Narrative:

Shortly after takeoff; flight attendants called from aft of aircraft and said they smelled something like hot lint from a clothes dryer and some haze in the cabin. I told the flight attendants that we departed through a cloud/wildfire smoke layer at about 1500 ft AGL and to give a little time to see if smell would go away. Flight attendants called back and said smell went away and everything normal. I made a PA and explained to some concerned passenger that we flew through some wildfire smoke from the local area fires. We then pressed on to ZZZ1. After about 30 mins; the flight attendants called back and said fumes were back in cabin at about row 23 on back; but no smoke/haze. Flight attendants said smell was more intense. We elected to declare emergency and divert to ZZZ2; told center that we were carrying hazmat in forward cargo and asked them to notify dispatch and also have crash fire rescue equipment standing by at ZZZ2. On approach; I asked flight attendants of cabin condition and they reported everything normal. We then had fire captain follow us to gate and again told them of hazmat in forward cargo. Awaiting jetbridge and door; I made PA and relayed to passenger that fire captain reported everything appears normal. I told passenger to keep boarding pass and proceed up jetbridge to lounge and await further instructions for the flight. As passenger started to deplane; fire captain halted deplaning temporarily to set up a secure perimeter in terminal. Passenger deplaned. Aircraft was taken OTS. We got new plane and flew to ZZZ1.

Google
 

Original NASA ASRS Text

Title: B757-200 DIVERTS DUE TO ODORS OF UNKNOWN ORIGIN.

Narrative: SHORTLY AFTER TKOF; FLT ATTENDANTS CALLED FROM AFT OF ACFT AND SAID THEY SMELLED SOMETHING LIKE HOT LINT FROM A CLOTHES DRYER AND SOME HAZE IN THE CABIN. I TOLD THE FLT ATTENDANTS THAT WE DEPARTED THROUGH A CLOUD/WILDFIRE SMOKE LAYER AT ABOUT 1500 FT AGL AND TO GIVE A LITTLE TIME TO SEE IF SMELL WOULD GO AWAY. FLT ATTENDANTS CALLED BACK AND SAID SMELL WENT AWAY AND EVERYTHING NORMAL. I MADE A PA AND EXPLAINED TO SOME CONCERNED PAX THAT WE FLEW THROUGH SOME WILDFIRE SMOKE FROM THE LCL AREA FIRES. WE THEN PRESSED ON TO ZZZ1. AFTER ABOUT 30 MINS; THE FLT ATTENDANTS CALLED BACK AND SAID FUMES WERE BACK IN CABIN AT ABOUT ROW 23 ON BACK; BUT NO SMOKE/HAZE. FLT ATTENDANTS SAID SMELL WAS MORE INTENSE. WE ELECTED TO DECLARE EMER AND DIVERT TO ZZZ2; TOLD CTR THAT WE WERE CARRYING HAZMAT IN FORWARD CARGO AND ASKED THEM TO NOTIFY DISPATCH AND ALSO HAVE CFR STANDING BY AT ZZZ2. ON APCH; I ASKED FLT ATTENDANTS OF CABIN CONDITION AND THEY RPTED EVERYTHING NORMAL. WE THEN HAD FIRE CAPT FOLLOW US TO GATE AND AGAIN TOLD THEM OF HAZMAT IN FORWARD CARGO. AWAITING JETBRIDGE AND DOOR; I MADE PA AND RELAYED TO PAX THAT FIRE CAPT RPTED EVERYTHING APPEARS NORMAL. I TOLD PAX TO KEEP BOARDING PASS AND PROCEED UP JETBRIDGE TO LOUNGE AND AWAIT FURTHER INSTRUCTIONS FOR THE FLT. AS PAX STARTED TO DEPLANE; FIRE CAPT HALTED DEPLANING TEMPORARILY TO SET UP A SECURE PERIMETER IN TERMINAL. PAX DEPLANED. ACFT WAS TAKEN OTS. WE GOT NEW PLANE AND FLEW TO ZZZ1.

Data retrieved from NASA's ASRS site as of May 2009 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.