Bromoxynil-butanoate

Bromoxynil-butanoate	Last updated: 22/08/2024
(Also known as: bromoxynil butyrate)

SUMMARY

A herbicide for post-emergence weed control. It has a low aqueous solubility and a low volatility. There is a low potential for leaching to groundwater based on its chemical properties. It is not expected to be persistent in soil or water systems. It is moderately toxic via the oral route to mammals, is an endocrine disrupting chemical and a skin sensitiser. It is highly toxic to fish but less so to other aquatic and terrestrial biodiversity.

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 Low alert: Non-persistent; Potential for particle bound transport: Low Warning: Significant data are missing	Ecotoxicity High alert: Fish acute ecotoxicity: High; Fish chronic ecotoxicity: High	Human health High alert: Endocrine disrupter; Reproduction/development effects

GENERAL INFORMATION

Description

An HBN herbicide used for post-emergence control of annual broad-leaved weeds

Example pests controlled

Ragweed; Smartweed; Nightshade; Kochia; Wild mustard

Example applications

Alfalfa; Garlic; Corn; Sorghum; Cereals including wheat, barley; Turf; Non-cropped areas including rights-of-way, pathways

Efficacy & activity

Efficacy proven from prolonged use in the EU and from experimental studies

Availability status

Current

Introduction & key dates

circa 1980, introduced

GB regulatory status

GB COPR regulatory status

Phasing out

Date COPR inclusion expires

Expired

GB LERAP status

Check label - may vary with formulation

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Not approved

Dossier rapporteur/co-rapporteur

France/Germany

Date EC 1107/2009 inclusion expires

Expired

EU Candidate for substitution (CfS)

Listed in EU database

Yes (as bromoxynil)

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, Latin America, USA

Chemical structure

Isomerism

None

Chemical formula

C₁₁H₉Br₂NO₂

Canonical SMILES

CCCC(=O)OC1=C(C=C(C=C1Br)C#N)Br

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

PGMZYNZXIYOOHJ-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C11H9Br2NO2/c1-2-3-10(15)16-11-8(12)4-7(6-14)5-9(11)13/h4-5H,2-3H2,1H3

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
bromoxynil	Parent

General status

Pesticide type

Herbicide

Substance groups

Hydroxybenzonitrile herbicide; Nitrile herbicide

Minimum active substance purity

967 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Select contact action with some systemic activity. Inhibits photosynthesis (photosystem II).

CAS RN

3861-41-4

EC number

223-374-9

CIPAC number

87.403

US EPA chemical code

035303

PubChem CID

62526

CLP index number

608-006-00-0

Molecular mass

347.0

PIN (Preferred Identification Name)

2,6-dibromo-4-cyanophenyl butanoate

IUPAC name

2,6-dibromo-4-cyanophenyl butyrate

CAS name

2,6-dibromo-4-cyanophenyl butanoate

Other status information

Potential marine pollutant

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

Light beige coloured powdery solid

Related substances & organisms

bromoxynil

bromoxynil-heptanoate

bromoxynil-octanoate

bromoxynil-potassium

Formulations

Property

Value

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

Example products using this active

Dragonmate Broadleaf Herbicide
Buctril

Formulation and application details

Spray application

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

5.4

Low

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

70000

Ethanol

23000

n-Hexane

600000

Toluene

600000

Acetone

Melting point (°C)

Boiling point (°C)

353

Degradation point (°C)

320

Flashpoint (°C)

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

7.24 X 10⁰³

Calculated

Log P

3.86

High

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

Vapour pressure at 20 °C (mPa)

0.28

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

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

1.80 X 10^-02

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

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

In methanol: 213nm= 48122, 283nm=723, 294nm=633

Surface tension (mN m⁻¹)

68.60

at 20 °C 97.6%

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

0.58

Non-persistent

DT₅₀ (lab at 20 °C)

0.58

Non-persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

1.99

Non-persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU 2017 dossier lab studies DT₅₀ range 0.5-0.67 days, DT₉₀ range 1.69-2.29 days, Soils =2

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

0.12

Fast

Note

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

Value

Moderately persistent

Note

DT₅₀: pH 4: 44 days; pH 9: 1.1 days

Water-sediment DT₅₀ (days)

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)

K_oc (mL g⁻¹)

Notes and range

Freundlich

K_f (mL g⁻¹)

K_foc (mL g⁻¹)

¹/_n

Notes and range

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

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

Value

Cannot be calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Calculated

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

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

bromoxynil (Ref: ENT 20852)

Major fraction

0.379

3,5-di-bromo-4-hydroxybenzamide

Major fraction

0.150

3,5-di-bromo-4-hydroxybenzoic acid

Minor fraction

0.057

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)

bromoxynil (Ref: ENT 20852)

Relevant

0.003

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

2,6-dibromohydroquinone glucoside

Plant

2-Bromo-4-cyanophenyl octanoate

Surface water; Sediment

3,4-Dihydroxybenzonitrile

Surface water; Sediment

3,5-di-bromo-4-hydroxybenzamide

Plant; Surface water; Sediment

3,5-di-bromo-4-hydroxybenzoic acid

Mammal; Plant

3,5-Dibromo-4-hydroxyphenyl D-glucopyranoside

3-Bromo-4,5-dihydroxybenzonitrile

Surface water; Sediment

3-Bromo-4-hydroxybenzonitrile

Surface water; Sediment

4-Hydroxybenzonitrile

Surface water; Sediment

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

116

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

(ppm diet)

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

Birds - Acute LD₅₀ (mg kg⁻¹)

420

Colinus virginianus

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

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

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

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

2.3

Eisenia foetida EC10 corr

Moderate

Soil micro-organisms

Nitrogen mineralisation: Low, transient effect

Dose: 2.57 mg kg⁻¹ 28 Day

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

125

Folsomia candida

Non-target plants

Honeybees (Apis spp.)

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

199

Apis mellifera unknown test duration

Low

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

76.4

Apis mellifera unknown test duration

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

14.5

Apis mellifera as bromoxynil

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)

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

Aphidius rhopalosiphi as octanate

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

9.47

Typhlodromus pyri as octanate

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

> 655

Poecilus cupreus

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

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

0.032

Oncorhynchus mykiss

High

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

0.008

Pimephales promelas

High

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

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

0.208

Daphnia magna

Moderate

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

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)

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

0.15

Lemna gibba

Moderate

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

0.75

Navicula pelliculosa 96 hr

Moderate

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)

116

Rat

Moderate

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

1.217

Rat

Other Mammal toxicity endpoints

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

0.003

as bromoxynil

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

0.013

as bromoxynil

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

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

0.003

as bromoxynil

Dermal penetration studies (%)

Dangerous Substances Directive 76/464

Exposure Routes

Public

Minimal risk from dietary exposure
Risk assessment indicates ARfD would not normally be execeeded

Occupational

MRLs

European

EU MRL pesticide database

Great Britain

GB MRL Register

Notes

GB MRL expected to deviate from the EU MRL in mid-2023

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

Mammalian dose elimination route and rate

Almost completely eliminated as bromoxynil phenol within 7 days via the urine

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 toxicant

Handling issues

Property

Value and interpretation

General

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

CLP classification 2013

Health: H301, H317, H319, H332, H360d
Environment: H400, H410

WHO Classification

II (Moderately hazardous)

UN Number

UN3082

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

bromoxynil-butanoate

French

German

Danish

Italian

Spanish

Greek

Polish

Swedish

Hungarian

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