Date: 201902
Local time of day: 0601-1200
Location: ZZZ.TRACON, US
Flight conditions: IMC
Light: Dawn
Aircraft: EMB ERJ 170/175 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Human factors: Time Pressure
Second reporter function: Flight Attendant In Charge
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Illness / Injury; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Attendant
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Diverted; Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: The captain; myself and two flight attendants were pulled off reserve for Flight X to ZZZ1 and were all scheduled to deadhead back after. The preflight and start of the trip was fairly uneventful; except for a few maintenance discrepancies that were fixed before we left. I believe we may have blocked out a little late due to maintenance needing to be brought in a few times. The pushback and start up were normal. Taxi and departure were normal; with the Captain as PF and I was monitoring. On our climb out; just before reaching 10;000 feet; we received an emergency call from FA-A (Flight Attendant). I took the airplane and radios while the Captain spoke with the Flight Attendant. After he hung up the call with the FA; he explained to me that there is a fume smell in the cabin that is concerning to them but that the Flight Attendant also doesn't feel well and that he could tell she wasn't okay when they spoke. While he was explaining this; we got a frequency change from Departure. The Captain took over the radios and explained the situation to departure. ATC gave us a left turn and a lower altitude which I put in the FGP (Flight Guidance Panel) as the Captain started coordinating with company through ACARS. The Captain got us set up for [Runway] XXR in the FMS (Flight Management System) and we briefed/completed checklists as we were descending. There was a short time I again took radios/airplane as he checked with FAs and made a passenger call. At some point in this time; ATC [gave us priority handling]. The Captain took over the aircraft before our turn on final. I was a little slow on answering radio calls at this point because they asked us things like 'are they on oxygen?' 'Is oxygen deployed?' and the Captain had to tell me what to say; as I hadn't talked to the FA in this time; but I don't think it was necessary for me to know as everything was happening quickly. Captain performed a normal landing; and we were followed to the gate with emergency vehicles. I believe ATC helped us as much as they could to get us back on the approach; coordinating emergency vehicles and giving us gate information. After the completion of the parking check; the captain communicated with the passengers and called company. I took these few minutes to write down a quick review of what happened to have a more accurate [report]/debrief. Eventually; the Captain got through to the Chief Pilot on the phone and got approval to deplane. The sick Flight Attendant immediately left with first responders. I informed the Customer Service Agent at the counter and we deplaned. During this time the Captain made numerous calls to company and [the Union]. I took a few minutes to push a wheelchair passenger up the jet bridge then completed my post flight walk around; where I found no abnormalities.I do feel like the cabin smelled slightly of fumes as I was walking in and out of the plane after we landed but there was no definite spot it was coming from.After I completed my walk around; I checked in with the Captain who was still speaking with company and checking in on the sick Flight Attendant. I honestly assumed we would be continuing either on reserve or have to fly to ZZZ1 on a later flight; I didn't think we had a choice. Around this time; I started thinking about how if one crew member was affected by possible fumes; could the rest of us also be affected? After discussing with the Captain the next steps; it was mutually agreed we would ask to be released from duty. The Captain had his own reasons and I had many reasons myself. The night before I had minimum rest. The lack of rest; early show after being acclimated to the [schedule] I was assigned all week; stress from my first actual [event] on my 3rd day off IOE (Initial Operating Experience); and the hours we had to wait to be told what we were going to do after the flight contributed to the decision to ask to be released. The Captain was pushed by company to have us stay on duty but we bothcontinually agreed that we may not be able to perform at our best. We were actively trying to break the chain of events that so many GA and airline accidents occur from fatigue; over saturation and being pushed into uncomfortable situations. After 3 hours of back and forth; we were asked to do a quick run up. We completed the run up and were released from duty over 2 hours later. Suggestions: One thing the captain and I both discussed after the flight was that we should have donned our oxygen masks. It did go through my mind briefly but we didn't have any fumes or smoke in the cockpit and when I thought about the need for oxygen masks; we were about to land. From this situation; I learned that if there is ever the possibility of unsafe air; I am going to take the few seconds to put on my mask even if we will be on the ground shortly after.


Second narrative: Shortly after takeoff; I started smelling a strange; plastic/chemical odor coming from the general vicinity of the main cabin door. I was sitting in the forward jumpseat; so the smell was very close to me. Shortly after noticing the smell; I started to feel a little lightheaded and dizzy. I called FA-B (Flight Attendant) to report this abnormality; and by the time I was done with that call; I was also having a hard time breathing and my heart rate had elevated quite a bit. I made the decision to make an emergency call (as we were still in sterile) to the pilots. When I hung up the phone; I called FA-B back and asked him to come up and see if he could smell the odor. He could. The Captain called back and notified us that we were returning to [the origin airport] and paramedics would meet us at the gate. We arrived back at the gate and were met by fire and paramedics. They checked out the plane and escorted me to the terminal to check vital signs. As a precaution; and because I was still having difficulty breathing normally; I went to urgent care to be checked out when I left the airport.


Synopsis: EMB-175 First Officer and Flight Attendant reported cabin fumes and resulting health symptoms.