The Hague has become the first city in the Netherlands to ban the use of steel slag in public space. The material, a by-product of steel production, has long been sold under names such as Duomix and Beaumix and widely used in roadbuilding and other construction projects across the country. From now on, The Hague no longer allows these products to be applied in any top layer, and the city will phase them out entirely, even in deeper ground layers where there is no direct contact.
Like many municipalities, The Hague had used Duomix and Beaumix for decades. Their application seemed practical and sustainable at first, but growing evidence shows that steel slag can release hazardous substances, including heavy metals, into soil and groundwater. In some cases, fine dust particles can also enter the air, raising concerns for public health.
The turning point came at Koningsplein, where children playing in the local playground experienced respiratory problems. After complaints from residents, the municipality investigated the material beneath the playground and decided to remove it immediately. Alderman Robert Barker subsequently introduced a citywide ban on its use.
Robert Barker, Alderman for Welfare, Animals and the Environment: “I have been advocating for many years to end the use of steel slag. Its negative effects on health are well known, and our residents deserve to be protected from these risks. With this ban, The Hague is taking responsibility and showing that public health and the environment cannot be compromised.”
Recent investigative reporting by platform Investico revealed that steel slag is present at 216 locations across the Netherlands, far more than previously known. Many of these locations were never officially registered. While Tata Steel produces much of the slag used nationally, this is far from a Dutch-only problem: similar environmental issues have been identified in other European countries and worldwide.
Image: Koningsplein in The Hague being cleaned up to remove steel slag. Picture credits: J. de Jong
