Beflubutamid (Ref: UBH 820)

Beflubutamid (Ref: UBH 820)	Last updated: 11/04/2025
(Also known as: UR-50601)

SUMMARY

Beflubutamid is a selective herbicide used to control broadleaved weeds in cereals. It has a low aqueous solubility and is quite volatile. There is a low risk of groundwater contamination and it is non-persistent in soil. However, it can be quite persistent in water bodies. It has a moderate oral toxicity to mammals and has been shown to cause reproduction or development issues in humans. It is moderately toxic to birds, earthworms and most aquatic organisms. It has a low toxicity to honeybees.

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: Drainflow: Slightly mobile; Potential for particle bound transport: Medium	Ecotoxicity Moderate alert: Fish acute ecotoxicity: Moderate; Fish chronic ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate; Daphnia chronic ecotoxicity: Moderate; Earthworms acute ecotoxicity: Moderate; Earthworms chronic ecotoxicity: Moderate	Human health High alert: Reproduction/development effects

GENERAL INFORMATION

Description

A phenoxy herbicide for pre- and early post-emergence control of broadleaved weeds

Example pests controlled

Chickweed; Loose silky bent; Field pansy; Scented mayweed; Wild pansy; Field speedwell; Ivy-leaved speedwell; Groundsel

Example applications

Cereals including wheat, barley, rye, triticale

Efficacy & activity

Efficacy established from ield trials and extensive use.

Availability status

Current

Introduction & key dates

1998, first registered USA

GB regulatory status

GB COPR regulatory status

Approved

Date COPR inclusion expires

31/07/2029

GB LERAP status

No data

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Germany/Lithuania

Date EC 1107/2009 inclusion expires

31/10/2026

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

A chiral molecule. The racemate mixture is comprised of equimolar amounts of R- and S-beflubutamid.

Chemical formula

C₁₈H₁₇F₄NO₂

Canonical SMILES

CCC(C(=O)NCC1=CC=CC=C1)OC2=CC(=C(C=C2)F)C(F)(F)F

Isomeric SMILES

CC[C@H](Oc1ccc(F)c(c1)C(F)(F)F)C(=O)NCc2ccccc2

International Chemical Identifier key (InChIKey)

FFQPZWRNXKPNPX-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C18H17F4NO2/c1-2-16(17(24)23-11-12-6-4-3-5-7-12)25-13-8-9-15(19)14(10-13)18(20,21)22/h3-10,16H,2,11H2,1H3,(H,23,24)

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance groups

Amide herbicide; Phenoxybutamide herbicide; Phenoxy herbicide

Minimum active substance purity

985 g/Kg

Known relevant impurities

EU dossier - none declared

Substance origin

Synthetic

Mode of action

Bleaching - Carotenoid biosynthesis inhibitor.

CAS RN

113614-08-7

EC number

601-267-1

CIPAC number

662

US EPA chemical code

Not listed

PubChem CID

6451159

CLP index number

616-165-00-2

Molecular mass

355.3

PIN (Preferred Identification Name)

rac-(2R)-N-benzyl-2-[4-fluoro-3-(trifluoromethyl)phenoxy]butanamide

IUPAC name

(RS)-N-benzyl-2-(α,α,α,4-tetrafluoro-m-tolyloxy)butyramide

CAS name

2-[4-fluoro-3-(trifluoromethyl)phenoxy]-N-(phenylmethyl)butanamide

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

Physical state

White fluffy powder

Related substances & organisms

beflubutamid-M

Formulations

Property

Value

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

Example products using this active

Herbaflex
Beflex

Formulation and application details

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

3.29

Low

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

600000

Acetone

571000

Ethyl acetate

473000

Methanol

2180

n-Heptane

Melting point (°C)

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

128

Flashpoint (°C)

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

1.91 X 10⁰⁴

Calculated

Log P

4.28

High

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

1.33

Dissociation constant pKa) at 25 °C

N/a

Unlikely to dissociate

Vapour pressure at 20 °C (mPa)

1.10 X 10^-02

Low volatility

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

9.40 X 10^-04

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 soln: 281.5nm=2621; Acidic soln: 281.5nm=2645; Basic soln: 281.5nm=2621

Surface tension (mN m⁻¹)

64.5

at 20 °C

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Not readily biodegradable

Soil degradation (days) (aerobic)

