Critical Assessment of the JRC Methodology for Establishing EU-Wide Leaching Limit Values for Recycled Aggregates under End-of-Waste Criteria

FEAD, the European Waste Management Association, welcomes the opportunity to react to the JRC proposed EU-wide limit values for the leaching of pollutants from recycled aggregates, in the context of the development of EU-wide End-of-Waste criteria for mineral construction and demolition waste. These values are based on a comparative analysis of national criteria and a statistical methodology. Although the intention to establish a harmonised baseline while allowing for flexibility at a Member State level is sound in principle, there are serious concerns regarding both the method used to derive the proposed limit values and the practical consequences of the resulting thresholds.

This paper sets out why the current JRC proposal risks undermining circularity rather than enabling it, and why the methodology used to establish the proposed leaching limit values requires fundamental reconsideration before progressing further.

Arbitrary Exclusion of National Limit Values and Uses

A central concern relates to the selection of national limit values used as the basis for the EU-wide proposal. The JRC has excluded several national or regional criteria on grounds such as ‘too lenient’, ‘application-specific’, or ‘outside scope’, without sufficiently justifying these exclusions from an environmental or regulatory perspective.

Notably excluded are:

• Ireland, where EoW criteria distinguishes different uses and leaching values, including for low-permeability conditions, which are under the scope of the EU wide EoW but were excluded from the leaching values dataset.
• France, where the 2010 EoW criteria proposal distinguishes road types 1, 2 and 3, but only the most stringent ‘road type 3’ values were retained, while road types 1 and 2 were discarded while being under the scope of the EU wide EoW.
• Wallonia, where criteria were excluded for being considered too lenient.
• Germany, where RC3 category was excluded, despite reflecting a defined and regulated use class, which is also under the scope of the EU wide EoW.

These exclusions are not neutral technical decisions. They correspond directly to the exclusion of certain legitimate uses of recycled aggregates from the analytical basis of the study. If Member States have developed differentiated thresholds and use classes, this is precisely because risk profiles differ depending on application, local conditions and regulatory objectives.

By excluding these values without a thorough analysis of why they exist and how they function in practice, the JRC implicitly redefines which uses of recycled aggregates are deemed acceptable at EU level—without an explicit policy discussion or impact assessment. Such exclusions therefore require robust justification, which is currently lacking, and are not aligned with the proposed scope of the EU wide EoW, in which all these uses are covered.

Limits of the 90th Percentile Statistical Approach

On top of the arbitrarily excluded national limit values, the JRC proposal relies heavily on a 90th percentile rule to discard ‘lenient’ national limit values and derive EU-wide thresholds. However, when reintegrating the arbitrarilty excluded national limit values into the dataset, the resulting percentiles—and therefore the proposed EU limit values—change substantially for several parameters.

This demonstrates a fundamental weakness of the method:

• The outcome is highly sensitive to initial limit values selection.
• Statistical approach substitutes a real environmental risk assessment.

In the absence of a thorough evaluation of environmental and economic consequences for each parameter, the choice of percentiles becomes arbitrary rather than science-based.

Insufficient and Non-Representative Data Basis

The JRC proposal assesses the ‘workability’ of the proposed limit values based primarily on full datasets from only two countries: Belgium and Italy. In addition, a limited number of literature data points from Denmark, Spain and Czechia are used.

This data basis is not sufficient to support EU-wide conclusions:

• It does not cover the diversity of geological, climatic and construction practices across the EU.
• It does not reflect the full range of recycled aggregate applications covered by the proposed EoW criteria.
• Literature data are limited in number, heterogeneous in methodology, and not designed to assess regulatory workability.

The JRC itself acknowledges that Member States are better placed to regulate local use patterns. Yet the proposed EU-wide limits are tested against an insufficiently broad dataset, making it impossible to reliably assess whether the limits are workable across Europe and across uses.

Concrete Evidence of Negative Circular Economy Impacts

The Belgian certification body COPRO, whose data underpin part of the JRC analysis, certifies on average around 20 million tonnes of recycled aggregates per year. All data provided by COPRO to the JRC concern materials that are fully compliant with existing regional EoW criteria and are safely used on the market.

However, based on the JRC’s proposed EU-wide leaching limit values, a significant proportion of aggregates currently meeting the EoW criteria would no longer do so. More specifically, up to 10% of Belgian recycled aggregate, which has been assessed as compliant with regional EoW, would no longer meet the criteria. This represents around two million tonnes of material losing its product status and being discarded, in Belgium only.  

