Oils used in soap have been used for centuries in a variety of ways. Good quality soap is made from vegetable oils. However, vegetable oils are rather expensive, so coconut oil was often used because it is the cheapest material available. Fish oil and animal oil were also used.
When oil is mixed with an alkaline substance such as caustic soda, a solid is formed. This solidified product is usually called soap, but it is difficult to use in this state, so salt is added to extract only the pure soap. Salt is used to extract the pure soap, then color and odor components are added, and finally the soap is placed in a mold to form the final product. Finally, the soap is placed in a mold.

Liquid synthetic detergents are widely used these days. These detergents are chemically synthesized from petroleum. Compared to soap, liquid detergents remove oil better, but because they are used in large quantities in households, environmental pollution problems have also been pointed out.