Aligning and Simplifying Chemical, Industrial Emission and Water Quality Regulations: Towards a Coherent EU Framework for Persistent, Mobile and Toxic (PMT) and very Persistent, very Mobile (vPvM) Substances

Water is a relentless traveler. It flows through soil, seeps into aquifers, and moves across oceans, carrying with it whatever dissolves in its path. For most pollutants, this journey eventually leads to dilution or breakdown; the sun, microbes, or time itself can erase the trace. But a specific group of chemicals defies this natural cleanup crew. These substances are persistent, meaning they refuse to break down over time, and mobile, meaning they travel easily through water without sticking to soil or sediment. When these two traits combine with toxicity, they create a unique threat: once released, they spread silently and permanently, contaminating drinking water sources and ecosystems in ways that are incredibly difficult, and often impossible, to reverse.

Scientists and regulators have long worried about these "forever chemicals," but a new regulatory shift has finally given them a specific name and a set of rules to identify them. In 2023, the European Union updated its chemical classification system to officially recognize a hazard class for substances that are Persistent, Mobile, and Toxic (PMT), as well as a more extreme category called very Persistent and very Mobile (vPvM). This change was a major step forward, forcing manufacturers to label these dangerous substances. However, a team of researchers from the German Environment Agency, the Norwegian Geotechnical Institute, and consulting firms has found that simply labeling the problem is not enough. Their analysis reveals that the rest of Europe's environmental laws are still operating on old maps, failing to connect the new labels to the actual rules that control pollution, emissions, and water safety.

The researchers set out to examine how the European Union's three main pillars of chemical regulation—the rules for registering chemicals, the rules for industrial emissions, and the rules for protecting water—are currently handling these newly identified threats. They looked at the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) regulation, which governs how chemicals are brought to market; the Industrial Emissions Directive (IED), which controls what factories are allowed to release into the air and water; and the Water Framework Directive (WFD), which sets standards for the quality of rivers, lakes, and groundwater. By reading the legal texts and reviewing scientific data, the team discovered a significant gap: while the new hazard classes exist on paper, they are not yet woven into the fabric of these other laws.

Under the current system, the process to stop these chemicals is slow and inefficient. In the REACH regulation, which is the primary tool for managing chemical safety, there is no automatic way to flag a substance as a PMT or vPvM hazard just because it meets the new criteria. Instead, regulators must treat each chemical as a special case, proving that it is just as dangerous as other known toxic substances. This requires a massive amount of time and data, often delaying action until the damage is already done. The researchers found that this "case-by-case" approach means that many of these spreading pollutants slip through the cracks, remaining unregulated even after they have been identified as dangerous.

The problem continues in the industrial sector. The rules that limit what factories can emit are largely tied to the lists of chemicals already flagged by the registration system. Because the registration system is slow to catch PMT and vPvM substances, the emission limits often do not apply to them either. A factory might be legally allowed to release a highly mobile, toxic chemical simply because it hasn't yet been formally added to a restricted list, even though the new hazard classification says it is dangerous. Similarly, the water protection laws rely heavily on monitoring data—measuring what is actually in the water—to decide which chemicals need to be controlled. But because these substances are so mobile and hard to detect with standard methods, they often go unnoticed until they have already spread widely. By the time they are found in a river or a drinking water supply, the contamination is often too extensive to clean up.

The paper argues that the solution lies in creating a direct, automatic link between the new hazard labels and the existing laws. The researchers propose that the EU should update its regulations so that once a substance is classified as PMT or vPvM, it automatically triggers stricter rules. This would mean that under the registration law, these substances would be immediately recognized as high-risk, speeding up the process to ban or restrict them. For factories, this would mean that using or producing such chemicals would automatically require stricter emission controls and monitoring, regardless of whether the chemical was previously on a specific restricted list. For water protection, it would mean that the presence of these hazard properties alone would be enough to prioritize a substance for monitoring and cleanup, rather than waiting for years of data to prove it is widespread.

The study suggests that making these changes would create a much more coherent system. Instead of three separate laws that sometimes talk past each other, the regulations would work together as a single, preventive shield. If a chemical is identified as a persistent and mobile threat, the registration law would flag it, the industrial law would tighten the screws on its release, and the water law would ensure it is watched closely in the environment. This approach aligns with the broader goal of preventing pollution before it starts, rather than trying to fix it after the water is already contaminated. The researchers note that while the new hazard classes are a vital first step, their true value will only be realized if the rest of the legal framework is updated to match them. Without these updates, the new labels risk becoming a formality that identifies the danger but fails to stop it.

The findings also highlight the scale of the challenge. The researchers identified hundreds of substances in existing chemical databases that likely meet the criteria for these dangerous categories, yet very few have been formally regulated as such. This suggests that the current system is missing a vast number of potential threats. By integrating the new hazard classes into the core of EU legislation, the researchers believe the Union can better protect its water resources from long-term, irreversible damage. This would not only safeguard drinking water but also support the broader European goal of a zero-pollution environment. The path forward is clear: the laws need to be rewritten so that the moment a substance is known to be persistent and mobile, the system responds with the full force of prevention, ensuring that these invisible travelers are stopped at the source.