Do aircraft sometimes jettison kerosene before they land?

In principle, jettisoning kerosene is prohibited. It is only permitted for safety reasons, for example if an aircraft unexpectedly has to return to Schiphol after take-off. On the ground, kerosene jettisoned by aircraft will not be noticed. Kerosene nebulises at higher altitudes. Kerosene may not be jettisoned at lower altitudes.
If an aircraft operator requests permission to jettison kerosene, air traffic control will direct the aircraft to an area where this can take place without risks for other aircraft. For aircraft that have to return to Schiphol, an area above the North Sea will preferably be designated.