Cabin air quality
Cabin air quality has long been a concern for crewmembers and passengers for many, many years. For decades, passengers were permitted to smoke onboard the aircraft and crewmembers would be subject to constant mass volume of secondhand smoke which leads to health problems and risks. Now, for more than two decades, a different health-related issue has been brought up front and center, this time coming from the aircraft itself. There have been numerous reports of smoke and fumes events in the cabin occurring at airlines around the world. Specific aircraft make, model, and series, as applicable, will be identified in the news sources you read. As I am not a statistician, I won’t get into the breakdown of the aircraft types involved. The only thing which I have noticed from the news reports is that when these events happen, there is not one constant factor, meaning it is not exclusive to specific tail numbers, and it does not appear to occur every single time on an airplane that is reported having a smoke or fume event. From my perspective, it seems that these occurrences are somewhat random in nature. Thankfully, since this subject has been receiving heightened attention for the past decade, reporting of fume events is now a part of flight attendant training.
Thinking back over my 30 years in aviation, there were instances where I was on aircraft that generated unusual odors, ranging from the smell of jet fuel or burning engine oil coming through the air conditioning system, to then difficult-to-describe odors while on the ground, waiting for passenger boarding. Back then, we just informed the PIC about what we smelled, or a mechanic, if present. They would take appropriate actions to clear the smell, and it seemed what they did was appropriate since the smell would go away. Those events that we encountered and dismissed as, “whatever, it’s gone now, let’s carry on,” and never mentioned it in our irregularity report. Those were in fact, smoke and fume events. The point of mentioning this is, such events have been randomly occurring for decades, and the data referenced in reports are likely underreported.
Knowledge, not fear
Mind you, considering the world we live in where the media seeks sensationalism and some medical websites will indicate you’re going to die when searching, “I sneezed, what’s wrong with me?”, the information shared is not for stoking fear. We can and should live and travel well informed. What are the odds of a smoke or fume event happening on the flight you’re on? It’s hard to say, but when I consider the 9,000+ hours I have been on planes compared to the number of events I encountered, there were very few fume events. Knowing this occasionally occurs, will these events ever stop me from traveling? Not a chance in the world, as I love to travel and I love aviation. I love the smell of jet fuel as it gives me fantastic memories of all the years I’ve been traveling on planes. I don’t want to inhale it all day long, just a whiff or two is enough to think of the wonderful times traveling to the places I’ve been, and I’m looking forward to aviation and tourism returning back to normal again.
Resources provided on this webpage are information only
Please note that I neither agree nor disagree with the information and/or positions of the various sources of information. I provide this information to you only as an easier means for gathering the information you may be wanting for your peruse and needs.
If you know of other good cabin air quality-related resources not listed on this webpage, please send me the information and I will gladly add it to the site. Thank you!
Global Cabin Air Quality Executive
Preview from the Global Cabin Air Quality Executive website:
“The Global Cabin Air Quality Executive (GCAQE), established in 2006, is now a UK registered not-for-profit limited company. The GCAQE is the leading organization representing air crew (pilots, cabin crew and engineers) and consumers, that deals specifically with contaminated air issues and cabin air quality. We currently represent 33 organisations, and over one hundred thousand workers around the world.
The primary purpose of the GCAQE is to effect the changes in the aviation industry that are necessary to prevent crewmembers, passengers, and ground workers exposed to turbine emissions from being exposed to oil and hydraulic fluid in the ventilation air supplied to the cabin and flight deck.
We are the credible, unified voice of airline workers, engineers and consumers regarding the hazards posed by exposure to contaminated ventilation supply air on aircraft. We offer practical tools to assist our member unions, and we connect our members across the globe to work together to prevent exposure to toxic fumes on aircraft.”
Aircraft Cabin Air
Preview from the Aircraft Cabin Air website:
“By way of expert global independent and industry speakers, the 2021 Aircraft Cabin Air Conference will provide a unique insight into the subject matter. Through a modular format, over 4 days (1500-2000 GMT), conference participants will have the opportunity to participate via Zoom, for free, in a wide selection of presentations and talks. These will range from the basic issues of contaminated air, the history, previous research, the flight safety implications and findings, medical aspects of exposures, current research and policymaking, review of ICAO, IATA, EASA, IFALPA, ITF, GCAQE and FAA positions and guidance related to the issue, the new GCARS reporting system or discover the very latest news in the development of sensors and filtration technologies to detect and filter contaminated air.
The conference will seek to achieve the following key objectives:
- To provide a historical overview of the contaminated air issue and its causes from the 1950s to present day.
- Map out the flight safety aspects of contaminated air through case studies, discussion and air accident investigation findings.
- Disseminate the latest medical and scientific theories and findings on the health aspects of exposure to contaminated air.
