Analysis of Unpleasant Odor-emitting Mechanism and Development of Deodorant Technology

Unpleasant odors not only cause problems in daily life but can also sometimes have adverse effects on human relationships. For solving odor problems and providing a more comfortable life, Kao has been investigating substances causing unpleasant odors and the emission mechanism in order to control them.
Neither sweat nor urine alone has a bad smell. The unpleasant odor comes out when bacteria decompose sweat and stains on clothes, or substances in urine, which are sources of bad smells.
For example, Kao has found that the odor of sweaty clothes consists of multiple short- to medium-chain fatty acids that are produced by specific bacteria involved in decomposing sweat and stains on clothes. By advancing research on such microorganisms and developing detergents collaboratively, a new technology for controlling bacteria causing sweaty odors has been developed and applied to our fabric detergents.
The smell of urine is not strong immediately after being discharged from the body. Phenol compounds (p-cresol, etc.) are responsible for urine odor, though initially exist as substances bound with sugars. These odor precursors are decomposed by bacteria, thus the smell becomes stronger over time after urination. We have obtained results showing that even after the bacteria have died, enzymes remain active and continue decomposing the odor precursors, and thus produce urine odor. As a countermeasure for urine odor, “Urine Odor Blocker” ingredients that inhibit those enzymes have been explored and applied to deodorant products, such as fabric detergents, toilet bowl cleaners, and cleaning sheets used in the household.
Studies on substances causing unpleasant odors and the emission mechanism will lead to various unique approaches for developing effective deodorant technology.