Fluroxypyr-meptyl

Fluroxypyr-meptyl	Last updated: 28/01/2021
(Also known as: fluroxypyr-MHE)

GENERAL INFORMATION

Description

A post-emergence herbicide used to control economically important broad-leaved weeds

Example pests controlled

Annual and perennial broad-leaved weeds including kochia, lespedeza and dogfennel; Woody brush

Example applications

Rangeland; Permanent pasture; Non-crop areas; Cereals including wheat, corn

Efficacy & activity

Availability status

Current

Introduction & key dates

UK regulatory status

UK COPR regulatory status

Not approved

Date COPR inclusion expires

Not applicable

UK LERAP status

Not applicable

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Sweden/Slovenia

Date EC 1107/2009 inclusion expires

31/12/2021

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

Chemical structure

Isomerism

Fluroxypyr is not itself isomeric but the meptyl ester has a pair of enantiomers.

Chemical formula

C₁₅H₂₁Cl₂FN₂O₃

Canonical SMILES

CCCCCCC(C)OC(=O)COC1=NC(=C(C(=C1Cl)N)Cl)F

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

OLZQTUCTGLHFTQ-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C15H21Cl2FN2O3/c1-3-4-5-6-7-9(2)23-10(21)8-22-15-12(17)13(19)11(16)14(18)20-15/h9H,3-8H2,1-2H3,(H2,19,20)

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance group

Pyridine compound

Minimum active substance purity

950 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Selective, foliar uptake causing auxin-type response

CAS RN

81406-37-3

EC number

279-752-9

CIPAC number

US EPA chemical code

128968

PubChem CID

54745

Molecular mass

367.24

PIN (Preferred Identification Name)

rac-(2R)-octan-2-yl [(4-amino-3,5-dichloro-6-fluoropyridin-2-yl)oxy]acetate

IUPAC name

(RS)-1-methylheptyl 4-amino-3,5-dichloro-6-fluoro-2-pyridyloxyacetate

CAS name

1-methylheptyl ((4-amino-3,5-dichloro-6-fluoro-2-pyridinyl)oxy)acetate

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

Cabbage family; other dicotyldons such as bugloss, comon poppy, corn marigold

Physical state

White crystalline solid

Formulations

Property

Value

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

Agrostar
Bofix FFC
Awac
Cabadex
Cascade

Example products using this active

Barclay Chemicals
Dow AgroSciences
Agrotech
AgriGuard

Formulation and application details

Often supplied as an emulsifiable concentrate that is mixed with water and applied as a spray

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

0.136

Low

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

62300

n-Heptane

3770000

Methanol

3300000

Acetone

2500000

Ethyl acetate

Melting point (°C)

57.5

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

312

Flashpoint (°C)

Not expected to self ignite; Not highly flammable

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

1.10 X 10⁰⁵

Calculated

Log P

5.04

High

Bulk density (g ml⁻¹)

1.322

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

Vapour pressure at 20 °C (mPa)

0.01

Low volatility

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

2.7 X 10^-02

Non-volatile

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

290nm=10.01, no maxama 290-900nm

Surface tension (mN m⁻¹)

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

1.0

Non-persistent

DT₅₀ (lab at 20 °C)

1.0

Non-persistent

DT₅₀ (field)

Non-persistent

DT₉₀ (lab at 20 °C)

2.4

Non-persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀ range 0.5-1.8 days (normalised); DT₉₀ range 1.0-6.0 days; Other studies: DT₅₀ 3-55 days (lab), 34-70 (field)

Dissipation rate RL₅₀ on plant matrix

Value

Note

Dissipation rate RL₅₀ on and in plant matrix

Value

2.69

Note

Rice, whole plant, n=1

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Stable

Note

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

Value

Stable

Note

At pH 5 stable; At pH 9 DT₅₀ = 3.2 days

Water-sediment DT₅₀ (days)

34.7

Moderately fast

Water phase only DT₅₀ (days)

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

188.75

Non-mobile

K_oc

19550

Notes and range

EU dossier (2011) K_d range 95-260 mL g⁻¹, K_oc range 6200-43000 ml/g, soils =4

Freundlich

K_f

K_foc

¹/_n

Notes and range

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

-0.14

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

Low

Calculated

Potential for loss via drain flow

Non-mobile

Calculated

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

4-amino-3,5-dichloro-6-fluoro-2-pyridinol

Soil

0.115

4-amino-3,5-dichloro-6-fluoro-2-pirydynil-2-methoxypyridine

Soil

0.178

fluroxypyr (Ref: DOW 43304-H)

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

CT₅₀ (days)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 2000

Rat

Low

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)

> 2000

Colinus virginianus

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

> 5000 mg kg feed⁻¹

Colinus virginianus

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

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

> 0.225

Oncorhynchus mykiss

Moderate

Fish - Chronic 21 day NOEC (mg l⁻¹)

0.2

Oncorhynchus mykiss

Moderate

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

> 0.183

Daphnia magna

Moderate

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

0.06

Daphnia magna

Moderate

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)

0.13

Chironomus riparius

Moderate

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

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

> 2.31

Lemna gibba

Moderate

Non-target plants

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

> 0.5

Scenedemus subspicatus

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)

> 100

Low

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

> 100

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)

1.96

Eisenia foetida corr

Moderate

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Other arthropod (1)

LR₅₀ g ha⁻¹

1301

Aphidius rhopalosiphi

% Effect

100

Mortality [Dose: 578 g ha⁻¹]
Aphidius rhopalosiphi

Other arthropod (2)

LR₅₀ g ha⁻¹

2200

>
Typhlodromus pyri

% Effect

33.3

Mortality [Dose: 578 g ha⁻¹]
Typhlodromus pyri

Soil micro-organisms

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

Dose: 2 kg ha⁻¹

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)

> 2000

Rat

Low

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 1.0

Rat 4 hr

Other Mammal toxicity endpoints

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

0.8

Rat SF=100

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

None allocated

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

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

0.8

Rat SF=100

Dermal penetration studies (%)

4-22

concentration dependent

Dangerous Substances Directive 76/464

List II

Exposure Routes

Public

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

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

Possible kidney toxicant

Handling issues

Property

Value and interpretation

General

Prevent generation of mists
Not explosive or oxidising

CLP classification 2013

Environment: H400, H410

EC Risk Classification

N - Dangerous for the environment: R50, R53

EC Safety Classification

S60, S61

WHO Classification

U (Unlikely to present an acute hazard)

UN Number

Usually 3077

Waste disposal & packaging

TRANSLATIONS

Language

Name

English

fluroxypyr-meptyl

French

fluoroxypyr-meptyl

German

Danish

Italian

Spanish

fluroxipir meptil

Greek

Polish

fluroksypyr meptylu

Swedish

fluroxipyr-1-metylheptylester

Hungarian

Dutch

Record last updated:	28/01/2021
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