During the construction of the Hallandsås Tunnel, it quickly became apparent that the water leakage from the ridge was much greater than estimated. Therefore, extensive sealing work was initiated. The sealing consisted of ultrafine cement that was pumped (injected) into cracks. It eventually became clear that cement alone was not sufficient to prevent leakage and that a flowable substance was needed to reach all the cracks and then solidify.

In the spring and summer of 1997, Rhoca-Gil from the French company Rhône-Poulenc was tested as a sealant. The substance is based on acrylamide and methyl acrylamide, both of which are highly toxic and carcinogenic.

In the fall of 1997, the first warning signs appeared. Measurements showed that the limits for the release of toxins had been exceeded. Fish in Vadbäcken on the ridge died, and grazing cows showed symptoms of paralysis.

In the cold and damp environment, the components of the substance did not combine properly, and large amounts of poison followed the leaking water out of the tunnel. It also turned out that tunnel workers had been poisoned upon contact with the substance. Tunnel construction was halted in October 1997 and did not resume until 2005.

The Rhoca-Gil displayed in the exhibition is fully cured and completely harmless.