Among the following washing products, soap has the least damage to the environment, because it degrades fastest when discharged into the natural environment, such as soil water. The residue depends at least on the composition, but soap is still less.

The main component of soap is sodium benzoate, which is extracted from animal and vegetable fats. There are many natural ingredients, which are harmless to human body. And the sewage discharged after washing with soap is also the least harmful to the environment.

The composition of washing powder contains phosphorus, which will make the water eutrophication; The composition of toilet cleaner mainly contains acidic substances, which will harm the environment if used in large quantities; The main component of bath milk is surfactant, in addition to foam stabilizer, essence, thickener, skin care agent, pigment and so on. , a large number of use is easy to cause environmental damage.

Extended data:

In the mid-20th century, the development of synthetic chemistry and petrochemical industry provided cheap chemical raw materials for detergents, promoted the rise of synthetic detergents and greatly changed the development of soap industry.

In recent years, handmade soap, which has been neglected in environmental protection, has risen again. Handmade soap is easily biodegradable and decomposed by microorganisms in sewage treatment because of its natural and unique properties, so it will not cause pollution problems in rivers, lakes and waterways.