The weed-killing pesticide glyphosate, made by Monsanto and widely used in agriculture and by gardeners, probably does not cause cancer, according to a new safety review by United Nations health, agriculture and food experts.
In a statement likely to intensify a row over its potential health impact, experts from the UN's Food and Agriculture Organization (FAO) and World Health Organization (WHO) said glyphosate is "unlikely to pose a carcinogenic risk to humans" exposed to it through food.
It is mostly used on crops.
Having reviewed the scientific evidence, the joint WHO/FAO committee also said glyphosate is unlikely to be genotoxic in humans.
In other words, it is not likely to have a destructive effect on cells' genetic material.
The conclusion contradicts a finding by the WHO's Lyon-based International Agency for Research on Cancer (IARC), which in March 2015 said glyphosate is "probably" able to cause cancer in humans and classified it as a so-called Group 2A carcinogen.
Seven months after the IARC review, the European Food Safety Authority, an independent agency funded by the European Union, published a different assessment, saying glyphosate is "unlikely to pose a carcinogenic hazard to humans".
The differing findings thrust glyphosate into the centre of a row involving EU and US politicians and regulators, the IARC experts, environmental and agricultural specialists and the WHO.
Diazinon and malathion, two other pesticides reviewed by the WHO/FAO committee, which met last week and issued its conclusions in a statement on Monday, were also found to be unlikely to be carcinogenic.