Cross-contamination of food is the transfer of harmful microorganisms between food items and food contact surfaces. Prepared food, utensils and surfaces may become contaminated by raw food products and microorganisms. These can be transferred from one food to another by using the same knife, cutting board or other utensil without washing it between uses. A food that is fully cooked can become re-contaminated if it touches raw foods or contaminated surfaces or utensils that contain pathogens. For example, you should never:

• allow raw meat to touch cooked meat
• put cooked meat on a cutting board that has just been used for raw meat without cleaning it first (Figure 8.5)
• store raw meat on a shelf above cooked meat so that it could leak blood and raw juices on to the cooked meat below.