Phenoxyethanol

• BPPhenoxyethanol
• Ph. Eur.Phenoxyethanol

2-Phenoxyethanol; ethylene glycol monophenyl ether; β-hydroxyethyl phenyl ether; phenoxetol; phenoxyethanolum; phenyl cellosolve

2-Phenoxyethanol · [122-99-6]

UNII HIE492ZZ3T · PubChem CID 31236

C8H10O2 · 138.16

Antimicrobial preservative

Typical concentrations: 0.5–1% · Dosage forms: Semi-solid, Sterile (parenteral/ophthalmic)

An antimicrobial preservative used in topical creams, lotions and shampoos, usually at 0.5–1.0% w/w, and in some vaccines and other injectable products at about 0.5%. It is widely used in cosmetics, where the EU maximum is 1%. It is often combined with parabens or other preservatives to broaden the spectrum of activity.

A colourless, slightly viscous, oily liquid with a faint, pleasant aromatic odour and a burning taste.

Boiling point

about 245 °C

Melting point

about 14 °C

Density

about 1.11 g/cm³ (20 °C)

Solubility

slightly soluble in water (roughly 2.5% w/v); miscible with acetone, ethanol and glycerol; slightly soluble in fixed oils

Stable and not volatile at room temperature; aqueous solutions can be sterilised by autoclaving. Store in a well-closed container in a cool, dry place, protected from light.

Its antimicrobial activity can be reduced by nonionic surfactants and by sorption onto some plastics such as PVC. It is incompatible with strong oxidising agents.

Prepared by reacting phenol with ethylene oxide in an alkaline medium (hydroxyethylation of phenol), followed by purification by distillation.

At the concentrations used as a preservative it is generally well tolerated on the skin, although irritation and rare contact allergy have been reported. It is an eye irritant in concentrated form, and ingestion of large amounts can cause central nervous system depression.

Observe normal precautions for the quantity handled. Avoid contact with the eyes and prolonged skin contact; eye protection and gloves are recommended.

Included in the FDA Inactive Ingredient Database (injections, including vaccines, and topical preparations) and in medicines licensed in Europe. Permitted as a preservative in cosmetics in the EU up to 1%.

Benzyl alcohol; phenylethyl alcohol; phenoxypropanol.

Phenoxyethanol is particularly active against Gram-negative bacteria, including Pseudomonas aeruginosa, but is weaker against Gram-positive bacteria, yeasts and moulds, which is why it is usually paired with a second preservative. Its activity is little affected by pH over the usual formulation range.