Benomyl (Ref: T 1991)

Benomyl (Ref: T 1991)	Last updated: 31/12/2020
(Also known as: benosan; kribenomy; D-1991; BBC; BNM)

SUMMARY

Benomyl is a foliar fungicide that no longer has EU approval for use. It has a low aqueous solubility, is volatile, is slightly mobile and, based on its chemical properties, is not expected to leach to groundwater. It is generally not persistent in soil systems but may persist in some water systems under certain conditions. Benomyl has a low mammalian toxicity with a low potential for bioaccumulation. It is also reported to have harmful effects on human development/fertility. It is moderately toxic to birds, honeybees, earthworms and most aquatic organisms

GENERAL INFORMATION

Description

A broad-spectrum foliar fungicide used to control a wide range of Ascomycetes and Fungi Imperfecti in a wide range of crops

Example pests controlled

Fruit spot; Powdery mildew; Scab; Post-harvest decay; Blosson end rot; Blosson blight; Brown rot; Collar rot; Phoma leaf blotch; Black spot; Corm rot; Loose smut; Sclerotina rot

Example applications

Field crops; Nuts; Muschrooms; Ornamentals; Turf; Apples & pears; Peaches; Curcubits; Peppers; Peas; Grapes

Efficacy & activity

Availability status

Current

Introduction & key dates

1968, Introduced

UK regulatory status

UK COPR regulatory status

Not approved

Date COPR inclusion expires

Not applicable

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

Germany

Date EC 1107/2009 inclusion expires

Not applicable

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

USA

Chemical structure

Isomerism

None

Chemical formula

C₁₄H₁₈N₄O₃

Canonical SMILES

CCCCNC(=O)N1C2=CC=CC=C2N=C1NC(=O)OC

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

RIOXQFHNBCKOKP-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C14H18N4O3/c1-3-4-9-15-13(19)18-11-8-6-5-7-10(11)16-12(18)17-14(20)21-2/h5-8H,3-4,9H2,1-2H3,(H,15,19)(H,16,17,20)

2D structure diagram/image available?

Yes

General status

Pesticide type

Fungicide, Miticide

Substance group

Benzimidazole

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Systemic with protectant and eradicant activity. Also has ovicidal activity against mites. Inhibition of mitosis and cell division (Beta-tubulin assembly in mitosis)

CAS RN

17804-35-2

EC number

241-775-7

CIPAC number

206

US EPA chemical code

099101

PubChem CID

28780

CLP index number

613-049-00-3

Molecular mass

290.32

PIN (Preferred Identification Name)

methyl [1-(butylcarbamoyl)-1H-1,3-benzimidazol-2-yl]carbamate

IUPAC name

methyl 1-(butylcarbamoyl)benzimidazol-2-ylcarbamate

CAS name

methyl [1-[(butylamino)carbonyl]-1H-benzimidazol-2-yl]carbamate

Other status information

Chemical subject to PIC regulations (some formulations); Marine Pollutant

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

Tan coloured crystals

Related substances & organisms

copper oxychloride

thiram

Formulations

Property

Value

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

Benlate
Tersan 1991
Benex
Benefit
Comply
Agrocut
Benosan

Example products using this active

DuPont
Dongbu Fine Chemicals Co. Ltd.
King Tech

Formulation and application details

Usually supplied as an oil dispersible product or as a wettable powder.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

Low

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

94000

Chloroform

18000

Acetone

10000

Xylene

4000

Ethanol

Melting point (°C)

Decomposes before melting

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

140

Flashpoint (°C)

Not expected to self ignite; Not highly flammable

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

2.51 X 10⁰¹

Calculated

Log P

1.4

Low

Bulk density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

4.48

Weak acid

Vapour pressure at 20 °C (mPa)

0.005

Low volatility

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

4.00 X 10^-04

Non-volatile

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)

67.0

Moderately persistent

DT₅₀ (lab at 20 °C)

0.8

Non-persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

Other sources: Very variable data DT₅₀ 0.1-100 days, more usually 3-12 months

Dissipation rate RL₅₀ on plant matrix

Value

6.1

Note

Apple leaves, n=1

Dissipation rate RL₅₀ on and in plant matrix

Value

1.7

Note

Published literature RL₅₀ range 1.6-1.8 days, 3 undercover grown crops, various matrices, n=3

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Stable

Note

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

Value

0.8

Non-persistent

Note

Water-sediment DT₅₀ (days)

Water phase only DT₅₀ (days)

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

Slightly mobile

K_oc

1900

Notes and range

Best available data

Freundlich

K_f

K_foc

¹/_n

Notes and range

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

-0.07

Calculated

Low leachability

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

Value

9.09 X 10^-05

Calculated

Note

Potential for particle bound transport index

High

Calculated

Potential for loss via drain flow

Slightly mobile

Calculated

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

carbendazim (Ref: BAS 346F)

Soil

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

N,N-dibutylurea
Note: Toxic

Soil

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)

> 10000

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

125

Rat

Moderate

(ppm diet)

2500

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

Birds - Acute LD₅₀ (mg kg⁻¹)

1000

Anas platyrhynchos

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

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

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

0.17

Oncorhynchus mykiss

Moderate

Fish - Chronic 21 day NOEC (mg l⁻¹)

0.011

Oncorhynchus mykiss LOEC

Moderate

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

0.28

Daphnia magna

Moderate

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

0.025

Daphnia magna LOEC

Moderate

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

0.14

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)

2.2

Lemna gibba

Moderate

Non-target plants

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

Scenedesmus acutus

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)

Moderate

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)

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)

10.5

Moderate

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

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Other arthropod (1)

LR₅₀ g ha⁻¹

% Effect

Harmful

Typhlodromus pyri

Other arthropod (2)

LR₅₀ g ha⁻¹

% Effect

Soil micro-organisms

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)

> 10000

Rat

Low

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

5000

Rabbit

Mammals - Inhalation LC₅₀ (mg l⁻¹)

2.0

Rat

Other Mammal toxicity endpoints

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

0.1

JMPR 1995

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

Exposure Routes

Public

Occupational

Occupational exposure may occur through inhalation and dermal contact

MRLs

European

EU MRL pesticide database

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

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

Eye irritant

Phototoxicant

No data found

General human health issues

May cause eye defects in new borns - anophthalmia
May cause contact dermatitis and may be a skin sensitiser
Endocrine issues - Increase of estrogen production and aromatase activity

Handling issues

Property

Value and interpretation

General

No information available

CLP classification 2013

Health: H315, H317, H335, H340, H360FD
Environment: H400, H410

EC Risk Classification

Mutagenic category 2: R46
Reproduction risk category 2: R60, R61
Xn - Harmful: R43
Xi - Irritant: R37, R38
N - Dangerous for the environment: R50, R53

EC Safety Classification

S43, S53, S61, S60

WHO Classification

U (Unlikely to present an acute hazard)

UN Number

Waste disposal & packaging

TRANSLATIONS

Language

Name

English

benomyl

French

bénomyl

German

Benomyl

Danish

benomyl

Italian

benomil

Spanish

benomil; benomyl

Greek

benomyl

Polish

benomyl

Swedish

benomyl

Hungarian

benomil

Dutch

benomyl

Record last updated:	31/12/2020
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