WHO review of pesticide exposure models raises questions over global food safety standards

International health authorities are reassessing how pesticide residues in food are judged to be safe, following a quiet move by the World Health Organization (WHO) and the Food and Agriculture Organization (FAO) to review long-standing exposure models used worldwide — including those underpinning New Zealand’s food safety limits.

In February 2026, the WHO issued a technical call for scientific experts to re-examine dietary exposure assessment methods used to calculate how much pesticide consumers ingest through food. The notice, published without a public briefing, signals growing scientific debate over whether existing regulatory models accurately reflect real-world eating patterns and potential health risks.

According to advocacy group No More Glyphosate NZ, New Zealand’s pesticide residue standards are largely based on international recommendations developed through the Joint FAO/WHO Meeting on Pesticide Residues (JMPR) and adopted globally via the Codex Alimentarius Commission. These frameworks establish Maximum Residue Limits (MRLs), which regulators use to determine whether chemical residues in food fall within acceptable safety thresholds.

Central to the review are concerns about how exposure is calculated. Traditional assessments rely heavily on lifetime average consumption models, which assume exposure is evenly distributed over decades and that short-term spikes are unlikely to pose significant risk if long-term averages remain low. The WHO has now asked experts to examine whether these assumptions adequately account for vulnerable life stages such as pregnancy and childhood, or for people with consistently high consumption of certain foods.

The agency is also reviewing newer modelling approaches designed to better capture higher-intake diets and regional consumption differences, reflecting uncertainty about whether current systems sufficiently represent how people actually eat on a daily basis.

Another issue under examination is the reliance on agricultural field trial data when setting residue limits, rather than monitoring pesticide levels in food as it is ultimately consumed. Experts have been asked to consider whether processing, cumulative dietary exposure, and real-world consumption patterns are being fully reflected in safety assessments.

The review follows requests from within the Codex system itself for greater transparency and clearer treatment of scientific disagreement during pesticide evaluations — signalling that debate is emerging from within regulatory institutions rather than external advocacy groups.

While the WHO’s call does not suggest current residue limits are unsafe or identify any specific pesticide as harmful, it indicates that the scientific methodologies used to define “safe” exposure remain under active reassessment.

The outcome of the planned expert meeting later this year is expected to inform future international guidance, which in turn influences national food safety regulations, including those applied in New Zealand.

No More Glyphosate NZ said the review highlights the importance of transparency as scientific understanding evolves, arguing consumers should be informed when the models underpinning regulatory assurances are being reconsidered.

“Transparency matters. Accountability matters. And informed choice begins with understanding how decisions are made — especially when those decisions shape what ends up on our plates.”

Read No More Glyphosate’s full analysis here.