Bromoxynil-octanoate

Bromoxynil-octanoate	Last updated: 11/04/2025
(Not known by any other names)

SUMMARY

A widely used herbicide for post-emergence 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 and aquatic invertebrates 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 Moderate alert: Potential for particle bound transport: Medium	Ecotoxicity High alert: Fish acute ecotoxicity: High; Fish chronic ecotoxicity: High; Daphnia acute ecotoxicity: High; Daphnia chronic ecotoxicity: High	Human health High alert: Endocrine disrupter

GENERAL INFORMATION

Description

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

Example pests controlled

Annual sowthistle; Mustard; Cocklebur; Pennycress; Ragweed; Groundsel; Henbit; Russian thistle; Velvetleaf; Morning glory; Lambsquarter; Kochia; Wild buckweed

Example applications

Cereals including wheat, barley, oats, rye; Flax; Sweetcorn; Field corn; Onions & garlic; Turf

Efficacy & activity

Efficacy has been proven via prolonged use in the EU and via 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

C₁₅H₁₇Br₂NO₂

Canonical SMILES

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

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

DQKWXTIYGWPGOO-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C15H17Br2NO2/c1-2-3-4-5-6-7-14(19)20-15-12(16)8-11(10-18)9-13(15)17/h8-9H,2-7H2,1H3

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

945 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

1689-99-2

EC number

216-885-3

CIPAC number

87.407

US EPA chemical code

035302

PubChem CID

15533

CLP index number

608-006-00-0

Molecular mass

403.10

PIN (Preferred Identification Name)

2,6-dibromo-4-cyanophenyl octanoate

IUPAC name

2,6-dibromo-4-cyanophenyl octanoate

CAS name

2,6-dibromo-4-cyanophenyl octanoate

Other status information

Marine Pollutant; PAN Bad Actor Chemical

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

Fine white powder

Related substances & organisms

bromoxynil

bromoxynil-butanoate

bromoxynil-heptanoate

bromoxynil-potassium

Formulations

Property

Value

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

Bayer CropScience
Makhteshim-Agan
Nufarm

Example products using this active

Alpha Briotril 24/16
Biotril Plus 19/19
Bromolin 225 EC
Flagon 400EC
Oxytril CM
Stellox

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)

0.05

Low

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

1215000

Acetone

847000

Ethyl acetate

207000

Methanol

813000

Toluene

Melting point (°C)

45.3

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

180

Flashpoint (°C)

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

1.58 X 10⁰⁶

Calculated

Log P

6.2

High

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

1.638

Dissociation constant pKa) at 25 °C

Not applicable

No disocciation

Vapour pressure at 20 °C (mPa)

0.024

Low volatility

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

0.19

Moderately volatile

Volatilisation as max % of applied dose lost

From plant surface

24 hr

Volatilisation is not considered critical for air pollution

From soil surface

24 hr

Volatilisation is not considered critical for air pollution

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

In methanol: 214nm = 61353, 295nm = 1494

Surface tension (mN m⁻¹)

56.58

at 20 °C 98.1%

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

1.68

Non-persistent

DT₅₀ (lab at 20 °C)

1.68

Non-persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

3.08

Non-persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

2.48

representative worst case

Note

EU 2017 dossier lab studies DT₅₀ range 0.13-6.87 days, DT₉₀ range 0.48-7.53 days, Soils=12

Dissipation rate RL₅₀ (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

2.5

Note

Published literature RL₅₀ range 1.9-3.2 days, 2 field grown crops, various matrices, n=2

Aqueous photolysis DT₅₀ (days) at pH 7

Value

16.7

Slow

Note

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

Value

Non-persistent

Note

DT₅₀: 34.1 days at pH 5, 1.7 days at pH 9

Water-sediment DT₅₀ (days)

3.7

Fast

Water phase only DT₅₀ (days)

0.25

Fast

Sediment 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)

738

Non-mobile

K_foc (mL g⁻¹)

24739

¹/_n

1.03

Notes and range

EU 2016 dossier K_f range 302-1236 mL g⁻¹, K_foc range 8751-32540 mL g⁻¹, ¹/_n range 1.00-1.07, Soils=5

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

-0.09

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

33.6

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)

180

Threshold for concern

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

0.446

3,5-di-bromo-4-hydroxybenzamide

Major fraction

0.324

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

Minor fraction

0.072

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

,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)

> 141

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)

170

Colinus virginianus

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

1315 mg kg feed⁻¹

Colinus virginianus

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

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

Eisenia foetida as acid

Moderate

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

Soil micro-organisms

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Folsomia candida

Non-target plants

11.8

Tomato
Vegetative vigour, 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)

> 119.8

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

14.5

Apis mellifera as bromoxynil

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 Mortality ER₅₀ g ha⁻¹

> 709.4

Chrysoperla carnea

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

30.0

Aphidius rhopalosiphi

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

9.47

Typhlodromus pyri

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)

0.041

Oncorhynchus mykiss

High

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

0.0034

Oncorhynchus mykiss

High

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

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

0.044

Daphnia magna

High

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

0.0036

Daphnia magna

High

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

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

0.087

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)

0.06

Chironomus riparius 22 day

Moderate

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

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

> 0.073

Lemna gibba

Moderate

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

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

> 28.0

Pseudokirchneriella subcapitata

Low

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)

> 141

Rat

Moderate

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

0.72

Rat

Other Mammal toxicity endpoints

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

0.003

Rat as bromoxynil

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

0.013

Rat 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

Rat 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 the metabolite bromoxynil phenol via the urine within 7 days

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

No data found

General human health issues

Possible liver toxicant
Some weak evidence to suggest carcinogenicity

Handling issues

Property

Value and interpretation

General

Containers may explode when heated to extreme
Substance is not oxidising
IMDG Transport Hazard Class 6.1
Not expected to auto-ignite

CLP classification 2013

Health: H302, H317, H331, H361d
Environment: H400, H410

WHO Classification

II (Moderately hazardous)

UN Number

UN2811

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

bromoxynil-octanoate

French

German

Danish

Italian

Spanish

Greek

Polish

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