In addition, cutting creates deep grooves in the plastic where bacteria can linger, which makes used plastic cutting boards very difficult to fully disinfect in a dishwasher. You really need to be using a brush to get into those grooves. So if you do use a plastic board, opt to give it a good scrub yourself instead of placing it in the dishwasher.
In one older study5 out of the University of Wisconsin, researchers placed several bacteria, including E. coli and Salmonella, on both used and new wood and plastic cutting boards. The wood cutting boards consistently outperformed the plastic boards in terms of bacterial safety. Moral of the story? Wooden cutting boards may turn out to be more sanitary than plastic, and prove better for your hormonal health (provided they don’t use plastic-containing glues to stick the wooden pieces together).
Some plastic cutting boards are also coated with antibacterial substances to prevent bacteria from growing, but this only trades in bacteria growth for other chemicals, often endocrine disrupters. A very common antibacterial chemical used for such purposes is Microban, which contains the antibacterial ingredient triclosan6. The FDA does not recognize triclosan as safe due to its hormone-disrupting properties6. While triclosan has been phased out of handwash and sanitizers7, it still lurks in other everyday products—including cutting boards.
Some people also use strong chemicals, such as bleach diluted with water, to clean plastic cutting boards. That creates the fearful possibility of contaminating your food with such chemicals. If you’ve ever put tomato or turmeric-rich foods into a plastic container, you’ll see that it turns red or yellow. This is because the ingredients have seeped into the matrix of the plastic. Harsh cleaning agents could also be seeping into your board, potentially contaminating the food you cut on it.
Vivian Chen, MD