This would be a significant setback for the circular economy, not due to demonstrated environmental risk, but due to newly imposed thresholds that are more restrictive than necessary. Similar effects can reasonably be expected in other Member States, although data have not yet been collected to quantify them.

Comparability of Test Methods and Measurement Bias

Comparability between Member State data is further undermined by differences in testing methodologies. For example, some national methods (such as in the Netherlands) involve full grinding of the sample, which systematically increases measured leaching values. Paradoxically, such methods may appear ‘lenient’ in a numerical comparison with other national limit values, while in reality they are more conservative and harder to comply with. Without correcting for methodological differences, cross-country comparisons of limit values are unreliable and risk distorting conclusions.

Additionally, the current methodology compares the limit values, and their stringeness, in a purely numerical sense, without analysing how national limit values were derived. This approach is fundamentally flawed:

• National limit values are the result of decades of regulatory development, risk assessments and adaptation to local conditions.
• A numerical value that is stringent in one Member State may be lenient in another due to differences in groundwater levels, soil types or exposure scenarios.
• Without understanding the underlying risk assessment, it is impossible to determine whether a given value is genuinely protective.

Comparing values without understanding their context risks producing misleading outcomes.

Additionally, it must be noted that all leaching measurement methods have inherent strengths and limitations, and their use reflects different regulatory objectives and national contexts. Methods such as percolation tests used in some Member States aim to describe time-dependent release under defined use scenarios, while batch shake tests at L/S 10—also widely applied across Europe—provide a conservative snapshot of leaching behaviour. Both approaches serve specific regulatory purposes, and it is therefore questionable whether one method should be prioritised over another in EU-wide EoW criteria, particularly where Member States have already developed appropriate regulatory frameworks and testing capacity for specific methods.

Interface with Construction Products Regulation

Finally, FEAD would remain cautious on the proposed interaction with the Construction Products Regulation. Indeed, the CPR focuses on compliance with harmonised standards and does not make End-of-Waste status a condition for placing construction products on the market. Introducing compliance with End-of-Waste criteria as a de facto precondition for CE marking would therefore impose additional market access requirements outside the scope of harmonised product standards and would risk creating an unjustified barrier to trade within the internal market. Therefore, such interface between the EU-wide EoW and the CPR shall be carefully assessed to avoid uninteded consequences.

Need for a Revised Approach

FEAD supports the development of EU-wide end-of-waste criteria for recycled aggregates, including the establishment of harmonised EU-level leaching values as a backdrop, combined with the option for Member States to implement stricter national requirements where local environmental conditions, usage patterns or risk assessments justify it. In principle, this two-tier approach could enhance legal certainty, support the internal market, and provide a common baseline of environmental protection.

However, this model can only function effectively if the EU-wide limit values are proportionate and sufficiently flexible. Backdrop values that are set too stringently at EU level leave no practical margin for Member State differentiation and risk becoming de facto maximum thresholds, rather than minimum safeguards. In such a scenario, the flexibility foreseen at national level becomes purely theoretical, while the EU-wide criteria themselves act as a barrier to circularity.

As demonstrated in this paper, the proposed leaching limit values are tested against a non-representative data basis, rely on arbitrary exclusions of national criteria, and apply a statistical methodology that is highly sensitive to initial assumptions. The result is a set of thresholds that would render large volumes of currently compliant recycled aggregates non-conforming, without a demonstrated environmental justification.

Before any EU-wide leaching limit values can be finalised, additional data collection and testing are essential. This must include:

• A better understanding of how national limit values were derived, including risk assessments, testing methods and local conditions.
• Broader datasets from competent authorities and certification bodies across multiple Member States.
• Data covering the full range of recycled aggregate applications foreseen under the EoW criteria.
• A structured assessment of the workability and circular economy impacts of proposed limits at Member State level.

Only on the basis of such evidence can it be determined whether proposed EU-wide limit values are achievable in practice, environmentally justified, and compatible with existing recycling systems. FEAD therefore calls for a recalibration of the current JRC approach and a reassessment of the leaching limit values to ensure that they enable circularity rather than restrict it.

FEAD is the European Waste Management Association, representing the private waste and resource management industry across Europe, including 21 national waste management federations and 3,000 waste management companies. Private waste management companies operate in 60% of municipal waste markets in Europe and in 75% of industrial and commercial waste. This means more than 500,000 local jobs, fuelling €5 billion of investments into the economy every year. For more information, please contact: info@fead.be