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A bar of soapLiquid soap
Soap is achemical compound resulting from the reaction of an alkali (commonlysodium orpotassium hydroxide) with afatty acid. Soaps are the metallic salts of long chain fatty acids. When mixed withwater duringbathing, cleansing, orwashing, they help people and clothes getclean by lowering the chance ofdirt andoil to get to the skin orfabric. Soaps are made fromanimalfats orvegetable oils. There are two basic steps in making soap. They are called Saponification and Salting-out of soap. Some people like to make their own soap.[1]
Soap cleans very well insoft water. It is nottoxic to water life. It can be broken down bybacteria. However, it is slightlysoluble in water, so it is not often used inwashing machines. It does not work well inhard water. It cannot be used in stronglyacidicsolutions. Mild hand soaps are onlybasic enough to remove unwanted skin oils. For other forms of oil, dishwashing soap is strong enough to remove almost all forms of oil without damaging petroleum products such asplastics. It does not damage skin either. Soap suds physically capture and liftgerms (a virus, bacteria etc.) off of the surface of the skin and then water rinses them into the sink.
Soap has been made in many ways. Humanity has used soap-like things for thousands ofyears. The earliest recorded evidence of the making of soap-like materials dates back to around 2800 BC in AncientBabylon[2] andSumeria.[3] They were soap solutions, or soapy water. People made them by mixing ashes with water and fat and boiling them.[3] The Babylonians usedwater,alkali andcassia to make soap.[4]
Ancient Gauls added salt to the soap solution to make the solid soapfall out.[3]
TheEbers papyrus (Egypt, 1550 BC) suggests thatancient Egyptians bathed often and had animal and vegetable oils with alkalinesalts to make a soap-like substance. Egyptiandocuments say that a soap-like substance was used in the preparation ofwool forweaving.[5]
↑Willcox, Michael (2000). "Soap". In Hilda Butler (ed.).Poucher's Perfumes, Cosmetics and Soaps (10th ed.). Dordrecht: Kluwer Academic Publishers. pp. 453.ISBN9780751404791.The earliest recorded evidence of the production of soap-like materials dates back to around 2800 BCE in ancient Babylon.
↑3.03.13.2Hugh W. Saltzberg (1991). "Ancient Technology".From Caveman to Chemist. American Chemical Society. pp. 6–7.ISBN0-8412-1787-4.
