One of the problems with this issue is the lack of focus demonstrated by groups like AOPIS. Maybe this can be forgiven if we assume that most of the instigators are not experts in the field, but the collection of advice above is way too vague to be useful. For example, what constitutes "contaminated"? If I can smell the hot breakfasts sitting in the forward galley on the 146, does that mean that the air is "contaminated"? Because all we are talking about here is smells. It's easy for AOPIS to urge us to enter "contamination" (which is defined as...? anybody...?) in the tech log, but then it isn't their careers or livelihoods that are on the line. As far as asking a company for a risk assessment of the dangers of breathing contaminated air... why limit it to aircraft? The air being breathed on the drive to work, in many cities, is just as contaminated. People get sick all the time, so perhaps we should also report every instance of a colleague coughing at work - they could easily contaminate you. You could ask you MP or whatever to ensure that regulations are being enforced, however their first question will be "what regulation are you referring to?" When they find that there isn't any specific regulation... and that you have just wasted their time... expect little further help. Don't let the engineers sign off a defect with a "please report further"? That is , in equal measures, naive and stupid. A pilot can't stop an engineer doing so, particularly as the engineer will be unable to find any problem in most cases. And while we are on the subject, please tell me how the suspicion of contamination (a condition that AOPIS conveniently fail to define) makes the aircraft non-airworthy. If you want to get picky, virtually all aircraft that use bleed air are to some extent contaminated, so let's just ground 90% of the worlds fleet. And as for "we are winning..." - no, you really aren't, not in any demonstrable way. Some interesting work is being done, but samples are still too small and not enough is known yet. It's just been setback after setback for the fumes people. Those payouts are a way off yet... And I'm not on the side of the manufacturers... no reason to be. Just disenchanted with the sort of worthless advice and ambulance-chaser mentality evident amongst some (and only some) of the cabin air quality advocates. If you are going to fight the good fight, do it properly.