They must be optical smoke detectors because steam should not set off an ionization smoke detector.
But regardless, having a smoke detector alarm call the fire brigade? That seems wrong to me – false smoke detector alarms happen all the time. Are you sure the fire brigade is attending? In our system, only a water sprinkler trigger will bring the fire brigade.
Still, the false alarms would be very annoying. And it should not be that hard to relocate the detector or replace it with a different type.