Campaigners call for ban on use of weedkiller glyphosate at harvest time

Campaigners are calling for a ban on the use of the weedkiller glyphosate to dry crops at harvest time because of concerns about its impact on human health.

Many farmers argue the chemical is necessary but the Soil Association warns that its use as a drying agent leaves residues in foods such as bread, breakfast cereals and beer.

Though multiple regulatory reports have found it to be safe, some scientific studies have suggested possible links between glyphosate use and cancer and other illnesses.

The government's Health and Safety Executive (HSE) will soon launch a consultation on whether to allow its use on crops beyond December 2026, when the licence to use the chemical is set to expire.

Use of glyphosate as a pre-harvest drying agent was banned in the EU in 2023, and campaigners are now calling on the UK government to do the same. The chemical is still licensed for other uses on the continent.

On Wednesday, the Soil Association launched a campaign to end its use as a pre-harvest desiccant [drying agent] in the UK, ahead of the HSE's consultation later this year.

Speaking to BBC Radio 4's Today programme, farmer and founder of Riverford Organic Farmers Guy Singh-Watson said the campaign was not seeking an outright ban on the product in the UK.

Instead, he said the UK should ban the practice of spraying glyphosate "onto crops just days before they're harvested, in the full knowledge that traces of that chemical are going to end up in our bread, in our breakfast cereals, in our beer."

He said the use of glyphosate to dry crops was a "relatively modern practice", adding: "To say that it's essential to the growing of wheat, I'm afraid, is... not true."

Roundup weedkiller, which contains glyphosate, was originally developed by Monsanto in the 1970s. Its patent expired in 2000 and the chemical is now sold by various manufacturers.

Bayer, the German bio-tech company that now owns Monsanto, has previously said there is no regulatory authority that has found that glyphosate is carcinogenic.

A spokesperson said glyphosate was an important tool amid the UK's climate.

"Using glyphosate for pre-harvest desiccation in seasons when it's needed helps to protect high quality crop yields and reduce use of fossil fuels for crop drying, contributing to farm incomes in an otherwise unpredictable environment, contributing to food security and increasing resilience in farming," they added.

In response, Singh-Watson said many chemicals that had previously been cleared for use on crops by regulators were now banned. "I don't have a lot of faith in the regulatory regime", he said.

The government says the product is strictly regulated and only authorised for use if the evidence shows it is safe.

Glyphosate remains approved for use in Great Britain until December, after ministers extended its authorisation to give regulators time to review new data.

This summer, the HSE will launch a two-month public consultation on whether approval for the use of glyphosates should be renewed, taking account of any new "scientific, technical and regulatory" evidence.

Farmer Dave Bell, chair of the Voluntary Initiative for the use of Plant Protection, told BBC Radio 4's Today programme that he relies on herbicides like glyphosate.

"To promote and maintain soil health, and a good healthy rotation in my crops, I need to utilise glyphosate to reduce my wear and tear, reduce my reliance on other weed control, to reduce my carbon footprint," he said.

"If I don't use glyphosate to ripen the standing crop before harvest, I have to use more diesel to burn, to dry the crop", he said.

The National Farmers Union (NFU) and some other farming organisations support the continued use of glyphosate-based weedkillers – including as a pre-harvest drying agent.

NFU deputy president Paul Tompkins said the chemical was an "essential tool for our farmers and growers" that can be used on cereals "to make harvesting easier, to control weeds, and reduce disease, and help produce sustainable and affordable food for all".

Regulatory bodies around the world have consistently found that glyphosate is safe when used responsibly. Tompkins added he would like to see the UK review process renew the approval of glyphosate "for a full 15 years".

There is conflicting and longstanding scientific and regulatory debates about the safety of glyphosate.

In 2015 the International Agency for Research on Cancer (IARC), the World Health Organization's cancer agency which aims to promote international collaboration in cancer research, concluded the chemical was "probably carcinogenic to humans". This term is used when there is limited evidence of carcinogenicity in humans but sufficient evidence in experimental animals.

Subsequent regulatory reviews have disputed this finding. An assessment by the United States Environmental Protection Agency (EPA), for example, "found that glyphosate is unlikely to be a human carcinogen".

In 2022, the European Chemicals Agency (ECHA)'s Committee for Risk Assessment concluded it was "not justified" to classify glyphosate as a carcinogen.

Meanwhile, in March this year a group of international scientists gathered to review new science published over the last decade. They found glyphosate and glyphosate-based herbicides (GBHs) "harm human health and can cause cancer", according to its expert statement.

"The evidence that glyphosate and GBHs harm human health at levels of current use is now so strong that no additional delays in regulation of glyphosate can be justified,"said Kurt Straif, research professor at Boston College and expert in cancer control.

A government spokesperson said: "Like all pesticides, glyphosate is subject to strict regulation in Great Britain and are only approved for use if the evidence shows that they won't harm human or animal health, and won't have unacceptable effects on the environment.

"Our UK pesticides national action plan supports moves by farmers, growers and other land managers to minimise the use of pesticides and increase integrated pest management – a holistic and sustainable approach to pest, weed and disease control."

Update 10 May: This article has been updated to add a fuller response from bio-tech company Bayer. It has also been updated to better reflect the findings from regulatory reviews into glyphosate, and provide further context to the discourse around its usage at harvest time.