Silthiofam (Ref: MON 65500)

Silthiofam (Ref: MON 65500)	Last updated: 21/10/2020
(Also known as: silthiopham)

GENERAL INFORMATION

Description

A new 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

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

30/06/2033

UK LERAP status

None (may vary with mixtures)

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
✓		✓	✓			✓		✓

Also used in

Chemical structure

Isomerism

Chemical formula

C₁₃H₂₁NOSSi

Canonical SMILES

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

Isomeric SMILES

No data

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 group

Thiophene

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

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 Classification (HRAC)

Not applicable

Herbicide Resistance Classification (WSSA)

Not applicable

Insecticide Resistance Classification (IRAC)

Not applicable

Fungicide Resistance Classification (FRAC)

Examples of recorded resistance

Physical state

White powder

Formulations

Property

Value

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

Latitude

Example products using this active

Monsanto

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)

Not expected to self ignite; Not highly flammable

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

5.25 X 10⁰³

Calculated

Log P

3.72

High

Bulk 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

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

5.40 X 10^-01

Moderately volatile

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 on plant matrix

Value

Note

Dissipation rate RL₅₀ 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

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

K_oc

Notes and range

Freundlich

K_f

3.7

Moderately mobile

K_foc

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

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

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

Soil

0.229

Major fraction, Relevant

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

Soil

0.102

Major fraction, Relevant

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

Soil

0.123

Major fraction, Relevant

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

Soil

0.133

Major fraction, Relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

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

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

Whole fish

Low potential

CT₅₀ (days)

Not available

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

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

Lepomis macrochirus

Moderate

Fish - Chronic 21 day NOEC (mg l⁻¹)

0.89

Pimephales promelas

Moderate

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

Daphnia magna

Moderate

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

0.47

Daphnia magna

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)

Non-target plants

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

8.6

Rhapidocelis subcapitata

Moderate

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

> 105.7

Apis mellifera

Low

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

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 pollinators (1)

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

Mode of exposure

Other pollinators (2)

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

Mode of exposure

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

133

Eisenia foetida

Moderate

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

0.27

Eisenia foetida

Moderate

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

2.66

Folsomia candida 28d

Other arthropod (1)

LR₅₀ g ha⁻¹

% Effect

Mortality / Fecundity [Dose: 0.04 kg ha⁻¹]
Aphidius rhopalosiphi adult

Other arthropod (2)

LR₅₀ g ha⁻¹

% Effect

-41.8

Mortality and Fecundity [Dose: 0.04 kg ha⁻¹]
Typhlodromus pyri protonymph

Soil micro-organisms

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

Dose: 0.08 kg ha⁻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)

0.064

Rat 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)

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

0.1

Dog 90 day SF=100

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

European MRLs

EU MRL pesticide database

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

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

CLP classification 2013

Environment: H412

EC Risk Classification

Xn - Harmful: R43
N - Dangerous for the environment: R52, R53

EC Safety Classification

WHO Classification

NL (Not listed)

UN Number

Waste disposal & packaging

TRANSLATIONS

Language

Name

English

silthiofam

French

silthiopham

German

Silthiofam

Danish

silthiofam

Italian

siltiofam

Spanish

siltiofam

Greek

Polish

siltiofam

Swedish

siltiofam

Hungarian

Dutch

Record last updated:	21/10/2020
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