01

Rat SF=100

Dermal penetration studies (%)

2.1-19.9

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

No unacceptable risks to bystanders determined

Occupational

Potential risk to operators and other farm workers - PPE advised

MRLs

European

EU MRL pesticide database

Great Britain

GB MRL Register

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

0.01

EU Dir 89/778/EC limit; Calc MAC=0.06 µg l⁻¹

Mammalian dose elimination route and rate

80-90% in 48 hours almost complete by 96 hours

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

General human health issues

May reduce blood haemoglobin levels
Possible thyroid and liver toxicant
US EPA - possible human carcinogen

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
Not expected to auto-ignite; Not highly flammable

CLP classification 2013

Health: H312
Environment: H400, H412

WHO Classification

III (Slightly hazardous)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

clofentezine

French

clofentezine

German

Clofentezin

Danish

clofentezin

Italian

clofentezine

Spanish

clofentezin

Greek

Polish

chlofentezyna

Swedish

klofentezin

Hungarian

klofentezin

Dutch

clofentezin

Norwegian

Record last updated:	09/04/2025
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