Toxic fumes in airliner cabins ignored by authorities

By David Learmount


Slow progress in taking action to protect crews and passengers from the effects of toxic air contamination in aircraft is causing many in the aviation industry to fume.
Contaminated air events in the UK Civil Aviation Authority's database of mandatory occurrence reports from mid-1985 to July 2006 number nearly 1,800. A few were reports of smoke that may have had an electrical source, but most involved a mist or vapour containing heated engine oil constituents introduced via the engine or auxiliary power unit compressors that deliver outside air to the aircraft's air conditioning packs.
That is 85 reported events a year in one country - and then there are the unreported incidents. Many pilots say fume events are not worth reporting unless they are severe and they estimate the unreported incidents probably exceed the reported events - although the CAA says it has no evidence to support that.
The US Federal Aviation Administration, on the other hand, concluded that under-reporting of fume events is endemic after studying air-contamination events. At a conference on smoke in the cockpit in 2006, the FAA's director of flight standards Jim Ballough said: "FAA data analysis indicates numerous [smoke/fumes] events not being reported."
APU Start-Up
The vast majority of the CAA's mandatory occurrence reports involved BAe 146s or Boeing 757s, but 18 other jet or turboprop types were also included in reports, with events on Airbus A320s, Boeing 737s and Embraer ERJ-145s the most common. The BAe 146 incidents frequently occur on the ground after APU start-up, according to the reports.

In 2002 the CAA asked the FAA to ensure Boeing action to eliminate cabin air contamination on 757s. The US manufacturer said that 757s with Rolls-Royce RB211-535C engines "appear to have a higher incidence of events than expected". These were originally owned by British Airways, and some are now flown by freight operator DHL. Boeing points out that events occur on other types also.
Former BAe 146 training captain John Hoyte says: "I flew the 146 for about 16 years. The worst time I remember for experiencing contaminated air was on the ground from the APU before the first flight of the day, when the engine was started from cold. Frequently we would have the cabin full of blue smoke as a result of the air system overcooking this meant the whole crew was affected by these visible fumes, but maybe only for 10-15min. No detecting device has ever been used to verify exactly what the blue smoke represents. Clearly the strength is there and I don't think many people would dispute the undesirability of this frequent occurrence." Hoyte, who submitted this description as part of a statement filed to the CAA and a number of other official bodies, has stopped flying because of ill health.
Exploratory Tests
The UK Department for Transport is now running exploratory tests to decide the best methods for identifying chemicals present in cabin air contamination events. The DfT tests target specific BAe 146 and 757 airframes in current airline service which have a history of reported fume events. These trials aree deemed necessary despite the fact that, in 2000, an Australian Senate inquiry concluded that toxic fumes generated by organophosphates from heated engine oil additives had not only threatened safety by disabling or incapacitating pilots and cabin crew, but had caused chronic sickness in some flight and cabin crew. Possible effects on passengers have not been studied. Mobil Jet Oil II is one lubricant identified as a source of toxic chemicals found in the cabins of the now-defunct Australian carrier Ansett, whose BAe 146s were studied by the Senate. In addition, the Royal Australian Air Force quickly acknowledged there was a problem after experiencing similar events with aircraft such as the Lockheed Martin C-130 Hercules and the General Dynamics F-111.


