NonHazCity 3 (January 2023 – December 2025) addressed a persistent blind spot in sustainable construction: hazardous substances that remain embedded in buildings, construction sites and materials, creating long-term risks for human health, circularity, and the aquatic environment - including the Baltic Sea. The project brought municipalities, businesses and residents together to strengthen life-cycle thinking in construction and renovation, and to shift material choices toward safer alternatives.

Over the course of the project, partners developed and tested four solution models to reduce exposure to substances of concern in homes, workplaces and the environment. The work focused on closing a practical “knowledge gap” by making chemical information more usable (e.g., simplified guidance), embedding chemical safety into procurement, design and supervision routines, and demonstrating feasibility through pilots across the Baltic Sea Region – from kindergartens and public buildings to housing renovations.

Stakeholder feedback from the NonHazCity3 survey (around 150 responses) shows strong uptake of project results. Municipalities, experts and professionals report improved knowledge on hazardous substances in construction, adoption of tools such as the Building Materials Catalogue and training materials, and integration of tox-free and circular criteria into procurement and design practices. The stakeholders unisono reported strengthened institutional capacity and increased cooperation across the Baltic Sea Region.

The project’s key lessons are clear:

• transparency on building materials composition must be translated into actionable decision support,
• implementation depends on consistent verification on construction sites, and
• clear communication can empower households to make safer renovation choices without requiring specialist expertise.

With the project now completed, NonHazCity 3 leaves a concrete foundation for continued action: tested approaches that connect chemical safety with circular construction and climate objectives, and a shared direction toward cities where hazardous substances are systematically designed out of materials and managed through transparent information and robust routines.