In the Huta Sendzimira works of Mittal Steel in the Polish city of Krakow, nitrogen has been used for heat treatment since the beginning of May – another milestone in a dynamic collaboration. Mittal Steel is by far the biggest steel producer in Poland. Messer has been supplying the Huta Cedler plant with liquid nitrogen and hydrogen for six years, while the Huta Sendzimira steel plant has been receiving cylinder gases since 2005. At the beginning of 2006, both sides expanded this collaboration significantly: Messer has since been supplying gas to all the Polish steel plants of Mittal Steel.