What Is Alum: Definition, Types, And Uses

What is Alum?

Normally when we talk about Alum, we refer to Potassium Alum. Potassium Alum is a hydrated state of Potassium Aluminum Sulfate (KAl(SO4)2·12H2O). In reality, any compound that has the empirical formula of AB(SO4)2·12H2O is regarded as an alum.

Types of Alum

1. Soda Alum (NaAl(SO4)2·12H2O)

It is used as an acidulant and baking powder in food.

2. Potassium Alum (KAl(SO4)2)

It is also called Tawas and potash alum. It is found in grocery stores in the form of baking powder and is used for pickling. Other than that, it is used in aftershave. It is also used to treat fireproof textiles.

3. Chrome Alum or Chromium Alum (KCr(SO4)2·12H2O)

Chrome alum is deep violet and it serves its purpose in tanning. It is often added to other alum salts to make purple or lavender crystals.

4. Ammonium Alum (N4Al(SO4)2·12H2O)

This type of alum serves a lot of diverse purposes just like soda alum and potassium alum and soda alum. Ammonium alum is used in dyeing textiles, tanning industries, and the making of text. The unique property of Ammonium alum is that it is flame-retardant and is used in vegetable glues and the production of porcelain cement.

5. Selenate Alum (SeO42-)

This type of alum comes into being when the compound selenate replaces sulfur and as a result, a selenate is formed. Alums that contain selenium are very strong oxidizing agents which is why they work as antiseptics.

What Is Alum Used For?

Alum is used for a lot of industrial and household purposes. The most used alum lump is the Potassium alum. Here are the uses of alum:

• It is used to purify drinking water and acts as a chemical flocculant.
• It is also used to stop bleeding in the case of minor cuts.
• Alum acts as the chemical that improves immune response in vaccines (also known as adjuvant).
• It also acts as a pickling agent that keeps pickles fresh and crisp.
• Another use of alum is as a flame retardant.
• Alum acts as the acidic component in a lot of baking powders.
• People also use alum as a skin whitener.

Alum Crystal Uses

Here are some uses of alum crystals:

• Crystals of alum are used in pickling.
• They are also used in the treatment procedures of canker sores.
• Some people use crystals of alum as a personal deodorant.

Alum Spices Uses

Spices made from alum powder are used as:

• It was used in baking powder as a substitute for cream of tartar.
• Plus, it is used to purify drinking water.
• It acts as an emetic and helps induce vomiting.

What is Alum Powder?

When you heat Alum, you get a white powder which is known as Alum Ash or Alum powder. It forms from alum and has been used a lot in history. Despite its extensive use, its use as a culinary ingredient has started only recently. Alum powder is short for Potassium Aluminum Sulfate, it is used as an ancient antiseptic and is known for its deodorizing properties.

Is Alum Safe?

Yes, alum is considered to be fairly non-toxic. It has chronic and acute oral LD50 and both of them are more than 5,000mg/kg but this substance can still cause burns, respiratory problems, and irritation, etc. If you accidentally inhale alum, you may experience respiratory irritations, nausea, and headaches. Moreover, it is not considered a carcinogen by OSHA, NTP, and IARC.