Pyridate (Ref: CL 11344)

Pyridate (Ref: CL 11344)	Last updated: 23/08/2024
(Also known as: puridate)

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 Moderate alert: Potential for particle bound transport: Medium	Ecotoxicity Moderate alert: Birds acute ecotoxicity: Moderate; Birds chronic ecotoxicity: Moderate; Fish acute ecotoxicity: Moderate; Fish chronic ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate; Daphnia chronic ecotoxicity: Moderate; Earthworms acute ecotoxicity: Moderate	Human health High alert: Endocrine disrupter

GENERAL INFORMATION

Description

A post-emergence herbicide used to control annual broad-leaved weeds

Example pests controlled

Broad-leaved weeds including nightshade, cleavers, nettles, chickweed;dead-nettle, fathen, ragweed; Grasses including barnyard grass, crabgrass, foxtail

Example applications

Cereals; Brassicas including cauliflowers, kohlrabi, broccoli, Brussels; Alliums including onions, shallots, chives, leek; Fodder beet; Lupins; Rape

Efficacy & activity

Availability status

Current

Introduction & key dates

circa 1980, introduced

GB regulatory status

GB COPR regulatory status

Approved

Date COPR inclusion expires

31/12/2030

GB LERAP status

Crop over 5m DRT - See Authorisation for Crop LERAP Details

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Austria/Latvia

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

C₁₉H₂₃ClN₂O₂S

Canonical SMILES

CCCCCCCCSC(=O)OC1=CC(=NN=C1C2=CC=CC=C2)Cl

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

JTZCTMAVMHRNTR-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C19H23ClN2O2S/c1-2-3-4-5-6-10-13-25-19(23)24-16-14-17(20)21-22-18(16)15-11-8-7-9-12-15/h7-9,11-12,14H,2-6,10,13H2,1H3

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance groups

Pyridazine herbicide

Minimum active substance purity

900 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Selective with contact action, absorbed mainly by the leaves. Photosynthetic electron transport inhibitor at the photosystem II.

CAS RN

55512-33-9

EC number

259-686-7

CIPAC number

447

US EPA chemical code

128834

PubChem CID

41463

CLP index number

607-232-00-7

Molecular mass

378.92

PIN (Preferred Identification Name)

IUPAC name

O-6-chloro-3-phenylpyridazin-4-yl S-octyl thiocarbonate

CAS name

O-(6-chloro-3-phenyl-4-pyridazinyl) S-octyl carbonothioate

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

Colourless crystals

Formulations

Property

Value

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

Syngenta
Sino Agro-Chemical Industry Ltd., Chemie Linz

Example products using this active

Tough
Lentagran WP

Formulation and application details

Usually supplied as an emulsifiable concentrate or wettable powder

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

1.49

Low

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

9000000

Acetone

9000000

Kerosene

9000000

Ethyl acetate

9000000

Xylene

Melting point (°C)

26.5

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

250

Flashpoint (°C)

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

1.02 X 10⁰⁴

Calculated

Log P

4.01

High

Fat solubility of residues

Solubility

Insoluble

Data type

Regulatory data - rapid hydrolysis of pyridate to CL 9673 occurs

Density (g ml⁻¹)

1.28

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

Vapour pressure at 20 °C (mPa)

0.00048

Low volatility

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

1.21 X 10^-04

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

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

Neutral soln: 295nm=2533, 246nm=14415, 204nm=22393
Acidic soln: 295nm=2790, 247nm=14275, 204nm=24257
Basic soln: 307nm=8809, 295nm=7491,260nm=8581, 227nm=21374, 204nm=33893

Surface tension (mN m⁻¹)

Not applicable

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

0.8

Non-persistent

DT₅₀ (lab at 20 °C)

0.8

Non-persistent

DT₅₀ (field)

2.2

Non-persistent

DT₉₀ (lab at 20 °C)

3.9

Non-persistent

DT₉₀ (field)

5.4

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀ range 0.3-3.3 days, DT₉₀ range 1.2-10.8 days, field studies DT₅₀ range 0.4-2.2 days, DT₉₀ range 1.4-8,9 days, soils=7

