Phenethyl alcohol, also known as phenylethyl alcohol or 2-phenylethanol, is an aromatic alcohol consisting of a benzene ring attached to a two-carbon alcohol chain. It is a colorless, transparent and slightly viscous liquid with a characteristic rose-like odor.

The ingredient occurs naturally in plants, microorganisms and animals and has been identified in numerous essential oils, foods, spices, tobacco, beer, wine and other fermented products. Although it can be obtained from natural sources, commercial phenethyl alcohol is most commonly produced synthetically because natural extraction, particularly from rose oil, is economically inefficient.

INCI Name: Phenethyl Alcohol
Other Names: Phenylethyl Alcohol, 2-Phenylethanol
CAS Number: 60-12-8
EINECS Number: 200-456-2
Molecular Formula: C8H10O
Molecular Weight: 122.17 g/mol
Chemical Class: Aromatic Alcohol
Function: Fragrance Ingredient, Preservative-supporting Ingredient, Masking Agent

Fragrance Properties

Phenethyl alcohol has a characteristic soft, sweet and rose-like floral odor and is an important material in perfumery.

It can be used to impart a floral character to a formulation or to modify and mask undesirable odors originating from other ingredients. Because of its relatively mild and pleasant odor, it is frequently used in fragrances for personal care and cosmetic products.

Phenethyl alcohol is also naturally present in rose oil and contributes to the characteristic aroma of roses.

Preservative and Antimicrobial Properties

Phenethyl alcohol has antimicrobial activity and can inhibit the growth of certain microorganisms. For this reason, it is frequently used in cosmetic formulations as part of a preservation system.

Its antimicrobial effect can help prevent or retard bacterial growth and therefore contribute to the protection of a cosmetic product against microbial spoilage.

However, phenethyl alcohol should not automatically be considered a complete broad-spectrum preservative when used alone. Its effectiveness depends on the concentration, formulation pH, water activity, packaging and the other components of the preservation system.

In practice, it may be combined with other antimicrobial or preservative ingredients to provide more comprehensive protection against bacteria, yeasts and molds.

Cosmetic Applications

Phenethyl alcohol is used in a wide variety of cosmetic and personal care products.

It can be found in skincare products, haircare products, cleansers, creams, lotions, fragrances, deodorants and other fragranced formulations. It can function simultaneously as a fragrance component, odor-masking ingredient and antimicrobial component of the preservation system.

Its dual fragrance and antimicrobial properties make it particularly useful in formulations where both functions are desirable.

Formulation Considerations

Phenethyl alcohol is a liquid ingredient that can be incorporated into a variety of cosmetic formulation systems.

Because it is both a fragrance material and an antimicrobial ingredient, its concentration should be selected according to the intended purpose. A concentration chosen primarily for fragrance may not provide sufficient preservation, while a concentration chosen for antimicrobial activity may have a significant effect on the sensory profile of the finished product.

The ingredient should therefore be evaluated as part of the complete preservation strategy rather than considered in isolation.

Compatibility with the other fragrance components, preservatives, emulsifiers and active ingredients should be evaluated during formulation development.

Stability

Phenethyl alcohol is relatively stable under normal formulation and storage conditions. Nevertheless, the stability of the ingredient and the finished product can be influenced by temperature, light, oxygen and interactions with other formulation components.

Finished products containing phenethyl alcohol should undergo appropriate stability testing to evaluate changes in odor, appearance, color, pH, viscosity and microbiological quality throughout the intended shelf life.

Skin Compatibility

Phenethyl alcohol is generally well tolerated at the concentrations commonly used in cosmetic products. However, as with many fragrance materials, individual sensitivity can occur.

The potential for irritation or sensitization should be considered according to the concentration and the intended application. Products intended for sensitive skin or prolonged leave-on exposure should be evaluated particularly carefully.

The safety of a finished formulation depends on the total exposure to phenethyl alcohol and other fragrance and preservative ingredients present in the product.

Natural Occurrence

Phenethyl alcohol occurs naturally in a wide range of biological materials. It has been identified in rose oil and other essential oils, as well as in various foods, spices, tobacco and fermented alcoholic beverages.

It is also produced naturally by microorganisms, plants and animals and has been detected as a metabolite in humans, including in urine.

Despite its natural occurrence, the phenethyl alcohol used commercially in cosmetics is frequently produced synthetically because this provides a more consistent and economically practical source of the ingredient.

Safety

The safety of phenethyl alcohol in cosmetic products has been evaluated by the Cosmetic Ingredient Review Expert Panel.

The CIR Expert Panel concluded that phenethyl alcohol is safe for use in cosmetics and personal care products at concentrations of up to 1%. The conclusion was subsequently reaffirmed during the CIR's scheduled re-evaluation in 2006 after consideration of additional available data.

The appropriate concentration in a finished cosmetic product should nevertheless be determined according to the product type, exposure conditions, intended use and applicable regulations.

Toxicological Information

Historical acute oral toxicity data report an LD50 of approximately 1,790 mg/kg body weight in rats.

This is an acute oral animal toxicity value and should not be interpreted as a safe cosmetic concentration or directly extrapolated to topical exposure.

A reliable ingredient-specific NOAEL for topical cosmetic exposure is not provided in the supplied source and should not be inferred from the oral LD50 value.

Regulatory Information

The U.S. Food and Drug Administration includes phenethyl alcohol among direct food additives permitted for use as a synthetic flavoring substance under applicable conditions.

For cosmetic use, the CIR Expert Panel has concluded that phenethyl alcohol is safe at concentrations up to 1% based on its assessment of the available safety data.

Regulatory requirements may differ between markets and product categories. The final concentration and intended function should therefore be assessed against the applicable cosmetic and fragrance regulations in the target market.

References

Dweck, Anthony. Handbook of Natural Ingredients. Dweck Books.

Cosmetic Ingredient Review Expert Panel. Final Report on the Safety Assessment of Phenethyl Alcohol.

Cosmetic Ingredient Review Expert Panel. Annual Review of Cosmetic Ingredient Safety Assessments, 2006.

U.S. Food and Drug Administration. Food Additive Status List – Phenethyl Alcohol.

European Commission. CosIng – Cosmetic Ingredients Database.

National Center for Biotechnology Information. PubChem – Phenethyl Alcohol.

National Center for Biotechnology Information. PubMed – Phenethyl Alcohol safety and toxicology.

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