Silthiofam (Ref: MON 65500)

Silthiofam (Ref: MON 65500)	Last updated: 06/06/2024
(Also known as: silthiopham)

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	Ecotoxicity Moderate alert: Fish acute ecotoxicity: Moderate; Fish chronic ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate; Daphnia chronic ecotoxicity: Moderate; Earthworms acute ecotoxicity: Moderate; Earthworms chronic ecotoxicity: Moderate	Human health Moderate alert: Reproduction/development effects

GENERAL INFORMATION

Description

A protectant fungicide seed dressing for cereals used mainly to control 'take-all'

Example pests controlled

Take-all

Example applications

Cereals including winter wheat, barley, triticale

Efficacy & activity

Availability status

Current

Introduction & key dates

1999, introduced

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

30/06/2033

UK LERAP status

None

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Ireland/Belgium

Date EC 1107/2009 inclusion expires

30/06/2033

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

Chemical structure

Isomerism

None

Chemical formula

C₁₃H₂₁NOSSi

Canonical SMILES

CC1=C(SC(=C1C(=O)NCC=C)[Si](C)(C)C)C

Isomeric SMILES

International Chemical Identifier key (InChIKey)

MXMXHPPIGKYTAR-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C13H21NOSSi/c1-7-8-14-12(15)11-9(2)10(3)16-13(11)17(4,5)6/h7H,1,8H2,2-6H3,(H,14,15)/f/h14H

2D structure diagram/image available?

Yes

General status

Pesticide type

Fungicide

Substance groups

Thiophene fungicide; Amide fungicide

Minimum active substance purity

980 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Protective action with long-lasting activity. Respiration inhibitor - ATR production.

CAS RN

175217-20-6

EC number

605-752-9

CIPAC number

635

US EPA chemical code

PubChem CID

16116

CLP index number

616-233-00-1

Molecular mass

267.47

PIN (Preferred Identification Name)

4,5-dimethyl-N-(prop-2-en-1-yl)-2-(trimethylsilyl)thiophene-3-carboxamide

IUPAC name

N-allyl-4,5-dimethyl-2-(trimethylsilyl)thiophene-3-carboxamide

CAS name

4,5-dimethyl-N-2-propenyl-2-(trimethylsilyl)-3-thiophenecarboxamide

Other status information

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)

Not applicable

Fungicide Resistance Class (FRAC MOA class)

Examples of recorded resistance

Physical state

White to beige coloured free-flowing powder

Formulations

Property

Value

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

Monsanto

Example products using this active

Latitude

Formulation and application details

Often supplied as a flowable concentrate for use as a seed treatment

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

0.04

Low

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

15500

n-Heptane

250000

p-Xylene

250000

Methanol

250000

Ethyl acetate

Melting point (°C)

Boiling point (°C)

322

Degradation point (°C)

Flashpoint (°C)

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

5.25 X 10⁰³

Calculated

Log P

3.72

High

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

1.07

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

Vapour pressure at 20 °C (mPa)

81.0

Highly volatile. If applied directly to plants or soil, drift is a concern & mitigation is advisable

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

5.40 X 10^-01

Moderately 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: 245nm=8277
Acid soln: 245nm=8395
Basic soln: 245nm=8530

Surface tension (mN m⁻¹)

60.4

at 20 °C 99.7%

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

42.3

Moderately persistent

DT₅₀ (lab at 20 °C)

42.3

Moderately persistent

DT₅₀ (field)

Moderately persistent

DT₉₀ (lab at 20 °C)

137.5

Persistent

DT₉₀ (field)

241

DT₅₀ modelling endpoint

Note

EU 2016 dossier lab studies DT₅₀ range 26.5-60.8 days, Soils=9; EU 2003 dossier lab studies DT₅₀ range 25-34 days, DT₉₀ range 110-164 days, field study DT₅₀ range 8-116 days (EU), DT₉₀ range 86-387 days

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

Slow

Note

Data for irradiated sterile water at 25 °C

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

Value

Stable

Note

pH and temp sensitive: DT₅₀ 73hrs pH4, 20 °C; 45hrs pH4, 25 °C; 5.2hrs pH4, 50 °C; 61days pH5, 25 °C; 448days pH7, 25 °C; 118days pH7, 50 °C; 77yrs pH9, 20 °C; 314days pH9, 25 °C; 196days pH9, 38 °C; 99days pH9, 50 °C

Water-sediment DT₅₀ (days)

269

Slow

Water phase only DT₅₀ (days)

Moderately 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)

K_oc (mL g⁻¹)

Notes and range

Freundlich

K_f (mL g⁻¹)

3.7

Moderately mobile

K_foc (mL g⁻¹)

250.3

¹/_n

0.90

Notes and range

EU dossier K_f=0.98-6.41 mL g⁻¹, K_foc range 173-328 mL g⁻¹, ¹/_n range 0.81-0.95, Soils=4

pH sensitivity

Adsorption decreases as pH increases

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

2.91

Calculated

High leachability

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

Value

2.78 X 10^-01

Calculated

Note

Potential for particle bound transport index

Medium

Calculated

Potential for loss via drain flow

Moderately mobile

Calculated

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

Bio-concentration factor

BCF (l kg⁻¹)

Whole fish

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

4-(allylcarbamoyl)-3-methyl-5-(trimethylsilyl)thiophene-2-carboxylic acid (Ref: MON 65533)

Major fraction

0.123

4-carbamoyl-3-methyl-5-(trimethylsilyl)thiophene-2-carboxylic acid (Ref: MON 65534)

Major fraction

0.133

N-allyl-4,5-dimethylthiophene-3-carboxamide (Ref: CP-240659)

Major fraction

0.229

4,5-dimethyl-2-(trimethylsilyl)thiophene-3-carboxamide (Ref: MON 65561)

Major fraction

0.102

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)

4-(allylcarbamoyl)-3-methyl-5-(trimethylsilyl)thiophene-2-carboxylic acid (Ref: MON 65533)

Relevant

4-carbamoyl-3-methyl-5-(trimethylsilyl)thiophene-2-carboxylic acid (Ref: MON 65534)

Relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Ref: MON 65513
Note: LC50(fish) = 71 mg/l

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)

Rat

(ppm diet)

> 1000

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

287

Rat Reproductive NOAEL

Low

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2250

Colinus virginianus

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

> 5670 mg kg feed⁻¹

Colinus virginianus

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

250

Colinus virginianus NOEL

Low

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

133

Eisenia foetida

Moderate

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

0.27

Eisenia foetida

Moderate

Soil micro-organisms

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

Dose: 0.08 kg ha⁻¹

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

2.66

Folsomia candida

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)

> 105.7

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

> 50

Aphidius rhopalosiphi

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

> 40

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)

Lepomis macrochirus

Moderate

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

0.89

Pimephales promelas

Moderate

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

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

Daphnia magna

Moderate

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

0.47

Daphnia magna

Moderate

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)

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)

8.6

Raphidocelis subcapitata

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)

> 5000

Rat

Low

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

5000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 2.8

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)

0.2

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

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

0.1

Dermal penetration studies (%)

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

No data found

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

No data found

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

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

Environment: H412

WHO Classification

Not listed (Not listed)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

silthiofam

French

silthiopham

German

Silthiofam

Danish

silthiofam

Italian

siltiofam

Spanish

siltiofam

Greek

Polish

siltiofam

Swedish

siltiofam

Hungarian

Dutch

Norwegian

Record last updated:	06/06/2024
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