For years, the EU has judged pesticide risk with a flawed measuring stick. A harmless product sold in bulk could look dangerous, while a truly toxic chemical used in tiny amounts could look safe. Now the European Commission’s own scientists say they’ve found a fix.
The finding comes from a new report by the Commission’s own scientists at the Joint Research Centre (JRC). They say the EU’s main pesticide risk indicator is flawed. Their fix would weigh how pesticides are actually used on farms against how toxic each one really is.
The Harmonised Risk Indicator 1 (HRI-1) is the EU’s main tool for tracking pesticide risk reduction. It relies on sales statistics and broad regulatory hazard classes. That approach can overstate the risk of pesticides used in large amounts, and understate the risk of those used in small amounts. That raises doubts about how well one of the EU’s key pesticide indicators reflects what is actually happening on European farms.
Tonnes don’t tell the whole story
The Sustainable Use of Pesticides Directive introduced it in 2019. Good pesticide-use data are still hard to come by across member states, so the indicator relies mostly on sales figures instead. It sorts active substances into four groups, from low-risk to non-approved, and gives each group a heavier weight the more dangerous it gets.
But that structure barely tells chemicals apart. Around 79 per cent of approved active substances, representing 84 per cent of sales volumes in 2023, fall into the same ‘standard’ category. Swap one standard pesticide for another with a different hazard profile, and the indicator may not move at all.
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This is not a new problem. In a 2020 report, the European Court of Auditors said HRI-1’s usefulness was limited because it ignored how, when and where farmers used plant protection products. It called on the Commission to improve the indicators.
Commission scientists tested two fixes
The first fix divides total pesticide sales by reference application rates. That turns a raw measure of mass into an estimate of how many times pesticides were actually applied.
Second, the JRC replaces the four broad regulatory weights with more specific hazard scores. Those scores come mostly from the EU’s Classification, Labelling and Packaging (CLP) framework, the bloc’s system for grading chemical hazards. The authors conclude that normalisation can cut the bias towards high-volume pesticides, and bring low-volume risks into view.
A different picture of pesticide risk
When researchers applied the new methodology to pesticide sales data from France, Germany and Belgium, the indicator’s make-up shifted considerably. Insecticides and acaricides (mite-killers) saw their share rise from 6 per cent under the current method to 21 per cent under the proposed one. Herbicides, haulm destructors (which kill off plant stems before harvest) and moss killers, by contrast, fell from 45 per cent to 34 per cent.
That does not mean farmers suddenly used more insecticides. It shows, instead, how the method used to measure risk can decide which substances look most significant. The researchers then tested a more detailed hazard-scoring system, using human health hazard classifications instead of broad categories. That produced a 37 per cent reduction against the 2011–2013 baseline. The calculation covered 99.98 per cent of the pesticide sales volumes examined.
Combining all the reforms produced a 29.3 per cent reduction from the baseline scenario. The calculation used sales data from Belgium, France and Germany, covering the 496 pesticides that have a reference application rate. The JRC says some method choices affect how much individual substances or groups of pesticides contribute to the total. However, its uncertainty and sensitivity analysis found the proposed refinements were generally robust to plausible alternative application rates and hazard weights.
Environment remains a blind spot
The proposed system still has an important weakness. The classification data offers far more detail on human health hazards than on environmental ones, so it gives a much narrower view of ecological risk.
The JRC therefore says more work is needed before the indicator can fully account for environmental hazards. It believes existing research on pesticide toxicity and environmental fate could feed into a more thorough approach. That matters for EU pesticide policy, because human exposure is not the only concern: biodiversity, soil, water and pollinators matter too.
Reform without more paperwork
The review found gaps too: harmonised hazard classifications exist for some approved substances but not all. It also flagged weaknesses in updating classifications for pesticides that are no longer approved, and called for better accessibility, completeness and harmonisation of the data. Even so, the JRC stops short of recommending a definitive alternative to HRI-1. Instead, it maps out the indicator’s flaws and weighs possible fixes.
Swapping the ruler used to measure pesticide risk would change which chemicals get flagged for reduction.
Future figures may need to factor in application rates, and a more careful hazard-scoring system could fix some of the indicator’s biggest weaknesses. That matters politically for Brussels: swapping the ruler used to measure pesticide risk would change which chemicals get flagged for reduction, and which do not.
