Pyraflufen-ethyl (Ref: ET 751)

Pyraflufen-ethyl (Ref: ET 751)	Last updated: 03/03/2021
(Also known as: NH 9301)

GENERAL INFORMATION

Description

A herbicide used to control broad-leaved weeds and grasses in crops

Example pests controlled

Black nightshade; Clover; Dandelion; Cleavers; Groundsel; Fat hen; Field bindweed; Field pansy; Knotgrass; Shepherd's purse; Volunteer OSR

Example applications

Potatoes; Vines; Non-cropped areas; Turf

Efficacy & activity

Availability status

Current

Introduction & key dates

1993, first reported; 1999, first introduced

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

31/03/2031

UK LERAP status

Buffer probably required in UK - see product label

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Netherlands/Lithuania

Date EC 1107/2009 inclusion expires

31/03/2031

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

Chemical formula

C₁₃H₉Cl₂F₃N₂O₄

Canonical SMILES

CCOC(=O)COC1=C(C=C(C(=C1)C2=NN(C(=C2Cl)OC(F)F)C)F)Cl

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

APTZNLHMIGJTEW-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C15H13Cl2F3N2O4/c1-3-24-11(23)6-25-10-4-7(9(18)5-8(10)16)13-12(17)14(22(2)21-13)26-15(19)20/h4-5,15H,3,6H2,1-2H3

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide, Dessicant

Substance group

Phenylpyrazole

Minimum active substance purity

956 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Selective with contact action. Inhibition of protoporphyrinogen oxidase (PPO).

CAS RN

129630-19-9

EC number

CIPAC number

605.202

US EPA chemical code

030090

PubChem CID

182951

Molecular mass

413.18

PIN (Preferred Identification Name)

IUPAC name

ethyl 2-chloro-5-(4-chloro-5-difluoromethoxy-1-methylpyrazol-3-yl)-4-fluorophenoxyacetate

CAS name

ethyl [2-chloro-5-[4-chloro-5-(difluoromethoxy)-1-methyl-1H-pyrazol-3-yl]-4-fluorophenoxy]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

Physical state

Cream powder

Related substances & organisms

pyraflufen

Formulations

Property

Value

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

OS-169
Quickdown
Thunderbolt

Example products using this active

Certis
Nichino Europe

Formulation and application details

Usually supplied as an emulsifiable concentrate

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

0.082

Low

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

234

n-Heptane

7390

Methanol

175000

Acetone

107000

Ethyl acetate

Melting point (°C)

126.8

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

240

Flashpoint (°C)

Not expected to self ignite; Not highly flammable

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

3.09 X 10⁰³

Calculated

Log P

3.49

High

Bulk density (g ml⁻¹)

1.57

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

Vapour pressure at 20 °C (mPa)

4.30 X 10^-06

Low volatility

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

2.20 X 10^-05

Non-volatile

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

203nm = 28700, 243nm = 12800, 291nm = 5900, No further maxima between 291 and 700nm

Surface tension (mN m⁻¹)

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

0.32

Non-persistent

DT₅₀ (lab at 20 °C)

0.32

Non-persistent

DT₅₀ (field)

1.2

Non-persistent

DT₉₀ (lab at 20 °C)

3.6

Non-persistent

DT₉₀ (field)

4.0

DT₅₀ modelling endpoint

Note

EU dossier lab studies: DT₅₀ range 0.22-0.41 days, DT₉₀ range 0.73-10.4 days; Field studies DT₅₀ range 0.4-1.4 days, DT₉₀ range 0.9-13.1 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

1.4

Moderately fast

Note

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

Value

13.1

Non-persistent

Note

pH sensitive: Stable at pH 4, rapid at pH 9

Water-sediment DT₅₀ (days)

0.1

Fast

Water phase only DT₅₀ (days)

