Warunika was only 16-years-old when she took a swallow from an old bottle of Gramoxone weedkiller she found hidden on a ledge above a toilet in her family home. Her parents are sure she had not intended to die...

The bottle she had grabbed was in her home because her parents were small-scale farmers, and at the time it was what they used to clear weeds from their few acres of rice fields in the northern central province of Sri Lanka...

At the time Warunika died, around 20 years ago, paraquat was causing hundreds of deaths a year in Sri Lanka.

No one knows the total number of people who have died from swallowing this chemical since the British company Imperial Chemical Industries (ICI) first put Gramoxone on the market in 1962. But according to one leading global authority on pesticide poisoning, University of Edinburgh professor of clinical toxicology Michael Eddleston, the figure must be at least in the tens of thousands...

Syngenta, the Swiss-headquartered, Chinese-owned agrochemical giant that inherited ICI’s pesticides business, continues to export thousands of tonnes of Gramoxone each year... Syngenta claims it has “helped address the problem of accidental ingestion” with the ‘safening’ agents it has added to Gramoxone since the 70s - a dye and an odour to warn people not to drink it, and an ‘emetic’ drug, to induce vomiting...

But now, a lawsuit in the US has unearthed an enormous cache of internal company documents which reveals how Syngenta and its predecessors knew for decades that the emetic in Gramoxone did little or nothing to prevent poisoning deaths - but continued to present it as effective to regulators and the public.

The documents show how ICI successfully used the addition of this drug to Gramoxone to help keep the product on the market at a time when it faced real threats of being banned in key markets; that it saw this patented additive as a way of blocking competition from other paraquat manufacturers; that the company continued with these strategies despite knowing it had no evidence the emetic would save lives at the concentration in which it was added; that it was repeatedly told by its own scientists that the amount of emetic in Gramoxone was too low to prevent fatal poisonings; and that it consistently resisted widespread introduction of safety measures like dilution because it did not consider them to be “economically acceptable” solutions to “the suicide problem”...

[A] British scientist called Jon Heylings ... is now speaking out, for the first time publicly, to repeat what he first told his superiors at the company more than three decades ago - that he believes the Gramoxone Syngenta still sells in many countries is a lot less safe than it could be...

Syngenta rejects Heylings’ allegations, and denies its decisions about the emetic were motivated by anything other than the desire to make paraquat safer. “While it may sound appealing on first encounter,” a Syngenta spokesman said, “Heylings’ argument that increasing the level of emetic improves the safety of the product is overly simplistic; the reality is complex and modern medical and scientific opinion does not support Heylings’ viewpoint.” He added: “We reject any suggestion that in developing this product Syngenta and its predecessor companies had any motive other than to find the most appropriate level of emetic in paraquat to best address the risk from accidental and deliberate ingestion.”

He added that the US EPA and the FAO had “not changed their recommendation about the emetic” since being contacted by Heylings. The FAO itself told Unearthed and Public Eye it had held a “special session” to review its paraquat specifications in response to Heylings’ concerns, and its report was “currently being finalised”...