What are two ways that foods can become cross contaminated?

Answer 1

Cross contamination is when a contaminated food (such as raw meat) contaminates a non contaminated food, via coming in contact with each other. eg. using the same chopping board for both vegetables and uncooked chicken.

Answer 2

Dirty hands, equipment and utensils.
Cross contamination occurs most commonly when utensils and surfaces are not properly disinfected before reusing them, especially when the surface of utensil is used on foods that will be cooked and subsequently used on foods which will not be heated or will not be heated to a temperature sufficient to eliminate foodborne bacteria. For example, you have a cutting board and a knife, which you use to cut up a chicken, then you use the same cutting board and knife to cut carrots and celery which will be used raw. The surfaces which came into contact with the chicken are contaminated with fluids which potentially harbor salmonella, the chicken, you will likely cook to an internal temperature of 165 degrees fahrenheit thus eliminating that bacteria. The vegetables however, will not be heated and thus could be contaminated with the bacteria upon consumption. Simply rinsing the board and the knife are not sufficient to remove the bacteria. It is not usually understood that the antibacterial properties in most kitchen soaps, must be in contact with the contaminated surface for more than 30 seconds. Washing in hot water, for more than 30 seconds, with an antibacterial soap will generally do the trick. Another common cause of cross contamination, is poor handwashing practices. Like the surface of the board and knife, it takes 30 seconds or more for the antibacterial properties to be effective. Further, the utensils you use to handle raw meat products should not be used to handle those same products after they have been cooked. Wash utensils between uses, or use a new utensil to the finished foods. Always sanitize your cutting surfaces, countertops. It is best to keep one cutting board for raw fruits vegetables and other foods, and a separate board for raw meat products.

Answer 3

After you have cooked something, it has no (or very few) dangerous microbes left in it. However, if it comes in contact with something that is not prepared or safe - the contamination - it is very dangerous when it is not known to be, and assumed safe to eat. Someone eats it but is poisoned by the bacteria. Salmonella and E. coli are two noted microbes, and chicken is notorious for causing both as well as many of the other contaminants that cause food poisoning.