Stearyl & Cetyl Vs. Isopropyl & Ethyl Alcohol In Hair Products
You have likely heard that alcohol is bad for your hair and you should never choose a product that contains it. What this advice fails to take into account, however, is that there are two main types of alcohol, one of which does indeed cause damage to your hair but the other is actually good for your hair.
The difference in classification depends on the actual structure of a given alcohol with short-chain alcohols such as isopropyl and ethyl alcohol causing damage and fatty ones such as stearyl and cetyl helping your hair. Once you know this, you will quickly realize why it is nearly impossible to find hair products that don’t contain alcohol and why it can actually be beneficial.
As we mentioned earlier, short-chain alcohols are the ones that do indeed cause damage; these will dry out your hair, creating frizz
. In addition to isopropyl and ethyl alcohols being included in this category, others include: isobutane, propyl alcohol, propanol, alcohol denat, SD alcohol 40, SD alcohol and ethanol. The problem with short-chain alcohols is that their structure is similar to that of water molecules so when they have less than 3 carbons in their tail, they mix in water very easily. In addition to dissolving in water, they can also easily dissolve oil or other things that don’t usually mix with water.
Why They Are Used
If short-chain alcohols dry out the hair, why do manufacturers use them in the first place? You will most commonly find them in products designed to help your hair dry more quickly because these alcohols have a low molecular weight. But the problem with relying on short-chain alcohols to quickly dry your hair is that when the alcohol evaporates, it takes some of the water (and natural oils like sebum) with it, leaving your strands dry. It can also roughen the cuticle. Another common place that you will find these alcohols is in styling products because they help make sure that the solution spreads out evenly.
As you would expect based on the fact that “bad alcohols” cause damage due to their short chain structure, the “good” ones help because of their longer chain structure. In addition these tend to come from natural sources. They are referred to as fatty alcohols because the higher number of carbons (their carbon chains usually have 12 to 20 per molecule), makes them oilier, hence the term “fatty alcohols.” In addition to stearyl and cetyl alcohols, other fatty ones include: behenyl alcohol, myristyl alcohol, lauryl alcohol and cetearyl alcohol.
Why They Are Used
Unlike short-chain alcohols, fatty ones serve a healthy purpose in products. They will help your hair’s cuticles lie flat on the surface. You may have to be careful when using hair products with fatty alcohols, however. If you use them in excessive quantities, they can combine with your hair’s sebum and make your locks appear greasy.
In addition to smoothing, fatty alcohols can also be found in many shampoos
and conditioners to thicken it as well as to serve as emulsion stabilizers and nonionic surfactants. While it is possible to get the same results using a polymer, fatty alcohols are generally much cheaper, making production of these hair products more affordable.
It is important to remember that not all alcohols are bad for your hair; the difference lies in their structure. So if you see stearyl or cetyl alcohol in the ingredients for a hair product, you should choose it but avoid those that contain isopropyl or ethyl alcohol.