Was this an early morning departure? I did not see any timings on the reports, but searching by flight number, recently it seemed to leave at 04:00 from Cologne. The passengers will have been up all night in that case, which can be a factor. There have also been problems in the past with toilet deep cleaning overnight before the first flight of the day. I have certainly experienced very pungent chemical smells when operating in these circumstances. With hindsight I am pretty sure the crew will be regretting not diverting.
Last edited by lederhosen; 4th Nov 2021 at 20:28.