These days we don’t expect shampoo to simply clean away dirt and grease, we also expect shampoo to have a secondary function; to condition and beautify our hair.
To achieve this you need to remove just enough sebum for the hair to be clean whilst simultaneously leaving behind enough conditioning agents to leave the hair soft, shiny and manageable.
This fine balance is possible by using the right balance of ingredients at the shampoo formulation stage with anionic and amphoteric surfactants, cationic polymers, film formers, humectants, moisturisers and more.
The word ‘shampoo’ comes from the Indian ‘champoo’ a Hindi word meaning ‘to press or massage’ hair through cleaning. The very first shampoo came onto the market in the 1930’s, so for the last 90 years we have stopped using ‘soap’ bars as a cleaner for our hair - and there’s a very good reason for that!
A proper definition of a shampoo is a cleaning agent that ‘does not leave a soap residue’, unfortunately soap does leave a residue which means that ‘soap’ is not actually a shampoo.
All too frequently I am asked questions regarding soaps and shampoos such as: Is it OK to use soap on hair? What happens if you wash your hair with soap? Does Soap cause hair loss? Can you wash your hair with hand soap? Which soap is best for hair? All of which shows that there is a 'grey' knowledge area surrounding this important topic that needs clarification - so read on for your answers!
Soap is the oldest surfactant known to man. Surfactants or, to give them their full long name surface cleaning agents, include the bubbling, foaming, lathery cleaners that remove dirt and grease from our clothes, skin, hair, carpets, dishes and so much more.
They are the primary ingredients, of which there are four categories, the largest group being ‘anionic’ surfactants (the negatively charged foaming cleaners) found in our laundry detergents, washing up liquids, cleaners, shampoos, shower gels and soaps. Also as these surfactants also make it possible to mix oil and water, they can also be found in everyday products which we eat, such as mayonnaise, and products we put on our skin, such as lotions and creams.
Traditional soap (also anionic) has been around for hundreds of years and was made using animal fats and wood ash - which is mainly potassium carbonate - that when heated with some water would release lye (sodium hydroxide). The lye (being extremely alkaline measuring a pH14 on the pH scale of 0-14 with pH 7 being neutral) is needed to turn the oils into soap through a process called ‘saponification’.
Nowadays soap is made with vegetable oils and store-bought lye (Sodium hydroxide) and requires careful handling.
However, the end result is still a very alkaline product (pH 9-11) and scientific research has shown that this causes issues for our hair.
The hair shaft’s outermost layer is the ‘cuticle’ and is made up of flattened cells that overlap like tiles on a roof.
Years of scientific research (see some references below) has found that if you use soap (and other alkaline surfactants) to shampoo your hair it damages it in several ways:
Note: Using an acidic cider vinegar rinse will not undo the damage caused by an alkaline product.
The hair follicle, otherwise known as the hair root, is the living part of the hair located beneath the surface of the skin. Humans have almost five million hair follicles, 80,000 to 100,000 of which are located on our scalp. The hair follicle is the growth structure that produces the hair, and it also anchors the hair shaft in the skin. The hair follicle is made up of four parts:
Damage to the hair shaft can cause breakage, limiting hair length, which can make it seem like hair growth has slowed down. If you take up healthy hair care habits, like using the best and right shampoo for your hair, reducing heat styling, stopping chemical straightening treatments and definitely no bleaching this can help minimise breakage and damage.
Just because it says 'shampoo on the label doesn't actually mean that it is one - in fact in a large proportion of cases it most certainly isn't but is in fact a soap bar in disguise! So there a few things you can investigate for yourself.
Firstly look at the price. Soap uses far less expensive ingredients than those found in formulated shampoos. Both lye and carrier oils are inexpensive, so these soap bars can start from just a couple of pounds.
The main cost in these bars are the herbs (if large amounts are needed to be infused into the oils) and the essential oils that are added for their natural scent and other therapeutic benefits. Many essential oils are too expensive to use in soap or their scents too delicate and lost through the lye process.
Whilst man-made fragrances survive the soap making process and are inexpensive, they have their own issues and can cause skin irritations, rashes, headaches and more.
Secondly check the ingredients. If the label states just a bunch of oils as the ingredients or names such as ‘Sodium Olivate’, ‘Sodium Cocoate’. These, for example, are the terms used for Olive Oil and Coconut Oil after the ‘saponification’ process - turning carrier oils into soap.
They have been combined with the very alkaline Lye to make a bar of soap. A popular ingredient in soap bars is ‘Sodium Palmate’ – palm oil saponified, as it adds both hardness and foam to soap bars, though we all know the current environmental effects of using palm oil.
