Facial cleansing

Clean yourself before washing gel

In ancient Greece, cleansing the body could involve oil and a strigil, a curved instrument used to remove what remained on the surface. The Metropolitan Museum maintains examples of these objects. This gesture reminds us that cleaning did not always mean lathering a product under water: we could also mobilize the deposits with a fatty substance, then remove them mechanically.

Chemistry makes it possible to produce more soap

Soap results from the transformation of fatty substances in the presence of an alkaline agent. Its production therefore also depends on access to these raw materials. In 1791, the Leblanc process made it possible to manufacture sodium carbonate from salt; it constitutes an important step for industries which use this alkali, including glassmaking and soapmaking.

From soap to synthetic detergents

Syndets, a contraction of synthetic detergents, use surfactants different from conventional soaps. They can take the form of a solid bar or a liquid and make it possible to formulate products with a less alkaline pH. Their development broadens the possibilities: we can seek to cleanse while reducing certain undesirable effects on the skin barrier.

Research is then interested in something other than the simple ability to remove fat. A study comparing four cleansers on the forearm, for example, measures the pH and characteristics of the skin over the course of their use. This type of test does not automatically designate the best product for each face, but illustrates the change in the question: after cleansing, what state do we leave the skin in?

New uses require appropriate cleaning

Water-resistant sunscreens and certain makeup form films designed to stay on the skin. Their removal therefore poses a different question from that of a simple rinse after sweating. A study published in 2019 compared water, a cleanser and a cleansing oil to remove sunscreen products; it shows that the result depends in particular on the resistance of the solar tested.

The point of current routines is to be able to choose a method adapted to the residues, not to accumulate as many steps as possible. A two-step cleanse can help, but its popularity doesn't make it necessary for everyone. The useful progress consists of obtaining satisfactory removal with less friction and good tolerance.