Dissipation rate RL₅₀ (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

Note

Aqueous photolysis DT₅₀ (days) at pH 7

Value

1.8

Moderately fast

Note

pH sensitive: DT₅₀ 3.5 days at pH 5, 2.2 days at pH 9

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

Value

2.5

Non-persistent

Note

pH and temperature sensitive: DT₅₀ 4.9 days at pH 4 and 25 °C, 0.44 days at pH 4 and 50 °C, 0.28 days at pH 9 and 25 °C, 0.3 hours at pH 9 and 50 °C

Water-sediment DT₅₀ (days)

0.5

Fast

Water phase only DT₅₀ (days)

0.3

Fast

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)

Non-mobile

K_oc (mL g⁻¹)

223800

Notes and range

Freundlich

K_f (mL g⁻¹)

K_foc (mL g⁻¹)

¹/_n

Notes and range

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

-0.46

Calculated

Low leachability

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

Value

5.35 X 10^-03

Calculated

Note

Estimated concentrations of chemicals with Koc values greater than 9995 ml g⁻¹ are beyond the scope of the regression data used in SCI-GROW development. If there are concerns for such chemicals, a higher tier groundwater exposure assessment should be considered, regardless of the concentration returned by SCI-GROW

Potential for particle bound transport index

Medium

Calculated

Potential for loss via drain flow

Non-mobile

Calculated

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

16.8

Calculated using the Atkinson method

Below the level of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

116

Whole fish

Threshold for concern

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

pyridafol (Ref: CL 9673)

Major fraction

0.907

pyridafol-O-methyl (Ref: CL-9869)

Major fraction

0.163

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)

> 2000

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Dog

High

(ppm diet)

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

110

Rat Reproductive NOAEL

Moderate

Birds - Acute LD₅₀ (mg kg⁻¹)

1269

Colinus virginianus

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

> 5000 mg kg feed⁻¹

Colinus virginianus

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

100.4

Moderate

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

125.0

Eisenia foetida corr

Moderate

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

Soil micro-organisms

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

Dose: up to 19 mg kg⁻¹ soil

Collembola

Acute LC₅₀ (mg kg⁻¹)

111.25

Folsomia candida corr

Chronic NOEC (mg kg⁻¹)

Non-target plants

49.6

Beta vulgaris
Vegetative vigour, ER₅₀
as g ha⁻¹

717

Beta vulgaris
Seedling emergence, ER₅₀
as g ha⁻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)

> 109.8

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 at dose 898 g ha⁻¹

6.9

Aphidius rhopalosiphi corr

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

> 1362

Typhlodromus pyri

Beneficial insects (Ground beetles) as % Mortality at dose 1.369 kg ha⁻¹

Poecilus cupreus

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

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

> 1.01

Oncorhynchus mykiss

Moderate

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

0.08

Oncorhynchus mykiss

Moderate

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

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

0.49

Daphnia magna

Moderate

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

0.01

Daphnia magna

Moderate

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

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

3.3

Americamysis bahia

Moderate

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)

> 2.0

Lemna gibba

Moderate

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

> 0.75

Anabaena flos-aquae

Moderate

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

Unknown species

Low

Mesocosm study data

NOEAEC mg l⁻¹

Marine bivalves – Acute EC₅₀ development (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)

> 4.37

Rat 4 hr (head/nose exposure)

Other Mammal toxicity endpoints

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

0.036

Rat SF=100

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

0.4

Rat SF=400

AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)

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

0.036

Rat SF=100

Dermal penetration studies (%)

3-6

concentration dependent

Dangerous Substances Directive 76/464

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

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

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

Potential liver and kidney toxicant
May induce haematological changes
Endocrine issues - Binding to estrogen and androgen receptors

Handling issues

Property

Value and interpretation

General

IMDG Transport Hazard Class 9
Not explosive or oxidising
Not expected to auto-ignite; Not highly flammable

CLP classification 2013

Health: H315, H317
Environment: H400, H410

WHO Classification

III (Slightly hazardous)

UN Number

UN3077

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

Stability may be affected by light

TRANSLATIONS

Language

Name

English

pyridate

French

pyridate

German

Pyridat

Danish

pyridat

Italian

piridate

Spanish

piridato

Greek

pyridate

Polish

pyridat

Swedish

pyridat

Hungarian

Dutch

pyridate

Norwegian

pyridat

Record last updated:	23/08/2024
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