The Copper Case: when science and policy find a solution to the “Unsolvable”. A Deep Dive into the New EU Limits under Regulation 2026/840

The approval of Regulation (EU) 2026/840, which redefines the Maximum Residue Limits (MRLs) for copper compounds, is not merely a bureaucratic update: it represents the final chapter of one of the most paradoxical and fiercely debated regulatory sagas in recent European agricultural history. To understand the true magnitude of this measure and the collective sigh of relief from thousands of farmers, one must step back to 2018, a year when copper faced a serious risk of being banned from European fields.

In that year, the European Food Safety Authority (EFSA) published a review of residue limits that triggered a shockwave across the sector. The Authority’s calculations indicated a theoretical exceedance of safety thresholds for chronic consumer exposure. The paradox, openly acknowledged by EFSA itself, was that this “exceedance” did not stem from the use of plant protection products, but was almost entirely driven by the natural background levels of copper present in staple foods such as wheat, soy, and bovine liver.

Faced with the practical impossibility of “banning” copper naturally present in the soil and food, EFSA applied a purely mathematical logic to balance the safety equations. It suggested reducing the limits to zero for the only crops where regulatory intervention was possible. Outlining the calculations for potential risk mitigation measures, EFSA set out a drastic scenario for fundamental crops, explicitly stating that: “The critical GAPs authorised on wine grapes will be withdrawn (no fall-back GAP identified)”. This exact categoric phrasing of withdrawal was also suggested for tomatoes and potatoes in Northern Europe,.

This essentially meant suggesting the eradication of entire agricultural sectors—first and foremost organic viticulture, which without Bordeaux mixture and other copper compounds would have no viable defence against downy mildew—simply to offset a calculation anomaly. Faced with this politically and agronomically unacceptable scenario, the European Commission decided to freeze the cuts. It tasked the scientific community with abandoning standard pesticide calculations and studying copper for what it truly is: not just a pesticide, but an essential micronutrient for life. The real revolution that saved copper in agriculture arrived a few years later.

1. The Scientific Foundation: The 2023 EFSA Opinion on Copper Homeostasis

The turning point for the current regulation is the scientific opinion adopted at the end of 2022 and published in 2023 by the EFSA Scientific Committee. The Commission mandated EFSA to resolve historical discrepancies regarding copper safety limits and to estimate total intake from all sources.

Unlike classic plant protection products, copper is an essential element whose biologically active form participates in the cellular redox cycle. The human body possesses a highly regulated system of specific transport proteins and “escort” molecules (carrier proteins) that manage the absorption, transport, and excretion of copper. These mechanisms safely deliver the metal to its cellular destinations, preventing oxidative damage toxicity as long as the homeostatic mechanisms are not saturated.

The Scientific Committee abandoned the classical toxicological approach in favour of an Acceptable Range of Oral Intake (AROI) model, focusing on early biomarkers. EFSA identified hepatic copper retention (copper retention in the liver) as the most sensitive critical endpoint. By studying patients with Wilson’s disease—a genetic pathology causing copper accumulation in the liver due to a biliary excretion defect—it became clear that prolonged hepatic retention is predictive of toxicity that can manifest suddenly and fatally.

Based on clinical studies, EFSA concluded that an intake of 5 mg per day in adults does not lead to any net copper retention in the liver. Without applying further unjustified uncertainty factors (since retention is already an ultra-conservative early indicator), EFSA established a new Acceptable Daily Intake (ADI) of 0.07 mg/kg of body weight per day.

Regarding exposure, EFSA combined the food consumption database with monitoring data on real concentrations, concluding that the primary source of copper for humans is the natural background levels present in food and, for infants, infant formula. Conversely, the use of copper as a plant protection product or fertiliser contributes negligibly to direct dietary exposure, despite causing long-term accumulation in agricultural soils. The final conclusion in 2023 was unequivocally reassuring: current copper exposure poses no health risk for any age group, including children. The only evaluative exception concerns infants under 16 weeks of age, whose homeostatic mechanisms are not yet fully developed and who rely on specific nutritional requirements drawn from fetal hepatic reserves.

2. The 2025 EFSA Statement: The Scientific “Menu” for New MRLs

Backed by the confirmation of safety, the European Commission entrusted EFSA with a complex task: updating the MRL proposals for an element that is not only sprayed on leaves but is naturally ubiquitous in all soils and physiologically absorbed by plants.

Due to this ubiquitous nature, the Authority had to set aside the standard mathematical model normally used to evaluate synthetic chemical pesticides. EFSA thus adopted a tailored approach, elaborating not a single rigid threshold, but two distinct lists of limits, effectively offering political decision-makers a technical “menu” of options:

• The “Agricultural” Limit (based on Good Agricultural Practices – GAP): This first list reflects the theoretical residue strictly linked to agricultural practices. It indicates the maximum copper quantities expected on crops when the farmer applies the fungicide (e.g., Bordeaux mixture) in strict compliance with authorised doses and timings. It is the essential parameter to ensure that phytosanitary care in the field remains legally viable.
• The “Real” Limit (based on monitoring data): This second list captures the reality of the market and what actually reaches the table. To elaborate this, EFSA analysed a massive volume of data: exactly 81,730 analytical results collected across Europe between 2004 and 2022. Using rigorous statistical methods to interpret even the samples where laboratory instruments detected minimal metal traces, the Authority calculated the threshold encompassing the 95th percentile (P95) of the real copper concentrations measured. This final value includes all copper present in the food: both from pesticide treatments and the substantial portion naturally absorbed from the soil.

