Tolerable.

Caustic soda from caustic soda producers can corrode fibers, skin, glass, ceramics, and even some metals. The toilet itself happens to be ceramics. The alkalinity of caustic soda is too strong, and it will pollute water resources. It is not suitable for daily life from the point of view of environmental protection. As a preparation for removing oil pollution, caustic soda is generally used reasonably and properly under the premise of safety and environmental protection.

Extended information:

Caustic soda toilet is to use caustic soda is sodium hydroxide, and sodium hydroxide when water into sodium carbonate, while releasing carbon dioxide to achieve dredging purposes.

It can dissolve protein, and has strong irritation and corrosiveness (alkali burn is more difficult to heal than acid burn because of its solubility to protein).