Solid shampoos

Hair shampoos in one piece, so-called hair soaps or solid shampoos, are being offered by more and more manufacturers and can now also be found in drugstores and supermarkets.

 

Solid shampoos or hair soaps?

Although solid shampoos and hair soaps look the same, solid shampoos are produced without the saponification process. Hair soaps are produced in a classic saponification process. This involves mixing fats or oils with caustic soda. Soaps are surfactants that have the property of reducing the surface tension of a substance, causing substances that are not actually miscible to mix. Solid shampoos bypass the saponification process. Oils and fats are mixed with a chemically produced surfactant. Natural products, on the other hand, use surfactants that are obtained from renewable, plant-based raw materials.

In addition, both products often contain essential oils or fragrances and colourants, which are preferably of plant origin. Preservatives are usually not used in the solid and therefore water-free products. This is a plus point for solid products. As water-free products, they do not require preservatives, as microorganisms cannot form without water.

Solid shampoos and hair soaps have another important distinguishing feature: the pH value. Solid shampoos with natural or synthetically produced surfactants have a pH value in the slightly acidic range, while soaps are always basic or alkaline. The acidic pH value corresponds to that of the hair and helps to close and smooth the cuticle after shampooing. Hair soaps, on the other hand, work with classic soaps as the active washing substance and therefore have an alkaline pH value.

Alkaline soaps, i.e. classic soaps, can form poorly soluble compounds with calcium from tap water, which must be dissolved with an acidic rinse to prevent the hair from looking grey and dull. You can make your own conditioner by mixing one to two tablespoons of lemon juice or apple cider vinegar in a litre of cool or lukewarm water and pouring it over your hair at the end of shampooing without rinsing the solution out. Solid shampoos are therefore more practical to use because they do not require the subsequent acid rinse step.

Both solid product types score highly in terms of coverage. On average, one wash can be used for as many washes as two bottles of liquid shampoo.

It is important to store the solid products in a soap dish with drainage holes or in a suspended net. This also applies to body soaps to keep them dry.

In addition, both types of product do not require plastic bottles, but only paper, cardboard or innovative materials such as grass fibres, or can also be unpackaged.

One disadvantage is their price. They are usually more expensive than conventional products. So far, solid shampoos and hair soaps have been produced in small quantities of less than 10,000 units.

 

Hair soap or body soap?

Hair soaps and body soaps differ in the degree of excess fat. While body soaps have a degree of excess fat of seven to nine per cent, hair soaps have a degree of excess fat of three to five per cent. The degree of excess oil is the proportion of fats and oils that do not saponify and form an unsaponifiable surplus that has a moisturising effect and cares for the skin and hair. The choice of oils plays an important role here. Olive oil strengthens the skin barrier and hair structure and gives the hair shine. Wheat germ oil soothes itching of the body and scalp. Castor oil supports foam formation.

 

Surfactants

Solid shampoos contain up to 80 per cent surfactants. Surfactants can be chemically produced and then adjusted in their pH value, i.e. they can also be acidic or neutral.

Coconut or sugar surfactants, such as sodium cocoyl glutamate or coco glucoside, are considered to be skin and hair-friendly surfactants. They are rather expensive, do not foam well and are mostly used in natural cosmetics. In the INCI list, they can usually be recognised by the ending glucoside. Their advantage is that they are made from renewable raw materials and are kind to the skin.

In contrast, sodium lauryl sulphate (SLS) forms a full foam, which is one of the critical ingredients due to its aggressive cleansing effect – and is also authorised in natural cosmetics. So take a close look.

 

Solid shampoos: not the best choice for every hair type

Solid shampoos are very suitable for hair that is not exposed to high stress from styling or chemical colouring, while hair soaps without an acidic conditioner are not recommended for hair in the long term. Anyone who puts the hair under a lot of stress when styling with heat, chemicals and the trendy silver hair needs conventional hair care products with appropriate care aspects, treatments and masks that balance out the styling stress.

 

Without critical substances

Solid shampoos and hair soaps usually do not need any critical substances. This is partly due to the fact that these products are water-free and specifically cater to conscious consumers who pay attention to natural products, sustainable, low-irritant ingredients and zero waste.

Without acrylates: They are used as film and gel formers and viscosity regulators. They can damage the skin’ s barrier function. The base material is acrylic acid, from which plastics are also made; as a result, acrylates are sometimes categorised as microplastics.

Without PEGs: The synthetically produced polyethylene glycols are mainly used in cosmetic products as emulsifiers and surfactants. They remove dirt and make-up from the skin. They are sometimes suspected of being carcinogenic, can damage the skin barrier and make the skin more permeable to foreign substances.

Without sulphate surfactants: The cationic surfactants are aggressive, can dry out the skin and make it more permeable to harmful substances. Sulphates are salts that cleanse effectively but can damage the skin and hair. They open the horny layer or cuticle and remove the skin’s own lipids and proteins. They can usually be recognised by the INCI ending sulfate.

Without SLS: Sodium Laureth Sulfate is an anionic surfactant, dissolves water-soluble and oil-soluble dirt, foams well, cleans aggressively.

Without silicones: They have a softening and smoothing effect, fill in wrinkles, improve sensory properties and spreadability. Silicone oils are used in hair care to improve combability, smooth the hair or protect against split ends. They are not easily degradable in the environment and can seal the skin and hair in the long term and accumulate on the surface. They are listed as dimethicones in the INCI declaration.

Without polyquaternium: The compounds of ammonium and diallyl dimethyl ammonium chloride form long-chain molecules and have approx. 40 representatives. They are listed as polyquaternium with a number, e.g. polyquaternium-7, which indicates the size of the molecule. They are used as surfactants, film formers and for their antistatic properties and are found in many conventional hair shampoos, conditioners, shower gels and nail varnishes. Some manufacturers now use them as a silicone substitute. However, polyquaternium molecules have been criticised because they accumulate on the skin and hair and thus have a sealing and drying build-up effect. Due to their acrylamide content, they are considered potentially carcinogenic and some of their representatives are categorised as microplastics.

Without paraffins: Paraffins, INCI Paraffin / Paraffinum Liquidum, have film-forming, protective, antistatic and hydrophobic properties. The mineral oil derivatives can dry out and seal the skin and hair in the long term. Due to their highly occlusive effect and poor biodegradability in the environment, they are banned in organic products.

Without formaldehyde, without parabens: Both preservatives can trigger allergies. However, solid shampoos and hair soaps do not require preservatives.

Without animal ingredients: As solid shampoos dispense with the saponification process and hair soaps usually work with plant-based surfactants, neither product type contains any animal ingredients.

 

Right on trend and sustainable

Solid shampoos are on the rise and will probably account for a larger market share in the future. Their advantages lie in their practical handling and the fact that they are water-free. The latter makes it possible to avoid preservatives and to choose uncomplicated wrapping and paper alternatives or even the unpackaged solution in the packaging. This also helps to fulfil the concept of zero waste. In terms of conditioning effect, they are superior to hair soaps and do not require an acidic rinse.

Cosmacon is happy to implement this trend for your hair care range!