Narrative:

Approximately 15 minutes after takeoff during climb to FL390; and while climbing through FL340; the first officer and I noticed an acrid smell in the cockpit. The first officer and I talked about it very briefly for less than a minute as we tried to identify what the smell could be. As the fumes increased in intensity; I commanded the crew to go on oxygen. The first officer continued to fly the aircraft and I opened the QRH to the smoke; fire or fumes checklist. We notified ARTCC and asked to land at the nearest suitable airport. ARTCC recommended ZZZ2. We evaluated that as a good destination. ARTCC immediately gave us a vector direct and a decent. With changes to the FMC for the diversion and approach; we were able to get to step 20 in the QRH checklist as we approached 10000 feet. I elected at that point to concentrate on safely navigating and flying the aircraft to the approach and landing at ZZZ2 and did not have time to proceed further in the QRH. I did have time as we passed 12000 feet; to very briefly pull my mask slightly away from my face and sample a short breath of air from the cockpit to see if 'smoke or fumes continue or are increasing' as stated in the QRH. The fumes were still present. At no time did the crew notice visual indications of smoke. To expedite our decent and maintain an expedited profile to ZZZ2; we did go above 250 KIAS below 10;000 feet. At approximately 4000 feet we were below 250 KIAS. We were given emergency priority with vectors to runway xxl at ZZZ2. The approach was flown and landed normally. The aircraft safely exited the runway at the first available taxiway. The aircraft was stopped immediately after clearing the runway. The crew ran the evacuation checklist; where crash; fire; rescue personnel and equipment met the aircraft. The crew noted the same fume smell again as we exited the cockpit; but not in the aft compartment as we left the cockpit and approached the L1 door. We opened the L1 door; and because we did not smell fumes at that position; to avoid injury; we elected to use the air stair that the fire department had immediately available outside the aircraft. In the past; I have had electrical fires on aircraft that have the smell of ozone. That was not the smell. It was also not a petroleum type smell. I can only characterize it as an acrid chemical smell that I have never encountered before. I cannot say for sure weather it is a smell associated with a chemical fire or simply chemical fumes.

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Original NASA ASRS Text

Title: B767 flight crew reported an uneventful emergency diversion due to a fume event during flight.

Narrative: Approximately 15 minutes after takeoff during climb to FL390; and while climbing through FL340; the First Officer and I noticed an acrid smell in the cockpit. The First Officer and I talked about it very briefly for less than a minute as we tried to identify what the smell could be. As the fumes increased in intensity; I commanded the crew to go on oxygen. The First Officer continued to fly the aircraft and I opened the QRH to the Smoke; Fire or Fumes checklist. We notified ARTCC and asked to land at the nearest suitable airport. ARTCC recommended ZZZ2. We evaluated that as a good destination. ARTCC immediately gave us a vector direct and a decent. With changes to the FMC for the diversion and approach; we were able to get to step 20 in the QRH checklist as we approached 10000 feet. I elected at that point to concentrate on safely navigating and flying the aircraft to the approach and landing at ZZZ2 and did not have time to proceed further in the QRH. I did have time as we passed 12000 feet; to very briefly pull my mask slightly away from my face and sample a short breath of air from the cockpit to see if 'Smoke or fumes continue or are increasing' as stated in the QRH. The fumes were still present. At no time did the crew notice visual indications of smoke. To expedite our decent and maintain an expedited profile to ZZZ2; we did go above 250 KIAS below 10;000 feet. At approximately 4000 feet we were below 250 KIAS. We were given emergency priority with vectors to Runway XXL at ZZZ2. The approach was flown and landed normally. The aircraft safely exited the runway at the first available taxiway. The aircraft was stopped immediately after clearing the runway. The crew ran the Evacuation Checklist; where crash; fire; rescue personnel and equipment met the aircraft. The crew noted the same fume smell again as we exited the cockpit; but not in the aft compartment as we left the cockpit and approached the L1 door. We opened the L1 door; and because we did not smell fumes at that position; to avoid injury; we elected to use the air stair that the fire department had immediately available outside the aircraft. In the past; I have had electrical fires on aircraft that have the smell of ozone. That was not the smell. It was also not a petroleum type smell. I can only characterize it as an acrid chemical smell that I have never encountered before. I cannot say for sure weather it is a smell associated with a chemical fire or simply chemical fumes.

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.