Every year, approximately 600 million people worldwide contract foodborne illnesses. According to the CDC, 48 million people in the United States become ill each year as a result of eating contaminated food.
Cross-contamination is one of the many ways that food can become contaminated and cause food poisoning. While most foodborne illness outbreaks are traced back to retail food establishments, they can also occur at home.
Fortunately, you can avoid cross-contamination by following the proper food safety precautions. This article will walk you through everything you need to know about preventing cross-contamination.
What Is Cross-Contamination?
Cross-contamination is the unintentional transfer of pathogens from one surface or food to another. It usually happens when Potentially Hazardous Foods (or PHFs) come into contact with uncontaminated ready-to-eat food. PHFs are more likely to harbor and support the growth of harmful microorganisms. Examples of PHFs include raw or undercooked meat, poultry, fish, eggs, leafy greens, and unpasteurized dairy products.
There are three major types of bacterial cross-contamination:
- Food to food – when contaminated food comes into contact with uncontaminated food
- Equipment-to-food – when the different equipment that comes into contact with food, for instance, utensils, harbor harmful bacteria, and other microorganisms
- People-to-food – when the person handling food at different stages—production, transportation, prepping, cooking, storing, etc.—unknowingly transfers harmful pathogens to food.
Handle Shopping Bags Safely
Cross-contamination can occur during shopping and check-out if food is not handled with care. Here are some of the ways you can avoid cross-contamination when shopping:
- Separate raw foods (especially raw meat, poultry, and seafood) from other foods in your shopping trolley or basket
- Use separate shopping bags to pack raw foods and other foods at check-out
- Designate some shopping bags for placing raw foods if you use reusable shopping bags
- Pack food separately from other household items
- Place raw foods in plastic bags if you must pack them together with other foods. This will prevent chances of the juices dripping to other foods in the bag
- Replace old plastic bags often
When shopping, try to avoid damaged packages, including a dented can.
Wash Your Hands When Handling or Prepping Food
Washing your hands properly before, during, and after prepping any food is vital in preventing cross-contamination. If your hands come into contact with some germs, you can easily spread them to foods and around the kitchen.
According to a study done by the USDA’s Food Safety and Inspection Service (FSIS):
- Most participants did not wash their hands 97% of the time, they should have
- 48% cross-contaminated spice containers
- 5% spread bacteria to the salads they prepared
To prevent cross-contamination around the kitchen, always wash your hands with soap and warm water for at least 2o minutes after:
- Handling food, especially raw meat, poultry, seafood, fruits, and vegetables
- Touching garbage
- Coughing or sneezing onto your hands
- Using your mobile phone and any other unsanitized item
After washing your hands, use a single-use paper towel to wipe your hands. Avoid wiping your hands with an apron or a used towel.
Use Separate Kitchen Tools When Preparing Food
It’s easy to cross-contaminate when using the same utensils when prepping food. Here are some proper food safety practices you can follow when prepping food:
- Invest in at least two chopping boards – one for raw meats and another for fresh produce
- Don’t use the same chopping boards and utensils for both cooked and raw foods
- Wash chopping boards, knives, and other utensils with warm soapy water after placing raw foods on them
Disinfect Kitchen Surfaces Regularly
If a kitchen surface is contaminated unknowingly and not cleaned properly, it’s possible to transfer harmful bacteria to food. These bacteria can survive for extended periods of time on surfaces such as countertops. Bacterial cross-contamination in the kitchen can occur when you place unwashed produce on countertops, prep food, or wash raw meat and its juices splash onto the sink area and other surfaces. A study by the national sanitization Foundation (NSF) found sinks to be the second germiest place in the household.
Below are tips for disinfecting kitchen surfaces to prevent cross-contamination:
- Don’t wash raw meat
- Use hot soapy water and clean cloths to wipe kitchen surfaces, especially after handling raw meat
- Wash the prep sink and work area with hot soapy water after preparing any food item and before proceeding to another. You should also disinfect the sink area, including sink strainers, once or twice every week with a disinfecting cleaner
- Sanitize the surfaces that are touched most in the kitchen, such as refrigerator handles or cabinet knobs, or pulls
Prepare and Serve Food Hygienically
How do you avoid cross-contamination when preparing and serving food? Here are some tips:
- Replace excessively scratched or worn chopping boards
- Avoid leaving cut fruits and vegetables at room temperature for long
- Don’t serve cooked food on the same plate or cutting boards that you’d placed raw foods on
- Rinse fresh fruits and vegetables under running water before peeling, cutting them, or cutting away damaged parts
- Thoroughly cleanse utensils, including chopping boards, before reusing them, especially if they’ve previously held raw meat
- Discard sauces and marinades that have come into contact with raw meat juices, as they may transfer germs to cooked foods
- Don’t touch the food contact surfaces of dishes and utensils
- Don’t touch and serve ready-to-eat foods with bare hands when serving others
Store and Preserve Food Safely
How can cross-contamination be prevented in storage? Where and how you store food is vital in preventing cross-contamination. Whether you’re storing food on a shelf or in a refrigerator, it’s important to follow food safety practices.
Here are some of the ways you can avoid cross-contamination when storing foods:
- Keep raw and ready to eat foods separate
- Place raw meat, poultry, and fish in covered containers or sealed plastic bags and store them on the bottom shelf of your fridge. It prevents raw juices from dripping onto other foods in the fridge
- Refrigerate eggs as soon as possible
- Place meat that you aren’t using in the next few days in a freezer
- Don’t place raw meat and ready to eat food on the same fridge shelf or next to each other
- Eat leftovers within three to four days. If you mix refrigerated leftovers with other foods, don’t store them as leftovers again. Leftovers kept in the fridge for an extended period of time can cause bacterial overgrowth
- Wrap or cover food before storing it in a refrigerator
- Refrigerate cut vegetables like tomatoes and leafy greens at 41°F (5°C) or lower
- Move your shopping to the right storage place immediately
- Store food and food equipment a few inches off the ground to avoid splash
Clean Dishrags or Kitchen Sponges Thoroughly
A study conducted by the National Sanitization Foundation (NSF) found that the sponges and dishrags used to wash utensils and kitchen counters to be the germiest in most homes. The kitchen sponges or dishcloths easily pick up bacteria during the cleaning process. If not properly sanitized, they can promote the growth and spread of the bacteria.
To prevent cross-contamination, clean the wet sponges frequently by placing them in a microwave when wet for two minutes. If you use dishcloths, towels, and rags, you can wash them in the hot cycle of your washing machine or boil them for 15 mins to remove any pathogens. Be sure to replace washable linens frequently, preferably after a day or two.
Store Utensils and Kitchen Equipment Properly
Utensils must be stored correctly to prevent cross-contamination. Here are some guidelines that you can follow to keep your utensils and non-food items like knives correctly:
- Store utensils that carry food some inches off the floor (about six inches) to prevent splashes and spills
- Store cups and glasses upside down on sanitized utensil holders or surfaces
- Store items with handles up to prevent anyone from touching the food contact surface
Cross-contamination is a leading cause of food poisoning, but it can be prevented by following proper food safety advice. It’s always a good idea to separate raw food, particularly Potentially Hazardous Foods (or PHFs) such as unpasteurized milk and raw meats, from ready-to-eat foods.
While anyone can get sick due to cross-contamination, certain groups are at a higher risk and should always observe food safety practices. These groups include people with weakened immune systems, people above 65 years, pregnant women, and children.