Pyroxsulam (Ref: XDE 742)

Pyroxsulam (Ref: XDE 742)	Last updated: 31/10/2024
(Also known as: DE 742; X666742; XR 742)

SUMMARY

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: GUS: High leachability; Drainflow: Mobile	Ecotoxicity Moderate alert: Birds chronic ecotoxicity: Moderate; Fish acute ecotoxicity: Moderate; Earthworms acute ecotoxicity: Moderate; Earthworms chronic ecotoxicity: Moderate	Human health Moderate alert: Neurotoxicant

GENERAL INFORMATION

Description

A post-emergence herbicide useful for the control of annual grass and broad-leaved weeds in cereals.

Example pests controlled

Cheat grass (Bromus japonicus); Ryegrass (Lolium perenne); Canary grass (Phalaris paradoxa); Wild oats (Avena sterilis)

Example applications

Cereals including wheat, barley, rye, triticale

Efficacy & activity

Availability status

Current

Introduction & key dates

1998, discovered; 2007, registered Chile

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

30/04/2031

UK 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

Denmark/Finland

Date EC 1107/2009 inclusion expires

30/04/2025

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

USA, Australia, Canada, Morocco

Chemical structure

Isomerism

None

Chemical formula

C₁₄H₁₃F₃N₆O₅S

Canonical SMILES

COC1=CC(=NC2=NC(=NN12)NS(=O)(=O)C3=C(C=CN=C3OC)C(F)(F)F)OC

Isomeric SMILES

International Chemical Identifier key (InChIKey)

GLBLPMUBLHYFCW-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C14H13F3N6O5S/c1-26-8-6-9(27-2)23-13(19-8)20-12(21-23)22-29(24,25)10-7(14(15,16)17)4-5-18-11(10)28-3/h4-6H,1-3H3,(H,21,22)

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide, Graminicide

Substance groups

Pyridine herbicide; Sulfonamide herbicide; Triazolopyrimidine herbicide

Minimum active substance purity

965 g/Kg

Known relevant impurities

EU dossier - none declared

Substance origin

Synthetic

Mode of action

Very broad spectrum having both foliar and soil activity, translocates and inhibits acetolactate synthase

CAS RN

422556-08-9

EC number

610-007-6

CIPAC number

793

US EPA chemical code

108702

PubChem CID

11571555

CLP index number

613-327-00-4

Molecular mass

434.35

PIN (Preferred Identification Name)

N-(5,7-dimethoxy[1,2,4]triazolo[1,5-a]pyrimidin-2-yl)-2-methoxy-4-(trifluoromethyl)pyridine-3-sulfonamide

IUPAC name

N-(5,7-dimethoxy[1,2,4]triazolo[1,5-a]pyrimidin-2-yl)-2-methoxy-4-(trifluoromethyl)pyridine-3-sulfonamide

CAS name

N-(5,7-dimethoxy(1,2,4)triazolo(1,5-a)pyrimidin-2-yl)-2-methoxy-4-(trifluoromethyl)-3-pyridinesulfonamide

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

Physical state

White crystalline powder

Formulations

Property

Value

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

Dow AgroSciences

Example products using this active

Admitt
PowerFlex
Broadway Sunrise
GF-1274
Crusader
Quasar
Broadway star

Formulation and application details

Available in a range of formulations including water dispersible granules and oil dispersions

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

3200

High

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

2790

Acetone

2170

Ethyl acetate

1010

Methanol

35.2

Xylene

Melting point (°C)

208

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

213

Flashpoint (°C)

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

9.77 X 10^-02

Calculated

Log P

-1.01

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

1.62

Dissociation constant pKa) at 25 °C

4.67

Weak acid

Vapour pressure at 20 °C (mPa)

1.0 X 10^-04

Low volatility

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

6.94 X 10^-07

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

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

Neutral soln.: 297nm=8000. Acidic soln.: 297nm=7600
Basic soln.: 292nm=11100

Surface tension (mN m⁻¹)

63.0

1.0% solution

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

3.3

Non-persistent

DT₅₀ (lab at 20 °C)

3.3

Non-persistent

DT₅₀ (field)

Non-persistent

DT₉₀ (lab at 20 °C)

11.6

Non-persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀ range 1-15.2 days, DT₉₀ range 2.6-55.4 days; Dow Agrosciences datasheet, Fields studies for Canada. US EPA states 4.6 days in clay and clay loam

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 0.4-2.0 days, wheat & blackgrass, whole plant, n=5

Aqueous photolysis DT₅₀ (days) at pH 7

Value

3.2

Moderately fast

Note

Main degradation route

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

Value

Stable

Note

Stable to hydrolysis at pH 5, 7, and 9 at 25 °C

Water-sediment DT₅₀ (days)

Water 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)

0.604

Mobile

K_oc (mL g⁻¹)

33.22

Notes and range

EU dossier K_d range 0.183-1.82 mL g⁻¹, K_oc range 8,42-54.19 mL.g, soils=10

Freundlich

K_f (mL g⁻¹)

0.519

Mobile

K_foc (mL g⁻¹)

28.31

¹/_n

0.987

Notes and range

EU dossier K_f range 0.16-1.55 mL g⁻¹, K_foc range 6.4-53.3 mL g⁻¹, ¹/_n range 0.93-1.25, Soils=10

pH sensitivity

Yes

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

2.84

Calculated

High leachability

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

Value

1.19 X 10^-01

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

2.149

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)