To clarify this a bit further, when 'fake' shampoo bars, with a cheaper lye base are made the manufacturers usually add a significant number of oils - such as coconut, olive and palm, often all three and maybe others too - to create a hardened bar.
These oil are mixed with the lye (an alkali substance) and a process called saponification takes place, i.e. the production of soap and glycerol.
As the oils are composed of fatty acids, they require a certain amount of an alkali to saponify them, or change them into soap. This is an important step in soap-making and when done correctly should leave you with no lye left in the end article, which will be a hardened soap substance - but this is to create a soap not a shampoo.
During the saponification process there is a change to the oils as follows:
- and so on and so forth.
Oils in their pure form are 'generally' fine and are added to shampoos in small quantities. It is when you see the 'sodium' word prefix before an oil name that is the key indicator that they have been saponified and therefore used to create a soap.
There are also many imported inexpensive soap bases (some with the Glycerine removed, a natural humectant that draws moisture to your body that is sold off to lotion companies for profit), leaving the skin feeling rough and dry. All these types of soap bars are usually fine to use on the body but not for the hair and scalp.
This is because your skin has an approximate pH 5.5 and will replace the acid mantle (an acid film barrier on the surface of the skin) that when washed away by soap will replace itself in under an hour of washing. Crucially, this acid mantle is not found on the hair and thus leaves it wide open to damage from alkaline products.
Other alkaline surfactants are now also proving popular in shampoo bars, such as ‘Sodium Coco Sulfate’ and ‘Decyl glucoside’ (ranging from pH 7.5-12.5).
Unless there is an acidic element to the formulation, these alkaline ingredients are not going to prove much better than soap.
Sodium lauryl sulfate (SLS) is another alkaline surfactant that is inexpensive and harsh, commonly found in household cleaning products and also used to clean car engines. It has a small molecular structure which penetrates the skin and causes irritation with much research also stating other negative long-term side effects.
Ideally a shampoo bar should have a pH balanced variety of anionic and amphoteric co-surfactants (we use no less than five). Surfactants with a larger molecular structure (SLS free) that are gentle to the scalp and impart excellent foaming and lathering properties that together will also work to increase mildness, thickness and viscosity.
If you have one or two anionic powdered surfactants only which I’ve also seen, this can be a little harsh on the hair, as a shampoo bar is a concentrated form after all.
There should also be cationic emulsifiers(such as BTMS that leaves hair feeling soft and conditioned), eco-friendly silicon alternatives (ideally vegan plant based alternatives that will increase the conditioned feel as well as decrease static and friction), proteins and film formers (that will create a protective coating over the hair strands and decrease friction) and a humectant, moisturiser and shine improver such as pro-Vitamin B5.
Ideally finding these ingredients in a palm oil free and vegan version (as we have) though it has been a long, hard process to do so.
A note for those with fine hair, a conditioner containing a cationic quaternary compound such as ‘Cetrimonium chloride’ is good as well as a mix of proteins (both found in our conditioner bars) as fine hair has a smaller diameter than other hair types and more cuticle, so is more static and fly-away.
Not only are shampoo bars highly convenient, fitting will into our busy lifestyles, they are easy to travel with and leak-free. As they aren’t diluted with huge amounts of water, they are also not bulky or heavy either and of course they are free of plastic, making them a very eco-friendly, contemporary solution. However, they also need to do the job of a proper shampoo.
The Solid Bar Company have formulated our shampoo and conditioner bars over the past five years to bring you the best ingredients for your hair and allow you to truly make the permanent switch away from diluted formulations in plastic bottles.
What makes them even more beneficial to liquid shampoos is that shampoo bars can be formulated to cover a whole host of different hair types in one bar in a way you cannot do with a liquid shampoo (which can only use specific, liquid surfactants and limited ingredients which then has to be targeted for specific hair formulations and types, such as curly hair, fine hair, anti-frizz, clarifying, etc.).
This is because you are able to add so many more emollients to a water-less shampoo bar as well as moisturising butters, BTMS (highly conditioning ingredient) and cetyl alcohol (a vegetable derived emollient that in itself adds moisture and boost any cationic quaternary compound ingredients).
If these were added to liquid shampoos and conditioners at the formulation stage, they would just separate (believe me, I have done it). This is because they won’t mix with anionic surfactants and water. However, as water isn’t added until we actually wash our hair with a shampoo bar or conditioner bar, the bar can’t separate and we get the benefit of all those lovely ingredients.
For fantastic hair care products, shop here with us today.
Rebecca and The Solid Bar Company Team
PS. And while you are here why not check out this great read on the 2020 Definitive Guide To Aluminium Free Deodorants!
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