Benfluralin (Ref: EL 110)

Benfluralin (Ref: EL 110)	Last updated: 22/08/2024
(Also known as: bethrodine; benfuraline; benefin; benthrodine; balan)

SUMMARY

Benfluralin is a pre-emergence herbicide. It has a low aqueous solubility and is quite volatile. It is not expected to leach to groundwater. It is moderately persistent in soil systems and not usually persistent in water. It has a low mammalian toxicity but there is concern regarding its potential to bioaccumulate. It is moderately toxic to birds, honeybees, earthworms and most aquatic organisms.

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

GENERAL INFORMATION

Description

A pre-emergence herbicide used for grass and other weed control in a range of edible and non-food crops

Example pests controlled

Johnssongrass; Chickweed; Lambsquarter; Purslane; Knotweed; Clover; Pigweed; Plantains

Example applications

Alfalfa; Turf; Lettuce; Some speciality crops including chicory; Ornamentals including Christmas trees; Non-bearing fruit and nut trees; Non-cropped areas such as rights-of-way, pavements, railways

Efficacy & activity

Shown to be affective in the field via many years of use across Europe and the world.

Availability status

Current

Introduction & key dates

1963, first registered USA

GB regulatory status

GB COPR regulatory status

Approved

Date COPR inclusion expires

28/02/2024

GB LERAP status

No data

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Not approved

Dossier rapporteur/co-rapporteur

Norway/Netherlands

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

Chemical structure

Isomerism

None

Chemical formula

C₁₃H₁₆F₃N₃O₄

Canonical SMILES

CCCCN(CC)C1=C(C=C(C=C1[N+](=O)[O-])C(F)(F)F)[N+](=O)[O-]

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

SMDHCQAYESWHAE-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C13H16F3N3O4/c1-3-5-6-17(4-2)12-10(18(20)21)7-9(13(14,15)16)8-11(12)19(22)23/h7-8H,3-6H2,1-2H3

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance groups

Dinitroaniline herbicide

Minimum active substance purity

960 g kg⁻¹

Known relevant impurities

EU dossier - ethyl-butyl-nitrosamine: < 0.085 mg kg⁻¹

Substance origin

Synthetic

Mode of action

Microtubule assembly inhibition

CAS RN

1861-40-1

EC number

217-465-2

CIPAC number

285

US EPA chemical code

084301

PubChem CID

2319

CLP index number

No data found

Molecular mass

335.28

PIN (Preferred Identification Name)

N-butyl-N-ethyl-2,6-dinitro-4-(trifluoromethyl)aniline

IUPAC name

N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine

CAS name

N-butyl-N-ethyl-2,6-dinitro-4-(trifluoromethyl)benzenamine

Other status information

OSPAR soc

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

Physical state

Colourless to yellow crystals depending on purity

Formulations

Property

Value

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

Sigma-Aldrich
Dow AgroSciences
Helena Chemical Co
Makhteshim Agan

Example products using this active

Bonalan
Carpidor
Benefex
Emblem
Balan

Formulation and application details

Often available as an emulsifiable concentrate that is mixed with water and used as a spray

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

0.064

Low

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

250000

Xylene

41000

Methanol

250000

Acetone

250000

Ethyl acetate

Melting point (°C)

66.4

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

205

Flashpoint (°C)

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

1.86 X 10⁰⁵

Calculated

Log P

5.27

High

Fat solubility of residues

Solubility

Soluble

Data type

Regulatory data - observed in metabolism and farm animal feeding studies

Density (g ml⁻¹)

1.42

Dissociation constant pKa) at 25 °C

-0.59

Very strong acid

Vapour pressure at 20 °C (mPa)

1.8

Low volatility. If applied directly to plants or soil, drift is a concern & mitigation is advisable

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

9.5

Moderately volatile

Volatilisation as max % of applied dose lost

From plant surface

16.8

24 hr

Volatilisation is not considered critical for air pollution

From soil surface

15.8

24 hr

Volatilisation is not considered critical for air pollution

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

Neutral solution: 239nm = 9180, 283nm = 8010
Acidic solution: 248nm = 4390, 298nm = 4580, 448nm = 3870
Basic solution: 238nm = 7550, 283nm = 6370, 431nm = 3720

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)

70.8

Moderately persistent

DT₅₀ (lab at 20 °C)

70.8

Moderately persistent

DT₅₀ (field)

39.9

Moderately persistent

DT₉₀ (lab at 20 °C)

305.3

Persistent

DT₉₀ (field)

201.5

DT₅₀ modelling endpoint

Note

EU 2022 dossier lab studies DT₅₀ (normalised) range 27.3-198 days, DT₉₀ (measured) range 105-675 days, Soils=6; Field studies DT₅₀ (normalised) range 32.4-46.1 days, DT₉₀ (measured) range 115-349 days, Soils=4

Dissipation rate RL₅₀ (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

61.6

Note

Turfgrass thatch, n=1

Aqueous photolysis DT₅₀ (days) at pH 7

Value

0.1

Fast

Note

Unstable in UV light

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

Value

Stable

Note

Stable pH 4 to pH 9

Water-sediment DT₅₀ (days)

