How should a manager deal with a cutting board that is no longer easily cleanable because of scratching and scoring?

Anything that touches your food can be a source of contamination and foodborne illness – including cutting boards.

For example, if you cut up a raw chicken, and then use the same cutting board to slice a tomato for your salad, you run the risk of cross-contamination – with bacteria from the chicken being transferred to the tomato. That, of course, would be bad.

And vegetarians aren’t off the hook either. Fruits and vegetables can also carry pathogens (and transfer them to cutting boards).

To reduce the risk of foodborne illness in your kitchen, here are some things you should know about cutting boards.

Plastic Versus Wood

For a long time, most (if not all) cutting boards were made of wood. But at some point people began using plastic cutting boards. The idea was that they were easier to clean (and sanitize), and therefore were safer.

But in the late 1980s, a UC Davis researcher named Dean Cliver – the de facto godfather of cutting board food safety – decided to investigate whether plastic cutting boards really were safer. Answer: not really.

Plastic cutting boards, Cliver found, are easier to sanitize. But cutting on them also leaves lots of grooves where bacteria can hide. Wood is tougher to sanitize, but it’s also (often) tougher in general – you won’t find as many deep scratches in the surface.

In addition, researchers have discovered that the type of wood your cutting board is made from also makes a difference.

“Hardwoods, like maple, are fine-grained, and the capillary action of those grains pulls down fluid, trapping the bacteria – which are killed off as the board dries after cleaning,” says Ben Chapman, a food safety researcher at NC State. “Soft woods, like cypress, are less likely to dull the edge of your knife, but also pose a greater food safety risk,” Chapman explains. “That’s because they have larger grains, which allows the wood to split apart more easily, forming grooves where bacteria can thrive.”

Which type of cutting board should you use? Chapman recommends using plastic cutting boards for meat and wood cutting boards for fruit, vegetables, or any ready-to-eat foods (like bread or cheese).

Why use plastic cutting boards for meat? Because of how you wash them.

Cleaning Your Cutting Board

Plastic and wood have different characteristics, so you have to handle them differently.

Plastic cutting boards can be placed in the dishwasher, where they can be sanitized by washing at high temperatures. But wood cutting boards would quickly be ruined by a dishwasher, and not everyone owns a dishwasher. If you’re washing a cutting board by hand, you should:

• Rinse the debris off the cutting board (being careful not to splatter contaminated water all over the place);
• Scrub the cutting board with soap and water (to get out anything in the scratches or grooves on the board’s surface); and
• Sanitize the cutting board (you should use different sanitizers for wood cutting boards than for plastic ones).

For plastic cutting boards, you should use a chlorine-based sanitizer, such as a solution of bleach and water (one tablespoon of bleach per gallon of water – has a shelf life of a week or two). But for wood cutting boards, you should use a quaternary ammonium sanitizer, such as a solution of Mr. Clean and water (follow the dilution instructions on the label).

“This is because chlorine binds very easily to organic materials, like the wood in a cutting board, which neutralizes its antibacterial properties,” Chapman says. “Quaternary ammonium is more effective at killing bacteria on wood or other organic surfaces.”

It’s worth noting that you should also sanitize your kitchen sponge/rag/brush after you’ve used it to scrub the chicken-juice off your cutting board – or else you run the risk of contaminating the next thing you wash (which is the exact opposite of what you’re trying to do).

The last step in cleaning your cutting board is an important one – dry it.

“Make sure you put the cutting board somewhere that air circulates, so that it can dry completely,” Chapman says. Bacteria need moisture to grow, and you don’t want to give them a welcoming environment.

“Historically, butchers used to put salt on their butcher blocks to keep them from smelling bad,” Chapman says. “This worked because the salt drew the moisture out of the wood and prevented bacterial contamination, which is what caused the smell – though the butchers didn’t know it at the time.”

When To Replace Your Cutting Board

At some point, scrubbing and sanitizing might not be enough. When your cutting board has accumulated a lot of deep grooves from repeated use, you probably need to replace it.

“The more grooves it has, and the bigger they are, the more area is available for trapping moisture and giving bacteria a place to proliferate,” Chapman says.

Cutting boards come in all shapes, sizes, and materials. You might have one made of glass, plastic, marble, wood, or even stainless steel.

No matter what kind of cutting board you use, it can easily become a source of contamination and foodborne illness if you’re not careful.

How can a cutting board make people sick?

