Using fat and caustic soda to produce chemical reaction, sodium fatty acid and glycerol are generated, and sodium fatty acid is separated to form soap. Soap can remove dirt, which is called "soap" by the people. There are similar objects made of earth, such as pancreas. In some places, soap is called "foreign pancreas" and "foreign alkali". The standardized name "soap" should be agreed by the importer when the imported soap enters China, and it is named after the combination of China's "soap" and the raw material of soap. This fat word "soap" won't have a corresponding "thin soap", but there was a "slimming soap" a few years ago, and I won't comment on the effect. from:/question/ 10840335 . html？ si=2