Commercial Fixed Wing
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Physiological - Other; Situational Awareness; Communication Breakdown; Confusion
Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
General Flight Cancelled / Delayed; General Maintenance Action
Environment - Non Weather Related
Started APU shortly after arrival to cockpit and noticed a dusting of what we thought was debris coming from the ducts.  I asked the support crew to get in touch with maintenance to take a look.  Me and the crew continued with our duties and at some point we noticed an odor.  We felt it must be the COVID spray so we were not alarmed.  Spoke with maintenance about the dusting but language was a barrier.  Later alerted by the crew that smoke in the supernumerary was getting worse.  In the cockpit we had not noticed.  Maintenance came into the cockpit and told us to leave and shut down.  We vacated immediately.
Air Carrier Captain reported during pre-flight duties the crew noticed dusting in the air and believed it to be spray for COVID. Captain was told by Maintenance to shut down and vacate the aircraft.