A team of researchers has filed a complaint against Tesco, saying its “biodegradable” tea bags do not live up to that claim following an experiment that involved burying them in the ground for a year to see what would happen.

Dr Alicia Mateos-Cárdenas from University College Cork (UCC) set out to investigate how well tea bags advertised as biodegradable break down. She buried 16 Tesco Finest Green Tea with Jasmine Pyramid tea bags in the garden soil. However, when the tea bags were dug up, they remained intact.

He checked them at three weeks, just over three months, six months, and 12 months, and found no change. He sent his article to two researchers from the UCC Environmental Law Clinic, who have now collectively reported the supermarket to a consumer protection watchdog in Ireland.

The complaint says that a customer would reasonably expect a product labeled biodegradable to break down in the open environment within a year or sooner. Tesco Finest Green Tea with Jasmine pyramid bags showed no signs of degradation after 12 months due to the type of bioplastic they are made from, according to the complaint sent to the Competition and Consumer Defense Commission (CCPC).

The company has recently switched suppliers, but academics argue that the tea bags are still made from the same plant-based bioplastic, called polylactic acid (PLA).

Tesco said the packaging clearly states that its tea bags are not approved for disposal on the ground or in home composting, but must be industrially composted (after being placed in a local council food waste bin). A Tesco spokesperson said: “We strongly dispute the claims made in this study and believe the findings are misleading. The tea bag breakdown method used in the study does not reflect the advice we give customers on the package.

“All of our own-brand herbal tea bags have been certified industrially compostable, meaning they can be disposed of in food boxes and municipal collections, biodegrading with organic matter through bin composting. We do not recommend customers dispose of these tea bags in their household compost bins or on the ground.”

The researchers say Tesco should change “biodegradable” to “plant-based” or “compostable” if they cannot rot in gardens or compost bins. “It’s fair to assume that any PLA tea bag will not biodegrade in an open environment,” said Mateos-Cárdenas, of the UCC’s School of Biological, Earth and Environmental Sciences, who published an article about the biodegradability of tea bags in Frontiers in Bioengineering and Biotechnology. His findings formed the basis of the subsequent complaint.

“The fact that they come from another vendor doesn’t make sense,” he said. “We have shown that Tesco is misleadingly selling its tea bags using greenwashing practices. We hope JPAC will act urgently.”

Since the tea bag showed no signs of disintegration after a year, it’s reasonable to believe that it could persist in the soil for much longer, the researchers argue. If the average consumer drinks two cups of tea a day, they could have over 700 tea bags in their home or garden compost bin after one year. This makes Tesco’s claim “not only false, but also misleading and unsubstantiated” under Irish and EU consumer protection law, the complaint says.

The researchers want researchers to look at the broader problem of retailers making misleading claims about the biodegradation of materials, with such claims being “abundant.”

“It is up to Tesco and others to make sure their products live up to the advertised claims,” ​​said Mindy O’Brien, coordinator of Voice of Irish Concern for the Environment, who is calling on JPAC to investigate the claim to prevent more laundering. green. “Now more than ever, consumers are motivated to buy a product that appears to be more sustainable. There is no room for false or misleading ecological claims.”

The complaint follows research led by Professor Mark Miodownik of University College London which found that most plastics marketed as “home compostable” don’t actually work, with up to 60% failing to disintegrate after six months.

“The results do not surprise me,” he said, commenting on this latest research, in which he was not involved.

“If the product sits for years before biodegrading, which is the reality of many products labeled as biodegradable, they are part of the problem, not the solution. There are innovative companies trying to make a difference, but they don’t use the term biodegradable because they know it’s greenwashing code.”

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