Low risk

Based on LogP < 3

Low risk

CT₅₀ (days)

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

N-(6-chloro-7-hydroxy-5-methoxy-(1,2,4)triazolo(1,5-alpha)pyrimidin-2-yl)2-methoxy-4-trifluoromethyl)-3-pyridinesulfonamide

Major fraction

0.262

N-(1,5-dihydro-7-methoxy-5-oxo(1,2,4)triazolo(1,5-alpha)pyrimidin-2-yl)-2-methoxy-4-trifluoromethyl 3-pyridinesulfonamide

Major fraction

0.244

pyridine sulfonamide

Major fraction

0.132

pyridine sulfonic acid

Minor fraction

0.059

N-(7-hydroxy(1,2,4)triazole(1,5-alpha)pyrimidin-2-yl)-2-methoxy-4-(trifluoromethyl)-3-pyridinesulfonamide

Major fraction

0.137

N-(5,7-dihydroxy(1,2,4)triazolo(1,5-alpha)pyrimidin-2-yl)-2-methoxy-4-(trifluoromethyl)-3-pyridinesulfonamide

N-(5-amino-1H-1,2,4-triazol-3-yl)-2-methoxy-4-trifluoromethyl 3-pyridinsulfonamide

5,7-dimethoxy(1,2,4)triazolo(1,5-alpha)pyrimidin-2-amine

N-cyano-2-methoxy-4-(trifluoromethyl)pyridine-3-sulfonamide

Aerobic

Known groundwater metabolites

Metabolite

EC SANCO/221/2000 relevancy

ADI (mg kg⁻¹ bodyweight day⁻¹)

WHO drinking water guidance value (μg L⁻¹ day⁻¹)

N-(7-hydroxy(1,2,4)triazole(1,5-alpha)pyrimidin-2-yl)-2-methoxy-4-(trifluoromethyl)-3-pyridinesulfonamide

Not relevant

N-(6-chloro-7-hydroxy-5-methoxy-(1,2,4)triazolo(1,5-alpha)pyrimidin-2-yl)2-methoxy-4-trifluoromethyl)-3-pyridinesulfonamide

Not relevant

pyridine sulfonic acid

Not relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

N-(5,7-dihydroxy(1,2,4)triazolo(1,5-alpha)pyrimidin-2-yl)-2-methoxy-4-(trifluoromethyl)-3-pyridinesulfonamide

5,7-diOH-XDE-742

Animal

N-(5-amino-1H-1,2,4-triazol-3-yl)-2-methoxy-4-trifluoromethyl 3-pyridinsulfonamide

XDE-742 ATSA

Water/sediment

2-methoxy-3-trifluoromethyl 3-pyridinesulfinic acid

XDE-742 sulfinic acid

Water (photolysis)

5,7-dimethoxy(1,2,4)triazolo(1,5-alpha)pyrimidin-2-amine

XDE-742 ADTP

Water (photolysis); Animal

N-(5,7-dimethoxy(1,2,4)triazolo(1,5-alpha)pyrimidin-2-yl)2-hydroxy-4-(trifluoromethyl)-3-pyridinesulfonamide

2-dedmethyl-XDE-742

Rat (Urine & Faecal)

N-(7-hydroxy(1,2,4)triazole(1,5-alpha)pyrimidin-2-yl)-2-methoxy-4-(trifluoromethyl)-3-pyridinesulfonamide

7-OH-XDE-742

Plant; Water/sediment; Animal

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

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)

> 1000

Rat Reproductive NOAEL

Low

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2000

Anas platyrhynchos

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

> 988 mg kg bw⁻¹ day⁻¹

Colinus virginianus

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

46.3

Anas platyrhynchos

Moderate

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

> 78.0

Eisenia foetida

Moderate

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

1.07

Eisenia foetida

Moderate

Soil micro-organisms

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

Dose: 0.125 mg kg⁻¹ soil 28 Day

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

16.39

Beta vulgaris
Seedling emergence, ER₅₀
as g product ha⁻¹ (GF-1274: Conc 75g kg⁻¹)

14.86

L. perenne
Vegetative vigour, ER₅₀
as g product ha⁻¹ (GF-1274: Conc 75g kg⁻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)

> 107.4

Apis mellifera

Low

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

Chronic

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

> 37.5

Aphidius rhopalosiphi

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

> 37.5

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)

> 87.0

Oncorhynchus mykiss

Moderate

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

> 10.1

Pimephales promelas

Low

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

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

> 100

Daphnia magna

Low

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

> 10.4

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)

100

Chironomus riparius

Low

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

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

0.924

Pseudokirchneriella subcapitata Growth

Moderate

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

> 5.1

Rat 4 hr (nose only)

Other Mammal toxicity endpoints

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

0.9

Dog 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)

Not applicable

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

0.7

Dog SF=100

Dermal penetration studies (%)

for concentrate

Dangerous Substances Directive 76/464

List II

Exposure Routes

Public

Acceptable for proposed uses

Occupational

Acceptable for proposed uses

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

Rapid and extensive elimination with 48Hr in the urine and faeces

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

No data found

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 liver toxicant

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
Not expected to auto-ignite; Not highly flammable

CLP classification 2013

Health: H317
Environment: H400, H410

WHO Classification

III (Slightly hazardous)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

pyroxsulam

French

German

Danish

Italian

Spanish

Greek

Polish

piroksulam

Swedish

pyroxsulam

Hungarian

Dutch

Norwegian

pyrokssulam

Record last updated:	31/10/2024
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