How does the segregation distance between two different IMDG classes change based on the mode of transport (e.g., on deck vs. under deck)?

The segregation distance between different IMDG classes, as defined in the IMDG Code segregation table, often increases when dangerous goods are stowed under deck compared to on deck because under-deck stowage presents a greater risk in the event of an incident, such as a fire or spill. The rationale behind this difference is that incidents occurring under deck are more difficult to control due to limited access, ventilation, and escape routes. Therefore, increased segregation distances are required to minim....