Isoxaflutole (Ref: RPA 201772)

Isoxaflutole (Ref: RPA 201772)	Last updated: 15/02/2021
(Not known by any other names)

GENERAL INFORMATION

Description

A broad-spectrum pre-emergence soil herbicide for the control of weeds in maize and sugarcane

Example pests controlled

Broad-leaved-weeds; Annual grasses

Example applications

Maize; Sugar cane

Efficacy & activity

Availability status

Current

Introduction & key dates

1998, USA

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

31/07/2034

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

Italy/Slovenia

Date EC 1107/2009 inclusion expires

31/07/2034

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; USA

Chemical structure

Isomerism

Chemical formula

C₁₅H₁₂F₃NO₄S

Canonical SMILES

CS(=O)(=O)C1=C(C=CC(=C1)C(F)(F)F)C(=O)C2=C(ON=C2)C3CC3

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

OYIKARCXOQLFHF-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C15H12F3NO4S/c1-24(21,22)12-6-9(15(16,17)18)4-5-10(12)13(20)11-7-19-23-14(11)8-2-3-8/h4-8H,2-3H2,1H3

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance group

Oxyacetamide

Minimum active substance purity

950 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Systemic absorbed by roots and leaves. Bleaching: inhibition of 4-hydroxyphenyl-pyruvate-dioxygenase.

CAS RN

141112-29-0

EC number

CIPAC number

575

US EPA chemical code

123000

PubChem CID

84098

Molecular mass

359.32

PIN (Preferred Identification Name)

IUPAC name

(5-cyclopropyl-1,2-oxazol-4-yl)(α,α,α-trifluoro-2-mesyl-p-tolyl)methanone

CAS name

(5-cyclopropyl-4-isoxazolyl)[2-(methylsulfonyl)-4-(trifluoromethyl)phenyl]methanone

Other status information

Phytotoxic

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

Off-white solid

Related substances & organisms

flufenacet

Formulations

Property

Value

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

Cadu Star
Balance Herbicide
Balance Pro
Merlin
Flexx
Spade

Example products using this active

Bayer CropScience
Rhone-Poulenc Ag Company

Formulation and application details

Usually supplied as water dispersible granules

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

6.2

Low

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

293000

Acetone

142000

Ethyl acetate

31200

Toluene

13800

Methanol

Melting point (°C)

140

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

205

Flashpoint (°C)

Not expected to self ignite; Not highly flammable

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

2.19 X 10⁰²

Calculated

Log P

2.34

Low

Bulk density (g ml⁻¹)

1.59

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

Vapour pressure at 20 °C (mPa)

3.22 X 10^-05

Low volatility

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

1.87 X 10^-05

Non-volatile

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

Neutral solution: 204nm = 22668, 269.4nm = 11764, No absorption <290nm
Acid solution: 205.4nm = 22393, 269.2nm= 11788
Basic solution: 218.4nm = 18262, 292nm = 12861

Surface tension (mN m⁻¹)

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

0.9

Non-persistent

DT₅₀ (lab at 20 °C)

0.9

Non-persistent

DT₅₀ (field)

1.3

Non-persistent

DT₉₀ (lab at 20 °C)

30.1

Moderately persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU dossier (2016) lab studies DT₅₀ range 0.2-5.9 days, DT₉₀ range 0.94-35.8 days, Soil =5; Field study DT₅₀ range 0.5-2.4 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

1.7

Moderately fast

Note

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

Value

0.8

Non-persistent

Note

pH sensitive: DT₅₀ 11 days pH 4 and pH 5, 3.2 hours at pH 9, all at 25 °C

Water-sediment DT₅₀ (days)

0.36

Fast

Water phase only DT₅₀ (days)

0.36

Fast

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

2.8

Moderately mobile

K_oc

145

Notes and range

Literature data K_d range 1.24-3.77 mL g⁻¹, K_oc range 124-160 mL g⁻¹, soils=4

Freundlich

K_f

2.73

Moderately mobile

K_foc

79.8

¹/_n

0.94

Notes and range

EU dossier (2016)K_d range 0.24-8.15 mL g⁻¹, K_foc range 48-109 mL g⁻¹, ¹/_n range 0.87-1.03, Soils=4; Other litertaure data K_f range 1.17-3.22 mL g⁻¹, K_foc range 117-136 mL g⁻¹, Soils=4 (R4)

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

0.24

Calculated

Low leachability

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

Value

8.47 X 10^-04

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Moderately mobile

Calculated

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

(2RS)-3-cyclopropyl-2-(2-(methylsulfonyl)-4-(trifluoromethyl)benzoyl)-3-oxopropanenitrile (Ref: RPA 202248)

Soil

0.964

Major fraction, Relevancy unknown

2-mesyl-4-trifloromethylbenzoic acid (Ref: RPA 203328)

Soil

0.900

Major fraction, Relevancy unknown

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

Ref: RPA 205834
Note: LC50(fish) = 35 mg/l; LC50(Daphnia) = 100 mg/l

Water; Sediment

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

Low potential

CT₅₀ (days)

Not available

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 5000

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat 2 year

High

(ppm diet)

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

500

Rat Reproductive NOAEL

Low

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2150

Anas platyrhynchos

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

> 4150 mg kg feed⁻¹

Anas platyrhynchos

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

Colinius virginianus NOAEL

Moderate

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

> 1.7

Oncorhynchus mykiss

Moderate

Fish - Chronic 21 day NOEC (mg l⁻¹)

0.08

Oncorhynchus mykiss

Moderate

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

> 1.5

Daphnia magna

Moderate

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

0.35

Daphnia magna

Moderate

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

0.014

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)

0.1

Chironomus riparius

Moderate

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

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

0.016

Lemna gibba

Moderate

Non-target plants

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

0.12

Raphidocelis subcapitata 120 hour

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)

> 168.7

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)

> 1000

Low

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

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Other arthropod (1)

LR₅₀ g ha⁻¹

% Effect

Parasitism [Dose: 0.15 kg ha⁻¹]
Aphidius rhopalosiphi adult

Other arthropod (2)

LR₅₀ g ha⁻¹

% Effect

Mortality and Fecundity [Dose: 0.15 kg ha⁻¹]
Typhlodromus pyri protonymph

Soil micro-organisms

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

Dose: 1.0 mg kg⁻¹ soil

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)

> 5.23

Rat 4 hr (whole body)

Other Mammal toxicity endpoints

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

0.02

Rat SF=100

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

0.05

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)

0.012

Rat SF=167

Dermal penetration studies (%)

0.7-3

concentration dependent

Dangerous Substances Directive 76/464

List II

Exposure Routes

Public

No unacceptable risks to bystanders identified

Occupational

No unacceptabe risk 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

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

Eye irritant

Phototoxicant

General human health issues

Possible liver toxicant
May damage corneal opacity
USEPA - probable human carcinogen

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
IMDG Transport Code is usually 9

CLP classification 2013

Health: H361d
Environment: H400, H410

EC Risk Classification

Reproduction risk category 3: R63
N - Dangerous for the environment: R50, R53

EC Safety Classification

S2, S36/37, S60, S61

WHO Classification

NL (Not listed)

UN Number

Usually 3077

Waste disposal & packaging

Packaging Group III (minor danger)

TRANSLATIONS

Language

Name

English

isoxaflutole

French

isoxaflutole

German

Isoxaflutol

Danish

isoxaflutol

Italian

isoxaflutolo

Spanish

isoxaflutol

Greek

isoxaflutole

Polish

izoksaflutol

Swedish

Hungarian

izoxaflutol

Dutch

isoxaflutole

Record last updated:	15/02/2021
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