Diflufenican (Ref: AE 088657)

Diflufenican (Ref: AE 088657)	Last updated: 01/11/2024
(Also known as: diflufenicanil; DFF)

SUMMARY

Diflufenican is a grasses and broad-leaved weed herbicide. It has a low aqueous solubility and a low volatility. It may be moderately persistent in soil systems depending on local conditions. It can also be very persistent in aquatic systems depending on local conditions. Based on its physico-chemical properties it is not expected to leach to groundwater. It demonstrates a high toxicity to algae, a moderate toxicity to other aquatic organisms, birds and earthworms. It has a low toxicity to honeybees. Diflufenican also has a low toxicity to mammals if ingested and is thought to be an eye irritant.

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

GENERAL INFORMATION

Description

A herbicide used to control grasses and broad-leaved weeds often used in mixtures

Example pests controlled

Wild radish; Hedge mustard; Charlock; Prickly lettuce; Chickweed; Loosestrife; Stinging nettles

Example applications

Clover-based pastures; Field peas; Lentils; Lupins; Winter cereals; Soybeans; Corn

Efficacy & activity

Efficacy demonstrated from extensive use and field trials

Availability status

Current

Introduction & key dates

1985, first reported

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

31/12/2027

UK LERAP status

Possible - check label

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Czech Republic

Date EC 1107/2009 inclusion expires

15/01/2026

EU Candidate for substitution (CfS)

Yes - two 'Persistent-Bioaccumulative-Toxic' criteria

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

C₁₉H₁₁F₅N₂O₂

Canonical SMILES

C1=CC(=CC(=C1)OC2=C(C=CC=N2)C(=O)NC3=C(C=C(C=C3)F)F)C(F)(F)F

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

WYEHFWKAOXOVJD-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C19H11F5N2O2/c20-12-6-7-16(15(21)10-12)26-17(27)14-5-2-8-25-18(14)28-13-4-1-3-11(9-13)19(22,23)24/h1-10H,(H,26,27)

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
diflufenican	-

General status

Pesticide type

Herbicide

Substance groups

Carboxamide herbicide; Anilide herbicide; Pyridine herbicide

Minimum active substance purity

970 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Selective contact and residual action. Bleaching - Carotenoid biosynthesis inhibitor.

CAS RN

83164-33-4

EC number

617-446-2

CIPAC number

462

US EPA chemical code

PubChem CID

91735

CLP index number

616-032-00-9

Molecular mass

394.29

PIN (Preferred Identification Name)

N-(2,4-difluorophenyl)-2-[3-(trifluoromethyl)phenoxy]pyridine-3-carboxamide

IUPAC name

2',4'-difluoro-2-(α,α,α-trifluoro-m-tolyloxy)nicotinanilide

CAS name

N-(2,4-difluorophenyl)-2-[3-(trifluoromethyl)phenoxy]-3-pyridinecarboxamide

Other status information

Relevant Environmental Water Quality Standards

Herbicide Resistance Class (HRAC MoA class)

Herbicide Resistance Class (WSSA MoA class)

Insecticide Resistance Class (IRAC MoA class)

Not applicable

Fungicide Resistance Class (FRAC MOA class)

Not applicable

Examples of recorded resistance

Raphanus raphanistrum

Physical state

Colourless crystals

Formulations

Property

Value

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

Bayer CropScience
DuPont
Headland
Makhteshim-Agan
Nufarm UK
Sipcam

Example products using this active

Absolute
Ardent
Bacara
Firebird
Graduate
Ingot
Javelin Gold
Hurricane SC
Othello
Pelican
Regatta
Herold SC600
AG-D1-500
Alliance

Formulation and application details

Often supplied as a soluble concentrate which is mixed with water and applied as a spray

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

0.05

Low

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

4700

Methanol

65300

Ethyl acetate

72200

Acetone

114000

Dichloromethane

Melting point (°C)

159.5

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

304.6

Flashpoint (°C)

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

1.58 X 10⁰⁴

Calculated

Log P

4.2

High

Fat solubility of residues

Solubility

Soluble

Data type

Regulatory data - observed in metabolism and farm animal feeding studies

Density (g ml⁻¹)

1.54

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

4.25 X 10^-03

at 25 °C

Low volatility

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

1.18 X 10^-02

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

0.3

Volatilisation is not considered critical for air pollution

From soil surface

0.01

Volatilisation is not considered critical for air pollution

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

205.5nm = 35616, 282.5nm = 11155, 292.5nm = 9402

Surface tension (mN m⁻¹)

71.46

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Not readily biodegradable

Soil degradation (days) (aerobic)

DT₅₀ (typical)

94.5

Moderately persistent

DT₅₀ (lab at 20 °C)

