For years it has been public knowledge that after SOx comes NOx on the global political shipping agenda. But the process is dragging out in terms of the nitrogen topic, NOx, and the introduction of the so-called NECA (NOx Emission Control Area) in the North Sea - that is, an area in the North Sea in which nitrogen emissions will be reduced and barred from exceeding a certain level, comparable with the SECA requirements which have been introduced for sulfur emissions, says Ditte Kristensen, AC technician at the Danish Environmental Protection Agency, EPA.