DT₅₀ (typical)

60.1

Moderately persistent

DT₅₀ (lab at 20 °C)

60.1

Moderately persistent

DT₅₀ (field)

21.0

Non-persistent

DT₉₀ (lab at 20 °C)

197

Persistent

DT₉₀ (field)

281

DT₅₀ modelling endpoint

Note

EU 2024 dossier lab studies DT₅₀ (normalised) range 4.6-1000 days, Soils=6; Field studies DT₅₀ (normalised) range 3.38-91.1 days, DT₉₀ (measured) range 34.9-765 days, Soils=6

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

Stable

Note

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

Value

Stable

Note

Stable at pH 5 to pH 9 for up to 30 days

Water-sediment DT₅₀ (days)

56.6

Moderately fast

Water phase only DT₅₀ (days)

5.91

Moderately fast

Sediment phase only DT₅₀ (days)

75.0

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

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)

23.6

Slightly mobile

K_foc (mL g⁻¹)

1213

¹/_n

0.908

Notes and range

EU 2024 dossier K_f 8.5-43.0 mL g⁻¹, K_foc range 496-1793 mL g⁻¹, ¹/_n 0.86-0.93, Soils=3

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

1.21

Calculated

Low leachability

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

Value

2.40 X 10^-02

Calculated

Note

Potential for particle bound transport index

Medium

Calculated

Potential for loss via drain flow

Slightly mobile

Calculated

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

3.5

Calculated using the Atkinson method, 12 hr

Below the level of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

140

whole fish

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

(RS)-2-(4-fluoro-3-trifluoromethylphenoxy)butanamide (Ref: UR-50624)

Minor fraction

0.067

(RS)-2-(4-fluoro-3-trifluoromethylphenoxy)butanoic acid (Ref: UR-50604)

Major fraction

0.370

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)

(RS)-2-(4-fluoro-3-trifluoromethylphenoxy)butanoic acid (Ref: UR-50604)

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

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)

> 5200 ppm

Colinus virginianus

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

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

366

corr

Moderate

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

< 2.5

Eisenia foetida corr

Moderate

Soil micro-organisms

Nitrogen transformation: No significant adverse effect

Dose: 0.8 mg kg⁻¹ soil

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

160

Folsomia candida corr

Non-target plants

14.8

Lactuca sativa
Vegetative vigour, ER₅₀
as g ha⁻¹

145

Lactuca sativa
Seedling emergence, ER₅₀
as g ha⁻¹

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)

> 100

Apis mellifera

Low

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

Chronic 10 day LD₅₀

> 199.2

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)

Beneficial insects (Lacewings) as LR₅₀ g ha⁻¹

> 255

Chrysoperla carnea Larva

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

> 255

Aphidius rhopalosiphi Adult

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

255

Typhlodromus pyri Protonymphs

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

> 255

Poecilus cupreus

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

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

1.86

Oncorhynchus mykiss

Moderate

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

0.11

Pimephales promelas

Moderate

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

> 4.4

Danio rerio

Moderate

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

1.64

Daphnia magna

Moderate

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

0.455

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)

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

0.06

Chironomus riparius

High

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

0.005

Lemna gibba

High

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

0.32

Myriophyllum spicatum

Moderate

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

0.0055

Pseudokirchneriella capricornutum

High

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)

> 5000

Rat

Low

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 5.0

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)

0.05

Rabbit SF=200

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

0.05

Rabbit SF=200

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

0.05

Rabbit SF=200

Dermal penetration studies (%)

100

default

Dangerous Substances Directive 76/464

List II

Exposure Routes

Public

Risks acceptable for intended uses

Occupational

Risks acceptable for intended 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)

Mammalian dose elimination route and rate

Extensively metabolised. Rapidly excreted within 248 hr mainly via urine and faeces

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

No data found

General human health issues

Possible liver, kidney and thyroid toxicant

Handling issues

Property

Value and interpretation

General

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

CLP classification 2013

Human: H361d, Environment: H400, H410

WHO Classification

Not listed (Not listed)

UN Number

UN3077

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

beflubutamid

French

beflubutamide

German

Beflubutamid

Danish

beflubutamid

Italian

beflubutamid

Spanish

beflubutamid

Greek

Polish

beflubutamid

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	11/04/2025
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