Some people nowadays use special liquid soaps and beauty bars to wash their hands, instead of regular soap. Think they're being snobby? Not really. Let's have a peep into what's in those special soaps.
What is soap in the first place?
Well, let's tackle this question first. Ordinary soap is made by reacting lye (NaOH) or potash (KOH) with vegetable oils or animal fat. Vegetable oils contain fatty acids, which are organic compounds that don't dissolve in water. When they react with NaOH or KOH, they form a cool chemical molecule. It has one end that dissolves in water (called the polar end), and another end that dissolves in greasy things (called the non-polar end)! A two-in-one molecule!
Okay, so much for gyan. But what does it really mean?
Well, soap molecules make bridges between greasy things (like the stains on your clothes or the grime in your hands) and the water used for washing. The greasy matter attaches to the non-polar end of the soap molecule, and then gets carried away with the soap as it dissolves in the water. That's why mom insists on you washing hands with soap before you eat.
So let's answer what's wrong with soap
Greasy things aren't just found in dirt. Our skin has a lot of fatty acids and amino acids on it, which are greasy too. These are needed for making our skin waterproof, and protect it from cold, heat and losing too much water. When you apply soap on your hands, it washes away the fatty acids and amino acids, making your skin feel dry. And if the soap was not of good quality, there will be some un-reacted lye in it, which can corrode your skin. That's why it's important to use a good brand of soap.
Never use clothes-washing soap to wash hands. That is a tougher soap made from vegetable oils and potash (KOH), which can hurt more. Body soap is softer, because it is made from lye (NaOH), which is less hurtful. Also, body soap is refined a lot more, to remove all the lye.
So how does neutral soap help?
Neutral soap does not contain any NaOH or KOH. It is often made from sodium or ammonium lauryl sulphate (SLS or ALS). SLS & ALS are preferred in things like toothpaste, shaving cream and shampoos, because they make a better lather than ordinary soap. Just check the label on your shampoo bottle.
The best thing about SLS & ALS is that they have no NaOH or KOH in them. So they do not cause damaging reactions, especially for people with sensitive skins. They have polar and non-polar ends too, so they do the work of soap quite well. They can still remove fatty acids and amino acids from skin, but not so much as ordinary soap. Moisturiser is often added to neutral soap to replace the fatty acids.
So next time you visit a supermarket, do have a closer look at the soap brands, and choose one that is made of SLS or ALS!