After a fire in a warehouse belonging to the Sandoz AG near Basel on 1st November 1986, firefighting water mixed with up to thirty tons of pesticides flowed into the Rhine and killed fish and other organisms along hundreds of kilometres of the Rhine.
This was the first time that citizens from Switzerland downstream to the Netherlands demonstrated solidarity with the Rhine and its protection. The considerable public pressure exercised on the governments of the states in the Rhine catchment contributed to the increasing influence of the ICPR.
Subsequently, the ministers adopted the ambitious "Rhine Action Programme" and confided its coordination and success control to the ICPR. The objective was to reduce the discharged quantities of 40 dangerous chemicals by half within 10 years. They wanted the Rhine to become clean enough for salmon to return to the river.
The Sandoz accident became a turning point for environment and water protection in the Rhine catchment.