0.1

Fast

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

Slightly mobile

K_oc

1949

Notes and range

EU dossier K_oc estimated value

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

0.06

Calculated

Low leachability

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

Value

2.02 X 10^-04

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Slightly mobile

Calculated

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

2-chloro-5-(4-chloro-5-difluoromethoxy-1-methylpyrazol-3-yl)-4-fluorophenoxyacetic acid

Soil

0.940

Major fraction, Relevant

2-chloro-5-(4-chloro-5-difluoromethoxy-1-methylpyrazol-3-yl)-4-fluorophenol

Soil

0.190

Major fraction, Relevant

4-chloro-3-(4-chloro-2-fluoro-5-methoxyphenyl)-5-difluoromethoxy-1-methylpyrazole

Soil

0.690

Major fraction, Relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

ethyl 2-chloro-5-(4-chloro-5-difluoromethoxylpyrazole-3yl)-4-fluorophenoxyacetate

pyrafluthren-ethyl metabolite E-8

Rat

2-chloro-5-(4-chloro-5-difluoromethoxylpyrazole-3yl)-4-fluorophenoxyacetic acid

pyrafluthren-ethyl metabolite E-9

Rat; Plant

2-chloro-5-(4-chloro-5-difluoromethoxylpyrazole-3yl)-4-fluorophenol

pyrafluthren-ethyl metabolite E-10

Rat

4-chloro-3-(4-chloro-2-fluoro-5-methoxyphenyl)-5-difluoromethoxylpyrazole

pyrafluthren-ethyl metabolite E-11

Rat

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)

> 5000

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat 2 year

(ppm diet)

> 2000

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

> 721

Rat Reproductive NOAEL

Low

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)

Anas platyrhynchos

Moderate

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

> 0.100

Oncorhynchus mykiss

Moderate

Fish - Chronic 21 day NOEC (mg l⁻¹)

0.0034

Pimephales promelas 35 day

High

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

> 0.100

Daphnia magna

Moderate

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

100

Daphnia magna

Low

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)

0.0026

Lemna gibba

High

Non-target plants

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

0.00023

Raphidocelis subcapitata 72 hour

High

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)

> 111.99

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)

> 250

Eisenia foetida corr

Low

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Other arthropod (1)

LR₅₀ g ha⁻¹

1.6

<, as L product ha⁻¹ (OS-169: Conc 26.5g l⁻¹)
Typhlodromus pyri

% Effect

2.1

Beneficial capacity [Dose: 1.33 l ha⁻¹]
Aphidius rhopalosiphi adult

Other arthropod (2)

LR₅₀ g ha⁻¹

1.6

<, as L product ha⁻¹ (OS-169: Conc 26.5g l⁻¹)
Aphidius rhopalosiphi

% Effect

100

Beneficial capacity [Dose: 1.33 l ha⁻¹]
Typhlodromus pyri protonymph

Soil micro-organisms

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

Dose: 0.1 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)

> 5000

Rat

Low

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

5.03

Rat 4 hr (nose only)

Other Mammal toxicity endpoints

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

0.2

Rat SF=100

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

0.2

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)

0.112

Mouse 90 day SF=100

Dermal penetration studies (%)

4-56.0

concentration dependent

Dangerous Substances Directive 76/464

List II

Exposure Routes

Public

No unacceptable risks to bystanders identified

Occupational

No unacceptable risks to operators or other workers identified

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

; ; ; ;

No data found

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

No data found

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

Possible kidney, liver and blood toxicant
USEPA - some evidence to suggest possible human carcinogen

Handling issues

Property

Value and interpretation

General

Corrosive
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

NL (Not listed)

UN Number

Waste disposal & packaging

TRANSLATIONS

Language

Name

English

pyraflufen-ethyl

French

pyraflufen-ethyl

German

Pyraflufen-ethyl

Danish

pyraflufen-ethyl

Italian

piraflufen-etil

Spanish

piraflufen-etil

Greek

pyraflufen-ethyl

Polish

pyraflufen etylu

Swedish

Hungarian

piraflufen-etil

Dutch

pyraflufen-ethyl

Record last updated:	03/03/2021
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