The move comes at a time when more electric vehicles are being moved by ocean transport and in the wake of a number of serious vessel fires at sea. In the most recent incident, the Mitsui OSK Line (MOL) vessel Felicity Ace caught fire in the mid-Atlantic with 4,000 vehicles aboard and eventually sank.  

While not exclusively the cause of finished vehicle fires at sea, the lithium-ion batteries used to power EVs are high and can burn with high intensity if they are damaged because of thermal runaway, in which an increase in temperature changes the conditions in a way that causes temperature feedback. It can be caused by an internal short circuit or by batteries coming into contact with each other or coming into contact with conductive material or metal surfaces; it can even be caused by an excessive movement that leads to damage.