Revealed: Much higher permitted levels of pesticide residues on food since Brexit

Analysis shows that the levels of pesticide residues permitted on many foods in England, Wales and Scotland have risen dramatically since Brexit, with some levels now thousands of times higher.

Changes to regulations in the UK mean more than 100 items can now be sold with increased levels of pesticides, ranging from potatoes to onions, grapes to avocados, 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 herbicide glyphosate, classified as a “probable human carcinogen“The World Health Organization (WHO) increased the MRL for beans by 7.5 times.

The aim 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 protection for consumers in Great Britain. Northern Ireland has retained EU MRLs.

The changes took place between 2022 and 2024 under the previous Conservative government and replaced stricter EU MRLs. Unlike Britain, the EU has not weakened pesticide MRLs and in some cases has made them stricter. Campaigners called on the Labour government to reverse the changes.

The MRLs have been lowered for 49 different pesticides, 15 of which are on a list of ‘very dangerous pesticidescompiled by Pesticides Action Network UK (Pan UK), based on data from national and international authorities.

The analysis of MRLs was carried out by Pan UK using data from the Health and Safety Executive (HSE), which regulates pesticides in the UK, and details were shared with the Guardian. In one example, MRLs for avocados and pomegranates for the insecticide bifenthrin, a hormone disruptor, were increased 50-fold. The pesticide is banned in both the UK and the EU, but not in many importing countries.

“Safety limits have been undermined for a worrying list of pesticides,” said Nick Mole of Pan UK. “At a time when cancer and other chronic diseases are on the rise, we should be doing everything we can to reduce our exposure to chemicals. The reality is that we have no idea what this continued exposure to dozens – or even hundreds – of different chemicals is doing to our health in the long term.” Scientists concluded in 2022 that global chemical pollution had exceeded safe limits for humanity.

A spokesman for the HSE said: “We make independent decisions based on a 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 an MRL must be supported by a risk assessment to ensure that internationally recognised safety requirements are met.” He said the UK MRLs were set below the level considered safe for people eating the food.

The new, weaker MRLs that Britain has adopted come from the Codex Alimentarius, a set of international food standards drawn up by the UN Food and Agriculture Organisation and the WHO. The Codex is criticized by campaigners for “a history of setting weaker safety standards than European counterparts due to the influence of the US and business lobby”.

Interestingly, the UK chose to adopt Codex MRLs only where they offered less protection to consumers. Where the Codex standard was stricter, the HSE decided to retain the weaker UK MRL.

“This really defies the imagination,” said Mole. “The new government urgently needs to turn this topsy-turvy approach on its head.” The HSE said a UK MRL could be higher because a pesticide was used in Britain in greater quantities than in the scenario considered for the Codex standard.

The Guardian revealed in January that the UK had dropped many of its EU-derived environmental protections, despite promises by Michael Gove, Boris Johnson and other architects of Brexit 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 banned none.

Fifteen of the pesticides whose MRLs were raised are banned in both the UK and the EU, including two neonicotinoids, which are notorious for damaging pollinating insects. Pan UK said this gave a competitive edge 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, has seen its MRL for oats increased 25-fold compared to the previous EU standard, while clothianidin’s MRL for wheat has increased 7.5-fold. In contrast, the EU will reduce its MRLs for these insecticides by up to 80% in 2026.

“We are effectively exporting our pesticide footprint abroad,” Mole said. “Because of the global biodiversity crisis, the new government must urgently undo this mess. We should be taking a precautionary approach, prioritising health and the environment over economic concerns.”

A Defra spokesperson said: “Decisions on MRLs are only made after rigorous risk assessments to ensure levels are safe for the public. This Government will change existing policy to ban the use of bee-killing pesticides and will draw up plans to minimise the risks and impact of pesticides by increasing the uptake of Integrated pest management.”