Beside their high mechanical strength, duplex stainless steels are a suitable choice in highly corrosive environments. These types of steels are used in steel bridges more and more frequently exposed to low temperatures and fatigue loads. However, for low temperature applications, it must be guaranteed that brittle fracture is avoided since duplex stainless steel shows a toughness-temperature relationship similar to that of carbon steel. For this reason, in the frame of the German national FOSTA research project “P 1390”, comprehensive investigations have been started into the material selection of duplex stainless steel to avoid brittle fracture considering the fracture mechanic based background of EN 1993-1-10. For this purpose, Charpy-V impact tests and fracture toughness tests have been systematically carried out for various duplex stainless steels in order to create the basis for the development of toughness requirements for new duplex classes. The validity of the already existing Master Curve concept and the applicability of the transition temperature correlation for duplex stainless steels based on experimental fracture toughness and Charpy-V impact tests have been investigated. The aim of this contribution is to present first results of these investigations. •A comprehensive investigation has been started and first results are presented based on Charpy-V impact and fracture toughness tests.•The highest nickel content in 1.4462 resulted in the lowest transition temperature followed by lean duplex 1.4662 and 1.4162.•The 3 °C temperature shift per percent of cold deformation in transition curve according to EN 1993-1-10 appears suitable for tested duplex steels.•Lower fracture toughness values are achieved for the specimens fabricated from thicker plates for both duplex 1.4462 and lean duplex 1.4162.•The results confirm that the transition temperature correlation in accordance with EN 1993-1-10 is valid for the studied duplex stainless steels.•The Master Curve approach presented in ASTM E1921 which was developed for carbon steel material is also valid for the tested duplex stainless steels.