medicinal alcohol

Most of us tend to assume that "alcohol" in cosmetics does not translate to happy hour. On the contrary, we might expect dry, irritated skin if we use a cosmetic product with alcohol. A few weeks ago, our anti-alcohol prejudice got a bit of a jolt when we spotted alcohol in Amala's products. How could this be, given Amala's wholesome, organic brand positioning? I have also noticed alcohol high up the ingredients list of another natural brand, Weleda.

Amala told us that they haven't figured out a way of excluding alcohol from their formulations and that they use a gentle form derived from wheat. In fact, there are "good" alcohols and "bad" ones. So which group does wheat derived alcohol fall into?

In benign form alcohols are glycols used as humectants that help deliver ingredients into skin. When fats and oils (see fatty acid) are chemically reduced, they become a group of less-dense alcohols called fatty alcohols that can have emollient properties or can become detergent cleansing agents.

The nasty ones have low molecular weights. These include ethanol, denatured alcohol, ethyl alcohol, methanol, benzyl alcohol, isopropyl alcohol, and sd alcohol, which not only can be extremely drying and irritating to skin, but may be cytotoxic.

Ethanol is made from fermented sugars of corn, wheat or sugar cane and is widely used in all kinds of products with direct exposure to the human skin (e.g. medicinal products like hand disinfectants in occupational settings, cosmetics like hairsprays or mouthwashes, pharmaceutical preparations, and many household products). I am guessing that Amala's "alcohol from wheat" is an ethanol.

I found a study that set out to test whether ethanol, of the kind used in cosmetics, caused apoptosis in human skin cells. It concluded that ethanol was toxic to cells in both a dose- and time-dependent manner and increased the percentage of cells undergoing apoptosis. The conclusion was that "even at low concentrations, ethanol may induce apoptosis in skin cells".

On the other hand, the evidence about the safety of topical applications of alcohol in the scientific literature seems to be contradictory, specifically  about whether there is a link to cancer. A German report in 2008 (interestingly Weleda and Amala are both German companies) said "so far there is a lack of evidence to associate topical ethanol use with an increased risk of skin cancer".

However, topically applied ethanol acts as a skin penetration enhancer and may facilitate the transdermal absorption of xenobiotics (e.g. carcinogenic contaminants in cosmetic formulations).  The same 2008 study also noted that ethanol use is associated with skin irritation or contact dermatitis, especially in humans with an aldehyde dehydrogenase (ALDH) deficiency.

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As to other alcohols that you might come across, it can get a bit confusing. Denatured ethyl alcohol may appear in the ingredient listing under several different names. You may see the abbreviation SD Alcohol (which stands for "specially denatured alcohol"), followed by a number or a number-letter combination that indicates how the alcohol was denatured, according to the formulary of the United States Bureau of Alcohol, Tobacco, and Firearms (BATF). Among the specially denatured alcohols acceptable for use in various cosmetics are SD Alcohol 23-A, SD Alcohol 40, and SD Alcohol 40-B.

The term "Alcohol Denat." was introduced in Europe as a generic term for denatured alcohol in the interest of harmonizing ingredient names internationally. It frequently appears on products that are marketed both in the U.S. and abroad. You also may see a dual declaration, such as "SD Alcohol-40 (Alcohol Denat.).

As for the good guys (with a few caveats) there is cetyl, stearyl, cetearyl. These are known as fatty alcohols, and their effects on the skin are quite different from those of ethyl alcohol.

Cetyl Alcohol

Extracted from coconut oil, it is an emollient that is included in skin care products to stabilize the formulations or to alter their consistencies, or to increase their foaming capacity. It is often included in baby lotions, hand creams, foundation, lipsticks, shampoos, mascara, deodorants, nail polish removers etc. Although generally regarded as a low hazard, there are some studies that have demonstrated that it is an irritant.

Stearyl Alcohol

Stearyl alcohol is also derived from coconut oil. Because it is an emollient as well as an emulsifier, it can be substituted for cetyl alcohol to firm skin care formulations. It is mostly found in creams, lubricants, depilatories and conditioners.

Cetearyl Alcohol

Cetearyl alcohol is an emulsifying wax that is used to soften thick formulas like skin ointments. Derived from natural oils and fats, it is very efficient in stabilizing skin care formulationsbecause it imparts an emollient feel to the skin. It can be used in water-in-oil emulsions, oil-in-water emulsions and anhydrous formulations. Cetearyl alcohol is widely used in cleansers, permanent hair color, face creams, eye make-up and sunblocks.

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