They were working in the kitchen when they were overpowered by an odour.
They became nauseous and had irritation in their eyes.
The Brussels Fire Service that attended the scene says that the fire was caused by substances that are used in the kitchen.
However, the fire service spokesperson wouldn’t elaborate on precisely what substances they are.
Staff from the Europa Building were evacuated to the nearby Justus Lipsiusgebouw to allow the Fire Service to carry out an investigation.