Fenbutatin oxide (Ref: ENT 27738)

Fenbutatin oxide (Ref: ENT 27738)	Last updated: 22/08/2024
(Also known as: hexakis; SD 14114; BAS 2981)

SUMMARY

Fenbutin oxide is an acaricide used to control a wide range of phytophagous mites and other insects although it is not now used in the developed world. It has a low aqueous solubility but is soluble in several organic solvents. This substance tends to be very persistent in soil and water systems. It is not highly volatile. Toxicity to fish is high but moderate to low for many other species. Fenbutin oxide has a low human oral toxicity but may be fatal if inhaled.

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: Potential for particle bound transport: High	Ecotoxicity High alert: Fish acute ecotoxicity: High; Fish chronic ecotoxicity: High; Daphnia acute ecotoxicity: High	Human health High alert: Reproduction/development effects

GENERAL INFORMATION

Description

An acaricide used to control a wide range of phytophagous mites and other insects

Example pests controlled

Spidermites, Aphids, Mealybugs, Thrips, Whitefiles, Scale

Example applications

Fruit trees including citrus, apples, apricots; Currants; Vines; Nuts; Ornamentals

Efficacy & activity

Availability status

Current

Introduction & key dates

1974, first registered in US

GB regulatory status

GB COPR regulatory status

Not approved

Date COPR inclusion expires

Expired

GB LERAP status

No UK approval for use as a pesticide

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Not approved

Dossier rapporteur/co-rapporteur

Belgium

Date EC 1107/2009 inclusion expires

Expired

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, USA

Chemical structure

Isomerism

None

Chemical formula

C₆₀H₇₈OSn₂

Canonical SMILES

CC(C)(C[Sn](CC(C)(C)C1=CC=CC=C1)(CC(C)(C)C2=CC=CC=C2)O[Sn](CC(C)(C)C3=CC=CC=C3)(CC(C)(C)C4=CC=CC=C4)CC(C)(C)C5=CC=CC=C5)C6=CC=CC=C6

Isomeric SMILES

International Chemical Identifier key (InChIKey)

HOXINJBQVZWYGZ-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/6C10H13.O.2Sn/c6*1-10(2,3)9-7-5-4-6-8-9;;;/h6*4-8H,1H2,2-3H3;;;/rC60H78OSn2/c1-55(2,49-31-19-13-20-32-49)43-62(44-56(3,4)50-33-21-14-22-34-50,45-57(5,6)51-35-23-15-24-36-51)61-63(46-58(7,8)52-37-25-16-26-38-52,47-59(9,10)53-39-27-17-28-40-53)48-60(11,12)54-41-29-18-30-42-54/h13-42H,43-48H2,1-12H3

2D structure diagram/image available?

Yes

General status

Pesticide type

Acaricide, Insecticide

Substance groups

Organometal compound; Organotin insecticide

Minimum active substance purity

970 g kg⁻¹

Known relevant impurities

EU dossier - bishydroxybis(2-methyl-2-phenoxypropyl)tinoxide, <20g/Kg

Substance origin

Synthetic

Mode of action

Selective, non-systemic with contact and stomach action, acts by inhibiting oxidative phosphorylation. Inhibitor of mitochondrial ATP synthase.

CAS RN

13356-08-6

EC number

236-407-7

CIPAC number

359

US EPA chemical code

104601

PubChem CID

16683004

CLP index number

050-017-00-2

Molecular mass

1052.68

PIN (Preferred Identification Name)

hexakis(2-methyl-2-phenylpropyl)distannoxane

IUPAC name

bis[tris(2-methyl-2-phenylpropyl)tin] oxide

CAS name

hexakis(2-methyl-2-phenylpropyl)distannoxane

Other status information

OSPAR soc; Severe Marine Pollutant

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)

12B

Fungicide Resistance Class (FRAC MOA class)

Not applicable

Examples of recorded resistance

Tetranychus turkestani, Tetranychus urticae

Physical state

Fine white powder

Formulations

Property

Value

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

BASF
DuPont
Sepro Corp
Shell

Example products using this active

Torque 50WP
Vendex

Formulation and application details

Often supplied as a wettable powder, suspension concentrate or liquid concentrate

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

0.015

Low

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

3490

Hexane

70100

Toluene

4920

Acetone

310000

Dichloromethane

Melting point (°C)

147.8

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

230

Flashpoint (°C)

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

1.41 X 10⁰⁵

Calculated

Log P

5.15

at 25 °C

High

Fat solubility of residues

Solubility

Soluble

Data type

Regulatory data - observed in metabolism and farm animal feeding studies

Density (g ml⁻¹)

1.31

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

Vapour pressure at 20 °C (mPa)

3.9 X 10^-05

Low volatility

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

2.70 X 10^-03

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 solution: 225nm = 3509333, 259nm = 1097, 290nm = <10
Acidic solution: 225nm = 3773333, 259nm = 1039, 290nm = <10
Basic solution: 224nm = 3524000, 259nm = 998, 290nm = <10