- Guidance of workers compensation, legal and the regulatory aspects of cabin air quality.
- Provide regulators, airlines, occupational health, policymakers, public health officials, engine manufacturers, researchers, academia, airline workers, passengers, media and other interested parties, the opportunity to expand their knowledge and understanding of the contaminated air issue.
- Examine the latest development towards bleed air filtration, contaminated air warning sensor systems and other potential solutions.”
Federal Aviation Administration
The FAA provides numerous resources related to cabin air quality, studies, events that have occurred, and other related content. This list is not all-inclusive yet does provide the key resources related to cabin air issues.
FAA Safety Alert For Operators (SAFO)
Air carriers should ensure their procedures and checklists specifically address recognition, differentiation and mitigation of odors, smoke and/or fumes in the cabin and/or flight deck. Odors, smoke and/or fumes may be introduced to the cabin atmosphere as a result of aircraft equipment malfunction/failure or by inadvertent or intentional actions. While the presence of an odor alone does not necessarily require crew action or medical response, events involving odor, smoke and/or fumes require targeted and timely action to protect aircraft occupants.
Airliner Cabin Environment Research
Preview from the Airliner Cabin Environment Research website (contains lots of source links):
“In 2004, the FAA’s Office of Regulation and Certification established a National Center of Excellence (COE) for Airliner Cabin Environment Research, which in 2007 was broadened and renamed to the National Air Transportation COE for Research in the Intermodal Transport Environment (ACERite). The ACERite COE brought together airliner cabin environment expertise from academic, industry, and government organizations.
Over the next decade, the FAA sponsored numerous cabin air environment research projects. Key research included: 1) health and safety effects of the airline cabin environment on passengers and crewmembers, 2) the efficiency and effectiveness of aircraft environmental control systems, and 3) the study of emerging technologies with the potential to eliminate bleed air contaminants and purify aircraft air supplies.”
Fact Sheet – Cabin Air Quality
Preview from the FAA Fact Sheet – Cabin Air Quality webpage (contains additional links):
The FAA is committed to protecting the safety and health of passengers and cabin crews on our nation’s airlines. The FAA has strict cabin air standards, and studies have shown cabin air is as good as or better than the air found in offices and homes. In rare instances, certain mechanical issues can cause fumes to enter the cabin. Airlines are required to report to these incidents to the FAA. The FAA thoroughly investigates the causes of these events and makes sure the cause is fixed before the aircraft is returned to service.
FAA Office of Aerospace Medicine: Aircraft Cabin Bleed Air Contaminants: A Review
Preview from the Aircraft Cabin Bleed Air Contaminants: A Review PDF research paper:
“The purpose of this paper is to describe potential health-related risks surrounding human exposure to bleed air contaminants generated during “fume events” inside pressurized aircraft. Information was obtained from available literature primarily in regard to carbon monoxide, carbon dioxide, ozone, volatile and semi-volatile organic compounds, and airborne particles.
The quality of air distributed throughout the cockpit and cabin during air transportation in a pressurized aircraft is critically important to human health. Since 1984, public law in the United States has directed research in cabin air quality, including investigation of health risks among individuals exposed to toxic fumes during flight.”
Cabin Air Quality Educational Materials for Crewmembers and AMTs
Preview from the Cabin Air Quality Educational Materials for Crewmembers and AMTs website (contains additional links):
“Section 326 of the FAA Reauthorization Act of 2018 (PDF) requires the FAA to provide access to educational materials enhancing air carrier training on how to react to smoke or fumes on flights. On March 1, 2021, the FAA Flight Standards Service published an Information for Operators (InFO) (PDF) informing stakeholders of this site, recommending they consider incorporating such content and reporting procedures into crewmember and Aircraft Maintenance Technician (AMT) training. The FAA has also commissioned a multi-year research study on cabin air quality as directed by Congress. Access the resources below for information applicable to Crewmembers (Pilots and Flight Attendants) and AMTs.”
U.S.A. National Center for Biotechnology Information (NCBI)
Preview of the study in a book format, The Airliner Cabin Environment and the Health of Passengers and Crew.
“Passengers and cabin crew have long complained about the air quality in commercial aircraft. These complaints include fatigue, dizziness, headaches, sinus and ear problems, dry eyes, sore throat, and occasionally more serious effects, such as nervous system disorders and incapacitation. Data on the overall percentages of passengers and cabin crew who report complaints about cabin air have not been systematically collected, a few small surveys provide illustrative examples (see Tables 6–3 through 6–6 in Chapter 6).
