Soap is one of the oldest industrial products, and there is a recipe for soap on a clay tablet from Ancient Babylon. One story has it that it was first developed widely in Roman times, with the name comes from the Italian city of Savona. Current soap can be traced back to muslim sources from the seventh century. All tablet soap is broadly the same in chemical terms with only the colour and the fragrance varying. If you are looking for something in your shopping basket to economise on, cheap soap is much the same as expensive soap. The premium you are paying is only for the fragrance. Personally I have no qualms about using the cheapest supermarket brand.
Chemically soap is a salt of fatty acids. Fatty acids are derived from any fat source. Traditionally beef tallow was used but since the BSE scare the big soapers have switched to vegetable sources. To my mind, vegetable sources give a slightly creamier lather which is nicer to look at. All soap has much the same cleaning power.
The problem with soap is that because of the way it is made it inevitably contains residual alkalis, usually in the form of sodium. Sodium is very disruptive to the stratum corneum, the upper layer of the skin. Repeated use of soap will have a drying effect because the sodium interferes with the ability of the skin to hold the body’s water in.
Most people’s skin is robust enough to stand it, but some people with particularly sensitive skin will be troubled.
What can you do about it if it is something you find to be a problem? There are a couple of options. There is one brand of soap called Oilatum which is marketed for people with eczema and can be found in bigger branches of Boots in the Uk and I imagine in pharmacies in other countries. This is ordinary soap like any other but it also contains a slug of mineral oil which forms a layer on the skin to stop it drying out so much. Some people really like soap despite its drying effect so this is a good option for them. It is also a perfectly good bar of soap for other members of the family to use.
The drawback with Oilatum Soap is that it still soap. You are still doing the damage even if you don’t notice it so much. If you want to avoid soap altogether, what are the alternatives?
For light cleansing you might want to consider using a lotion. Some lotions themselves contain soap. Check the INCI list. Avoid any that contain either sodium stearate or sodium hydroxide. (I know some of my fellow formulators read this page – I know that this advice is a bit broad brush but it would take another page to explain the details.) I will look at some big lotion brands and make a few suggestions when I get a chance. It isn’t always appreciated by everybody that a lotion can be a very effective cleanser. Put it on some cotton wool and apply it to the skin then rub it off. Be gentle – although your skin is remarkably tough it isn’t indestructable. Don’t subject it to any unnecessary stress.
Another option is to use a light oil like grape seed oil or fractionated coconut oil. These can be used in the same way as a lotion: applied gently to the skin and then rubbed off. If you want to go really mad you could use the approach the Romans used to use before they got hold of soap. In a Roman bath house they would be drenched in olive oil which was then removed with a knife. I am not sure I approve of the knife bit – I think it might a bit too abrasive. But the principle is a sound one. You might think that applying oil as a cleansing agent would be unwise if you have greasy skin. Well I don’t think that this is the case. If you have very active sebacious glands that are pumping oil onto your skin – there is a good chance that the reaction of the glands to the removal of the oil is simply to pump out more. Replacing the heavy sebum with a thin layer of a lighter oil might not only make your skin less greasy – it might fool your glands into thinking that their work is done. Everyone is different so it might not work for you, but why not give it a try? And I would love to hear how you have got on.