Manufacturers of skincare products often use short-chain alcohols such as ethanol and propanol as they help other ingredients to mix together, and they have germ-killing properties.
Alcohols are also included in some cosmetic products to help other ingredients penetrate the skin. In products like toners and cleansers, alochols are used to help shrink pore size and tighten skin. These alcohols are also very volatile and give products a quick-drying finish.
Despite how commonly they are used in skincare products, these short-chain alcohols are not ideal cosmetic ingredients as they can irritate the skin and they cause loss of water by disturbing the skin's protective barrier. You should avoid products with alcohols such as ethanol, propanol or isopropanol and benzyl alcohol, especially if your skin is dry.
The other type of alcohols used in skincare products, the long-chain, fatty alcohols (such as cetyl and stearyl alcohols and their mixture called cetostearyl or cetearyl alcohol) are non-irritating and can be very beneficial for dry skin. Unlike ethanol which has a drying effect for the skin, the fatty alcohols prevent drying and chapping of the skin and help to keep moisture in.
The CIR (Cosmetic Ingredient Review) Expert Panel has assessed Cetyl Alcohol, Stearyl Alcohol and Cetearyl Alcohol as non-irritating, non-toxic and safe to use in cosmetic products. Skin reactions caused by them are uncommon; however, there are rare cases of irritation or contact allergy associated with products containing these ingredients. Reactions occur for the most part in people with sensitive skin types, particularly in people suffering from eczema. So if you have a known allergy or irritation should occur, do not use products containing Cetyl or Cetearyl alcohol.
If you experience a reaction to skincare products, your dermatologist might suggest you get a patch test to check which of the ingredients your skin reacts to.