Food waste is a problem. Is getting rid of “use-bys” and “best befores” a solution?

The UK supermarket chain Waitrose became the latest in the country to scrap ‘best before’ dates on hundreds of products, following similar announcements by major retailers including Tesco and Marks and Spencer.

In January, Morrisons, another major UK grocery chain, scrapped ‘use-by dates’ on milk in favour of a best before date and the ‘sniff test’.

The new labelling customs are intended to combat the problem of food waste. According to UK recycling charity the Waste & Resources Action Programme (WRAP), around 9.5 million tonnes of food was wasted in 2018, and milk is the third most wasted food and drink product in the UK, despite research showing it can be used days after the ‘use-by’ date printed on the label.

Speaking on the BBC, Marija Rompani, director of sustainability and ethics at the John Lewis Partnership, which owns Waitrose, said: “By removing best before dates from our products, we want our customers to use their own judgement to decide whether a product is good to eat or not, which in turn, will increase its chances of being eaten and not becoming waste.”

No such moves have been touted in Australia, where 7.6 million tonnes of food are wasted each year — equivalent, says the Australian Government, of about 312 kilograms per person.

In the US, the Food and Drug Administration (FDA) reports that consumer confusion around product labelling may be responsible for around 20% of home food waste, costing an estimated US$161 billion per year.

Amid a major outbreak of the dangerous food poisoning bug Listeria in the US, Dr Jill Roberts, a professor of public health at the University of Florida, has written in The Conversation that food expiration dates — at least in the US — don’t always have solid science behind them.

Food waste isn’t just a problem in the face of a growing global food shortage: wasted food produces eight percent of global greenhouse gas emissions. To put it another way, if all the food wasted globally was a country, it would be the third highest greenhouse gas emitter in the world, behind the US and China.

The Australian government has set itself the goal of halving food waste by 2030, involving a suite of cross-sector projects, but food codes here are strict. So, is scrapping these dates a good idea? And could it ever happen?

How are ‘best before’ and ‘use by’ dates determined in Australia?

“A use-by date is a helpful level of warning for food that may still look, taste, and smell unchanged compared to the usual product, but could be risky to eat,” explains Dr Jessica Danaher, a senior lecturer in nutrition and dietetics at RMIT.

“This is because the microorganisms that cause foodborne disease are often present in small amounts and relatively few are required for us to get sick.

“A best before date on the other hand may indicate that the sensory aspects of the food will be changed. The microorganism levels may be fine, but people may not want to eat the food because of texture changes or undesirable colour changes.”

“The ‘best before’ date is more of a recommendation, it’s not legally binding under Australian law,” says Professor Rowland Cobbold, a microbiologist at the University of Queensland. “It’s really about when the food is at its best quality.”

On the other hand, it’s a legal requirement in Australia that food not be sold after its ‘use-by’ date.

“Only ‘use-by’ dates need to be followed strictly. Food can be sold after its ‘best-before’ date providing it is still fit for human consumption.”

Dr Jessica Danaher

“While both can help buyers decide whether to eat or drink something, only ‘use-by’ dates need to be followed strictly,” says Danaher. “Food can be sold after its ‘best-before’ date providing it is still fit for human consumption.”

So, what determines whether a food item gets a ‘best before’ or a ‘use by’ date?

“The ‘use-by’ date will generally be set based on the microbe count,” says Danaher. “In foods where these are likely to go up, there will be a level where the food is no longer safe.”

“The quality assurance and quality control people at those companies have done lots of work, looking at the bacteriological loads in that product,” adds Cobbold. “They have modelling exercises, they do microbiological counts and so forth, so they certainly use scientific principles to set the dates.”

“Perishable foods are a must for ‘use-by’ dates, and the main group would be what we call the ‘ready to eat’ foods, things like sliced ham, soft cheese, milk — things that don’t require any further processing — you just eat them.”

Similar principles hold true in the UK, according to the Food Standards Agency, where a ‘use-by’ date is about food safety, whereas a ‘best before’ date is about food quality.

What are the risks of food poisoning among groceries?

“Salmonella is a particular problem for eggs or poultry meat,” says Cobbold.

“Campylobacter is most frequently associated with poultry meat, some parasites like cryptosporidium are frequently associated with vegetables, Bacillus cereus is a food poisoning associated with rice.

“So, we do have these associations between certain foods and certain pathogens, and a lot of the time the companies that produce these foods are thinking of that pathogen when they set ‘use-by’ dates.”

But is a ‘sniff-test’, or a glance to see how a product looks, sufficient to keep consumers safe? According to Danaher and Cobbold, that’s a thorny question.

“You’ve got different populations of bacteria in our food,” says Cobbold. “One population is the spoilage bacteria, and they’re the things that make food smell bad, look bad, taste bad. Then, separately, you’ve got the pathogenic bacteria – salmonella, E. coli, and so forth, and they’re distinct groups.

“So, for instance, you could have milk that has had the spoilage organisms increased to the point where the milk is clearly spoiled, it smells bad, you wouldn’t drink it. But that doesn’t necessarily mean that the population of pathogens in that milk is a problem.”

But the same holds true in reverse: “Contaminated food will usually look, smell, and taste normal,” explains Danaher.

Cobbold agrees: “The other side of the coin is that just because a product doesn’t smell bad or look bad, it doesn’t necessarily mean that the pathogens have not increased to a dangerous level, either.”

“So, it’s an indicator, the sniff-test, it can give you some idea, but I wouldn’t rely on it for safety myself, especially for a product like milk.”

And there’s an added complication here, unique to this day and age.

“Another factor to consider is the impact of COVID-19 on our ability to smell,” says Danaher. “Several studies show that about half of people with COVID lost their sense of smell at some point while infected, and roughly 20-35 percent experienced a clinical reduction in their ability to smell.”

Those factors aside, Danaher says there are some general rules that can help consumers reduce food waste in their household.

“If there is a combination of no smell, no sign of spoilage, and no changes in texture, especially when we talk about semi-solid food, even if it expired a few days before, it may be safe to eat,” she says.

“Just because a product doesn’t smell bad or look bad, it doesn’t necessarily mean that the pathogens have not increased to a dangerous level, either.”

Professor Rowland Cobbold

“If it is a food that needs to be cooked, it will be safe because during cooking, if there is any contamination, the heat treatment can destroy the microorganism.”

But Danaher says at-risk groups in particular — people who are immunocompromised, pregnant, or breastfeeding — should avoid eating anything they think could pose a health risk.

So, is supermarkets scrapping these dates a good idea?

“I get that there’s a problem with food waste, and I think we do need to tackle it,” says Cobbold.

“But I don’t know that scrapping ‘use-by’ dates is necessarily going to solve the food waste problem.

“I would like to see a data-driven approach on this where you do surveys, you look at data from people who have thrown away food, and we get an understanding of whether it’s ‘use-by’ dates that are prompting this, or is it just poor inventory management?

“I suspect food waste is a multifactorial problem, and ‘use-by’ dates are just one of the issues.”

On the other hand, ‘best-before’ dates, which are about quality rather than safety, are a less risky bet, says Cobbold.

“They’re probably less risky to get rid of,” he says. “The main risk there is one of consumer confidence in the product.”

“Removing best before dates may be an effective way of reducing food waste, as buyers may be less likely to prematurely throw away food that is still safe to eat,” says Danaher. “However, there may still be changes in the quality of the food over time.”

What’s important, Danaher thinks, is education.

“Improving consumer understanding of what different food expiry dates mean is key to reducing waste and avoiding prematurely throwing out food that is safe to eat.”