Review
Fragrance material review on phenethyl butyrate

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Abstract

A toxicologic and dermatologic review of phenethyl butyrate when used as a fragrance ingredient is presented. Phenethyl butyrate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1–4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for phenethyl butyrate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, and skin sensitization data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances.

Belsito, D., Bickers, D., Bruze, M., Calow, P., Dagli, M., Fryer, A.D., Greim, H., Hanifin, J.H., Miyachi, Y., Saurat, J.H., Sipes, I.G., 2012. A toxicologic and dermatologic assessment of aryl alkyl alcohol simple acid esters when used as fragrance ingredients.

Introduction

This document provides a comprehensive summary of the human health toxicological data currently available pertaining to the safety evaluation of phenethyl butyrate when used as a fragrance ingredient. All safety data on phenethyl butyrate (see Fig. 1; CAS Number 103-52-6) were compiled with due diligence including published and unpublished data.

In 2010, a complete literature search was conducted on phenethyl butyrate. On-line toxicological databases were searched including those from the Chemical Abstract Services (e.g. ToxCenter [which in itself contains 18 databases including chemical abstracts]) and the National Library of Medicine (e.g. Medline, Toxnet [which contains 14 databases]) as well as 26 additional sources (e.g. BIOSIS, Embase, RTECS, OSHA, ESIS). In addition, all RIFM sponsored studies and studies from fragrance companies are included in this summary.

The safety data on this material were last reviewed by Opdyke, 1979. Data from all relevant references are summarized in this fragrance material review (FMR). Commonly used terms and their abbreviations are listed in Appendix A. More details have been provided for unpublished data. The number of animals, sex and strain are always provided unless they are not given in the original report or paper. Papers in which the vehicles and/or the doses are not given were included and noted in this summary because either they demonstrated an adverse effect or there were limited to no data on this fragrance ingredient.

Section snippets

Identification

  • 2.1

    Synonyms: Benzylcarbinyl butyrate; Butanoic acid, 2-phenylethyl ester; 2-phenylethyl butanoate; Phenylethyl butyrate; 2-phenylethyl butyrate

  • 2.2

    CAS registry number: 103-52-6

  • 2.3

    EINECS number: 203-119-8

  • 2.4

    Formula: C12H16O2

  • 2.5

    Molecular weight: 192.26

  • 2.6

    Council of Europe (2000): Phenethyl butyrate was included by the Council of Europe in the list of substances granted B - information required - hydrolysis study (COE No. 506).

  • 2.7

    FDA: Phenethyl butyrate was approved by the FDA as GRAS (21 CFR 172.515)

  • 2.8

    FEMA (1965):

Physical properties1

  • 3.1

    Physical form: Colorless liquid

  • 3.2

    Boiling point (calculated): 269.08 °C

  • 3.3

    Flash point: >200 °F;CC

  • 3.4

    Henry’s law (calculated): 3.312 e–005 Pa m3/mol

  • 3.5

    Log Kow (calculated): 3.55

  • 3.6

    Refractive index: Not available

  • 3.7

    Specific gravity: 0.993

  • 3.8

    Vapor pressure (calculated): 0.00859 mm Hg at 25 °C

  • 3.9

    Water solubility (calculated): 44.15 mg/l

  • 3.10

    UV spectra available at RIFM; peaks at 200–210 nm and returns to base line at: 230 nm

Usage

Phenethyl butyrate is a fragrance ingredient used in many compounds. It may be found in fragrances used in decorative cosmetics, fine fragrances, shampoos, toilet soaps, other toiletries, and non-cosmetic products such as household cleaners and detergents. This material has been reported to occur in nature, with highest quantities observed in mentha oils (VCF, 2011). The worldwide volume of use for phenethyl butyrate is in the region of 0.1–1.0 metric tons per year (IFRA, 2008a). This reported

Oral studies

The LD50 of phenethyl butyrate was 4.6 (4.2–5.0) ml/kg [4.57 (4.17–4.97) g/kg]. The test material was administered by oral gavage to rats (10/group) at doses of 4, 4.5 or 5 ml/kg (3.97, 4.47 or 4.97 g/kg) followed by a 14 day observation period. The incidence of mortality was 2/10, 4/10 and 7/10 from low to high dose. The sex and strain of the animals and clinical signs of toxicity were not reported. A necropsy was not conducted (RIFM, 1974a).

Dermal studies

The LD50 of phenethyl butyrate was greater than 5.0 

Conflict of Interest

This research was supported by the Research Institute for Fragrance Materials, an independent research institute that is funded by the manufacturers of fragrances and consumer products containing fragrances.

References (17)

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