Food can be unsafe for many reasons. It might be contaminated by germs—microbes such as bacteria, viruses, or fungi-like molds. These microbes might have been present before the food was harvested or collected, or they could have been introduced during handling or preparation. In either case, the food might look fine but could make you very sick. Food can also be unsafe because it has “gone bad.” Sometimes you may see mold growing on the surface.
Here's a Tip
U.S. Department of Agriculture Food Safety Programs
What's On Your Plate? is based on the nutrition recommendations for older adults in the Dietary Guidelines for Americans, 2010  from the U.S. Department of Agriculture (USDA) and the U.S. Department of Health and Human Services (HHS).