Carbon capture and storage is suggested as one of the solutions to reduce CO2 emissions. Material choice is an important part for the total cost of the transport system for CO2. The present work comprises investigations of corrosive situations which could occur during transport of CO2 for injection to reservoirs. As CO2 with various combinations and concentrations of impurities were tested in a systematic manner, it was clear that combinations from established CO2 transport recommendations resulted in formation of a separate aqueous phase that contained high concentrations of sulfuric and nitric acid. However, many new impurity combinations were basically inert and could be considered safe to transport in carbon steel pipelines. Altogether, the present work has identified many important aspects of corrosion and chemical reactions for CO2 transport. This results in a better understanding of the processes that leads to corrosion and is needed for the making of a CO2 specification which ensure the integrity of pipelines or ships.