Phenylethyl alcohol

• BPPhenylethyl Alcohol
• USP–NFPhenylethyl Alcohol

Benzeneethanol; benzyl carbinol; β-hydroxyethylbenzene; PEA; phenethyl alcohol; 2-phenylethanol; β-phenylethyl alcohol

2-Phenylethanol · [60-12-8]

UNII ML9LGA7468 · PubChem CID 6054

C8H10O · 122.16

Antimicrobial preservative

Typical concentrations: — · Dosage forms: Sterile (parenteral/ophthalmic)

Used as an antimicrobial preservative in ophthalmic, nasal and otic solutions, typically at 0.25–0.5% v/v, usually together with another preservative such as benzalkonium chloride or chlorhexidine for a synergistic effect. It is also widely used as a flavour and fragrance (rose odour) in foods, cosmetics and toiletries.

A clear, colourless liquid with a characteristic rose-like odour and a sharp, burning taste. It occurs naturally in rose oil and several other essential oils.

Boiling point

about 219–221 °C

Density

about 1.02 g/cm³ (20 °C)

Refractive index

about 1.53 (20 °C)

Solubility

sparingly soluble in water (about 1 in 60); miscible with ethanol, chloroform, ether, glycerol and fixed oils

Stable in bulk, and stable in aqueous solution including on autoclaving. Store in an airtight container, protected from light, in a cool, dry place.

Incompatible with oxidising agents and with protein-containing materials such as serum. Its antimicrobial activity may be partly reduced by polysorbates and other nonionic surfactants.

Produced synthetically, for example by Friedel–Crafts reaction of benzene with ethylene oxide in the presence of aluminium chloride, or by reduction of phenylacetic acid esters; it can also be obtained from natural sources.

Widely used in foods, cosmetics and topical and ophthalmic medicines, and generally regarded as non-toxic and non-irritant at the concentrations used as a preservative. Higher concentrations can irritate the eye, and concentrated material is irritant to the skin.

Observe normal precautions for the quantity handled. Eye protection and gloves are recommended; the liquid is combustible.

Included in the FDA Inactive Ingredient Database (nasal, ophthalmic and otic preparations) and in non-parenteral medicines licensed in Europe. Permitted as a synthetic flavouring substance in foods.

Benzyl alcohol; chlorobutanol; phenoxyethanol.

On its own phenylethyl alcohol has relatively weak, slow antimicrobial activity, being more effective against Gram-negative bacteria; it acts mainly by increasing cell-membrane permeability, which explains its usefulness in combination with other preservatives. Activity is greatest at acidic to neutral pH.