The amount of pesticide residue allowed on scores of food types in England, Wales and Scotland has soared since Brexit, analysis reveals, with some now thousands of times higher.
Changes to regulations in Great Britain mean more than 100 items are now allowed to carry more pesticides when sold to the public, ranging from potatoes to onions, grapes to avocados, and coffee to rice.
For tea, the maximum residue level (MRL) was increased by 4,000 times for both the insecticide chlorantraniliprole and the fungicide boscalid. For the controversial weedkiller glyphosate, classed as a “probable human carcinogen” by the World Health Organization (WHO), the MRL for beans was raised by 7.5 times.
The purpose of the pesticide MRL regime is to protect public health, wildlife and the natural environment. Campaigners said the list of pesticides included reproductive toxins and carcinogens and that the weaker MRLs reduced protections for consumers in Great Britain. Northern Ireland has retained the EU MRLs.
The changes took place between 2022 and 2024 under the previous Conservative government and replaced stronger EU MRLs. In contrast to Great Britain, the EU has not weakened the MRLs for the pesticides and in some cases is making them even stricter. The campaigners called on the Labour government to reverse the changes.
MRLs have been weakened for 49 different pesticides, 15 of which are on a list of “highly hazardous pesticides” compiled by Pesticides Action Network UK (Pan UK), based on data from national and international authorities.
The analysis of MRLs was conducted by Pan UK using data from the Health and Safety Executive (HSE), which regulates pesticides in the UK, and the details were shared with the Guardian. In one example, MRLs for avocados and pomegranates for the insecticide bifenthrin, a hormone disruptor, were raised 50 times. The pesticide is banned in both the UK and EU but not in many importing countries.
“Safety limits have been undermined for a worrying list of pesticides,” said Nick Mole from Pan UK. “At a time when cancers and other chronic diseases are on the rise, we should be doing everything we can to reduce our chemical exposure. In reality, we have no idea what this ongoing exposure to tens – or even hundreds – of different chemicals is doing to our health over the long term.” Scientists concluded in 2022 that global chemical pollution had passed the safe limit for humanity.
A spokesperson for the HSE said: “We make independent decisions based on careful scientific assessment of the risks, with the aim of achieving a high level of protection for people and the environment. The decision to change any MRL must be supported by a risk assessment to ensure internationally recognised safety requirements are met.” He said British MRLs were set below the level considered to be safe for people eating the food.
The new, weaker MRLs adopted by Great Britain come from the Codex Alimentarius, a set of international food standards produced by the UN Food and Agriculture Organization and the WHO. The Codex has been criticised by campaigners for “a history of setting weaker safety standards than European counterparts due to the influence of US and corporate lobbying”.
Strikingly, the UK chose to adopt the Codex MRLs only where they offered lower protection to consumers. Where the Codex standard was stricter, the HSE decided to retain the weaker British MRL. In the cases of residues of chlorantraniliprole and boscalid in teas, the EU also adopted the higher Codex MRL.
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“This really does beggar belief,” said Mole. “The new government urgently needs to flip this topsy-turvy approach on its head.” The HSE said a British MRL could be higher because a pesticide was applied in greater quantities in Britain than in the scenario considered for the Codex standard.
The Guardian revealed in January that the UK had dropped a swathe of EU-derived environmental protections, despite Michael Gove, Boris Johnson and other architects of Brexit having promised that they would be strengthened after the UK left the bloc. In particular, the EU has banned 30 harmful pesticides since Brexit – the UK has not banned any of these.
Fifteen of the pesticides for which MRLs have been increased are banned in both the UK and EU, including two neonicotinoids, notorious for their harm to pollinating insects. Pan UK said this gave a competitive advantage to growers in countries where these pesticides remain legal, such as the US, Canada and Australia in the case of the neonicotinoids.
One neonicotinoid, thiamethoxam, had its MRL for oats increased 25 times from the previous EU standard, while for clothianidin, the MRL for wheat has gone up 7.5 times. In contrast, the EU is to reduce its MRLs for these insecticides by up to 80% in 2026.
“We are essentially exporting our pesticide footprint abroad,” said Mole. “For the sake of the global biodiversity crisis, the new government urgently needs to undo this mess. We should be adopting a precautionary approach, which prioritises health and environment over economic concerns.”
A Defra spokesperson said: “Decisions on MRLs are only taken after rigorous risk assessments to make sure levels are safe for the public. This government will change existing policies to ban the use of bee-killing pesticides and will set out plans to minimise the risks and impacts of pesticides through an increased uptake of integrated pest management.”