Whenever you use a cutting board, foodborne pathogens can move from the food you’re preparing to the board. It doesn’t matter what kind of food you’re working with because all types of food can carry pathogens, from raw meat to lettuce to apples.

If you don’t clean and sanitize your cutting board often, these pathogens can grow to dangerous levels. Every time you use your board, pathogens can move to the food you prepare and make you, and everyone you serve, sick.

How to clean and sanitize different types of cutting boards

It’s important to note that cleaning and sanitizing aren’t the same thing. Cleaning refers to removing food particles, while sanitizing uses hot water (171°F minimum) or a chemical solution to kill pathogens. Both cleaning and sanitizing are important in preventing foodborne illness.

As a rule of thumb, it’s a good idea to clean and sanitize your cutting board after every use, even if you only used it for fresh produce. In addition, you should always clean and sanitize your cutting board after using it for a raw animal product, like meat.

In general, your cleaning and sanitizing process should look like this:

1. Scrape off food particles
2. Wash with warm, soapy water
3. Rinse in clean water
4. Sanitize (either in the dishwasher or by hand)
5. Air dry or dry with a clean cloth

If you run into any stubborn food particles that are sticking to the board, try using vinegar, lemon juice, hydrogen peroxide, or baking soda to break them down. After they’ve been broken down, they should be easier to remove.

You could also try scrubbing your board with coarse salt and half a lemon — unless it’s made of marble, wood, or stainless steel. Don’t use abrasive or acidic cleaners on these types of cutting board because they will wear away the finish on the boards.

While the cleaning step will be very similar for all kinds of cutting boards, certain boards may need to be sanitized differently.

Glass, plastic, and stainless steel

After you’ve cleaned them, you can use a dishwasher to sanitize cutting boards made from glass, plastic, and stainless steel. The high heat in the dishwasher will help kill pathogens.

If you don’t have a dishwasher, use a sanitizer approved by the FDA for use on food-contact surfaces. There are three main approved sanitizers: chlorine, iodine, and quaternary ammonium.

You can make a chlorine sanitizing solution at home by mixing one tablespoon of bleach into a gallon of water. Submerge your board in the solution and wait at least 10 seconds before taking it out and letting it air dry.

Note: a chlorine solution like this will remain effective for about a week, after which you’ll need to mix up a new one.

Marble and wood

If your cutting board is made of marble or wood, it shouldn’t go through the dishwasher. The abrupt temperature changes in a dishwasher can crack marble. Similarly, a wooden cutting board can be damaged in the dishwasher because the humid environment can quickly ruin wood.

Instead, after cleaning your marble or wooden cutting board, sanitize it by hand in a sanitizing solution. For marble, you can use the chlorine solution described above. For wood, it’s better to use a quaternary ammonium-based sanitizer like Mr. Clean.

According to North Carolina State University researcher Ben Chapman, quaternary ammonium is more effective at killing pathogens on organic surfaces like wood than other chemicals. Mix the sanitizer with water according to the dilution instructions on the label.

Immediately after the sanitizing step, dry your wooden cutting board with a clean towel or paper towel so it doesn’t have time to soak in moisture. For marble cutting boards, using a clean microfiber cloth to dry it will help prevent water stains.

When to replace your cutting board

All cutting boards have a limited life in your kitchen. The more cuts and scratches they accumulate, the harder it is to fully clean and sanitize them. Pathogens love to hide in deep scratches, so as soon as your board has a few deep scratches — or if it’s warped or cracked — it’s time to replace it.

Resurfacing a wooden board

Sometimes you can resurface a wooden cutting board instead of replacing it. This process has three steps:

1. Clean and sanitize the board
2. Sand the board until it’s smooth again
3. Rub a food-grade mineral oil into the board

After cleaning and sanitizing your cutting board, use sandpaper to remove the cuts on its surface. Start with a rougher piece of sandpaper (the San Francisco Gate recommends 50 grit), then move to finer sandpaper (100 grit) to get the board really smooth.

Once you’ve removed the cuts and scratches from the board, it’s time to give it a protective oil covering. What’s Cooking America suggests using a mixture of USP-grade mineral oil and beeswax, while Good Housekeeping recommends a mixture of beeswax and coconut oil. Either one should work.

Cutting boards aren’t the only thing in your kitchen that you should keep clean and sanitized. For more information, check out our Food Safety for Home Kitchens course. You’ll be amazed by how much you learn in 15 minutes!

— Jessica Pettit