The alcohol used in manicure is commonly 75% and 95%. The former is used to disinfect fingers and tools, and the latter is equivalent to cleaning liquid，which can be used for wiping floating glue or washing pens.
Why can only use 75% alcohol for disinfecting? Because the alcohol whose concentration is too high will forms a protective film on the surface of the bacteria, which can prevent them from entering the bacteria, so it is difficult to kill the bacteria completely. If the concentration of alcohol is too low, it can enter bacteria, but cannot coagulate its protein, nor can it completely kill the bacteria. So the concentration of 95% alcohol is too high, there is no way to kill the bacteria completely, the concentration of 75% alcohol is just fine.