The politically decisive passage of the 2025 document (deliberately classified as a technical Statement rather than a prescriptive opinion) lies in its conclusions. EFSA refrained from dictating a single, unappealable rule. Having already proven that chronic exposure to copper poses no danger, the Authority simply laid out the data, explicitly stating that: “all MRL proposals are suggested for further consideration by risk managers”. In plain terms: science provided the numbers and safety boundaries, but the final choice of which list to adopt—balancing consumer protection with the survival of agricultural supply chains—was handed entirely to politics.

3. The SCoPAFF Debate and Agricultural Pressures

Political decisions regarding pesticide thresholds take place within the Standing Committee on Plants, Animals, Food and Feed (SCoPAFF). Extracts from committee discussions highlight the strategic weight of copper. Organic farming, in particular, depends vitally on copper-based fungicides to combat downy mildew and other fungal diseases. During the Committee sessions, alarm bells were raised by organic farming expert groups: a potential severe restriction on copper compounds or unworkable MRL reductions would have had devastating impacts on the sector.

For many minor crops or those where phytosanitary use is indispensable, theoretical limits based solely on average monitoring data would have led to frequent compliance failures in the field. Faced with the prospect of having to lower MRLs to align with EFSA’s monitoring data list, several Member States and stakeholders fiercely opposed the cuts. The stakeholders’ argument was clear: given the absence of chronic toxicological risks certified by EFSA in 2023, there was no health emergency justifying immediate cuts to operational limits, which would only damage commercial supply chains and agricultural producers.

4. The Final Measure: Regulation (EU) 2026/840

The compromise between scientific guarantees and production necessities was crystallised in Commission Regulation (EU) 2026/840, adopted on April 15, 2026. The Regulation enters into force on the twentieth day following its publication in the Official Journal of the European Union, making it directly applicable across all Member States from May 6, 2026.

The European Commission and Member States applied a pragmatic approach, categorising the residue decisions into three main streams:

• Maintained Limits (Adequate MRLs): For products where the current limits faithfully reflect agricultural practices and the real concentrations found in food (e.g., cashew nuts, blackberries, cucumbers, courgettes, rhubarb), the thresholds were confirmed without variation.
• Increased Limits (Upward Adjustment): For a very substantial group of crops (including apples, pears, cherries, peaches, strawberries, potatoes, tomatoes, wine and table grapes), the MRLs were raised. The decision was based on EFSA’s GAP evaluations (supervised trials), which demonstrated that higher limits were required to cover current phytosanitary uses,. Since the risk to consumers is zero, politics embraced the more permissive limits in favour of agricultural feasibility.
• “Pending” Limits (The Political Compromise): The most critical knot involved products for which EFSA suggested a substantial lowering of limits, such as citrus fruits, apricots, figs, avocados, carrots, cabbages, dry legumes, and almost all products of animal origin (liver, milk, eggs). In these cases, the legislator chose not to lower the thresholds. Accepting the requests of Member States who deemed the cuts inappropriate and disconnected from agricultural reality, the Commission decided to keep the current MRLs in force, granting a transitional period until June 30, 2028.

This timeframe serves to allow EFSA and Member States to collect much broader and more accurate monitoring data, and to develop and validate better analytical methods. The Regulation highlights the current lack of validated methodologies for determining copper in complex matrices, such as high-oil products (e.g., oilseeds), dry matrices (coffee, cocoa, tea, spices), and animal origin matrices.

Furthermore, the Regulation updated the legal definition of the residue for enforcement (control analyses): shifting from the previous wording of “copper compounds (copper)” to the current “total copper”. This modification fully reflects the integrated approach required by EFSA, which considers phytosanitary copper and natural background copper as a single, inseparable entity within the food.

5. Comparative Table: EFSA Proposals and Approved Decisions

To fully grasp the magnitude of the political choices, it is useful to compare the pre-existing MRLs, the two options proposed by EFSA in 2025, and the final values established by Regulation 2026/840 for key matrices. The data show how, in the absence of toxicological risks, the legislator systematically opted for the most protective option for the production chain.

Conclusion

The case of Regulation 2026/840 is a perfect example of the separation and cooperation between risk assessment (science) and risk management (politics). EFSA provided the safety framework—excluding health risks—and offered various technical options, refraining from dictating an unworkable single rule. Member States, faced with the possibility of cutting residue limits, united to defend the needs of agriculture, aware that excessively low theoretical thresholds would have crippled key sectors like organic farming. The final decision favoured a pragmatic approach: consolidating limits where necessary for agricultural reality and avoiding premature cuts, taking until 2028 to gather better data without endangering either consumers or farmers.

References

• Commission Regulation (EU) 2026/840 of 15 April 2026 amending Annexes II and III to Regulation (EC) No 396/2005.
• EFSA (European Food Safety Authority), 2025. Statement on the update of maximum residue limits (MRLs) for copper compounds.
• EFSA Scientific Committee, 2023. Scientific Opinion on the re-evaluation of the existing health-based guidance values for copper.
• EFSA, 2018. Review of the existing maximum residue levels for copper compounds according to Article 12.
• Standing Committee on Plants, Animals, Food and Feed (SCoPAFF) Summary Reports.