[chem] 勞工鹼(laundry soap)問題

Soapmaking is used sodium hydroxide adding to oil. For laundry use soap, the residual alkaline is purposely leaving higher because this is used to wash clothing not human skin, also higher alkaline aiding the removal of dirts such as oil. For bath soap, you need to control the pH to closely near to our skin (pH=6-7), you need it mild enough to clean yet conditioning your skin. You need perfume, cosmetic dye, vitamins, protein, miosturizers, foam stablizers, other mild surfactants......& etc. Moreover you need special oils to make bath soaps. The processes are more complicate and the ingradients are much more expensive.