Klaus Hieronymi has contributed – together with representatives from leading companies – to the development of the content of the German and EU regulations regarding the strategies and details of the implementation of the legislation in Germany, the EU, and the member states. He developed a strategy for mandatory and voluntary Take Back of retired products for his employer, HP Inc., and supported national Country experts with direction and training. He discussed elements of the document in various lectures, e.g., Lausanne and Peking University, and international conferences (e.g., IRC/Salzburg, IRC Asia). Klaus Hieronymi published various articles on WEEE and related subjects.