Emb-175 first officer reported that fumes in the cabin resulted in a return to the departure airport...

Attributes
ACN	1719360
Time
Date	202001
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Daylight
Aircraft 1
Make Model Name	EMB ERJ 145 ER/LR
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Person 1
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 291 Flight Crew Total 1479 Flight Crew Type 491
Events
Anomaly	Aircraft Equipment Problem Less Severe Flight Deck / Cabin / Aircraft Event Illness Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor

Narrative:

At cruise the flight attendant said she smelt something bad in the back from the galley to zone B. We smelt it too and began to troubleshoot the situation. We noticed that the packs were still set to warm from the morning flight. Together we thought the smell could be a pack working too hard. We began to cool the cockpit and cabin; and the smell was no longer with us upfront. The flight attendant said she could still smell it and some passengers could now also taste it. She also said that passengers and herself were dizzy. So we worked with ATC to return to ZZZ.we believe the smell was caused by the packs and they needed to be cooled down.when the flight attendant said her and passengers felt sick we determined using all available information it would be best to return to ZZZ. There was a more than 100 knot head wind to ZZZ1 with an ETA of 48 minutes and only 22 back to ZZZ.we worked together as the whole crew using all available resources both inside and outside the aircraft to come to the decision to return to ZZZ.

Original NASA ASRS Text

Title: EMB-175 First Officer reported that fumes in the cabin resulted in a return to the departure airport.

Narrative: At cruise the Flight Attendant said she smelt something bad in the back from the galley to zone B. We smelt it too and began to troubleshoot the situation. We noticed that the packs were still set to warm from the morning flight. Together we thought the smell could be a pack working too hard. We began to cool the cockpit and cabin; and the smell was no longer with us upfront. The flight attendant said she could still smell it and some passengers could now also taste it. She also said that passengers and herself were dizzy. So we worked with ATC to return to ZZZ.We believe the smell was caused by the packs and they needed to be cooled down.When the flight attendant said her and passengers felt sick we determined using all available information it would be best to return to ZZZ. There was a more than 100 knot head wind to ZZZ1 with an ETA of 48 minutes and only 22 back to ZZZ.We worked together as the whole crew using all available resources both inside and outside the aircraft to come to the decision to return to ZZZ.

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.