'A sip can kill': did a chemical company misrepresent data to avoid making a safer product?

A former Syngenta scientist alleges lives could have been saved with tweaks to the formulation of weedkiller paraquat

• Scientist tells of relief after speaking out over weedkiller fears

Around the world, the deadly dangers of a weedkiller called paraquat are well known. When working with the highly toxic herbicide, farmers and other users take care not to splash or spill even small amounts of the product, heeding regulatory warnings that just a tiny amount - if swallowed - will kill them.

Related: Revealed: Monsanto owner and US officials pressured Mexico to drop glyphosate ban