A study produced by the UK's Cranfield University into fume events in aircraft cabins has found no danger to crew or passengers after a study of 100 flights.
Cranfield was contracted in 2008 by the UK Civil Aviation Authority and the UK Committee on Toxicity to carry out the study, and it cooperated with several airlines to test the air during 100 airline flights.
The report says that there were fume events during the trial, but none at levels that would have triggered a mandatory occurrence report.
It says that neurotoxins were present, but the levels measured were acceptable according to standards applied to the workplace or the home.
The UK Minster for Transport Theresa May said: "The Department will always take the health of persons on board aircraft very seriously and I hope the publication of this thorough and independent analysis by Cranfield University will provide reassurance on this issue.
"We will continue to keep in close touch on all aviation health matters with the UK's aviation regulator, the Civil Aviation Authority. The Department will now take forward the one remaining cabin air study outstanding - the swab test research being conducted by the Institute of Occupational Medicine in Edinburgh."
However, Tristan Loraine, a member of the Global Cabin Air Quality Executive and a former British Airways pilot who lost his pilot licence as a result of health damage by cabin air contamination, said he disagreed with the report's conclusions. He said that several isomers of the highly neurotoxic chemical tri-cresyl phosphate were detected in the cabins during the Cranfield tests, and that the presence of these is unacceptable even at the detected levels.
He said that there are no stated levels of toxic chemicals published for the travelling public's protection, so for the report to state, as it does, that the levels found were acceptable is meaningless.
The trial was invalid, he added, because it was not able to measure the chemicals present during a reportable event.