The UK DfT initially showed signs of being selective in sourcing the data on which it bases its terms of reference. It originally ignored a major reference document, "The Aviation Contaminated Air Reference Manual" (ACARM) that has been favourably reviewed by aviation medical specialist Dr Bhupi Singh, associate professor and head of research at the RAAF Institute of Aviation Medicine.
Delivering his verdict on the 815-page manual - the only single-source document that brings together referenced data on all known events, studies and inquiries on aero-toxicity - Singh says: "The events data pertain to a wide range of aircraft operators in many countries. All data is extensively researched and referenced, with its source clearly identified." Singh, one of those who acknowledged and studied the contaminated air problem in the RAAF, adds: "A notable element of the data is the widespread prevalence of denial of the existence of the problem, particularly among aircraft operators and aviation regulators."
Meanwhile, Prof Clement Furlong, research professor of genetics and medicine at the University of Washington, Seattle, who presented a paper on "Organophosphates: the effect on pilots and passengers" at the Flight International Crew Management Conference in Brussels in December, says he is close to establishing conclusively the neurological effects on the brain and nervous system of specific cocktails of organophosphates found in cabin air contamination events.
Organisations Rebuffed
Other organisations that offered evidence to the DfT investigation were also initially rebuffed. This selectiveness may be because of the vast quantity of data available, but another reason is the report on cabin air by the UK government Committee on Toxicity (COT), which alleges there is no proof that oil-contaminated air has been, or could be, the cause of chronic illness in flight and cabin crew. The Global Cabin Air Quality Executive (GCAQE), which represents pilots and cabin crew whose health has suffered from toxic air on aircraft, offered evidence to the COT, but it was refused, as was the ACARM.
Previously it had been established by a UK House of Lords inquiry that cabin air contaminants are a result of leaking engine oil seals releasing oil into the hot compressed air bled off to the cabin air conditioning system. In this process the oil, and specifically some of the synthetic anti-wear oil additives, which include a toxic organophosphate known as tri-cresyl phosphate (TCP), undergoes thermal decomposition (pyrolysis) into a range of substances such as volatile organic compounds, low molecular weight organic acids, esters, ketones and TCP isomers.
Yet the COT report insists there is no proof that TCP has been present in any of the documented cases. If the COT had checked the ACARM it would have known how many cases of TCP detection in cabins were documented, and where to find the evidence. More recently, the first tests in the DfT trials detected the presence of TCP during flights. The GCAQE says TCP is a critical component of the brain-affecting cocktail of organophosphates found in bleed air during a fumes incident, but it is still added to oil because it is an effective anti-wear additive that improves engine reliability.
French oil company Nyco makes a jet engine lubricant called Turbonycoil 600 that uses alternatives to TCP because of the latter's known toxicity. This oil is used by the US Navy and is approved for use on engines that power Airbus and Boeing aircraft.
Early Findings
Contaminated bleed air events were recorded almost immediately the test programme began, say early DfT reports. If contamination events were as rare as some allege, such early success would have been unlikely.
Chris Winder, professor in applied toxicology at the University of New South Wales, Australia, is critical of the DfT's planned sample-gathering techniques, but concedes that "even these flawed tests" have established the presence of TCP in the BAe 146 and the 757. Winder says collecting air samples for later analysis is not scientifically effective for "non-volatile mists". He says the only effective method is active, real-time analysis of the suspended chemicals and their concentration using a "direct reading machine on the aircraft during flight". But Winder concedes: "Overall, limited though these results may be, this study did identify the presence of tri-cresyl phosphate on aircraft, something that continues to be strenuously denied by sectors of the aviation industry."
Meanwhile in 2004 the RAAF's Singh pointed out that judging aviation air contamination using toxicity standards that apply in normal workplaces is invalid: "Aircrew members perform complex tasks requiring high-level cognitive skills, which may be much more sensitive to insult by hazardous contaminants in the smoke/fumes, such as tri-cresyl phosphate."
Crew Incapacitated
On 5 November 2000 a Jersey European Airways (now Flybe) BAe 146 (G-JEAK) crew only just managed to land safely at Birmingham after being badly incapacitated by a fumes event. The UK Air Accidents Investigation Branch (AAIB) report on the event says bleed air contamination was only a "possible" cause of the incapacitation, yet does not propose any alternative. In its conclusions, the report says: "The regulations JAR 25.831, JAR-APU-210, JAR-E-510 and JAR-E-690 all deal with unacceptable levels of contamination of the bleed air, but do not provide details of toxic contamination that is deemed as unacceptable."
Referring to a history of toxic air events in other aircraft types, the AAIB says: "TCP and TOCP [tri-cresyl orthophosphate] were detected in samples during research, but it was deemed that, at the measured levels, it was inconceivable that toxic effects on the occupants of aircraft would result." It adds: "There was a lack of general information available on potential contaminants of the bleed air by engine oil, and their effects on human physiology."
There are two available solutions to the bleed air contamination problem, but neither is officially under consideration: one is to use engine oil that does not contain TCP the other is to filter bleed air to remove the toxic organophosphates (see box and diagram). Most aircraft have high-efficiency particulate air filters (HEPA) that process recirculated cabin air, but the bleed air is continuously introduced into the cabin without filtration. HEPA filters take out only dust, bacteria and viruses but are not designed to eliminate organophosphates.
Considering that nobody denies contaminated air events occur, that there is a massive body of evidence they can be dangerously toxic, and that commercial off-the-shelf solutions for preventing them exist, it is remarkable that nothing is being done to protect crew and passengers while scientists identify the precise nature of the toxins and the harm they do. Meanwhile, some future aircraft will obtain outside air from systems other than engine or APU bleeds: the 787 will be the first.
Preventing Fumes Reaching The Cabin
There is, according to Capt Susan Michaelis, former BAe 146 captain, adviser to the Australian Senate Committee and the compiler of the ACARM , an alternative to industrial dissembling over the degree to which contaminated cabin air can be proven to incapacitate people: to prevent fumes getting into the cabin. This can be done by filtering the bleed air before it reaches the cabin environmental control system, or filtering it within the ECS before it mixes with recirculated air (see diagram). US-based Pall Aerospace says it can supply bleed air filters that would eliminate organophosphates from bleed air.

