Most people washed themselves with only one essential thing at the time, water. This, of course, happened until the development of soap in 2800 B.C. The soap was found in clay cylinders during the excavation of ancient Babylon. There were inscriptions discovered on the cylinders, which showed us that fats were boiled with ashes, which was the method of making the soap at this time.
Records have shown that Egyptians bathed regularly. There was a medical document found called “The Ebers Papyrus” which described the combining of animal and vegetable oils with alkaline salts to form soap-like material. These were used for treating skin diseases and washing. At around this time, Moses gave the Israelites specific laws about personal cleanliness. He related cleanliness to health and religious cleansing.
The early Greeks bathed for artistic reasons. Instead of washing with soap, they bathed themselves with blocks of clay, sand, pumice, and ashes. Then they anointed themselves with oil and scraped off the oil and dirt with a strigil. They washed their clothes in the streams without using soap.
According to an ancient Roman legend, soap got its name from Mount Sapo where animals were sacrificed. When it had rain, the water washed away the animal fat and wood ashes down into the clay soil along the Tiber River. Women had found this clay mixture and it made their wash much cleaner.
Soap making was a popular craft in Europe by the 17th century. Vegetable and animal oils were used with ashes of plants and fragrance. More varities of soap gradually became available for shaving and washing hair, as well as bathing and washing clothes. Italy, Spain, and France were the early centers of soap manufacturing. The English began making soap during the 12th century.
The chemistry of the soap manufacturing stayed the same until 1916 when the first synthetic detergent was developed in Germany. Synthetic detergents are non-soap washing and cleaning products that are “synthesized”. Household detergent products became known in the United States around the 1930s.
It is very important to understand the basic knowledge of soap and detergent chemistry. Water has a property called surface tension. In water, other water molecules surround each molecule, but at the surface, other water molecules only on the waterside surround those molecules. A tension is created as the surface molecules are pulled into the body of water. This tension causes the water to “bead up” on the surface, which slows down the cleaning process.
During the cleaning process, surface tension must be reduced so the water can spread and wet surfaces. Chemicals that do this are called surface-active agents. The surface-active agents perform many important jobs in cleaning. They are classified by their ionic properties in water. These properties are anionic which means a negative charge, nonionic which means no charge, cationic which means having a positive charge, and amphoteric which means having either a positive or negative charge.
Soaps are water-soluble sodium or potassium salts of fatty acids. The fats and oils used in soap making are made up of a unique mixture of several different triglycerides. In a triglyceride molecule, 3 fatty acid molecules are attached to one molecule of glycerine. Fatty acids are the mechanism of fats and oils that are used in soap. They are weak acids of two parts, which are a carboxylic acid group and a hydrocarbon chain attached to the carboxylic acid group.