Wood or synthetic cutting boards can be a breeding ground for germs and bacteria such as E. Coli. When a board has too many cuts and scratches to clean effectively it should be replaced. Small pieces of food caught in deep cuts can easily generate enough bacteria to make anyone seriously ill.
Always clean immediately after use with detergent rinse with clean water. If used for meat, fish or poultry then it is recommended to disinfect afterward. Soak the cutting board in bleach and water solution for a minimum of three minutes, then rinse with clean water. Washing with soap and water immediately after use is the best way to insure the spread of bacteria.