What They Say About Contamination
Engineers
Society of Automotive Engineers: "Engine compressor bearings upstream of the bleed air ports are the most likely source of lube oil entry into the engine air system and thence into the bleed system contaminating the cabin/cockpit air conditioning system."
Engine manufacturers
AlliedSignal (now Honeywell), whose LF502/LF507 engines power the BAe 146/Avro RJ series of aircraft: "Several BAe 146 aircraft are having reports of objectionable odours Very little work has been done in the aviation industry to pinpoint the chemical compounds causing such odoursthe odour appears to be coming from breakdown products of the oil."
Rolls-Royce, whose engines power the Boeing 757 versions that the airframe manufacturer says suffered the largest proportion of air contamination incidents: "In the majority of instances where cabin air contamination was a problem, it was mostly associated with small leakages of synthetic lubricant from bearing seals, and so on." (R-R discussion paper on limits for organic material in cabin air.)
Aircraft Manufacturers
BAE Systems, manufacturer of the BAe 146 and the derived Avro RJ Series of aircraft: "Every engine leaks oil from its seals and bearings" (Official record of evidence presented to the Australian Senate inquiry into cabin contamination.)
BAE service information leaflet 21-45: "Troubleshooting - source of contamination of the engine/auxiliary power unit: operator experience indicates the most likely sources are oil contamination of the engine/APU bleed air."
BAE service bulletin 21-150: "In the past, oil leaks and cabin/flight deck odours and fumes may have come to be regarded as a nuisance rather than a potential flight safety issue."
Airlines
Ansett Australia: "The source of the odours has been identified as Mobil Jet Oil II leaking past oil seals in the engines and/or APU into the air conditioning system."
Regulators
Despite crew incapacitation events, the Civil Aviation Safety Authority (CASA) of Australia said: "Oil fumes are more of a health problem than an aircraft technical defect as not all pilots are affected and there is no mandate [for CASA] to look at health." (CASA to the Occupational Health and Safety [OH&S] magazine in 2003.)
UK Civil Aviation Authority: "Although the exact cause of crew incapacitation is not known, the most probable source is oil leaking from the engines or APU and contaminating the air supply to the cabin and cockpit through the air conditioning system." (CAA Flight Operations department communication 21/2002, referring to incidents in which pilots and cabin crew have become incapacitated following cabin air contamination.)
Accident Investigators
Australian Transport Safety Bureau (ATSB): "The investigation found that smoke and fume contamination of cabin air is neither a new phenomenon nor a particularly rare event and that, over time, it has been experienced in many aeroplane types."
Medical Scientists
"Smoke and fumes in the cockpit is not a rare event and a clear threat to flight safety due to acute toxic effects." (Raymand and McNaughton, Aviation, Space and Environmental Medicine, 1983.)
"This compound [TCP] is is toxic by inhalation, ingestion or by absorbtion through the skin. It is also an irritant of the mucous membranes and respiratory tract. When heated to decomposition it emits toxic fumes of phosphorus oxides." (National Toxicology Programme chemical repository data for TCP.)
Pilots
British Airline Pilots Association (BALPA): "Smoke and fumes in the cockpit: the first actionshould be for the flightcrew to don their oxygen masks and establish communications. If during flight it appears that both pilots are suffering from some form of incapacitation or that one pilot appears to be incapacitated for no obvious reason, then the crew should don oxygen masks without delay.
"Before seeking the opinion of specialist consultants, members should first contact BALPA's legal department so that advice can be taken from solicitors. We cannot advise members more strongly that such consultations will become part of their medical records and, as such, will be disclosed in any future legal dispute or loss of licence claim. It is therefore vitally important that caution is exercised from an early stage with regard to medical investigation to avoid prejudice to any claim at a later date."
All this data can be viewed at source, but it is also assembled with much other expert material in the Aviation Contaminated Air Reference Manual

