Prevention of food poisoning (or "foodborne illness") begins with your trip to the supermarket. Follow these tips:

• Pick up your packaged and canned foods first. Purchase frozen foods and perishables such as meat, poultry, or fish last in order to prevent them from remaining at warmer temperatures for a longer period of time.
• Do not buy food in cans that are bulging or dented or in cracked jars with loose or bulging lids.
• Buy only pasteurized milk, cheese, or otherwise treated ciders and juices, especially if you have a health problem that impairs your immune system.
• Choose eggs refrigerated in the store. Open the carton to make sure that the eggs are clean and not cracked before purchasing.
• Keep meat, poultry, and fish products in separate plastic bags so that the drippings do not contaminate other foods in your shopping cart.
• Do not buy frozen seafood if the packages are open, torn, or crushed on the edges. Avoid packages above the frost line in the store's freezer. If the package cover is transparent, look for signs of frost or ice crystals. This could mean that the fish has either been stored for a long time or has thawed and refrozen.
• Check the cleanliness of the meat or fish counter and the salad bar. For instance, cooked shrimp lying on the same bed of ice as raw fish could become contaminated.
• When shopping for shellfish, buy from markets that get their supplies from state-approved sources; stay clear of vendors who sell shellfish from roadside stands or the back of a truck. If you are planning to harvest your own shellfish, heed posted warnings about the safety of the water.
• Take an ice chest to keep frozen and perishable foods cold if it will take more than one hour to get your groceries home.