Benzyl benzoate

Benzyl benzoate	Last updated: 15/09/2025
(Also known as: benzoic acid phenylmethyl ester; benzyl phenylformate; benzoic acid benzyl ester; benzylbenzenecarboxylate; benzylis benzoas)

SUMMARY

Benzyl benzoate is used mainly as a non-agricultural pesticide although it also has other manufacturing applications. It has a moderate aqueous solubility and is moderately volatile. Little information is available regarding its environmental fate. Benzyl benzoate is moderately toxic to birds and fish. It has a low oral mammalian toxicity and a neurotoxin as well as being a recognised irritant.

GENERAL INFORMATION

Description

A bridged diphenyl insecticide used topically to manage skin problems

Examples of veterinary uses

Most common use is for the treatment of "Sweet Itch" in horses. It is also sometiems used to treat mites responsible for causing scabies

Examples of species treated

Horses

Approval status

VMR 2013/2033 approval status (GB/UK)

Approved - usually available as an authorised veterinary medicine for general sale (AVM-GSL)

EU Regulatory approval status

Approved

Chemical structure

Isomerism

None

Chemical formula

C₁₄H₁₂O₂

Canonical SMILES

C1=CC=C(C=C1)COC(=O)C2=CC=CC=C2

Isomeric SMILES

International Chemical Identifier key (InChIKey)

SESFRYSPDFLNCH-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C14H12O2/c15-14(13-9-5-2-6-10-13)16-11-12-7-3-1-4-8-12/h1-10H,11H2

2D structure diagram/image available?

Yes

General status

Veterinary substance type

Antiparasitic

Other bioactivity & uses

Solvent; Biocide; Disinfectant; Algicide

Substance groups

Bridged diphenyl insecticide

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

It is believed to exert a neurotoxic effect, disrupting nerve cell membranes and leading to paralysis and death of the parasite

Molecular targets

[Unclear - proably affects voltage-gated ion channels &/or neurotransmitter signaling]

CAS RN

120-51-4

EC number

204-402-9

CIPAC number

None allocated

US EPA chemical code

009501

PubChem CID

2345

CLP index number

607-085-00-9

Therapeutic Class

Antiparasitic products, insecticides & repellents: Ecoparasiticides, insecticides & repellents

ATCvet Code

QP53AX11

Controlled Drug?

Regulation 37/2010 MRL Classification

Allowed substance (Table 1: All food producing species)

Molecular mass

212.25

PIN (Preferred Identification Name)

benzyl benzoate

IUPAC name

benzyl benzoate

CAS name

phenylmethyl benzoate

Forever chemical

Other status information

Relevant Environmental Water Quality Standards

Physical state

Colourless to pale yellow oily liquid with pleasant aromatic odour

Commercial

Property

Value

Availability status

Current

Introduction & key dates

Early 20th century, introduced

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

Carr Day and Martin Ltd
Schering-Plough Ltd

Example products using this active

Ascabin
Ascabiol
Killitch Cutaneous Emulsion
Savlon Veterinary Antiseptic

Formulation and application details

Veterinary formulations are usually emulsions for topical application. Non-agricultural formulations include foams and powders.

Commercial production

The production of benzyl benzoate typically involves an esterification reaction between benzyl chloride and sodium benzoate in the presence of a phase transfer catalyst. First, benzyl chloride is added to an aqueous sodium benzoate solution, where the catalyst facilitates the transfer of reactants between phases, promoting efficient ester formation. The resulting crude ester undergoes water washing to remove inorganic salts, followed by alkali washing to eliminate residual acidic or unreacted components. The purified mixture is then subjected to reduced pressure distillation, which isolates benzyl benzoate as a high-purity liquid product.

Impact on climate of production and use

Data for the amount of life cycle GHGs produced by benzyl benzoate are not available in the public domain. However, based on available data and comparable chemical processes, a rough estimate of GHG emissions for producing 1 kg of benzyl benzoate could range between 2 to 5 kg CO₂e. This estimate assumes (i) solventless transesterification using benzyl alcohol and methyl benzoate, (ii) use of moderate heating and biocatalysts like lipase, which reduce energy consumption compared to traditional chemical synthesis and (iii) distillation as the purification step, which is energy-intensive and contributes significantly to emissions.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

15.4

at 25 °C

Moderate

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

Miscible

Ether

Miscible

Ethanol

Miscible

Methanol

Miscible

Acetone

Melting point (°C)

Boiling point (°C)

323

Degradation point (°C)

Flashpoint (°C)

158

(closed cup)

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

9.33 X 10⁰³

Calculated

Log P

3.97

High

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

1.12

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

29.86

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)

0.284

Moderately 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)

Refractive Index

1.5681

Environmental release

Degradation

Property

Value

Source; quality score; and other information

Interpretation

Soil degradation (days) (aerobic)

DT₅₀ (typical)

DT₅₀ (lab at 20 °C)

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

Note

Manure DT₅₀ (days)

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Note

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

Value

Note

Water-sediment DT₅₀ (days)

Water phase only DT₅₀ (days)

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)

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

Bio-concentration factor

BCF (l kg⁻¹)

CT₅₀ (days)

Known soil and groundwater metabolites

None

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

benzoic acid

Human

benzyl alcohol

Human

hippuric acid

Human

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 2800

Rat

Low

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)

2000

Colinus virginianus

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

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

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

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

Soil micro-organisms

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

Vegetative vigour ER₅₀ (g ha⁻¹)

Seedling emergence ER₅₀ (g ha⁻¹)

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)

Chronic

Notes

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)

4.6

Unknown species

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)

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 (free-floating, fonds growth, fresh) - 7 day (mg l⁻¹)

Aquatic plants (rooted, growth rate, fresh) - 14 day (mg l⁻¹)

Algae - Acute (growth rate, fresh; mg l⁻¹)

Algae - Chronic (growth rate, fresh; mg l⁻¹)

Mesocosm study data

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)

Low (class I)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 2800

Rat

Low

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

Other Mammal toxicity endpoints

Intraperitoneal LD₅₀ > 500 mg kg⁻¹

Mouse

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

Exposure Routes

Public

No unacceptable risks identified

Occupational

May be absorbed through the skin

Mammalian dose elimination route and rate

Metabolised and excreted mainly in the urine

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

No data found

General human health issues

May cause nausea and vomiting
In large doses may cause skin blistering, crusting & scaling

Handling issues

Property

Value and interpretation

General

Combustible
IMDG Transport Hazard Class 9
Incompatible with alkalis and oxidising agents

CLP classification 2013

Health: H302
Environment: H411

WHO Classification

Not listed (Not listed)

UN Number

UN3082

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

benzyl benzoate

French

German

Danish

Italian

Spanish

Greek

Polish

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	15/09/2025
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