Diflubenzuron (Ref: OMS 1804)

Diflubenzuron (Ref: OMS 1804)	Last updated: 22/08/2024
(Also known as: DFB; difluron; ENT 29054)

SUMMARY

Diflubenzuron is a urea-derived insecticide. It has a low aqueous solubility and is volatile. Based on its chemical properties, it is not expected to leach to groundwater. It is not persistent in soils but can be in water in some circumstances. It has a low mammalian toxicity. It is moderately toxic to fish, honeybees and earthworms but more toxic to aquatic invertebrates. Diflubenzuron is relatively non-toxic to birds and algae

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: Potential for particle bound transport: Medium	Ecotoxicity High alert: Daphnia acute ecotoxicity: High; Daphnia chronic ecotoxicity: High	Human health High alert: Endocrine disrupter

GENERAL INFORMATION

Description

A persistent urea derivative insecticide used to control a wide range of leaf-eating insects

Example pests controlled

Scararid flies; Armyworms; Leafminers, Whiteflies; Termites; Fungus gnats; Shore flies

Example applications

Ornamentals in greenhouses, shadehouses and commercial structures; Building protection from termite colonies; Fruit

Efficacy & activity

Efficiacy has been shown via extensive use.

Availability status

Current

Introduction & key dates

1972, first reported; 1975, first introduced

UK regulatory status

UK COPR regulatory status

Not approved

Date COPR inclusion expires

Expired

UK LERAP status

Possible - check label

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Not approved

Dossier rapporteur/co-rapporteur

Greece/Slovakia

Date EC 1107/2009 inclusion expires

Expired

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

C₁₄H₉ClF₂N₂O₂

Canonical SMILES

C1=CC(=C(C(=C1)F)C(=O)NC(=O)NC2=CC=C(C=C2)Cl)F

Isomeric SMILES

International Chemical Identifier key (InChIKey)

QQQYTWIFVNKMRW-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C14H9ClF2N2O2/c15-8-4-6-9(7-5-8)18-14(21)19-13(20)12-10(16)2-1-3-11(12)17/h1-7H,(H2,18,19,20,21)

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
diflubenzuron	-

General status

Pesticide type

Insecticide, Other substance

Other bioactivity & uses

Chemosterilant

Substance groups

Benzoylphenylurea herbicide; Benzoylurea herbicde; Urea herbicide

Minimum active substance purity

950 g kg⁻¹

Known relevant impurities

EU dossier: 4-chloroaniline

Substance origin

Synthetic

Mode of action

Selective, non-systemic with contact and stomach action, acts by inhibiting chitin synthesis. Inhibitor of chitin biosynthesis affecting CHS1.

CAS RN

35367-38-5

EC number

252-529-3

CIPAC number

339

US EPA chemical code

108201

PubChem CID

37123

CLP index number

No data found

Molecular mass

310.68

PIN (Preferred Identification Name)

N-[(4-chlorophenyl)carbamoyl]-2,6-difluorobenzamide

IUPAC name

1-(4-chlorophenyl)-3-(2,6-difluorobenzoyl)urea

CAS name

N-(((4-chlorophenyl)amino)carbonyl)-2,6-difluorobenzamide

Other status information

Relevant Environmental Water Quality Standards

UK Environment Agency non-statutory standard for the protection of aquatic life in freshwater annual average 0.001 µg l⁻¹, max acceptable conc 0.015 µg l⁻¹
UK Environment Agency non-statutory standard for the protection of aquatic life in saltwater annual average 0.005 µg l⁻¹, max acceptable conc 0.01 µg l⁻¹

Herbicide Resistance Class (HRAC MoA class)

Not applicable

Herbicide Resistance Class (WSSA MoA class)

Not applicable

Insecticide Resistance Class (IRAC MoA class)

Fungicide Resistance Class (FRAC MOA class)

Not applicable

Examples of recorded resistance

Cydia pomonella, Plutella xylostella, Spodoptera littoralis, Lucilia cuprina, Spodoptera exigua

Physical state

White crystalline solid

Formulations

Property

Value

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

Certis
Chemtura
Duphar
BOC Sciences

Example products using this active

Dimilin Flo
Dimilin WG-80
Astonex

Formulation and application details

Supplied in a variety of formulations including wettable powders, oil-dispersable concentrates and granules

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

0.08

Low

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

6980

Acetone

n-Hexane

290

Toluene

1100

Methanol

Melting point (°C)

227.6

Boiling point (°C)

Decomposes before boiling at normal pressure

Degradation point (°C)

Flashpoint (°C)

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

7.76 X 10⁰³

Calculated

Log P

3.89

High

Fat solubility of residues

Solubility

Soluble

Data type

Regulatory data - observed in metabolism and farm animal feeding studies

Density (g ml⁻¹)

1.57

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

0.00012

Low volatility

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

4.70 X 10^-04

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

Negligible

From soil surface

Negligible

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

In acetonitrile 257nm = 15148, 290nm = 10500

Surface tension (mN m⁻¹)

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

Non-persistent

DT₅₀ (lab at 20 °C)

3.2

Non-persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀ range 2.0-6.7 days

