Pyridafenthion (Ref: ENT 23968))

Pyridafenthion (Ref: ENT 23968))	Last updated: 21/08/2024
(Also known as: piridafention; pyridiphenthion; CL 12503; NC 250; pyridiphenthion)

SUMMARY

Pyridafenthion is an organophosphate insecticide. It its moderately soluble in aqueous solution, is relatively volatile and is not persistent in soil. However, under certain conditions it may persist for a month or two in surface water. It is moderately toxic to mammals, is an acetyl cholinesterase inhibitor and a neurotoxicant. It is highly toxic to honeybees, earthworms and birds. data for aquatic organisms is limited but it is known to be moderately toxic to fish and algae.

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 High alert: Birds acute ecotoxicity: High; Bees acute unknown ecotoxicity: High; Earthworms acute ecotoxicity: High	Human health High alert: Acetyl cholinesterase inhibitor; Neurotoxicant

GENERAL INFORMATION

Description

An organophosphate insecticide used to control sucking and chewing insects

Example pests controlled

Aphids; Thrips; Leafhoppers; Sawflies

Example applications

Rice; Vegetables; Fruit

Efficacy & activity

Availability status

Introduction & key dates

1973, first introduced Japan

UK regulatory status

UK COPR regulatory status

Not approved

Date COPR inclusion expires

Expired

UK LERAP status

No UK approval for use

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Not approved

Dossier rapporteur/co-rapporteur

Not applicable

Date EC 1107/2009 inclusion expires

Expired

EU Candidate for substitution (CfS)

Not applicable

Listed in EU database

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

Chemical structure

Isomerism

None

Chemical formula

C₁₄H₁₇N₂O₄PS

Canonical SMILES

CCOP(=S)(OCC)OC1=NN(C(=O)C=C1)C2=CC=CC=C2

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

CXJSOEPQXUCJSA-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C14H17N2O4PS/c1-3-18-21(22,19-4-2)20-13-10-11-14(17)16(15-13)12-8-6-5-7-9-12/h5-11H,3-4H2,1-2H3

2D structure diagram/image available?

Yes

General status

Pesticide type

Insecticide

Substance groups

Organophosphate insecticide; Organothiophosphate insecticide

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Systemic, with stomach and contact action. Acetylcholinesterase (AChE) inhibitor.

CAS RN

119-12-0

EC number

204-298-5

CIPAC number

None allocated

US EPA chemical code

PubChem CID

8381

CLP index number

No data found

Molecular mass

340.33

PIN (Preferred Identification Name)

O-(1,6-dihydro-6-oxo-1-phenyl-3-pyridazinyl) O,O-diethyl phosphorothioate

IUPAC name

O-(1,6-dihydro-6-oxo-1-phenylpyridazin-3-yl) O,O-diethyl phosphorothioate

CAS name

O-(1,6-dihydro-6-oxo-1-phenyl-3-pyridazinyl) O,O-diethyl phosphorothioate

Other status information

PAN listed Highly Hazardous Chemical

Relevant Environmental Water Quality Standards

Herbicide Resistance Class (HRAC MoA class)

Not applicable

Herbicide Resistance Class (WSSA MoA class)

Not applicable

Insecticide Resistance Class (IRAC MoA class)

Fungicide Resistance Class (FRAC MOA class)

Not applicable

Examples of recorded resistance

Physical state

Pale yellow solid

Formulations

Property

Value

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

Mitsui Chemicals
Sipcan

Example products using this active

Ofunack
Oreste

Formulation and application details

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

100

Moderate

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

3880

Hexane

812000

Toluene

930000

Acetone

785000

Ethyl acetate

Melting point (°C)

56.2

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

180

Flashpoint (°C)

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

1.58 X 10⁰³

Calculated

Log P

3.2

High

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

1.325

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

0.00147

Low volatility

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

5.00 X 10^-06

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

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

Surface tension (mN m⁻¹)

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

Non-persistent

DT₅₀ (lab at 20 °C)

Non-persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

General literature states DT₅₀ 11-24 days

Dissipation rate RL₅₀ (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

9.5

Note

Published literature RL₅₀ range 4.5-17.6 days, rice field crop, various matrices, n=3

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Moderately fast

Note

DT₅₀ 19 days in sterile water, 7 days in natural water

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

Value

Moderately persistent

Note

pH sensitive: DT₅₀ 72 days at pH 5, 27 days at pH 9, all 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)

Non-mobile

K_oc (mL g⁻¹)

7211

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

0.18

Calculated

Low leachability

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

Value

6.39 X 10^-03

Calculated

Note

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

Bio-concentration factor

BCF (l kg⁻¹)

1.4

Low potential

CT₅₀ (days)

Not available

Known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

769

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

(ppm diet)

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

Birds - Acute LD₅₀ (mg kg⁻¹)

Coturnix japonica

High

Birds - Short term dietary (LC₅₀/LD₅₀)

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

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

> 2.87

Eisenia foetida

High

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

Soil micro-organisms

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)

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

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

0.08

Apis mellifera

High

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)

Beneficial insects (Predatory mites)

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)

7.5

Oncorhynchus mykiss

Moderate

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

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

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

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

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

1.0

Ceriodaphnia dubia

Moderate

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)

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

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

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

8.53

Pseudokirchneriella subcapitata 48 hr

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)

769

Rat

Moderate

Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)

2100

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 1.13

Rat 4 hr

Other Mammal toxicity endpoints

Intraperitoneal LD₅₀ = 64 mg kg⁻¹

Mouse

Subcutaneous LD₅₀ = 305 mg kg⁻¹

Rat

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

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

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

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

Dermal penetration studies (%)

Dangerous Substances Directive 76/464

List I; List II

Exposure Routes

Public

Occupational

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

Harmful if swallowed or inhalled

Handling issues

Property

Value and interpretation

General

IMDG Transport Hazard Class 6.1

CLP classification 2013

Handling: H224
Health: H319, H336

WHO Classification

II (Moderately hazardous)

UN Number

UN2783

Waste disposal & packaging

Packaging Group II (moderate danger)

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

pyridafenthion

French

pyridafenthion

German

Pyridafenthion

Danish

pyridafenthion

Italian

piridafention

Spanish

piridafention

Greek

Polish

pyridafention

Swedish

Hungarian

piridafentoin

Dutch

Norwegian

Record last updated:	21/08/2024
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