Toxic fumes in airliner cabins ignored by authorities

Can planes be poisonous?

he BBC has been told of new research linking toxins found in the air systems of commercial airliners and neurological damage suffered by pilots.

An international collaboration between scientists suggests a direct link between the so called aero-toxic syndrome and chemicals present in cockpit and cabin air supplies.
It is estimated that fume contamination occurs on at least one in 2000 flights.
For Tony Watson, a commercial pilot for the best part of a decade with a major UK carrier, flying was his life.
But Mr Watson believes he was poisoned by the aircraft he flew. Complaining of neurological symptoms like muscle twitching and tremors as well as problems with his short-term memory, he decided to quit.

Half the cabin air onboard aircraft is siphoned in through the engine
"It came to the point when I said I'm not fit to fly anymore," he says.
"I was worried that I was becoming unsafe because I couldn't function to a good enough standard in the cockpit."
He underwent neurological tests which he says show damage to the neurological system consistent with exposure to toxins, plus blood tests which show petroleum related chemicals which you find in the oil in the engine plus nickel and cadmium which you also find in aero engines.
"I can't see any other explanation for these things," he says.
According to pilots and campaigners, the problem lies with some aircrafts' air systems.
Half of the air we breathe on board is re-cycled. But the other half is drawn through the heart of the jet engines.
Evidence
This, known as bleed air, is cooled and pumped directly into the aircraft.
The problem comes when a fault occurs in the engines and they pump out a cocktail of potentially poisonous gases. And, with no air filters, these toxins end up in the cockpit and the cabin, in the air we breathe.
John Hoyte was a pilot for 30 years. He gave up his licence because of ill-health four years ago. In 2007 he set up the Aerotoxic Association.
He says that "a couple of hundred people" have contacted him over the past two years, "cabin crew mainly and pilots who've got problems".
Mr Hoyte points the finger at the air industry. In 2004, the British Airline Pilots Association highlighted the problem of fume contamination events, pointing out the main offenders as the BAe 146 and Boeing 757, popular commercial tourist and business airliners.

John Hoyte believes the airline industry is responsible for toxic cabin air
There are no accurate figures for the number of fume events - they aren't collated, but according to the independent Committee on Toxicity it's estimated that they occur on at least one in 2,000 flights.
Now one scientist has told the BBC of new evidence of a direct link between fume contamination and neurological damage in pilots.
Dr Peter Julu is a consultant Neurophysiologist at the Breakspear Clinic in Hertfordshire, the Royal London Hospital and Aalborg University in Denmark.
He has collaborated with other international research scientists, testing pilots said to be suffering from the so-called Aerotoxic Syndrome.
Researchers in the US have found toxins - known as organophosphates - in the blood and fat tissue of 26 pilots. Dr Julu has been carrying out further tests for neurological damage.
"The only connection I can derive from there is the organophosphate, meaning that the pilots who have been tested have suffered neurological damage because of organophosphates that they were exposed to while they were on the planes," he says
And, even though this research has yet to be peer reviewed, Dr Julu says that his science is safe. "With the autonomic nervous system you cannot manipulate it. What we get is objective, quantitative and standardised measurement."
Dr Julu has tested 18 pilots - half from the US study and the others independently. The tests show, he says, that they suffered chronic low level exposure to organophosphates.
Industry response
Both BAe Systems and Boeing declined the offer of an interview. In a statement BAe said it has trialled a new air filtration system which is currently being fitted to aircraft.
It added: "BAe Systems regards the safety of its fleet of aircraft and those who operate them as of the utmost importance. The air quality on the BAe 146 has been shown by independent studies to exceed all existing international standards."
Boeing issued the following statement: "It is our belief that air quality on airplanes is healthy and safe. This belief is based on a number of studies that show measured contaminant levels are generally low and that health and safety standards are met."

