What is the topic of the passage? [originaltext] Food that has come in contac

Food that has come in contact with floodwater can sicken anyone who eats it. Water from floods may contain animal and human waste. It can also contain other pollutants like chemicals from agriculture and industry. After a flood, food safety specialists have this advice : Throw away anything that is not stored in a waterproof container if there was a chance of contact. Also, throw away boxes of juice, milk or baby formula if they have come into contact with floodwater. Throw away anything in soft packaging.
    But food safety experts say that some unopened, undamaged all-metal cans can be saved. First, remove any labels. The paper may contain dirt and germs from the floodwater. Wash the cans with soap and water , and brush or wipe away dirt. Use hot water and water that is safe for drinking if they are available. Next, place the cans again in water and heat the water to one hundred degrees Celsius. Boil the cans for two minutes. Another way to disinfect the cans is in a freshly made solution of chlorine bleach. Use eight drops of unscented liquid bleach for every four liters of water. Use drinking water or the cleanest, clearest water available. Place the cans in the solution for fifteen minutes.