Halauxifen-methyl (Ref: DE-729)

Halauxifen-methyl (Ref: DE-729)	Last updated: 12/01/2021
(Also known as: XDE-729; XR-729; halauxiphen-methyl)

GENERAL INFORMATION

Description

A novel picolinic acid herbicide for use on cereals, rice and other crops the control of broad-leaved weeds

Example pests controlled

Broad-leaved weeds

Example applications

Wheat, barley

Efficacy & activity

Availability status

Unknown

Introduction & key dates

2014, Introduction

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

05/08/2025

UK LERAP status

Possible - check label

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

United Kingdom/France

Date EC 1107/2009 inclusion expires

05/08/2025

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

Pending Canada & USA

Chemical structure

Isomerism

Chemical formula

C₁₄H₁₁Cl₂FN₂O₃

Canonical SMILES

COC1=C(C=CC(=C1F)C2=NC(=C(C(=C2)N)Cl)C(=O)OC)Cl

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

KDHKOPYYWOHESS-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C14H11Cl2FN2O3/c1-21-13-7(15)4-3-6(11(13)17)9-5-8(18)10(16)12(19-9)14(20)22-2/h3-5H,1-2H3,(H2,18,19)

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance group

Picolinic acid

Minimum active substance purity

930 g kg⁻¹

Known relevant impurities

Substance origin

Synthetic

Mode of action

Synthetic auxin.

CAS RN

943831-98-9

EC number

CIPAC number

970.201

US EPA chemical code

PubChem CID

16656802

Molecular mass

345.16

PIN (Preferred Identification Name)

methyl 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylate

IUPAC name

methyl 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylate

CAS name

methyl 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)-2-pyridinecarboxylate

Other status information

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

White powdery solid

Formulations

Property

Value

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

Arylex Active

Example products using this active

Dow Agrosciences

Formulation and application details

Usually supplied as an emuslifiable concentrate to use as a broadcasted foliar spray

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

1830

High

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

38.1

Methanol

250

Acetone

129

Ethyl acetate

9.83

n-Octanol

Melting point (°C)

145.5

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

222

Flashpoint (°C)

Not expected to self-ignite; Not highly flammable.

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

5.75 X 10⁰³

Calculated

Log P

3.76

High

Bulk density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

2.84

Vapour pressure at 20 °C (mPa)

1.5 X 10^-05

Low volatility

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

1.11 X 10^-06

Non-volatile

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

Neutral: 212nm=16401, 249nm=18956
Acidic: 215nm=22496, 256nm=13770
Basic: 212nm=19023, 247nm=21979

Surface tension (mN m⁻¹)

72.5

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

1.3

Non-persistent

DT₅₀ (lab at 20 °C)

1.3

Non-persistent

DT₅₀ (field)

Moderately persistent

DT₉₀ (lab at 20 °C)

7.2

Non-persistent

DT₉₀ (field)

144

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀ range 0.9-2.0, DT₉₀ range 3.0-16.3; Field studies DT₅₀ range 2.1-43 days, DT₉₀ range 49-144 days

Dissipation rate RL₅₀ on plant matrix

Value

Note

Dissipation rate RL₅₀ on and in plant matrix

Value

Note

Aqueous photolysis DT₅₀ (days) at pH 7

Value

0.001

Fast

Note

Very rapid - 4-7 minutes

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

Value

155

at 27 °C pH 7

Persistent

Note

Highly variable with pH and temperature.

Water-sediment DT₅₀ (days)

1.8

Fast

Water phase only DT₅₀ (days)

1.8

Moderately fast

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

72.7

Slightly mobile

K_oc

1417

Notes and range

EU dossier K_d range 13-340 mL g⁻¹, K_oc range 473-2659 mL g⁻¹, soils=7

Freundlich

K_f

Slightly mobile

K_foc

995

¹/_n

0.87

Notes and range

EU dossier kf range 8-310 mL g⁻¹, K_foc range 190-1812 mL g⁻¹, ¹/_n range 0.76-0.98, soils=7

pH sensitivity

Weak

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

1.64

Calculated

Low leachability

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

Value

4.71 X 10^-02

Calculated

Note

Potential for particle bound transport index

Medium

Calculated

Potential for loss via drain flow

Slightly mobile

Calculated

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

halauxifen (Ref: X11393729)

Soil

0.727

Major fraction, Relevant

4-amino-3-chloro-6-(4-chloro-2-fluoro-3-hydroxyphenyl)pyridine-2-carboxylic acid (Ref: X11449757)

Soil

0.174

Major fraction, Relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

methyl 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-hydroxyphenyl)pyridine-2-carboxylate (Ref: X11406790)

Surface water; Soil; Sediment

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

217

Threshold for concern

CT₅₀ (days)

1.6

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 5000

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

(ppm diet)

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

443

Unknown species Reproductive NOAEL

Low

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2250

Colinus virginianus

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

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

36.9

Colinius virginianus NOAEL

Moderate

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

1.33

Cyprinodon variegates

Moderate

Fish - Chronic 21 day NOEC (mg l⁻¹)

0.0115

Cyprinodon variegates 28 day

Moderate

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

2.21

Daphnia magna

Moderate

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

0.144

Daphnia magna

Moderate

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

> 1.30

Americamysis bahia

Moderate

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

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

1.26

Chironomus riparius

Moderate

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

89.3

Chironomus riparius

Moderate

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

2.13

Lemna gibba

Moderate

Non-target plants

0.4

Soybean Carrot
Vegetative vigour, ER₅₀
as g ha⁻¹

0.417

Soybean Carrot
Seedling emergence, ER₅₀
as g ha⁻¹

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

> 0.855

Pseudokirchneriella subcapitata

Moderate

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)

> 98.1

Apis mellifera

Moderate

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

> 108

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)

> 500

Eisenia foetida corr

Moderate

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

5.0

Eisenia foetida corr

Moderate

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

500

Folsomia candida corr

Other arthropod (1)

LR₅₀ g ha⁻¹

1814

>
Typhlodromus pyri

% Effect

Other arthropod (2)

LR₅₀ g ha⁻¹

1462

Aphidius rhopalosiphi

% Effect

Soil micro-organisms

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

Dose: 0.05 mg kg⁻¹ soil 28 days

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)

Low (class I)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 5000

Rat

Low

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

5000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

Other Mammal toxicity endpoints

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

0.058

Rabbit SF=100

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

0.058

Rabbit 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)

0.058

Rabbit SF=100

Dermal penetration studies (%)

1-4%

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

Acceptable for proposed uses

Occupational

Acceptable for proposed uses

European MRLs

EU MRL pesticide database

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

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

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

Possible liver, kideny and bladder toxicant

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising

CLP classification 2013

Environment: H400, H410, H411

EC Risk Classification

EC Safety Classification

WHO Classification

NL (Not listed)

UN Number

Waste disposal & packaging

TRANSLATIONS

Language

Name

English

halauxifen-methyl

French

halauxifene-metyl

German

Danish

Italian

Spanish

Greek

Polish

Swedish

halauxifen-metyl

Hungarian

Dutch

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