The solid shampoo is a cosmetic product formulated as a traditional liquid shampoo, but without water. This allows to avoid the use of plastic for its packaging and to obtain a product as effective as the liquid shampoo but extremely more comfortable, simple to use and economical.
The solid shampoo contains surfactants with detergent properties, as well as active ingredients for the beauty and health of the hair, fragrances and sometimes dyes.
The solid shampoo foam just like a liquid shampoo and has the same washing power as a detergent in which water is present. It is used rubbing directly on the hair or creating a foam in the hands to be massaged then on the hair.
Although its appearance is reminiscent of soap, solid shampoo is not a soap: the soap is obtained by the reaction between fat and caustic soda, in a chemical process called saponification.
Soap has a basic pH, so if used for hair cleansing, it tends to make hair dry, frizzy and difficult to comb. This does not happen with the use of solid shampoo, since this product has a pH similar to that of our skin and, even if frequently used, does not damage the hair and does not make it appear frizzy.
As for soap, however, since there is no water, even in solid shampoo it is often unnecessary the addition of preservatives: bacteria and moulds in fact proliferate in environments where water is present, and cosmetics without water almost never require the use of preservatives.
The pros of solid shampoo definitely beat the cons. Thanks to the solid format, in fact, this type of shampoo is very convenient to use and practical to carry during trips. In the shower or suitcase takes up little space, there is no risk that it spills or that it wastes product, and travellers can carry it by plane without any problem.
The solid shampoo is cheaper than the liquid one: although the purchase price of a solid shampoo is on average higher than that of a liquid shampoo, with a stick of 100 grams solid shampoo you can make 30 to 50 washes, so the solid shampoo lasts much longer over time, allowing you to save money.
The solid shampoo does not require the addition of preservatives and this results in a lower exposure to ingredients that, even if present in cosmetics in small quantities, can still be harmful to health and the environment.
The main advantage of solid shampoo is the removal of plastic bottles, which makes this product environmentally friendly.
Finally, solid shampoos made with natural ingredients are also biodegradable, have less impact on the environment and can also be used during campsites and excursions.
The cons of solid shampoo are instead related mainly to the method of use and the difficulty of using a product in a different format from what we are used to.