Exposure to contaminated bleed air (air supply from the engines or APU) should not be regarded as a nuisance but as a serious risk to flight safety. Research shows the majority of flight crew are failing to use emergency oxygen during a contaminated air event, often resulting in pilot and cabin crew impairment and sometimes incapacitation. Commercial aircraft have no form of contaminated air detection system fitted and the bleed air is not filtered. Research shows that the vast majority of contaminated air events go unreported leading to under-recognition of the scale of the problem, delayed maintenance action and unnecessary risk to health and flight safety. Aviation regulations are not being adhered to or enforced when the above occur.