Bromoxynil octanoate

Bromoxynil octanoate	Last updated: 12/01/2021
(Not known by any other names)

SUMMARY

A widely used herbicide approved for use in the EU. 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 distrupting chemical and a skin sensitiser. It is highly toxic to fish and aquatic invertebrates but less so to other aquatic and terresitial biodiversity.

GENERAL INFORMATION

Description

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

UK regulatory status

UK COPR regulatory status

Phasing out

Date COPR inclusion expires

Expired

UK LERAP status

Buffer probably required in UK - see product label

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

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
	✓	✓	✓	✓	✓		✓	✓

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 group

Hydroxybenzonitrile

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

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 listed Highly Hazardous Chemical

Relevant Environmental Water Quality Standards

Herbicide Resistance Classification (HRAC)

Herbicide Resistance Classification (WSSA)

Insecticide Resistance Classification (IRAC)

Not applicable

Fungicide Resistance Classification (FRAC)

Not applicable

Examples of recorded resistance

Physical state

Fine white powder

Related substances & organisms

ioxynil octanoate

solvent naphtha

Formulations

Property

Value

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

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

Example products using this active

Bayer CropScience
Makhteshim-Agan
Nufarm

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)

Not expected to self ignite; Not highly flammable

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

1.58 X 10⁰⁶

Calculated

Log P

6.2

High

Bulk 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

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 on plant matrix

Value

Note

Dissipation rate RL₅₀ 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

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

K_oc

Notes and range

Freundlich

K_f

738

Non-mobile

K_foc

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

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

bromoxynil (Ref: ENT 20852)

Soil

0.446

Major fraction, Relevant

3,5-di-bromo-4-hydroxybenzamide

Soil

0.324

Major fraction, Relevant

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

Soil

0.072

Minor fraction, Relevant

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

180

Threshold for concern

CT₅₀ (days)

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)

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

0.041

Oncorhynchus mykiss

High

Fish - Chronic 21 day NOEC (mg l⁻¹)

0.0034

Oncorhynchus mykiss

High

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

0.044

Daphnia magna

High

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

0.0036

Daphnia magna

High

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 - Acute 7 day EC₅₀, biomass (mg l⁻¹)

> 0.073

Lemna gibba

Moderate

Non-target plants

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

> 28.0

Pseudokirchneriella subcapitata

Low

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

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 pollinators (1)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

Other pollinators (2)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

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

Eisenia foetida as the acid

Moderate

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

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Folsomia candida

Other arthropod (1)

LR₅₀ g ha⁻¹

% Effect

17.9 / -23.6

Mortality / Parasitism [Dose: 0.45 kg ha⁻¹]
Aphidius rhopalosiphi adult

Other arthropod (2)

LR₅₀ g ha⁻¹

% Effect

Mortality [Dose: 0.45 kg ha⁻¹]
Typhlodromus pyri protonymph

Soil micro-organisms

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)

> 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)

0.01

Mouse 18 mnths SF=100

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

0.04

SF=100

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

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

0.01

Dog SF=100

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

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

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

Handling issues

Property

Value and interpretation

General

Containers may explode when heated to extreme
Substance is not explosive or oxidising
IMDG Transport Code is usually 6.1

CLP classification 2013

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

EC Risk Classification

Reproduction risk category 3: R63
T - Toxic: R23
Xn - Harmful: R22, R43
N - Dangerous for the environment: R50, R53

EC Safety Classification

S1/2, S36/37, S45, S60, S61, S63

WHO Classification

II (Moderately hazardous)

UN Number

Usually 2588

Waste disposal & packaging

Packaging Group III (minor danger)

TRANSLATIONS

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Name

English

bromoxynil octanoate

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Record last updated:	12/01/2021
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