Narrative:

While in cruise at FL400; an unidentified odor like burning plastic was smelled in cockpit and cabin. O2 mask was donned and passenger masks deployed. Obtained clearance for descent and notified ATC of requirement for immediate landing. [We were] advised that the closest [airport] was approximately 100 NM. We agreed as we needed to descend from FL400. Pilot not flying coordinated divert and pulled charts. I then called for the cockpit cabin smoke/fire checklist and the pilot not flying ran the checklist. We did not execute an emergency descent nor declare an emergency; as we were still ascertaining the extent of the problem. We discussed and elected to have the emergency equipment stand by. We also elected to evacuate the aircraft rather than proceed to the ramp. We landed uneventfully and evacuated to the grass. Myself and one passenger complained of eye irritation and I felt lightheaded after leaving the aircraft. The pilot not flying reported a slight headache and eye irritation.

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Original NASA ASRS Text

Title: CE750 flight crew and passengers experience an unidentified odor like burning plastic at FL400. The crew elects to divert to the nearest suitable airport after deploying the passenger oxygen masks and donning their own. Flight lands uneventfully and both passengers and crew evacuate on the runway.

Narrative: While in cruise at FL400; an unidentified odor like burning plastic was smelled in cockpit and cabin. O2 mask was donned and passenger masks deployed. Obtained clearance for descent and notified ATC of requirement for immediate landing. [We were] advised that the closest [airport] was approximately 100 NM. We agreed as we needed to descend from FL400. Pilot not flying coordinated divert and pulled charts. I then called for the cockpit cabin smoke/fire checklist and the pilot not flying ran the checklist. We did not execute an emergency descent nor declare an emergency; as we were still ascertaining the extent of the problem. We discussed and elected to have the emergency equipment stand by. We also elected to evacuate the aircraft rather than proceed to the ramp. We landed uneventfully and evacuated to the grass. Myself and one passenger complained of eye irritation and I felt lightheaded after leaving the aircraft. The pilot not flying reported a slight headache and eye irritation.

Data retrieved from NASA's ASRS site as of April 2012 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.