94.5

Moderately persistent

DT₅₀ (field)

166.6

Persistent

DT₉₀ (lab at 20 °C)

416.12

Very persistent

DT₉₀ (field)

540.8

DT₅₀ modelling endpoint

94.5

normalised geometric mean

Note

EU 2018 dossier lab studies DT₅₀ (normalised) range 41.4-318 days, DT₉₀ (measured) range 138-1050 days Soils=17; Field studies DT₅₀ range 264.6-571.0 days, DT₉₀ range 127-1900 days, Soils=9

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

133

Stable

Note

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

Value

Stable

Note

Stable pH 5 to pH 9 over 30 days

Water-sediment DT₅₀ (days)

175

Slow

Water 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)

134.3

Non-mobile

K_oc (mL g⁻¹)

5504

Notes and range

EU 2018 dossier kd range 50.96-210.93 mL g⁻¹, K_oc range 3841-6598 mL g⁻¹, Soils=8

Freundlich

K_f (mL g⁻¹)

65.9

Slightly mobile

K_foc (mL g⁻¹)

2215

¹/_n

0.87

Notes and range

EU 2018 dossier K_f range 7.87-267.51 mL g⁻¹, K_foc range 1531.6-7431 mL g⁻¹, ¹/_n range 0.68-1.0, Soils=18

pH sensitivity

Yes

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

1.45

Calculated

Low leachability

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

Value

3.89 X 10^-02

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

120

Calculated using the Atkinson method. EU method.

Substance of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

1276

Threshold for concern

CT₅₀ (days)

2.4

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

2-(3-trifluoromethylphenoxy)nicotinamide (Ref: AE-0542291)

Major fraction

0.263

Bayer verified

2-(3-trifluoromethylphenoxy)nicotinic acid (Ref: AE-B107137)

Major fraction

0.662

Bayer verified

2-(3-trifluoromethylphenoxy)nicotinic acid (Ref: AE-B107137)

Major fraction

0.191

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-(3-trifluoromethylphenoxy)nicotinic acid (Ref: AE-B107137)

Not relevant

Other known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 5000

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat 2 yr

(ppm diet)

> 40

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

35.5

Rat Reproductive NOAEL

Moderate

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2150

Colinus virginianus

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

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

91.84

Colinus virginianus NOAEL

Moderate

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

> 500

Eisenia foetida corr

Moderate

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

> 500

Eisenia foetida corr

Low

Soil micro-organisms

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

Dose: Not given

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

5000

Folsomia candida corr

Non-target plants

Honeybees (Apis spp.)

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

> 100

Apis mellifera

Low

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

> 107.4

Apis mellifera

Low

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

> 113

Apis mellifera

Bumblebees (Bombus spp.)

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

> 100

Bombus terrestris

Low

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

> 122

Bombus terrestris

Low

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)

Beneficial insects (Lacewings)

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

> 250

Aphidius rhopalosiphi

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

> 250

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)

> 0.099

Cyprinus carpio

Moderate

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

0.015

Oncorhynchus mykiss

Moderate

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

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

> 0.24

Daphnia magna

Moderate

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

0.052

Daphnia magna

Moderate

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

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

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

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

0.0124

Chironomus riparius

Moderate

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

2.0

Chironomus riparius

Moderate

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

0.056

Lemna gibba

Moderate

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

0.00025

Scenedesmus subspicatus

High

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

0.0001

Scenedesmus subspicatus

High

Mesocosm study data

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)

> 5000

Rat

Low

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 5.12

Rat 4 hr (whole body)

Other Mammal toxicity endpoints

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

0.2

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)

0.11

Rat SF=100

Dermal penetration studies (%)

0.15-5.0

concentration dependent

Dangerous Substances Directive 76/464

List II

Exposure Routes

Public

Negligible risks for bystanders

Occupational

No significant risks identified for operators or other farm workers

MRLs

European

EU MRL pesticide database

Great Britain

GB MRL Register

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

Mammalian dose elimination route and rate

Mainly via faeces, urine and bile to a lesser extent.

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

Eye irritant

Phototoxicant

General human health issues

No further information available

Handling issues

Property

Value and interpretation

General

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

CLP classification 2013

Environment: H412

WHO Classification

III (Slightly hazardous)

UN Number

Not regulated

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

Chemically stable under standard ambient conditions

TRANSLATIONS

Language

Name

English

diflufenican

French

diflufenican

German

Diflufenican

Danish

diflufenican

Italian

diflufenican

Spanish

diflufenican

Greek

diflufenican

Polish

diflufenikan

Swedish

diflufenikan

Hungarian

Dutch

diflufenican

Norwegian

diflufenikan

Record last updated:	01/11/2024
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