Since 2004, Arnika - Toxics and Waste Programme participated in the international network “Zero Mercury Working Group”. In this network, we were originally active especially in the Czech Republic with the aim to make Czech chlor-alkali plants stop using mercury in chlorine production, which was partially achieved (see the web for hot spots of Spolana Neratovice and Spolchemie Ústí nad Labem).Since 2005, we have been active in negotiations of the European strategy for mercury reduction and later on we also participated actively in international talks on the grounds of the United Nations Environment Programme (UNEP), which resulted in launch of talks on a new international agreement on mercury in February 2009. Between November 2008 and April 2009, we coordinated an international project focused on research of mercury presence in items of everyday life and medical devices in eight countries. We host the secretariat of the IPEN Heavy Metals Working Group. Jindřich Petrlík, an executive director of the Arnika - Toxics and Waste Programme is one of two co-chairs of the IPEN Heavy Metals Working Group.