Florasulam (Ref: DE 570)

Florasulam (Ref: DE 570)	Last updated: 26/05/2025
(Not known by any other names)

SUMMARY

Florasulam is a post-emergence herbicide. 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 organisms and honeybees. It has a low toxicity to earthworms.

Data alerts

The following alerts are based on the data in the tables below. An absence of an alert does not imply the substance has no implications for human health, biodiversity or the environment but just that we do not have the data to form a judgement.

Environmental fate	Ecotoxicity	Human health
Environmental fate High alert: Drainflow: Mobile	Ecotoxicity Moderate alert: Birds acute ecotoxicity: Moderate; Earthworms chronic ecotoxicity: Moderate	Human health Low alert

GENERAL INFORMATION

Description

A herbicide used for post-emergence control of broadleaved weeds

Example pests controlled

Broadleaved weeds

Example applications

Wheat; Barley; Oats; Rye; Triticale

Efficacy & activity

Availability status

Current

Introduction & key dates

1998, discovered; 1999 first reported & introduced; 2023, withdrawn UK

GB regulatory status

GB COPR regulatory status

Approved

Date COPR inclusion expires

31/12/2030

GB LERAP status

Check label - may vary with formulation

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
✓	✓	✓	✓	✓	✓	✓	✓	✓

Approved for use (✓) under EC 1107/2009 by Mutual Recognition of Authorisation and/or national regulations in the following EEA countries

ISIceland	NONorway
✓	✓

Additional information

Also used in

Australia; Morocco

Chemical structure

Isomerism

None

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

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
florasulam	-

General status

Pesticide type

Herbicide

Substance groups

Triazolopyrimidine herbicide; Sulfonanilide herbicide

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

604-488-1

CIPAC number

616

US EPA chemical code

129108

PubChem CID

11700495

CLP index number

613-230-00-7

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 Class (HRAC MoA class)

Herbicide Resistance Class (WSSA MoA class)

Insecticide Resistance Class (IRAC MoA class)

Not applicable

Fungicide Resistance Class (FRAC MOA class)

Not applicable

Examples of recorded resistance

Amaranthus retroflexus

Physical state

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

Formulations

Property

Value

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

Dow AgroSciences

Example products using this active

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

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)

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

6.03 X 10^-02

Calculated

Log P

-1.22

Low

Fat solubility of residues

Solubility

Insoluble

Data type

Regulatory data

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

Volatilisation as max % of applied dose lost

From plant surface

1.7

24 hr

Volatilisation is not considered critical for air pollution

From soil surface

Negligible

24 hr

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 (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) 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

Sediment phase only DT₅₀ (days)

Air degradation

As this parameter is not normally measured directly, a surrogate measure is used: ‘Photochemical oxidative DT₅₀’. Where data is available, this can be found in the Fate Indices section below.

Decay in stored produce DT₅₀

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d (mL g⁻¹)

0.46

Mobile

K_oc (mL g⁻¹)

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 (mL g⁻¹)

0.45

Mobile

K_foc (mL g⁻¹)

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

Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk

40.94

Calculated using the Atkinson method. Assumed 1.5E+06 OH/cm³, 12 hr

Below the level of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

1.5

Low potential

CT₅₀ (days)

Not available

Known soil metabolites

Metabolite

Major/Minor fraction

$Click here for further information on Major/Minor fraction$

Estimated maximum occurrence fraction

Notes

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

Major fraction

0.716

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

Major fraction

0.178

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

Major fraction

0.400

1H-1,2,4-triazole-3-sulfonamide (Ref: TSA)

Major fraction

0.159

Known groundwater metabolites

None

Other known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

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)

Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)

> 1320

Eisenia foetida

Low

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

0.203

Eisenia foetida

Moderate

Soil micro-organisms

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

Dose: 0.05 mg kg⁻¹ soil

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

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)

Chronic

Notes

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 bee species (1)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

Other bee species (2)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

Beneficial insects (Ladybirds)

Beneficial insects (Lacewings)

Beneficial insects (Parasitic wasps) as Mortality LR₅₀ g ha⁻¹

> 15

Aphidius rhopalosiphi

Beneficial insects (Predatory mites) as Mortality LR₅₀ g ha⁻¹

> 15

Typhlodromus pyri

Beneficial insects (Ground beetles)

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Temperate Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

> 100

Oncorhynchus mykiss

Low

Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)

> 119

Oncorhynchus mykiss

Low

Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

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

> 292

Daphnia magna

Low

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

38.9

Daphnia magna

Low

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

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 (free-floating, growth) - Acute 7 day EC₅₀, biomass (mg l⁻¹)

0.001

Lemna gibba

High

Aquatic plants (rooted, growth) - Acute 14 day EC₅₀, biomass (mg l⁻¹)

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

0.00894

Unknown species

High

Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)

Mesocosm study data

NOEAEC mg l⁻¹

Marine bivalves

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

Great Britain

GB MRL Register

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

Mammalian dose elimination route and rate

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 Hazard Class 9
Not expected to auto-ignite; Not highly flammable

CLP classification 2013

Environment: H400, H410

WHO Classification

U (Unlikely to present an acute hazard)

UN Number

UN3077

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

Chemically stable under standard ambient conditions

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

Norwegian

florasulam

Record last updated:	26/05/2025
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