The UK Department for Transport has been carrying out exploratory tests to decide the best methods for detecting chemicals that are present in cabin air contamination events, following many well-documented serious incidents in commercial air transport aircraft in the past 25 years.
A high proportion of the events were associated with the British Aerospace 146 series and Boeing 757s, and the DfT exploratory tests have been targeting these, but some events have been reported in all aircraft types pressurised using engine bleed air.
A UK House of Lords inquiry established that are caused by leaking engine oil seals releasing oil that undergoes thermal decomposition (pyrolysis) into a range of substances such as volatile organic compounds, low molecular weight organic acids, esters, ketones and tri-cresyl phosphate isomers (TCP), yet the UK Committee on Toxicity (COT) report has stated there is no proof that TCP has been present in any of the documented cases.
Capt Susan Michaelis, chief researcher at the Global Cabin Air Quality Executive (GCAQF), which represents pilots and other aviation workers whose health has suffered from toxic air on board aircraft, says the COT conclusion is simply wrong, but she fears the DfT tests may not be specifically designed to detect TCP, which the GCAQE thinks is the critical component of the brain-affecting chemicals.
The GCAQF has questioned the DfT's appointment of a psychologist, Prof Helen Muir, to head its research. Muir's aviation-related research includes work on human behaviour during aircraft emergency evacuation.
In 2000 an Australian Senate inquiry ruled that toxic fumes generated by organophosphates from heated engine oil additives had caused chronic sickness in flight crew and cabin crew. Possible effects on passengers have never been studied.
The Royal Australian Air Force encountered similar problems with military aircraft, studied the problem and acknowledged its existence.