For maximum exfoliating power and minimum risk of mold and bacterial growth, you should replace a plastic mesh bath pouf after eight weeks and a natural sea sponge or loofah after three or four weeks. Disinfecting your bath sponge every day will also help reduce the amount of bacteria and mold that may be growing in it [source: Crean].
Keeping your bath sponge as dry as possible when not in use is one way to hold bacteria at bay. However, one study found that loofah sponges needed to air dry for at least two weeks to significantly lower the level of bacteria they contain [source: Bottone]. This means you need to take extra steps to ensure a germ-free sponge.
In addition to rinsing and hanging it in a well-ventilated area to dry, you can use a bleach solution to disinfect your bath sponge. To clean a synthetic sponge, you should soak it in three quarters of cup of bleach per gallon of warm water. For a natural sea sponge, use one-quarter cup of bleach per gallon of cool water. You should soak either type of sponge for at least five minutes [source: Columbia University]. An easier but possibly less effective approach entails throwing your sponge in the washing machine or the dishwasher. Laundry and dishwashing detergents are gentler and less toxic than bleach, but they may not kill all the bacteria and mold present.
By disinfecting your bath sponge each week and replacing it after several weeks, you can keep germs from taking root in your personal care items, bathroom and body. Read on for more information about keeping your skin clean and healthy.