Matthew Bass worked as cabin crew for two airlines in a 15 year career. He died suddenly last January, aged 35.
"He went round to stay with friends and died in his sleep. He fell asleep and didn't wake up,” his father Charlie Bass told ITV News.
“His friend were downstairs doing the washing-up. They heard the dog barking so they went upstairs and Mathew wasn't breathing. They were all cabin crew, they were all first responders, so they went straight into a CPR process and couldn't bring him back. Nor could the crew on the ambulance," Mr Bass said.
He says his son kept himself fit and healthy, although in the last six months of his life he frequently complained of tiredness and occasionally suffered mild bouts of trembling. He also had digestive problems and doctors believed he was suffering from Crohn's disease.
After his death, post mortem tests ruled out Crohn’s disease but failed to establish a cause.
The family decided to pay for a second post mortem examination which was carried out by a pathologist in Holland. Six weeks later they received the results.
Charlie Bass talks to ITV News
Organophosphate are found in synthetic fertilisers, insecticides and jet engine oil. In the case of aircraft engines, they are added to oil to help prevent parts from overheating and, most importantly, wearing out.
Last week ITV News revealed that the Senior Coroner for the County of Dorset has written to the Civil Aviation Authority and British Airways to express concern about evidence he had been looking at in his investigation into the death of a pilot Richard Westgate.
Richard Westgate was on medical leave when he died in 2012. The 43-year-old believed he had been poisoned by repeated exposure to contaminated cabin air.
Sheriff Stanhope Payne's investigation isn't complete, the inquest has yet to be heard, but Mr Payne said his inquiries revealed that "organophosphate compounds are present in aircraft cabin air", that there was a risk to health and there was no "real time monitoring to detect such compounds".
"In my opinion," he wrote "there is a risk that future deaths will occur unless action is taken".
Since the 1950s jet engines have been designed to take air from the engine and use it to supply the cabin. Most modern aircraft work in the same way, so in the event of a leak fumes can end up inside the aircraft.
According to the regulator, in the last five years pilots and crew have reported smelling fumes on 1,685 individual flights operated by British airlines. Of these, 162 were described as "oil-related".
Over the same period there were almost 11 million flights in and out of British airports.
So "fume events" are rare although campaigners say they are under-reported.
The government's position is that "normally" aircraft air is less contaminated than air "in many work environments such as office buildings".
The Department of Transport notes pilots and cabin crew have complained of ill-health but says a review by the independent Committee on Toxicity in 2007 "did not establish a link between cabin air and pilot ill health, but nor did it rule it out".
Professor Clement Furlong is a Professor of Medicine and Genome Sciences at the University of Washington. He gave evidence to the Committee and was puzzled by their conclusion.
"I think, as the airlines say, (cabin air) is generally safe," he told ITV News "but when it's not, it's really not. If you have a fume event or leaky seals and Tricresyl Phosphate (an organophospate compound) or other compounds come into the cabin it can cause permanent damage to individuals."
Professor Clement Furlong talks to ITV News
The Civil Aviation Authority declined our offer of an interview but told us safety is paramount and that independent research does not support the existence of a significant threat to the health of crew and passengers.
In Dorset a senior coroner appears to disagree.
Watch the full report by Joel Hills, Business Editor for ITV News: