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9 Things You Contaminate While You Cook (Without Realizing It)
From spice jars to your phone, these everyday items can pick up germs while you cook
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Key takeaways
- USDA test kitchens found sinks, boards and spice containers often spread bacteria despite cleanup.
- Phones, handles, towels and trash lids become part of a germ relay during multitasking.
- Separate tools, premeasuring and handwashing cut risk but do not erase it entirely.
Even if you’re careful in the kitchen, you may be spreading harmful bacteria without realizing it.
Cross-contamination is one of the most common ways foodborne illness spreads at home, and it often happens in unexpected ways. Even when people try to clean up properly, they can miss critical spots. In a USDA test-kitchen study, nearly one-third of participants failed to thoroughly clean their cutting boards after use.
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The CDC says foodborne illness sickens 9.9 million of Americans each year, and a Center for Science in the Public Interest report cited by UConn Extension found that roughly 30 percent of outbreaks were linked to food prepared at home — underscoring how important safe food handling is in the kitchen.
The good news is that small changes in behavior make a real difference. The bad news: They don't eliminate the problem entirely. Here are nine places where contamination is most likely hiding — and what to actually do about it.
1. Your cutting board (especially while prepping)
It’s one of the most common shortcuts in home kitchens: using the same cutting board for raw meat and then switching straight to vegetables or something that won’t be cooked. But that habit can spread bacteria from one food to another.
“Using separate cutting boards for raw meat/poultry/seafood and for produce or ready-to-eat foods is one of the simplest ways to prevent cross-contamination,” says Meredith Carothers, a public affairs specialist in food safety education at the USDA's Food Safety and Inspection Service.
When it comes to cutting-board materials, there’s plenty of debate over using wood, plastic or glass. The reality is that consumers are safe using either wood or nonporous surfaces such as plastic, marble or glass as long as the board is properly cleaned and maintained, says the USDA.
If you want to cut raw meat on wood, that’s fine — but know that nonporous materials like plastic are generally easier to sanitize thoroughly and can go in the dishwasher. Bamboo is harder and less porous than most hardwoods, making it more resistant to moisture and bacteria.
Whatever material you choose, the agency is clear on one thing: Once a board develops deep grooves or becomes excessively worn, it's time to replace it.
Tip: Keep it simple. As Carothers puts it, “One board for raw, one board for ready-to-eat.”
2. Spice jars (when you handle raw meat or eggs)
Using dirty hands to grab spice containers or other kitchen items and then ready-to-eat foods is one of the most common chains of contamination observed by the USDA, Carothers says.
In a study of 200 people, 12 percent contaminated their spice containers without even realizing it while preparing raw meats. And it’s not just raw meat to watch out for; eggs and flour can also carry bacteria that transfer easily to kitchen items and then to foods that aren’t going to be cooked.
Tip: Keep a dedicated “clean hand” habit when seasoning — or decant spices into a small dish before you start cooking so you don’t have to touch the container mid-prep.
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3. Your phone (while cooking and multitasking)
Between following viral recipes, setting timers, answering texts and playing music, the phone never really leaves the kitchen.
And the numbers back up what you probably already suspect. Of those who use their phone while cooking, only about a third wash their hands after using their device. Meanwhile, food poisoning bacteria like salmonella and E. coli can survive on a phone screen for more than 24 hours — and in one study, participants touched their phone an average of nearly six times during a single 30-minute cooking session.
Tip: Use a stand to keep your phone hands-free while you cook — and make it a rule not to touch it right after handling raw meat without washing up first, says Ellen Shumaker, director of outreach for Safe Plates in the Department of Agricultural and Human Sciences at North Carolina State University.
When you're done cooking, wipe down the screen with an antibacterial wipe containing at least 70 percent alcohol. It sounds like overkill until you think about where your hands have been.
4. Handles you touch mid-cook (fridge, faucet, cabinets)
Think about it: You may touch your fridge, faucet, drawer and oven handle — all within a matter of seconds.
Carothers flagged “fridge handles and cabinet pulls” along with “faucet handles and sink surfaces” as some of the top “high-touch” surfaces people should assume get contaminated after they handle raw ingredients.
And while the contamination rate for cupboard handles was lower than the sink or spice containers in the USDA consumer test-kitchen study, cupboard handles were contaminated 8 percent of the time. Tip: Some cooks keep a clean kitchen towel folded over the oven handle specifically for opening doors mid-cook — not for drying hands, just for handles.
5. Cooking oil bottle or spray
Whether you’re slicking a pan, spritzing veggies or giving the air-fryer basket a quick blast, the oil bottle is one of those “grab it without thinking” items. And that’s exactly the problem: If you have just handled raw meat, eggs or flour, it’s easy to turn a quick spritz into a “germ relay.”
“When hands aren’t washed after touching raw meat, poultry, eggs or flour, bacteria can easily transfer to frequently used items — and then to foods that won’t be cooked again,” says Carothers.
Tip: Before you start cooking, premeasure your oil into a small dish or ramekin. It sounds fussy, but it's actually faster once you get used to it, and it removes the bottle from the contamination chain entirely.
6. Your sink and the surrounding “splash zone”
The sink is where good intentions often turn messy. It’s where people wash their hands, rinse produce and, despite federal guidelines advising against it, sometimes even rinse raw poultry, making it one of the easiest places for contamination to spread.
Out of all the locations in the kitchen, “the surface most often contaminated was the sink basin (28 percent of participants),” according to the USDA.
And what happens in the sink doesn’t stay there. In the same study, researchers used a harmless “tracer” in raw meat to track contamination, and it showed up on ready-to-eat salad lettuce 17 percent of the time — meaning the germ relay reached food that wouldn’t be cooked again.
“The sink basin might not seem like a high-touch area, but it is frequently used to wash fruits and vegetables and for handwashing,” says Shumaker.
Tip: The sink isn’t self-cleaning. Surfaces and utensils “should be cleaned with soap and water first to remove the dirt, and then sanitized,” Shumaker says. “Sanitizer won’t work effectively if cleaning isn’t done first.” Turns out, Mom was right: You should shine your sink every night before bed, and probably more often than that.
7. Plates, tongs and utensils used for raw meat
It’s an easy autopilot mistake. "Never put cooked food back on a plate that held raw meat or poultry,” says Carothers, noting that juices from raw meat can contaminate cooked food.
You might bring raw chicken or steak to the grill on a plate, flip it with the same tongs, and then use those same tools to plate the finished food. But those shortcuts can undo your cooking — whether it’s the plate or the utensils, anything that touched raw meat can spread bacteria.
The same goes for whatever touched the raw food along the way.
Tip: Set out a clean plate before you start cooking — not after. If it’s already there, you won’t default to reusing the raw one. And clean tongs or spatulas you used to put the raw food on the grill before you remove the cooked food, or use a seperate clean set. .
8. Dish towels and sponges you reuse while cooking
Dish towels and sponges don’t seem risky, but they can quickly trigger a domino effect of cross-contamination. If your hands are dirty and you wipe them on a towel — or use the same sponge you used on raw-meat spills to clean up — you can spread bacteria to everything that comes next.One older study published in Scientific Reports found 362 different types of bacteria on kitchen sponges. The study authors noted that kitchens have more bacteria than bathrooms, mainly due to kitchen sponges, “which were proven to represent the biggest reservoirs of active bacteria in the whole house.”
Tip: Treat them like any other surface during raw prep — keep them clean and change them often. Sponges can be sanitized in the dishwasher or microwave, but they still need to be replaced regularly. Dish towels should be washed on a hot cycle and allowed to fully dry between uses.
9. Your trash can lid (during food prep)
Tossing packaging, scraps or trimmings in the trash is part of cooking — but the lid or handle can easily become another stop in the germ relay if you touch it with contaminated hands.
Tip: Washing your hands after handling garbage is one of the moments when handwashing matters most, says Shumaker.
The key takeaways were created with the assistance of generative AI. An AARP editor reviewed and refined the content for accuracy and clarity.
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