The compound responsible for the smell in human sweat is trans-3-methyl-2-hexenoic acid and its chemical formula is C7H12O2.
According to the article, perfumes and deodorants are alike in that the goal in using them is to eliminate (or at least hide) body odor. They are different in that perfumes merely cover up the odor, while deodorants actually kill the bacteria responsible for the odor.
The article mentions that baking soda and formaldehyde were used originally in deodorants.
The common property that baking soda and formaldehyde have is that they both kill bacteria.
Studies have shown that formaldehyde is toxic and can cause cancer.
Zinc oxide does not kill bacteria by itself, “…but, similar to baking soda, it neutralizes the fatty acid microbial waste products responsible for body odor.
Deodorants kill the bacteria that cause body odor, while antiperspirants block the pores through which sweat passes, thus preventing sweating and maintaining a dry environment in which bacteria cannot thrive.
Most antiperspirants contain aluminum-based compounds. Aluminum compounds form aluminum ions (Al3+) in solution. These ions plug your sweat ducts so that you don’t perspire.
The two types of sweat glands in underarms are eccrine glands and apocrine glands.
Most of the actual active ingredients of deodorants are solids, so they must be dissolved or suspended in liquids or gels to allow them to be applied easily. The solvents must evaporate easily so that they don’t leave a wet or greasy feeling and to leave behind the solid ingredient that actually deodorizes the armpit.
Natural “deodorant crystals” contain alum. When rubbed on damp skin, the alum on the surface of the crystal dissolves and is spread across the skin, leaving behind a slightly acidic solution that creates a hostile environment for bacteria.