Food Safety

Preventing Cross-Contamination in Your Kitchen

June 12, 2018   /


Reviewed and updated by Anne Danahy, MS, RDN, LDN


Cross contamination is the transfer of microorganisms that are naturally found in food from one food to another. This can happen easily when grocery shopping and when transporting, storing, or preparing food. If food is not stored or cooked correctly, cross contamination can result in bacteria growing in food and causing foodborne illness or “food poisoning.”


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Individuals who have cancer, are getting treatment for cancer, or have compromised immune systems for other reasons are at high risk for foodborne illness. The good news is that cross contamination is very easily prevented.


How cross contamination happens

It can happen in many ways. For example, a package of raw ground beef can leak onto the lettuce you also have in your grocery cart. The bacteria can move from the ground beef to the lettuce. These bacteria normally are killed in ground beef when it is cooked, but because lettuce is not cooked, the bacteria can grow. The lettuce has become cross contaminated and could cause foodborne illness, unless it is cleaned and stored correctly.

Transfer of bacteria from raw meats to uncooked foods, such as produce, is one of the biggest causes of cross contamination, but bacteria are also transferred to food from work surfaces or a person’s hand.

Foodborne illness can cause nausea, vomiting, diarrhea, fever, and other symptoms. While some people manage foodborne illness without a problem, it can result in serious illness or even death in some people, especially those who have a chronic disease such as cancer.


Preventing cross contamination

Proper handling of food is essential. Here are some tips:

  • Separate raw meats from foods that are eaten raw, such as produce, in your grocery cart, at the checkout, and in your refrigerator
  • Double-bag meats at the grocery store (most meat departments have plastic bags available), so that juices do not leak onto other foods
  • Refrigerate or freeze foods as soon as possible after going to the grocery store
  • Bring a cooler along for storing food (if you need to run errands after grocery shopping)
  • Make sure you always refrigerate perishable foods within 2 hours after shopping or 1 hour if it is hotter than 90° F outside
  • Unpack perishables and store them properly as soon as possible after you arrive home from the grocery store
  • Store meats away from produce, keeping the meats below the produce in the refrigerator to prevent the produce from becoming contaminated if the meat leaks
  • Keep meats and produce separate during food preparation
  • Place raw meats in sealed plastic bags or other sealed containers
  • Clean (wash) and sanitize (using antibacterial cleaner or 1 tablespoon bleach to 1 gallon of water) all knives, cutting boards, counters, and other equipment that is in contact with raw meat
  • Use hot soapy water and a clean dishcloth or paper towel to clean countertops
  • Put dishcloths or sponges in the dishwasher or “hot” cycle of your washing machine to clean
  • Wash your hands using soap and warm water for 20 seconds between handling produce and raw meat
  • Place cooked food on a clean plate, not one that has had raw meat sitting on it
  • Take extra care when cooking with marinades—if marinade or barbeque sauce was in contact with raw meat, boil it to kill bacteria before applying it to cooked meat


References and recommended readings

  1. Food Safety and Inspection Service. Fact sheets. US Dept of Agriculture Web site. Accessed April 17, 2018.
  2. Food Safety and Inspection Service. Kitchen Companion: Your Safe Food Handbook. US Dept of Agriculture Web site. Published February 2008. Accessed April 17, 2018.
  3. Food Safety and Inspection Service. Safe food handling fact sheets. Accessed April 17, 2018.
  4. National Restaurant Association Educational Foundation. ServeSafe Essentials. 5th ed. Chicago, IL: National Restaurant Association Educational Foundation; 2008.


Current review date: 6/12/18

Previous review date: 9/10/13