Florasulam (Ref: DE 570)

Florasulam (Ref: DE 570)	Last updated: 23/01/2021
(Not known by any other names)

SUMMARY

Florasulam is a post-emergent herbicide approved for use in the EU. It is highly soluble in water, volatile and there is a possibility, under certain conditions of it leaching to groundwater. It is not persistent in soil but may be persistent in aquatic systems. It has a low mammalian toxicity and is not thought to bioaccumulate. Whilst a recognised irritant no other serious human health issues have been reported. It is moderate to highly toxic to birds, most aquatic organims and honeybees. It has a low toxicity to earthworms.

GENERAL INFORMATION

Description

A herbicide used for post-emergence control of broad-leaved weeds

Example pests controlled

Broad-leaved weeds

Example applications

Wheat; Barley; Oats; Rye; Triticale

Efficacy & activity

Availability status

Current

Introduction & key dates

1998, discovered; 1999 first reported & introduced

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

31/12/2030

UK LERAP status

None

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Poland/Belgium

Date EC 1107/2009 inclusion expires

31/12/2030

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

C₁₂H₈F₃N₅O₃S

Canonical SMILES

COC1=NC=C(C2=NC(=NN21)S(=O)(=O)NC3=C(C=CC=C3F)F)F

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

QZXATCCPQKOEIH-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C12H8F3N5O3S/c1-23-12-16-5-8(15)10-17-11(18-20(10)12)24(21,22)19-9-6(13)3-2-4-7(9)14/h2-5,19H,1H3

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance group

Triazolopyrimidine

Minimum active substance purity

970 g kg⁻¹

Known relevant impurities

EU dossier - 2,6-DFA: <2.0 g kg⁻¹

Substance origin

Synthetic

Mode of action

Selective, absorbed by roots and shoots. Inhibits plant amino acid synthesis - acetohydroxyacid synthase AHAS.

CAS RN

145701-23-1

EC number

CIPAC number

616

US EPA chemical code

129108

PubChem CID

11700495

Molecular mass

359.28

PIN (Preferred Identification Name)

N-(2,6-difluorophenyl)-8-fluoro-5-methoxy[1,2,4]triazolo[1,5-c]pyrimidine-2-sulfonamide

IUPAC name

2',6',8-trifluoro-5-methoxy[1,2,4]triazolo[1,5-c]pyrimidine-2-sulfonanilide

CAS name

N-(2,6-difluorophenyl)-8-fluoro-5-methoxy(1,2,4)triazolo(1,5-c)pyrimidine-2-sulfonamide

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

Amaranthus retroflexus

Physical state

Off-white coloured solid at 25 DegC, 99.7% purity

Related substances & organisms

clopyralid

fluroxypyr

2,4-D

Formulations

Property

Value

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

Barton WG
Boxer
Cabadex
Galaxy
Junction
Starane Gold
Starane Vantage
Starane XL
Zypar

Example products using this active

Dow AgroSciences

Formulation and application details

Often supplied as wettable granules or soluble concentrate which are 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)

6360

High

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

0.019

n-Heptane

227

Xylene

9810

Methanol

123000

Acetone

Melting point (°C)

193.5

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

202.5

Flashpoint (°C)

Not expected to self ignite; Not highly flammable

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

6.03 X 10^-02

Calculated

Log P

-1.22

Low

Bulk density (g ml⁻¹)

1.53

Dissociation constant pKa) at 25 °C

4.54

Weak acid

Vapour pressure at 20 °C (mPa)

0.01

Low volatility

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

4.35 X 10^-07

Non-volatile

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

Acidic solution: 259.8nm = 12200
Basic solution: 262.4nm = 23600
Methanolic solution @ pH 12.60: 204.1nm = 27400

Surface tension (mN m⁻¹)

71.5

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

1.85

Non-persistent

DT₅₀ (lab at 20 °C)

1.85

Non-persistent

DT₅₀ (field)

8.5

Non-persistent

DT₉₀ (lab at 20 °C)

6.57

Non-persistent

DT₉₀ (field)

40.5

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀ range 0.58-4.29 days, DT₉₀ range 1.92-14.24 days, field studies DT₅₀ range 2-18 days, DT₉₀ range 23-61 days

