The top ten also shows Bayer selling $125m of acetochlor, a weedkiller that was banned in the EU over concerns about contamination of drinking water and genotoxicity. The EU ban also cited a “high acute risk” to birds from contaminated drinking water.

Unearthed submitted detailed questions to all the companies mentioned in this article, but all except Bayer allowed Croplife to respond on their behalf.

A spokesman for Bayer Crop Science said the company did not agree with the classification of Bayer products as HHPs, because these products were neither classified as highly toxic to humans by the WHO, nor listed for control under the Stockholm Convention, the Rotterdam Convention, or the Montreal Protocol.

This amounts to just four of the eight categories of HHPs that have already been agreed by the FAO and the WHO. But the Bayer spokesman said that for the other categories – including pesticides proven or presumed to be mutagens, reproductive toxicants, or carcinogens – there was “currently no internationally responsible body for classification”.

He added that it was “not correct” that the Phillips McDougall data treated all Monsanto sales from 1 January 2018 as Bayer sales, when the takeover was completed on 7 June 2018.

After this story was published on 20 February 2020, Bayer published a statement expanding on why it disagreed with the classifications used by PAN. The statement added that Bayer was in the process of withdrawing products containing the pesticides methiocarb and carbendazim. Methiocarb is classed as acutely toxic by the WHO, while carbendazim is classed by the ECHA as presumed mutagen and reproductive toxicant.

CropLife International’s director of international regulatory affairs Christoph Neumann added that of the 19 chemicals our investigation identified as its members biggest selling HHPs, 12 were registered for use in the EU and 18 were registered for use in the US.

He continued: “CropLife International members support the International Code of Conduct on Pesticide Management and agree with the principle of pesticide risk reduction. We support countries to identify, and if necessary, remove HHPs from their markets.”

He added: “When risk mitigation measures or good marketing practices are insufficient to ensure that the product can be handled without unacceptable risks to humans and the environment, then market withdrawal should be considered.”