If you have a well-used cutting board at home, it might be time to take a closer look.
Does it smell? Have deep grooves or gouges? Or does it have specks of mould?
Experts say they are all signs it could be a food safety risk and might be time to invest in a new one.
But with so many options available, from plastic, to timber, bamboo and glass, which cutting board is the best when it comes to food prep and safety? And what are the best methods to clean them?
Are cutting boards a food safety risk?
Deep grooves or gouges can happen over time when sharp knives are used on boards made from plastic or soft wood.
"Cutting boards with grooves, holes, or indentations can be risky as it provides hiding places for some pathogenic microbes," says Dr Senaka Ranadheera, a food scientist at the University of Melbourne.
He says boards like this are "difficult to clean and can lead to cross-contamination", where bacteria get onto your food.
Dr Emma Beckett, a food scientist based based in Newcastle/Awabakal, agrees.
"So that means your food is obviously going to make you unwell but also means your food might spoil more quickly when you're storing it as leftovers."
Boards that smell can also suggest bacteria is growing.
"That's where you get that kind of rank smell that can come from an old cutting board," Dr Beckett says.
"That's going to cause problems for your food quality, even if it's not directly compromising your health in an acute way."
If you're looking at your well-loved cutting board thinking "I never get sick", our experts advise caution.
"Which is totally fine for a large chunk of us, because we do have strong immune systems and low risk," Dr Beckett says.
"But as soon as we're in a situation where we're cooking for someone, a child or an older person, someone who's immunocompromised in any way, then that becomes a risk."
She says nothing is meant to last forever when it comes to kitchen utensils.
"Don't be afraid if your wooden cutting board is getting a bit manky, or your plastic cutting board is getting a bit manky, to get rid of it."
Which leads us to the next question.
Which cutting board is the best?
If you're in the market for a new board, which is better when it comes to food safety? Plastic, wood, bamboo or something else?
Dr Ranadheera says plastic and wood are the most common boards.
"Many plastics are non-porous, so it is easy to clean," he says.
"So [they] can be recommended for products like raw meat, also for poultry and seafoods, which are highly risky if they get cross-contaminated with cooked or ready-to-eat products.
"Wooden boards should be smooth, hard, and dense to resist pathogen growth, and such wooden boards would be easy to clean."
He says oiled or wax-treated wooden cutting boards can prevent water absorption and mould growth.
Dr Ranadheera also recommends people have more than one cutting board, or if you can't, clean the one you have in between uses.
"Keeping different cutting boards (maybe different colours to identify easily) for raw products and cooked/ready to eat products, will help a lot as this will minimise cross-contamination," he says.
Dr Beckett's number one choice for a chopping board is bamboo or hardwood.
"So, things that are hard and not porous and not going to be damaged easily," she says.
Dr Beckett says a 2022 study published by the Environmental Science & Technology journal found that chopping on plastic cutting boards, made from polyethylene and polypropylene, released microplastics into vegetables and meat.
"Whether or not that's something to really worry about … within our diets, I think is up for debate."
Dr Ian Musgrave, a molecular pharmacologist at the University of Adelaide, says "it is extremely unlikely that chopping board micro particles represent a health risk".
"Absorption of intact plastic particles from the gut is likely to be very limited."
But he says regularly replacing worn boards will "reduce the risk of micro-particles of plastic or wood and reduce places where bacteria can remain".
Will harder boards damage my knives?
Our experts say glass or ceramic cutting boards could also be worth considering as they're also non-porous and easy to clean.
Dr Beckett says people often don't choose these types of boards because they will "dull" their kitchen knives.
"If you're using marble … glass or the ceramic cutting boards, that's obviously a harder surface that's going to have more of an impact on your knives."
"People sometimes like the soft woods and the plastics, because they don't damage their knives, but that's when you're damaging the board."
"If the knife is winning, the board is getting damaged and so I would say … it's much better off to get your knife blunted than it is to get your chopping board with gouges in it."
How do I clean my board?
Dr Beckett says you should avoid using the dishwasher if you've got a plastic, wood or bamboo board.
"Cleaning them by hand with hot, soapy water is recommended pretty much for all types of chopping boards," she says.
Keep an eye on warping if you do put your plastic cutting boards in the dishwasher.
"For wood, it's going to cause it to essentially dry out and you want those oils to be in the wood.
"That is protective against all of the things that the wood might absorb and keeps it in that good structural quality that's going to stop it getting those cuts in it that then breed bacteria."
She says if your timber is looking dry, it is recommended to use an oil made specifically for cutting boards as cooking oils can go "rancid".
Dr Ranadheera also recommends using a chemical sanitiser for cleaning and ensuring the boards have dried properly before storage.
