The difference between alum and white alum

Alum and alum are different names for the same substance, both referring to potassium aluminum sulfate dodecahydrate, with the chemical formula KAlSO ₄₂ · 12H ₂ O. They are commonly used in traditional Chinese medicine and daily life as topical medicines or water purifiers for astringency, hemostasis, dryness, and itching relief.

Alum and alum are completely identical in chemical composition and usage, with the only difference being their naming conventions. Alum is more common in modern industry and chemical fields, while alum is mostly a traditional term in traditional Chinese medicine literature. Both are colorless transparent crystals or white powders, easily soluble in water, with a bitter taste, and easily lose their crystalline water when exposed to heat, turning into anhydrous aluminum potassium sulfate. In the application of traditional Chinese medicine, alum is often used as an external preparation, such as in the treatment of eczema, hemorrhoid bleeding, and can be formulated into a powder or solution for wet compress. It can also be used as an auxiliary ingredient in the preparation of medicinal herbs to reduce toxicity or enhance efficacy. It is also commonly used by the people to soak ingredients in its solution to achieve the effect of preservation and clarification of water quality.

When using alum or alum, attention should be paid to controlling the concentration and avoiding direct contact with mucous membranes or long-term use in large quantities. External use may cause skin irritation, while excessive oral intake can lead to gastrointestinal discomfort. Pregnant women, children, and individuals with renal insufficiency should use it with caution under the guidance of a physician. When storing, it should be sealed and moisture-proof to avoid mixing with alkaline substances. It is recommended to add no more than 0.1 grams per liter of water for daily use, and after boiling, it should be allowed to settle and filtered.