Cutting Board Food Safety: Wood or Plastic

There are divided views when it comes to the selection of wood or plastic cutting boards as they relate to food safety.

Some believe plastic cutting boards are preferable because they developed fewer grooves, and are less likely to retain harmful microbes, unlike the grooves cut into a wood surface that harbors bacteria.

Those preferring plastic also argue that nonporous surfaces like plastic or are easier to clean than wood and thus safer. Plastic cutting boards are the most often recommended by professional chefs.

Those who prefer wood cutting boards claim shallow cuts in the wood will close up on their own, and that wood also has natural anti-septic properties.

One study concluded that bacteria were not recoverable from wooden surfaces in a short time after they were applied, unless very large numbers were used. But plastic surfaces allowed the bacteria to persist.

“However, wooden boards that had been used and had many knife cuts acted almost the same as new wood, whereas plastic surfaces that were knife-scarred were impossible to clean and disinfect manually, especially when food residues such as chicken fat were present. Scanning electron micrographs revealed highly significant damage to plastic surfaces from knife cuts.”

The study added that although bacteria that disappeared from wood surfaces are found alive inside the wood for some time after application, they do not multiply, and gradually die.

Another study claims wood cutting boards harbored fewer bacteria than plastic, and suggests that because plastic is not water-absorbent, it stays wet longer, prolonging bacterial survival. Conversely, wood is water-absorbent so it dries faster, which means shorter bacterial survival.

Microbiologist Dean Cliver at the University of California, studied how bacteria behave on different surfaces, and conducted an experiment using marble, wood and plastic chopping boards.

Cliver put E. coli on each board, let it dry in place and then washed the boards off with common dish detergent.

Professor Cliver concluded plastic had a heavier bacterial growth than the wood, and was the least bacteria free after having been washed.

On wood the bacteria grew only where they were applied and didn’t spread, leaving a much cleaner overall surface. With plastic bacteria are able to breed in the cuts left by knives.

Thus wood was the decided favorite. “It’s a very porous material and the fluid is drawn into the wood by capillary action and if there are bacteria in the fluid they go in and they never come back alive,” Professor Cliver said.

The professor added that bacteria die off slowly. “It may take a few hours, but all the same, they aren’t in a position to cause any trouble.”

The professor recommends choosing a tight-grained hardwood board. “If the wood’s too soft, those pesky bacteria can multiply in deep knife cuts.”

The Bottom Line

Whether you use plastic or wood, wash both cutting boards after every use with hot water and detergent. Some people suggest having two cutting boards, one wood and one plastic. Use one for raw meat and the other for vegetables.