Confusion often arises over the safety of Alum because the press talk about Aluminium being bad for us.
Aluminium is the third most abundant element on the planet and we ingest it in large proportions every day in water and food.
In fact, in some parts of the world, its presence in water is the only thing that makes it safe to drink.
Aluminium is not particularly good for living organisms in the body, which is why over years Humans have evolved a system for allowing naturally occurring Aluminium and its salt derivatives to pass through the body without effect.
However when the press discuss Aluminium as being dangerous, they are often referring to specific types of manmade Aluminium, rather than naturally occurring forms; Aluminium Chlorohydrate for example.
Aluminium Chlorohydrate is designed to be absorbed into and block the pores under the arms, to prevent perspiration.
It is thought that Aluminium Chlorohydrate can enter the blood stream in this way.
There have been some claims that there may be a connection between breast cancer and Aluminium Chlorohydrate, but as yet no real concrete evidence.
There is also speculation about links between the extended use of Aluminium Chlorohydrate and a higher risk of developing Alzheimer's disease.
When it comes to differentiating between Aluminium Chlorohydrate (the active ingredient in most Antiperspirants) and Alum (the raw material in Crystal Deodorants) many people get a little confused.
There is much talk that these two ingredients are the same thing, but that is not the case.
Aluminium Chlorohydrate is a group of salts synthetically created using any number of Aluminium containing raw materials, such as aluminium metal, reacted with hydrochloric acid.
Alum (known as Potassium Aluminium Sulfate) however, is a naturally occurring mineral compound.
It is the potassium double sulfate of Aluminium.
Alum occurs as encrustations on rocks and is mined and used in natural deodorants in its natural form.
Alum differs to Aluminium Chlorohydrate, not only in form but also in use.
Alum has been used for many thousands of years in the Far and Middle East as a deodorant and for other topical applications.
Alum is used in deodorants for its antibacterial properties, which helps to inhibit the growth of body odour-causing bacteria on the skin.
Some people find that Alum also performs a basic antiperspirant function, as it is a little astringent.
The molecules of Alum are too large to pass through the skin, so they do not enter and block the pores.
Instead, alum leaves a fine layer of salts on the skin.