Do you defrost your chicken breast on the fridge's top shelf? Are you using your dish sponge to clean the counters? Do you cut everything on a single cutting board? Oh boy, if so, you’re guilty of cross-contaminating.
It's pretty much what it sounds like -- one thing is contaminating another. In this case, it's when food bacteria are transferred from one surface to another. Sounds harmless -- except it's not. When given enough time, the right temperature and some moisture, bacteria can grow and thrive to levels that make you sick.
The CDC identifies cross-contamination as one of the top 5 causes of food-borne illnesses -- so prevention is key. Think about these 6 things to keep things clean and safe.
Every kitchen should have at least two cutting boards (at least!) -- one for ready-to-eat foods and one for raw meats and poultry. Try to get different colors or types of cutting boards. These dishwasher-safe cutting boards are perfect because you can designate a color for each food type. Fish could be blue, raw meats red, poultry yellow and produce green.
Make sure to properly wash cutting boards. If you don’t have a dishwasher for the plastic cutting boards, make sure you use hot, soapy water -- and clean out your sink with detergent (or vinegar for a more natural alternative) often. Germs thrive in the sink. Once a cutting board has many cracks and crevices, it’s time to buy a new one. Don't give the bacteria a place to hide.
The signs in restaurants say this for a reason. Your hands are your most useful tool in the kitchen, but they can be detrimental to your health if you don’t wash them! Wash hands before you start prepping and re-wash them after handling raw foods, going to the bathroom, taking a break or talking on the phone (or browsing that recipe on your laptop).
Proper hand washing isn't just sticking your hands under some cold water for 2 seconds (even my 2-year old daughter knows better than that!). To wash your hands properly, first wet your hands with warm water and then apply soap. Vigorously scrub your hands, arms and between your fingers for 10-15 seconds. I tell my kids to sing "Happy Birthday" twice. Then, rinse and dry on a paper towel. Be careful drying your hands on hand towels, too, as you may just re-contaminate them.
When you store raw meats and poultry in the refrigerator, they can drip onto fruit, veggies and other foods that require no further cooking. This is just a disaster waiting to happen. These foods should be kept on the bottom of the fridge (I put mine in the lowest drawer) and you can even keep them in plastic bags to prevent dripping.
When marinating foods, make sure you do so in the refrigerator (not the counter) in a closed container. Sauce that is used to marinate raw meat, poultry or seafood should be discarded or boiled before being used on cooked foods. (Take note, grillers!)
In 2005, the USDA Dietary Guidelines for Americans came out with a perplexing guideline -- don’t rinse your meat or poultry before using it. Seems like the USDA found rinsing causes water to splash all over your countertops and any dishes in the sink or sitting nearby (yet another way to cross-contaminate). Instead, cook your meat, poultry or fish to the proper temperatures; the heat will kill off any bacteria or germs that you might think you're getting when you rinse.
Cross-contamination can result from slicing open a melon! The dirt on the outside of the melon (and bacteria found in that dirt) finds its way to the inside. Best thing to do is rinse fruits and veggies in running tap water to remove visible dirt. When prepping veggies such as lettuce or cabbage, remove and toss the outermost leaves.
Use hot, soapy water with a clean cloth or paper towel to wipe kitchen surfaces and counters. Wash cloths used for cleaning in the hot cycle of your washing machine often (when was the last time you did that?). You can sanitize sponges with a quick zap in the microwave or dishwasher, but you should still replace them often since they harbor bacteria.
Also, scrub down counters and dishes every time you prep a food and before moving on to the next item. One high-power solution is a mix of 1 tablespoon of unscented, liquid chlorine bleach with 1 gallon of water. Use that to sanitize surfaces and utensils.
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Cross-contamination is the process whereby harmful bacteria from food spreads to other foods, surfaces, hands, or equipment. It can be caused by many factors, such as if you use a chopping board to prepare raw chicken and then use the same board for ready-to-eat food.
Cross-contamination is dangerous as it can easily lead to food poisoning: an illness caused by consuming harmful bacteria, such as salmonella and E. coli.
It is everybody’s responsibility to prevent cross-contamination in the kitchen.
You must adopt safe food handling habits when preparing food, especially when handling raw meat, poultry, and seafood, which can easily carry salmonella and E. coli. These foods must be kept separate from ready-to-eat foods at all stages of the food handling process.
Our Food Hygiene Training is designed to ensure a comprehensive knowledge of all food safety and hygiene procedures.
This article outlines ways to avoid cross-contamination in your kitchen. There are two important areas where you must take extra care with food handling – refrigeration and food preparation.
Refrigeration
Correct refrigeration procedures are essential when handling food. Some simple steps to follow are:
- Place raw meat, poultry, and seafood on the lowest shelf of the refrigerator in containers or sealed plastic bags. This prevents any juices from the meat dripping onto, and contaminating, other food.
- Always keep ready-to-eat and cooked food separate from raw food.
- Refrigerate eggs as soon as possible to increase their longevity. You should also keep eggs in their original container, to reduce the risk of them smashing.
- Ensure your fridge is the correct temperature. The law states that, in catering environments, all refrigerators must operate at 8°C or below. It is good practice to set refrigerator temperatures between 1°C and 4°C.
- Don’t place hot foods in the fridge, as this raises the overall temperature. Remember: fridge temperatures should always be below 8°C.
Food Preparation
All food handlers must follow the correct procedures when preparing food to prevent cross-contamination.
You should:
- Wash your hands regularly. You must always wash your hands before handling food, and especially after handling raw meat and fish. Dry your hands using paper towels – never by wiping them on yourself.
- Use colour-coded chopping boards for different food groups, particularly raw foods and ready-to-eat foods. For example, use a red chopping board for raw meat, a blue one for raw fish, green for fruit and vegetables, etc.
- Use different knives, plates, and cooking utensils for different types of food. Ensure you cut raw chicken and vegetables with different knives, for example.
- After use, you must immediately wash utensils and crockery you use for raw meat, poultry, and raw fish. This helps to minimise the risk of their juices contaminating other foods and surfaces.
- Regularly replace your chopping boards, as bacteria can get caught in knife grooves. Generally, you should replace any utensil that shows extensive evidence of wear and tear.
- Regularly clean surfaces throughout the day and always after preparing food. Ensure you use both an antibacterial spray and hot soapy water, and always use clean cloths or paper towels.
- Always wash fruit and vegetables, regardless of if you plan to peel them. The soil and water in which fruit and vegetables grow can carry harmful bacteria and parasites, which can sit on the food’s surface.
- Remove any jewellery and watches before preparing food, except for a wedding band. Jewellery can collect and spread dirt and bacteria, and can even fall into food.
We hope this article is useful for explaining cross-contamination and the ways to avoid it. Follow the above procedures to reduce the risks of cross-contamination, and its associated health risks, in your kitchen.
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Ellie Collier is the Content Production Manager for Health & Social Care sector at High Speed Training. Ellie has always been passionate about mental health, for both adults and for children, and ensuring that everyone has the opportunity to talk about their problems. She has produced a range of materials to help teachers initiate positive conversations about mental health and has featured in publications like Education Today for her work. Ellie’s Mental Health Resource Pack for Schools, which features a School Mental Health Policy template, was shortlisted for the Teach Secondary Awards 2019.