A320
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Physiological - Other; Troubleshooting
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
General Maintenance Action; General Flight Cancelled / Delayed
Aircraft
During boarding process and immediately after turning on APU; F/A (Flight Attendant) informed us of toxic fumes in cabin. We called ZZZ Maintenance who assisted us. I walked into cabin and smelled the odor myself. Crew started experiencing headaches and scratchy throat. We then wrote up the discrepancy in the logbook causing maintenance to put the aircraft out of service. We continued on to our destination with another aircraft.Watching a video about smoke/fume events was very helpful. The odor resembled bleach and laundry detergent.
While boarding and after starting APU; cabin crew advised the Captain and I that there was an odor of 'dirty laundry' in the cabin. We agreed that this was a quite common odor just after APU was started from residual moisture in the air cycle machine. The Captain went back to the cabin to inspect the unknown odor while I advised Maintenance as well to come and ascertain what the odor may have been. In the flight deck there was no odor that I noticed out of the ordinary but the Captain and Maintenance couldn't isolate the source of the odor so in the interest of safety we promptly halted boarding and deplaned all the passengers and our crew was assigned a new aircraft to complete the flight to ZZZ1. I wasn't aware of anyone being incapacitated or injured during this event. I monitored the situation and assisted the Captain as necessary and concurred that we should not accept the aircraft in the interest of safety and stop boarding and deplane promptly then get passengers transferred to our next aircraft which we did.Nothing in particular [to suggest]; I think our crew communicated effectively and came to a conclusion to safety stop boarding and deplane promptly. Odors can be difficult to detect or figure out what they are but to take the action we did was the correct one and deplaning and not continuing on with the unknown odor.
A320 flight crew reported a fume event during boarding. Maintenance investigated and placed the aircraft out of service. Flight continued after aircraft swap.