Glyphosate: an active ingredient widely used in agriculture and a component of the well-known Roundup, the production patent for which the multinational Monsanto held until 2001. Commonly associated with GMO crops, which are genetically modified precisely to withstand heavy doses of the herbicide, glyphosate is the most widely used weedkiller in the world. In addition to being employed on a large scale across the entire agri-food industry, it is also used in the maintenance of gardens and green spaces.

The report by the Agency for Research on Cancer (Iarc), recently published in the journal The Lancet Oncology, examined five chemical substances used in agriculture: malathion and diazinon, insecticides declared probable human carcinogens; parathion and tetrachlorvinphos, recognised as possible human carcinogens, banned in the European Union but still in use in the United States; and glyphosate, the world's most popular herbicide. The report identified a clear epidemiological correlation between exposure to the latter and non-Hodgkin lymphoma, with "convincing evidence that it can cause cancer in laboratory animals".

Until now, the United States government had maintained that the active ingredient posed no danger; in 2013, Monsanto requested and obtained approval for an increase in the tolerance thresholds for Roundup from the American Environmental Protection Agency (Epa).

Monsanto, the multinational company that produces Roundup, immediately declared that the WHO had not examined all the new data, reaching conclusions incompatible with assessments from the United States and the European Union. "We don't know how Iarc could have arrived at a conclusion so dramatically different from those reached by all the regulatory agencies around the world," commented Philip Miller, vice president of Monsanto, in a statement.

Monsanto's annual sales of 15.9 billion dollars are closely tied to glyphosate. The majority of the seeds patented by the company were designed to be used in tandem with Roundup.