Emb-145LR captain reported a fume event prior to pushback.

Attributes
ACN	1745562
Time
Date	202006
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	EMB ERJ 145 ER/LR
Operating Under FAR Part	Part 121
Flight Phase	Taxi
Flight Plan	IFR
Component
Aircraft Component	Air Conditioning and Pressurization Pack
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural MEL Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor

Narrative:

After boarding was completed and main cabin door shut. Flight crew started both engines for turn out and flight attendant notified cabin secure but aircraft seemed hazy and had an odor. Shut down engines and had operations come back with stairs and opened main cabin door. Called dispatch and talked to maintenance while deplaned the passengers. Pack 2 on with pack 1 off produced smoke/haze. Flight crew detected with maintenance on the phone. Pack 2 started to make an unusual noise just prior to engine start but no other indication was noticed. Talking through with maintenance we discussed the cause was pack 2. Deplaned. MEL'd pack. Reloaded passengers and went to ZZZ1 as normal but delayed.

Original NASA ASRS Text

Title: EMB-145LR Captain reported a fume event prior to pushback.

Narrative: After boarding was completed and main cabin door shut. Flight Crew started both engines for turn out and Flight Attendant notified cabin secure but aircraft seemed hazy and had an odor. Shut down engines and had Operations come back with stairs and opened main cabin door. Called Dispatch and talked to Maintenance while deplaned the passengers. Pack 2 on with Pack 1 off produced smoke/haze. Flight Crew detected with maintenance on the phone. Pack 2 started to make an unusual noise just prior to engine start but no other indication was noticed. Talking through with Maintenance we discussed the cause was pack 2. Deplaned. MEL'd pack. Reloaded passengers and went to ZZZ1 as normal but delayed.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.