A-Closer-Look-At: Ethyl Alcohol aka Ethanol

Ethyl alcohol, also known as ethanolpure alcoholgrain alcohol, or drinking alcohol. In this article I will refer to it as ethanol, because that is the term I personally use the most.

I love, love, love to use ethanol in disinfection. I do a lab study and before and after, we have to clean/disinfect your work space. I usually spray some ethanol on the surface and wipe it off with a paper cloth. I have to wait a minute (or a few minutes if I used to much), during which time I get my supplies and voilà, a clean and sanitzed space. A tip: do wait at least 10 minutes before lighting any flame – not that I have any weird accidents with it, but just to be safe. I personally would recommend sanitizing with ethanol for non-plastic surfaces and testing a little patch before spraying it all over.

Ethanol is made by the fermentation of sugar by bacteria or by the hydration of ethylene (the adding of a hydrogen atom). I know for sure that the ethanol used in beer is made by the fermentation of sugar. Actually, the reason why some beers are stronger than others, depends on the bacteria culture and the amount of sugar added. Until the sugar runs out, the bacteria produces ethanol, or until the amount of ethanol is too high for the bacteria to survive in.

Because of hydroxide (the oxygen and hydrogen atoms, the characterizing group of any alcohol), ethanol can form hydrogen bridges with water molecules, helping dissolve organic compounds, such as sugars or parts of the celwall of bacteria. If you want to sanitize, keep in mind that a concentration of 70% or higher is to be used. Below that concentration, the ethanol isn’t effective enough. So, disinfecting with beer (5-10%) or wine (15%) is not really smart. Absinthe (70%) and Neutral grain spirit (90%) are somewhat better, but it’s still better to use regular ethanol (available in 70% or 96%) which can be found at drugstores or pharmacies. I’m alo guessing that Absinthe and Grain spirit do not need any preservative.

Oh, and, according to my old chemisttry teacher, 100% pure alcohol is a myth. Even if you attempt (as a chemist) to obtain a mixture of 100%, pure alcohol, it will disintegrate. 96% is the highest concentration of ethanol possible.

Ethanol can also be found in skin care. If it’s at the top of an ingredien tlist, (as in the first 5 ingredients) it can irritate the skin, but if it’s at the end of an ingredient list, the concentration isn’t considered a problem. High concentrations of alcohol can be found in most products for oily or skin with acne. The alcohol dehydrates the skin, making the skin produce more sebum, causing it to become more oily and clog the pores even more.

To sum it all up, ethanol is great for sanitizing, but not so good for the skin. And if you want to use ethanol for sanitizing, a concentration of 70-96% works best.

Until next time,