Brussels updates water pollution watch list

The European Commission has published an updated watch list of substances for monitoring under the Water Framework Directive on 28 February 2025. The list aims to improve data collection on potentially harmful chemicals that threaten European water bodies. This initiative supports future prioritisation exercises for environmental protection.

The revised watch list includes a range of pharmaceuticals, pesticides, industrial chemicals, and personal care products. Among the newly added substances are the industrial antioxidant 6PPD and its transformation product 6PPD-quinone, the antibiotic oxytetracycline, the antidepressants fluoxetine and propranolol, as well as a group of azole antifungals. These additions reflect growing concerns about the impact of chemical pollution on aquatic ecosystems and human health.

Addressing knowledge gaps

The European Commission’s selection process was based on available toxicity data, the persistence of substances in the environment, and their widespread use across multiple Member States. Emerging contaminants with insufficient monitoring data were prioritised for inclusion, ensuring that the most pressing knowledge gaps are addressed.

Pharmaceuticals and pesticides remain a concern

Pharmaceutical residues continue to be a key focus, with metformin and its metabolite guanylurea remaining on the list due to their potential additive effects. The presence of antibiotics such as tetracycline and oxytetracycline also highlights the growing challenge of antimicrobial resistance (AMR), a major public health concern. Their inclusion aligns with the EU’s One Health Action Plan against AMR, which promotes environmental monitoring of antibiotics to track their spread en to prevent antibiotic resistance.

Pesticides also feature prominently in the updated list. The continued presence of fipronil and the addition of etoxazole underline the risks posed by agricultural runoff. These chemicals have been linked to ecosystem disruption, particularly in freshwater habitats where they can harm aquatic organisms and pollinators.

Sunscreen chemicals under investigation

The European Commission has extended its scrutiny of UV filters used in sunscreens, adding octisalate to a group of previously listed compounds, including oxybenzone and octocrylene. These chemicals are suspected of contributing to water pollution and affecting marine life. The grouping of similar substances enables regulators to assess their combined effects and potential environmental risks.

Strengthened monitoring efforts

Member States are required to monitor the substances on the watch list and report their findings to the European Commission. While the minimum monitoring frequency remains once per year, authorities are encouraged to conduct biannual sampling to account for seasonal variations in pollutant levels. To ensure consistency, all substances will be analysed in whole water samples. The European Commission has also stressed the importance of using cost-effective analytical methods, ensuring that monitoring efforts remain feasible for all Member States.

EU priority subtances list

If future assessments reveal a significant risk associated with any substance, it may be added to the EU’s priority substances list, leading to stricter regulatory controls. In 2021 the European Chemicals Agency (ECHA) identified 290 new chemicals that may be dangerous. If their hazards are confirmed these substances are candidates for strict EU-rules.