Thursday, 26 June 2014

Ingredients Dictionary: Alcohol/ Ethanol/ Ethyl Alcohol/ Propanol/ Alcohol denat. (38b, lavender)/ Isopropyl Alcohol/ Isopropanol/ Benzyl Alcohol

Is this the longest title in blog history just for some booze? Isn't it amazing just how many valid names there are for alcohol? I can imagine how mind boggling that would be for the uninitiated.

Well, alcohol is a well discussed ingredient with strong opinions on whether it should be used or not in hair products.  I have quite often seen it referred to as 'bad' alcohol as opposed to the 'good' alcohol' that the fatty alcohols such as cetyl alcohol represent.

The picture you see is of ethanol burning. Anyone here heard of feuerzangenbowle.........this is mulled wine German style with a rum (80% alcohol!) soaked sugar cone set on fire for spectacular hubby does this every winter at my request!  Anyway, back to the subject at hand, here is the dictionary info for alcohol!


What is it? A clear liquid solvent
Where is it derived from? Can be made from fossil fuel or from fermentation of natural sugar. The choice is normally a case of which is the cheapest in that particular region.
What is its pH? A pure alcohol does not have a pH (no water, no pH!)
Is it water soluble? The proper terminology is that some alcohols can mix with water (miscible)  rather than dissolve in water (soluble=. For simplicity all of the alcohols listed above do mix with water to some degree.
What is the difference between all these types of alcohol There is not much difference -  Alcohol usually refers to ethanol,  ethyl alcohol, alcohol denat. (38b lavender) which are all the same and have 2 carbons. Isopropyl alcohol/isopropopanol/propanol are exactly the same and have 3 carbons. Benzyl alcohol has 7 carbons. In general the 2-3 carbon alcohols are more miscible in water while the 7 carbon alcohol is less so.
What does alcohol do in shampoo and conditioner? Almost always a solvent helping oil and water parts of a conditioner mix together. Sometimes an antiseptic (depending on how much is in the formula) or if using the 7 carbon Benzyl alcohol.
How much alcohol is added? Generally10-20% in hair conditioners but can be as much as 60% or more in hair stylers such as serums or sprays and even those hair growth tonics that some people use
Is alcohol  a major component of hair conditioner? It can be. You may find it just outside the top 5 or just towards the end of the top 5 ingredients after water in a hair conditioner. In some hair serums, sprays and tonics it can be the first or second ingredient and there may be no water in the formula at all.
Does alcohol do anything to hair itself Strictly speaking when alcohol is used as a solvent in water/oil mix such as hair conditioner then it is not really able to behave as a pure alcohol. Its action is to help the conditioner not separate as oil and water naturally do. It is not expected to work on hair so to speak.
A pure alcohol can: 
1. Evaporate easily (volatile!) and therefore give skin a feeling of dryness. This is not really possible when the alcohol is combined with oil and water as those interactions prevent it from easily separating off.
2. It is known that soaking for a long time in pure alcohol can weaken hair (once more this has to be pure alcohol!)
Does alcohol penetrate hair? Yep the 2-3 carbon alcohols are small and highly mobile. Non drinkers can have detectable alcohol byproducts on hair when using products with as little as 10% alcohol*.
Can alcohol absorb water from hair? Pure alcohol being volatile probably can but when mixed in with oil and water, probably unlikely.

Sources and extra reading  (references are in the articles):
1.*Analytical and Bioanalytical Chemistry, pp 183-188, 2011

2.What does 'bad' alcohol actually do to hair? 

Ethanol on Fire - Image Credit


  1. Feuerzangenbowle rocks! haha sorry it's not hair related :/ *hiccup*


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