As of this week, more than 2,600 people had signed an online petition calling on Minister for Agriculture Michael Creed to "stop spraying Roundup on cereal crops".

The advocacy group Uplift cites the 2015 assessment by the World Health Organisation's International Agency for Research on Cancer (IARC) that the herbicide ingredient glyphosate is "probably carcinogenic".

Burn-off

The petition specifically targets Monsanto's branded glyphosate-based Roundup herbicide and its use on grain crops. Glyphosate is the most popular herbicide active in the world and it is often used to burn off cereals prior to harvest.

This campaign is separate from the EU-wide petition that gathered more than 1m signatures last month, forcing the European Commission to consider a ban on glyphosate as it prepares to re-examine the chemical's authorisation before it expires at the end of this year.

10-year re-authorisation proposal

Discussions between experts mandated by EU countries are scheduled to start next week, with the European Commission proposing a 10-year re-authorisation of glyphosate as announced by European Commissioner for Health and Food Safety Vytenis Andriukaitis in a recent interview with the Irish Farmers Journal.

The proposal is based on the latest assessment by the European Chemicals Agency (ECHA), which confirmed an earlier report by the European Food Safety Agency (EFSA) that glyphosate does not cause cancer.

Conflicting opinions

Individual cancer and public health scientists have continued to give conflicting opinions on potential links between the chemical and the disease in recent weeks.

In court documents exposed by the Reuters news agency, US National Cancer Institute epidemiologist Aaron Blair admitted that the IARC may not have classed glyphosate as "probably carcinogenic" if it had seen a yet unpublished study of large rural US populations exposed to the chemical showing no evidence of an association with cancer.

Meanwhile, former director of the US National Center for Environmental Health and of the US Agency for Toxic Substances and Disease Registry Dr Christopher Portier argued that the EFSA study had overlooked instances of tumours in lab rodents exposed to glyphosate.

California listing

On 7 July, California placed glyphosate on its list of chemicals "known to the state to cause cancer" in application of its so-called Proposition 65 legislation on informing the public of known risks associated with chemicals.

"Glyphosate is not carcinogenic, and the listing of glyphosate under Prop 65 is unwarranted on the basis of science and the law," Monsanto countered in a statement announcing a legal challenge to the decision. "California's sole reason for listing glyphosate under Prop 65 is the fatally flawed classification by IARC, which ignored crucial scientific data that undermines its conclusion."

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