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 Alcohol in skin care - busting myths 

Natural alcohol has been used by people since pre-historic times in many different forms - beverages, medicine, household and industry. Now when organic cosmetics is on the rise, thanks to its antiseptic properties, alcohol has become an important ingredient. Still - some consumers are concerned that alcohol dries and irritates skin, therefore it should be avoided. MADARA investigates scientific data and busts the myth.   

What is alcohol?  

Natural grain ethyl alcohol, also called ethanol, pure alcohol, grain alcohol, or drinking alcohol is a colourless, volatile liquid that has a light odour. Derived from grains (wheat and rye) as a result of fermentation of sugars. Natural alcohol has been consumed by people in the form of alcoholic beverages like wine, beer, whiskey since ancient times. In medicine, natural alcohol has been used as solvent, antiseptic and disinfectant. Ethanol kills organisms by denaturing their proteins and dissolving their lipids and is effective against most bacteria, fungi, and many viruses.  

 When we say "alcohol" we usually mean ethyl alcohol. However in chemistry term alcohol stands for the large group of substances whose molecules contain hydroxyl (OH) group.  Methyl, butyl, isopropyl alcohol belong to the same group of alcohols as ethyl alcohol, but only ethyl alcohol is drinkable.  Cetearyl, steartyl alcohols belong to a different group of alcohols - these are waxy substances obtained from plant oil. Also glycerin and menthol are alcohols by chemical definition. When we see a single word Alcohol on the ingredient list of cosmetic product - this stands for ethyl alcohol.  

Because of its antiseptic properties ethyl alcohol is used as a natural and safe preservative for cosmetic products, as well as solvent for various active ingredients. Certified natural cosmetics contain only natural grain alcohol. Synthetic alcohols produced from petroleum, or Alcohol Denat. (denaturated alcohol), are natural alcohols made undrinkable by adding toxic substances, e.g. methyl alcohol are forbidden.

Why should alcohol be used in organic cosmetics? 

Natural and organic cosmetics can be preserved by a very limited number of preservatives and antiseptic agents. These include:  

Benzoic acid, its salts and esters  

Benzylic alcohol  
Formic acid and its sodium salt 
Propionic acid and its salts  
Salicylic acid and its salts  
Sorbic acid and its salts 
Natural ethyl alcohol 
Antiseptic essential oils 

In the 20th century most of these substances were tested on animals for its oral and dermal toxicity (now in most countries animal testing is discouraged or banned by law, depending on the industry, but we still have data from earlier tests). According to LD50(skin)RBT test results (substance is applied to rabbit skin) showed in graph1, concentrated natural alcohol is the mildest antimicrobial agent. It is 10 times less toxic than butylparaben and 10 times less toxic than phenoxyethanol (both are widespread synthetic preservatives).     

Among listed preservatives and antiseptic agents that are approved by ECOCERT for natural cosmetics, natural alcohol is the mildest preservation method. It is especially suitable for leave-on products (products that are not washed off), like face and body creams. Organic acids and benzyl alcohol have significantly higher irritation potential, therefore they are more appropriate for rinse-off products, like soaps, wahses and shampoos. Antiseptic essential oils  (sometimes labeled as perfum on the INCI ingredient list) have reasonable antiseptic properties only when used in high dosages, which results in strong smell of the product and higher irritation potential of the skin.  

Is Alcohol toxic when applied to skin?

Intoxication effect of alcoholic beverages - getting drunk and having hangover - is well known in historic and modern society. After drinking alcohol, ethanol within the human body is converted into acetaldehyde and then into acetic acid. Acetaldehyde is more toxic than ethanol and is linked to most of the clinical effects of alcohol.  

Pure concentrated ethanol applied to skin in great amounts can cause intoxication. However animal tests carried out in the 20th century report that acute dermal toxicity of alcohol is low in comparison to other preservatives used for cosmetics (see graph1). Alcohol is a volatile liquid and when applied to skin in small amount, alcohol evaporates and therefore toxicity potential of topical application insignificant.  

Does Alcohol irritate or dry my skin? 

Concentrated alcohol 30-40% can cause irritation and dryness of skin, eye and mucous membranes. Typical irritation of the mucous membrane in the mouth can be sensed when drinking spirits like cognac, rum, vodka etc. In concentrations below 15-20% (this is a typical alcohol content of topically applied medical preparations), irritation, sensibility and drying potential of alcohol drops significantly. Natural cosmetics is preserved using even lower concentration of alcohol. Normally such small concentration of topically applied alcohol solution does not pose risk of irritation and dryness, and products containing this dose of alcohol can be used even by individuals with sensitive and dry skin. Used in products for combination and oily, acne prone skin alcohol is beneficial because of its disinfection potential. It acts against most bacteria and helps to regulate action of sebocytes.

Dermatologist's opinion: Dr. Lauma Valeine, dermatologist, "Health Centre 4" beauty clinique "4 Dimensija":

Alcohol that is obtained from plants has the least side effects and is the optimal, and most beneficial substance for preserving natural cosmetic products, especially those that are permanently applied on skin. In comparison to organic acids and salts, and benzyl alcohol, natural alcohol has the lowest potential to irritate the skin. Natural alcohol is continuously used and tested in medicinal research for various drugs and preparations - significant experience in this field has been accumulated throughout the years. Adding natural alcohol in small doses (below 15%) to a skin care product can't cause negative side effects, such as skin dehydratation, irritation, whereas larger doses (30-40%) can. For dry and sensitive skin, the best option would be to use products with small doses of natural alcohol. For normal to combination, and oily skin type, the best would be to use larger doses, as it has disinfectant, and regulatory properties of sebaceous gland.

Sources:

Acute Toxicity Data. Journal of the American College of Toxicology, Part B. Vol. 15
JAMA, Journal of the American Medical Association. Vol. 244, Pg. 660, 1980
Journal of Pharmacology and Experimental Therapeutics. Vol. 84, Pg. 358, 1945
Raw Material Data Handbook, Vol.1: Organic Solvents, 1974. Vol. 1, Pg. 6, 1974
BIOFAX Industrial Bio-Test Laboratories, Inc., Data Sheets. Vol. 28-4/1973
American Industrial Hygiene Association Journal. Vol. 23, Pg. 95, 1962
Butylparaben. Final Review of Toxicological Literature. Research Triangle Park, North Carolina , 2004
Syndel Laboratories Ltd, Data Sheets, 2008