3.1

Fast

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)

Non-mobile

K_oc (mL g⁻¹)

10777

Notes and range

EU 2008 dossier 8519-14400 mL g⁻¹; Other literature K_oc range 4000-10,700 mL g⁻¹

Freundlich

K_f (mL g⁻¹)

185.6

Non-mobile

K_foc (mL g⁻¹)

12770

¹/_n

1.1

Notes and range

EU 2022 dossier K_f range 129.6-272.7 mL g⁻¹, K_foc range 10736-14400 mL g⁻¹, ¹/_n range 1.06-1.14, Soils=3

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

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

Medium

Calculated

Potential for loss via drain flow

Non-mobile

Calculated

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

5.76

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

Below the level of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

CT₅₀ (days)

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

N2-butyl-N2-ethyl-3-nitro-5-(trifluoromethyl)-benzene-1,2-diamine (Ref: B36)

Major fraction

0.232

Anaerobic

1-ethyl-7-nitro-2-propyl-5-(trifluoromethyl)-1H-benzimidazole (Ref: 379R)

Major fraction

0.272

Anaerobic

2,6-dinitro-4-(trifluoromethyl)phenol

Minor fraction

0.05

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-dinitro-4-(trifluoromethyl)phenol

Not relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

3-nitro-5(trifluoromethyl)-1,2-benzenediamine (Ref: 358R)

des-alkylbenfluralin diamine

Water (Photolysis)

0.141

4-nitro-2-propyl-6-(trifluoromethyl)-1H-benzimidazole (Ref: 371R)

propyl benzimidazole

Water (Photolysis); Sediment

0.154

2-methyl-4-nitro-6-(trifluoromethyl)-1H-benzimidazole (Ref: 372R)

methyl benzimidazole

Water (Photolysis); Sediment

0.198

1-ethyl-7-nitro-2-prpyl-5-(trifluoromethyl)-1H-benzimidazole (Ref: 379R)

ethyl propyl benzimidazole; U6#1

Water (Photolysis); Sediment

0.151

N2-butyl-N2-ethyl-3-nitro-5-(trifluoromethyl)-benzene-1,2-diamine (Ref: B36)

benfluralin diamine

Sediment

N-butyl-N-ethylnitrous amide (Ref: EBNA)

ethyl-butyl-nitrosamine

Impurity

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)

0.5

Rat

High

(ppm diet)

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

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2000

Colinus virginianus

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

> 5000 mg kg feed⁻¹

Colinus virginianus

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

6.7

Colinus virginianus

High

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

> 500

Eisenia foetida corr

Moderate

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

15.4

Eisenia foetida 56 day corr

Moderate

Soil micro-organisms

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

Dose: 45 l product ha⁻¹ 28 Day

Collembola

Acute LC₅₀ (mg kg⁻¹)

Folsomia candida corr

Chronic NOEC (mg kg⁻¹)

5.5

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)

> 110.7

Apis mellifera

Low

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)

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)

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

> 1673

Chrysoperla carnea Larva

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

< 83.6

Aphidius rhopalosiphi

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

> 1673

Typhlodromus pyri

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

> 1673

Poecilus cupreus

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

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

0.081

Oncorhynchus mykiss

High

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

0.0019

Oncorhynchus mykiss

High

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

> 1.57

Danio rerio

Moderate

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

> 0.034

Daphnia magna

High

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

0.046

Daphnia magna

Moderate

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

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

0.043

Americamysis bahia

High

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

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

0.231

Chironomus riparius

Moderate

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

0.112

Chironomus riparius

Moderate

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

> 0.032

Lemna gibba

Moderate

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

> 100

Pseudokirchneriella subcapitata

Low

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

Mesocosm study data

NOEAEC mg l⁻¹

Marine bivalves – Acute EC₅₀ development (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)

5000

Rabbit

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 2.16

Rat (dust nose only)

Other Mammal toxicity endpoints

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

0.005

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)

0.1

Rabbit SF=500

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

0.011

Rat SF=500

Dermal penetration studies (%)

2-11

concentration dependent

Dangerous Substances Directive 76/464

List II

Exposure Routes

Public

Negligible risk to bystanders

Occupational

PPE/PPC required for operators and 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

Elimination within 48 hr via approx. 73% faecal, 18% urine and 10% bile

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

Possible liver, thyroid and kidney toxicant
US EPA - some evidence of carcinogenicity but weak; CLP data - suspected carcinogen

Handling issues

Property

Value and interpretation

General

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

CLP classification 2013

Health: H351, H315, H317, H319, H371
Environment: H400, H410

WHO Classification

U (Unlikely to present an acute hazard)

UN Number

UN3077

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

benfluralin

French

benfluraline

German

Benfluralin

Danish

benfluralin

Italian

benfluralin

Spanish

benfluralina

Greek

Polish

benfluralina

Swedish

Hungarian

benfluralin

Dutch

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