Dissipation rate RL₅₀ on plant matrix

Value

Note

Dissipation rate RL₅₀ on and in plant matrix

Value

1.4

Note

Published literature RL₅₀ range 0.1-3.6 days, 4 field & undercover grown crops, various matrices, n=6

Aqueous photolysis DT₅₀ (days) at pH 7

Value

156

Stable

Note

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

Value

Stable

Note

Stable pH 5 to pH 7 after 30 days, DT₅₀ 99 days at pH 9, all at 25 °C

Water-sediment DT₅₀ (days)

13.3

Fast

Water phase only DT₅₀ (days)

Slow

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

0.46

Mobile

K_oc

22.0

Notes and range

EU dossier K_d range 0.08-0.94 mL g⁻¹, K_oc range 4-54 mL g⁻¹, Soils=6

Freundlich

K_f

0.45

Mobile

K_foc

20.37

¹/_n

0.945

Notes and range

EU dossier K_f range 0.03-1.88 mL g⁻¹, K_foc range 2.0-54.7 mL g⁻¹, ¹/_n range 0.86-1.04, Soils=14

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

2.50

Calculated

Transition state

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

Value

3.72 X 10^-02

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Mobile

Calculated

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

N-(2,6-difluorophenyl)-8-fluoro-5-hydroxy(1,2,4)triazolo(1,5-c)pyrimidine-2-sulfonamide

Soil

0.716

Major fraction, Relevancy unknown

N-(2,6-difluorophenyl)-5-aminosulfonyl-1H-1,2,4-triazole-3-carboxylic acid

Soil

0.178

Major fraction, Relevancy unknown

5-(aminosulfonyl)-1H-1,2,4-triazole-3-carboxylic acid

Soil

0.400

Major fraction, Relevancy unknown

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

1.5

Low potential

CT₅₀ (days)

Not available

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

5000

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

100

Rat

Moderate

(ppm diet)

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

500

Rat Reproductive NOAEL

Low

Birds - Acute LD₅₀ (mg kg⁻¹)

1046

Coturnix japonica

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

> 5000 mg kg feed⁻¹

Coturnix japonica

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

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

> 100

Oncorhynchus mykiss

Low

Fish - Chronic 21 day NOEC (mg l⁻¹)

> 119

Oncorhynchus mykiss

Low

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

> 292

Daphnia magna

Low

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

38.9

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)

10.0

Chironomus riparius

Moderate

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

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

0.001

Lemna spp.

High

Non-target plants

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

0.00894

Unknown species

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)

> 100

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)

> 1320

Eisenia foetida

Low

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

0.203

Eisenia foetida

Moderate

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Other arthropod (1)

LR₅₀ g ha⁻¹

% Effect

25.2

Beneficial capacity [Dose: 0.0075 kg ha⁻¹]
Aphidius rhopalosiphi adult

Other arthropod (2)

LR₅₀ g ha⁻¹

% Effect

12.3

Beneficial capacity [Dose: 0.0075 kg ha⁻¹]
Typhlodromus pyri protonymph

Soil micro-organisms

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

Dose: 0.05 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)

> 5.0

Rat 4 hr (nose only)

Other Mammal toxicity endpoints

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

0.05

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)

0.05

Dog 90 day SF=100

Dermal penetration studies (%)

12.0

Dangerous Substances Directive 76/464

List II

Exposure Routes

Public

Minimal risk of dietary exposure; Very low risk to bystanders

Occupational

Accetable risk for proposed uses with PPE/PPC

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

No data found

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

Potential blood, adrenals, kidney and liver toxicant

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
IMDG Transport Code is usually 9

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

Variable with formulation, usually 3077 or 3082

Waste disposal & packaging

Packaging Group III (minor danger)

TRANSLATIONS

Language

Name

English

florasulam

French

florasulam

German

Florasulam

Danish

florasulam

Italian

florasulame

Spanish

florasulam

Greek

florasulam

Polish

florazulam

Swedish

florasulam

Hungarian

floraszuram

Dutch

florasulam

Record last updated:	23/01/2021
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