Dissipation rate RL₅₀ (days) on plant matrix

Value

14.9

Note

Published literature RL₅₀ range 7.9-23.7 days, 3 field crops, various matrices, n=3

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

11.7

Note

Published literature RL₅₀ range 2.8-21.0 days, 4 field & undercover grown crops, various matrices, n=4

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Stable

Note

Not a significant degradation route

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

Value

Moderately persistent

Note

Stable pH 5 to pH 7, some hydrolysis at pH 9

Water-sediment DT₅₀ (days)

4.5

Fast

Water phase only DT₅₀ (days)

3.0

Moderately fast

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)

65.2

Non-mobile

K_foc (mL g⁻¹)

4620

¹/_n

1.1

Notes and range

EU dossier K_f range 34.2-97.7 mL g⁻¹, K_foc range 1983-6918 mL g⁻¹, ¹/_n range 0.97-1.22, Soils=4

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

0.17

Calculated

Low leachability

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

Value

1.26 X 10^-03

Calculated

Note

Potential for particle bound transport index

Medium

Calculated

Potential for loss via drain flow

Non-mobile

Calculated

Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk

3.08

Calculated using the Atkinson method

Below the level of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

320

(Other literature Log BCF range 2.9-3.6 (R3))

Threshold for concern

CT₅₀ (days)

0.6

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

4-chlorophenylurea

Major fraction

0.308

2,6-difluorobenzoic acid

Major fraction

0.133

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)

2,6-difluorobenzoic acid

Not relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

4-chloroacetanilide

PCAA

Animal

2,6-difluorobenzamide

DFBAM

Rat; Animal (Milk)

4-chloroaniline
Note: Mutagenic

PCA

Plant; Animal

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 4640

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

(ppm diet)

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

> 3200

Unknown species Reproductive NOAEL

Low

Birds - Acute LD₅₀ (mg kg⁻¹)

> 5000

Colinus virginianus

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

> 1206 mg kg bw⁻¹ day⁻¹

Colinus virginianus

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

42.7

Colinus virginianus NOEC

Moderate

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

> 500

Eisenia foetida corr

Moderate

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

500

Eisenia foetida 56 day corr

Low

Soil micro-organisms

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

Dose: 0.75 kg ha⁻¹

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

0.165

Folsomia candida corr

Non-target plants

Honeybees (Apis spp.)

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

> 74.2

Apis mellifera

Moderate

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

> 9.1

Apis mellifera

Moderate

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

Chronic as 10-day LDD₅₀ µg bee⁻¹ day⁻¹

> 175

Apis mellifera

Bumblebees (Bombus spp.)

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

0.1

Bombus terrestris

High

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

> 1.46

Bombus terrestris

Moderate

Literature DT₅₀ values range 0.06- 5.11 µg bee⁻¹ depending upon exposure time, 1-7 days

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) as Mortality LR₅₀ g ha⁻¹

168

Coccinella septempunctata Larva

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

1.3

Chrysoperla carnea Lifecycle

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

> 144

Aphidius rhopalosiphi Adult

Beneficial insects (Predatory mites) as Mortality LR₅₀ g.ha

> 144

Typhlodromus pyri Protonymph

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)

> 0.13

Oncorhynchus mykiss

Moderate

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

0.2

Oncorhynchus mykiss

Moderate

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

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

0.0026

Daphnia magna

High

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

0.00004

Daphnia magna

High

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

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

0.0021

Americamysis bahia

High

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

0.026

Chironomus crassicaudatus 5 day

High

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

> 0.0004

Chironomidae

High

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

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

> 0.19

Lemna gibba

Moderate

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

Pseudokirchneriella subcapitata

Low

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

Unknown species

Moderate

Mesocosm study data

NOEAEC mg l⁻¹

0.00007

Zooplankton EAC

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)

> 4640

Rat

Low

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

2000

Rabbit

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 2.5

Rat 4 hr (nose only dust)

Other Mammal toxicity endpoints

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

0.1

Dog 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)

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

None allocated

Dermal penetration studies (%)

0.2-13

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

No unacceptable risks identified

Occupational

Acceptable risks for proposed uses - PPE/PPC advised

MRLs

European

EU MRL pesticide database

Great Britain

GB MRL Register

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

0.1

EU Dir 89/778/EC limit; Calc MAC=60 µg l⁻¹

Mammalian dose elimination route and rate

Excreted mainly via the faeces.

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

Eye irritant

Phototoxicant

General human health issues

Reported to cause methaemoglobinaemia
Endocrine issues - Pregnane X cellular receptor activation
Possible liver & spleen toxicant

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
IMDG Transport Hazard Class 9
Not expected to auto-ignite; Not highly flammable

CLP classification 2013

Health: H302, H312, H332, H373
Environment: H400, H410

WHO Classification

III (Slightly hazardous)

UN Number

UN3077

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

Stable under normal conditions of use. Limited shelf-life.

TRANSLATIONS

Language

Name

English

diflubenzuron

French

diflubenzuron

German

Diflubenzuron

Danish

diflubenzuron

Italian

diflubenzuron

Spanish

diflubenzuron

Greek

Polish

diflubenzuron

Swedish

diflubensuron

Hungarian

diflubenzuron

Dutch

diflubenzuron

Norwegian

Record last updated:	22/08/2024
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