Professor Muir's report on aerotoxic syndrome is expected soon
In 2007, following concern about the lack of definitive research into fume events, the Department for Transport commissioned Cranfield University to investigate the problem. Professor Helen Muir has been working on the study since 2008 - she expects to report her findings in six months' time.
There will be organophosphates on the flight deck, she says. But, what matters is, are they there in sufficient concentrations to potentially cause harm to people?
"My report will simply be a detailed analysis of what we find. It will be then up to the medical side to determine whether what has been found in the atmosphere has the potential to cause some of the illnesses that have been reported," she says.
For most observers the jury is still out - they await the findings of Professor Muir's research. But it's understood that if it finds that there is a problem, some carriers are already preparing to pay out compensation.
For campaigners and victims alike this is an industry wide problem risking the health not only of pilots and cabin crew but the airborne travelling public world wide.

BBC - Today - Can planes be poisonous?

Odours disrupt 2 Air Canada flights

Odours disrupt 2 Air Canada flights

Hydraulics problem, cleaning product behind strong smells in cabin

Unusual odours with seemingly unrelated causes disrupted two Air Canada flights from Montreal Tuesday morning.

An Air Canada Jazz flight en route to Halifax from Montreal was forced to turn back after the flight crew noticed a strong odour shortly after takeoff that was later attributed to a product used to clean the plane's engine the night before.

In a separate incident earlier Tuesday, passengers on another Air Canada flight — to Toronto from Montreal — were forced to make an emergency exit from the plane when it landed at Pearson International Airport.

There were 99 passengers and six crew aboard the Montreal-Toronto flight.

Saad Saade, one of the passengers who spoke with CBC News inside Pearson airport, said he had noticed a "weird smell" when he entered the Airbus A-320 aircraft in Montreal.

After a light went on indicating an issue, the pilot announced there was a problem with one of the plane's three hydraulic systems, but told passengers the problem had been isolated and they should not worry.

Call to tower

The pilot radioed the tower to say that the plane might need a tow to get off the runway.

To be safe, fire trucks would meet the aircraft when it touched down in Toronto, the pilot said to passengers.

Flight 433 landed safely just after 9 a.m., but crews came out to tow the aircraft. Passengers said the strange smell had worsened after touching down and 15 minutes after landing, a haze developed in the cabin.

When the haze became more evident, the plane was evacuated and emergency slides were used to get passengers out of the aircraft.

Air Canada spokesman Peter Fitzpatrick said the smoke passengers saw appeared to have come from hydraulic fluid in the brakes.

Minor injuries

Six of the passengers suffered minor scrapes and bruises, according to the airline. One passenger was treated at a hospital, but has since been released.

The odour on the Air Canada Jazz flight was noticed inside the cabin by the flight crew shortly after takeoff at around 9:15 a.m.

The pilot was asked to return to Montreal, where the plane, which had 50 people aboard, landed safely, said an Air Canada spokesperson.

Upon arrival at the airport, the two pilots and one crew member were checked by paramedics and taken to hospital as a precautionary measure, they said.

Passengers were transferred to another flight.

An inspection later linked the odour to the engine cleaning product.


CBC News - Canada - Odours disrupt 2 Air Canada flights

I aint reading all that shit *****.

X2 lol

Robcardu said:

I aint reading all that shit *****.

Click to expand...

Summary: Airplanes cycle air from the engines through the plane to provide "fresh air". This assumes that seals are 100% effective in stopping exhaust fumes to also be circulated. Over time people in planes, especially crew, develop toxic sensitivities and chemical buildups. Some engine types are worse than others.