Surface tension (mN m⁻¹)

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

365

Very persistent

DT₅₀ (lab at 20 °C)

389

Very persistent

DT₅₀ (field)

Moderately persistent

DT₉₀ (lab at 20 °C)

1431

Very persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀ range 243-795 days, DT₉₀ range 1001-2303 days; Other sources: DT₅₀ 90 days (DW4)

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

Stable

Note

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

Value

100

Persistent

Note

Not sensitive to pH

Water-sediment DT₅₀ (days)

147

Slow

Water phase only DT₅₀ (days)

Moderately fast

Sediment 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)

K_oc (mL g⁻¹)

Notes and range

Freundlich

K_f (mL g⁻¹)

1677

Non-mobile

K_foc (mL g⁻¹)

139404

¹/_n

0.99

Notes and range

EU dossier kf range 1283-2333 mL g⁻¹, K_foc range 44353-298490 mL g⁻¹, ¹/_n range 0.94-1.04, Soils=3

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

-2.26

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

High

Calculated

Potential for loss via drain flow

Non-mobile

Calculated

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

0.217

Calculated using the Atkinson method. Assumed 1.56E+06 OH/cm³, 12 hr

Below the level of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

730

Threshold for concern

CT₅₀ (days)

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

1,3-dihydroxy-1,1,3,3-tetrakis(2-methyl-2-phenylpropyl)distannoxane (Ref: IN-CG 200)

Minor fraction

0.034

Photolysis

Known groundwater metabolites

None

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

1,3-dihydroxy-1,1,3,3-tetrakis(2-methyl-2-phenylpropyl)distannoxane (Ref: IN-CG 200)

SD 31723

Rat; Water; Plant

beta,beta--dimethylphenethylstannoic acid polymer

SD 33608

Water/sediment; Water (Photolysis); Plant

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 3000

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat 2 yr

(ppm diet)

> 100

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

Birds - Acute LD₅₀ (mg kg⁻¹)

> 969

Anas platyrhynchos

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

> 5620 mg kg feed⁻¹

Anas platyrhynchos

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

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

> 500

Eisenia andrei corr

Moderate

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

1.67

Eisenia andrei corr

Moderate

Soil micro-organisms

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

Dose: 10 mg kg⁻¹ soil 28 Day

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

> 1000

Onion Oat OSR Cucumber Pea Tomato
Vegetative vigour, ER₅₀
as g ha⁻¹

> 1000

Onion Oat OSR Cucumber Pea Tomato
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)

> 200

Apis mellifera

Low

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

> 200

Apis mellifera

Low

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

Chronic

Notes

[The residual time to 25% mortality (RT25) value for honeybees is 3 hrs - USEPA data]

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) as % Mortality at dose 8 kg ha⁻¹

15.4

Chrysoperla carnea corr

Beneficial insects (Parasitic wasps) as Mortality LR₅₀ g ha⁻¹ 48 hr

85.9

Aphidius rhopalosiphi

Beneficial insects (Predatory mites) as Mortality LR₅₀ g ha⁻¹ 7 day

468.6

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)

0.00114

Oncorhynchus mykiss

High

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

0.00127

Oncorhynchus mykiss

High

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

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

0.048

Daphnia magna

High

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

0.016

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)

> 1000

Chironomus riparius

Low

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

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

> 0.0036

Pseudokirchneriella subcapitata

High

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

Mesocosm study data

NOEAEC mg l⁻¹

0.1

Aquatic community

NOEAEC mg l⁻¹

Marine bivalves

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)

> 3000

Rat

Low

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

0.046

Rat 4 hr (whole body)

Other Mammal toxicity endpoints

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

0.05

Rat SF=100

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

0.1

Rat SF=100

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

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

None allocated

Dermal penetration studies (%)

1-20

concentration dependent

Dangerous Substances Directive 76/464

List I

Exposure Routes

Public

No unacceptable risks to bystanders identified

Occupational

MRLs

European

EU MRL pesticide database

Great Britain

GB MRL Register

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

0.1

EU Dir 89/778/EC limit

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

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

Highly toxic if inhaled

Handling issues

Property

Value and interpretation

General

Not oxidising or explosive
IMDG Transport Hazard Class 6.1
Not explected to auto-ignite, Not highly flammable

CLP classification 2013

Health: H315, H319, H330
Environment: H400, H410

WHO Classification

III (Slightly hazardous)

UN Number

UN2786

Waste disposal & packaging

Packaging Group II (moderate danger)

Shelf-life, storage, stability and reactivity

Chemically stable under standard ambient conditions

TRANSLATIONS

Language

Name

English

fenbutatin oxide

French

fenbutin oxyde

German

Fenbutatinoxid

Danish

fenbutatin oxid

Italian

fenbutatin ossido

Spanish

fenbutatin óxido

Greek

Polish

tlenek fenbutacyny

Swedish

Hungarian

fenbutalin-oxid

Dutch

fenbutatinoxide

Norwegian

Record last updated:	22/08/2024
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