Alum is a class of chemical compounds. It has four different types: potash, soda, ammonium, and chrome. In general, when we talk of alum powder, we refer to potash or hydrated aluminum potassium sulfate, which is chemically represented as KAl(SO4)2.12H2O. It is available in the form of a fine white powder. This is a naturally occurring mineral substance and is widely used for several commercial purposes.
Properties of Alum Powder
Alum powder is obtained from rock form of alum. Its fine grains are colorless, transparent and have a crystalline structure. It has some unique properties due to which we find so many different uses. Here is a list of properties that will help you to understand its characteristics.
- Alum powder readily dissolves in water and the solution thus obtained is slightly sweetish in taste.
- It is acidic in nature and turns a litmus paper red.
- On heating, it changes to liquid first and if heated further, then the salt tends to swell up to form froth.
- It possesses amazing antiseptic quality which helps to destroy germs and prevents their growth on the body tissues.
- It acts as an excellent astringent that enables the skin tissue to shrink and thus, do not let the germs get into skin pores.
Uses of Alum
- For Treating Canker Sores: Powdered alum can be used for treating canker sores. Simply, take a pinch of the powder and apply it on the affected area. It will bring down the pain and heal up the sores quite fast.
- As an Aftershave: It is being used as an aftershave for centuries. Take some alum powder and rub it thoroughly all over the freshly shaved face when the skin is still wet. Its astringent qualities will control bleeding from small shaving cuts and thus, prevent infection.
- For Purifying Water: When a small amount of alum powder is added to water, then the small particles of pollutants present in water tend to stick together and form colloid particles. Since colloid particles are heavy, they easily get settled down at the bottom of the container and the purified water can thus be strained out. Many people living in rural areas use this method to obtain clean water.
- For Reducing Body Odor: It controls body odor. It can be applied directly on the perspiring areas of the body. As it is soluble in water, it mixes up with the sweat and stop the growth of bacteria that causes body odor. Those who suffer from the problem of foot odor should apply it on their feet regularly before going to bed in order to get relief from it.
- For Pickling: It is popularly used in various pickling recipes particularly the cucumber and watermelon-rind pickles. Its ions strengthen the cell walls of the fruits and vegetables used in the pickles. This in turn maintains the natural crispness of those fruits and vegetable.
- Used in Baking Powder: Alum powder is used as the acidic component in certain brands of baking powder which gives a metallic taste to the baking powder.
- In Cosmetics: It is used in cosmetics like skin whitening toner and depilatory waxes.
- As an Ingredient in Mouthwash: It is used as an ingredient in mouthwash and toothpaste as it can fight against oral bacteria.
- In Fire Extinguishers: It has resistance towards fire and hence, used in fire extinguishers.
- Constituent in Play Dough: It is a constituent of play dough which is commonly used by children for making home modeling compound.
The use of alum powder as a food additive is approved by the U.S. Food and Drug Administration. Still, if taken in large quantities, it can be toxic for human health. Moreover, while handling it, avoid inhalation of the powder as it can cause harm to your health.