Results of a new animal study into possible health risks of the weedkiller glyphosate will be published in time to inform a key EU re-licensing vote due by the end of 2017, according to the researcher leading the trial.

A row over possible effects of glyphosate – an ingredient in Monsanto’s big-selling herbicide Roundup – has prompted investigations by congressional committees in the United States and forced a delay in Europe to a decision on whether it should be banned or re-licensed for sale.

Giving details and preliminary findings of the latest study to Reuters, Italian scientist Fiorella Belpoggi said experimental rats exposed to the herbicide at levels equivalent to those allowed in humans showed no initial adverse reaction.

“Exposed animals had no evident differences from non-exposed animals,” Belpoggi, who is director of the Cesare Maltoni Cancer Research Centre at the Ramazzini Institute in Italy, said in a telephone interview.

“But this tells us very little at the moment, because the examinations of key parameters that could be affected by exposure are still being done (and) we are waiting for those results,” Belpoggi added.

Those parameters include any genetic changes, as well as potential toxic effects on measures related to fertility, such as sperm, embryo development and offspring growth, she said.

Argument over glyphosate centers on whether it is carcinogenic. Scientists at the International Agency for Research on Cancer (IARC) say it probably does cause cancer, putting them at odds with scientists at the European Food Safety Authority, the U.S. Environmental Protection Agency and multiple other safety and regulatory agencies around the world, who say it likely doesn’t.