Narrative:

Climbing through ~FL200 fas (flight attendants) alerted us to possible odors/fumes in cabin. The 2 fas in rear did not notice a smell. I asked them to come to the forward part of the cabin to check for odor. All 4 fas confirmed an odor. I left the flight deck to check the odor. As soon as I stepped out I noticed a very strong musty; moldy noxious odor. When I returned to the cockpit I immediately turn off pack 1. I instructed the first officer (first officer) and the flight attendant in the cockpit to don oxygen mask. I included the flight attendant so that she wouldn't go nose blind and I could send her out to evaluate any change to the fumes/odors. Then I started the 'elimination of fume' checklist. After ~5 minutes there was no notable fume reduction. I switched pack 1 on and pack 2 off. After 3-5 minutes the flight attendant reported the fumes/odors got worse. I switched back to the first pack configuration and we begin a descent to [a nearby alternate airport]. At around 7000 feet there was a very strong choking fume in the cockpit. I switched all packs off and open the ram air inlet. Shortly after the plane depressurized; the air in cockpit was markedly better. We landed and taxied to the gate without further incident. Upon my request; paramedics met us at the gate. We made an announcement if anyone needed to see paramedics to raise their hand. One gentleman was removed and later taken to the hospital. All crew had various symptoms: headache; dizziness; nausea; shortness of breath; and sore throat. We went to er for testing and evaluation. We were discharged after 6 hours elapsed; as directed by the er staff and poison control.

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Original NASA ASRS Text

Title: A320 Captain reported reported noxious fumes in the cabin and cockpit resulted in a diversion.

Narrative: Climbing through ~FL200 FAs (flight attendants) alerted us to possible odors/fumes in cabin. The 2 FAs in rear did not notice a smell. I asked them to come to the forward part of the cabin to check for odor. All 4 FAs confirmed an odor. I left the flight deck to check the odor. As soon as I stepped out I noticed a very strong musty; moldy noxious odor. When I returned to the cockpit I immediately turn off PACK 1. I instructed the FO (First Officer) and the FA in the cockpit to don oxygen mask. I included the FA so that she wouldn't go nose blind and I could send her out to evaluate any change to the fumes/odors. Then I started the 'elimination of fume' checklist. After ~5 minutes there was no notable fume reduction. I switched PACK 1 ON and PACK 2 OFF. After 3-5 minutes the FA reported the fumes/odors got worse. I switched back to the first PACK configuration and we begin a descent to [a nearby alternate airport]. At around 7000 feet there was a very strong choking fume in the cockpit. I switched all PACKs off and open the RAM air inlet. Shortly after the plane depressurized; the air in cockpit was markedly better. We landed and taxied to the gate without further incident. Upon my request; paramedics met us at the gate. We made an announcement if anyone needed to see paramedics to raise their hand. One gentleman was removed and later taken to the hospital. All crew had various symptoms: headache; dizziness; nausea; shortness of breath; and sore throat. We went to ER for testing and evaluation. We were discharged after 6 hours elapsed; as directed by the ER staff and Poison Control.

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.