Aircraft passengers are sedentary most of the time on any flight, but that is not true of the cabin crew, who are responsible for the safety and comfort of the passengers. Cabin crew, who number over 105,000 in the United States, are 20–80 years old, with the majority being between 30 and 55 years. Flight attendants work at a higher energy level than passengers and are exposed to cabin air for longer durations. They are typically in flight 50–80 h per month, and their maximal flight hours range from 75 to 105 h per month (AFA 2001).”
Get a FREE, full PDF of the entire book, The Airliner Cabin Environment and the Health of Passengers and Crew!
U.S.A. Centers for Disease and Prevention Control (CDC)
Preview from the CDC webpage Aircrew Safety and Health. Cabin Air Quality – What you need to know (contains additional links):
“What you need to know
Potential cabin air hazards may include:
- Ventilation hazards, including carbon monoxide, ozone, and carbon dioxide levels
- Pesticide exposures on certain flights
- Transmission of communicable diseases from sick passengers
- Cabin altitude and pressurization changes
- Air contamination events, when cabin air becomes contaminated with breakdown products from heated engine oil or hydraulic fluid
Here you can learn more about cabin air quality and how you can lower your exposure to potential cabin air hazards.”
The United States Congress
Preview from the United States Congress H.R.2208 – Cabin Air Safety Act of 2019 bill:
“This bill directs the Federal Aviation Administration (FAA) to implement regulations regarding smoke or fume incidents on commercial aircraft (excluding helicopters).
Specifically, the bill requires
- flight attendants, pilots, aircraft maintenance technicians, airport first responders, and emergency response teams to receive annual training on how to respond to incidents involving smoke or fumes on board commercial aircraft;
- the FAA to develop a standardized form for reporting incidents involving smoke or fumes;
- the FAA to conduct an investigation after a report is submitted about incidents of smoke or fumes; and
- commercial air carriers to install and operate onboard carbon monoxide detectors.”
Skybrary, a resource provided by The Flight Safety Foundation
Preview from the Skybrary Cabin Air Quality and Contamination webpage (contains additional links):
“The issue of cabin air quality on commercial aircraft, as well as the possible contamination of that air with fumes and contaminants introduced via bleed air from the engine or auxiliary power unit as part of the pressurization and heating and cooling functions, remains controversial.
Most modern, pressurized commercial aircraft use heated air drawn or “bled” from the engines or auxiliary power unit (APU) for cabin and cockpit air conditioning. As described by the U.S. Federal Aviation Administration (FAA) Civil Aerospace Medical Institute (CAMI) in a 2015 report, “air supplied to a pressurized aircraft cockpit and cabin occurs via an environmental control system (ECS). Fresh air from outside the aircraft, known as replacement or make-up air, enters the ECS in most large transport category commercial airplanes via the aircraft engines. The compressed air is then ‘bled’ through ports and is cooled before being mixed in a manifold with recirculated air, ultimately becoming distributed throughout the cockpit and cabin.”
About: SKYbrary was initiated by EUROCONTROL in partnership with the following organisations:
Civil Aviation Safety Authority (CASA)
Preview from the document CASA – Contamination of aircraft cabin air by bleed air – a review of the evidence (downloadable PDF, 248 pages):
“Cabin air in commercial aircraft can be contaminated with hydraulic fluids, synthetic jet oils, or the compounds released when these fluids are heated or pyrolyzed. The incidence of contaminated air events and the nature of contaminants within the cabin air are difficult to determine as commercial aircraft do not have air quality monitoring systems on board and under-reporting is common amongst aircrew. The immediate effects of exposure to contaminated air have been well documented but debate continues about causation, diagnosis, and treatment of long-term effects.”
European Union Aviation Safety Agency (EASA)
Preview from the EASA website, EASA publishes two studies on cabin air quality (contains additional links):
“EASA publishes two studies it commissioned with the aim to gain solid scientific knowledge about cabin air quality on board large aeroplanes operated for commercial air transport.”
Past event in 2020, containing links to conference proceedings:
United Kingdom Parliament
The House of Lords is the upper house of the Parliament of the United Kingdom.
Preview from the House of Lords publication, Air Travel and Health, Report with Evidence (contains numerous sources of information, references, and interviews. PDF, 207 pages):
“Our report on Air Travel and Health, published in 2000, brought together for the first time the wide spectrum of health issues associated with air travel. The report stimulated research into air crew and passenger health, not only in the United Kingdom but beyond. Our understanding of the major health issues connected with air travel is now much improved—though there are still some crucial gaps in knowledge.
In 2001 the Aviation Health Working Group was created as a free-standing interdepartmental group to work with interested parties in taking forward the recommendations in the report. The Group has been generally well-received by industry, crew, and passenger representatives. The Aviation Health Unit was set up in 2003 within the Civil Aviation Authority to act as a focal point for aviation health in the United Kingdom, while the Civil Aviation Act 2006 gave the Secretary of State the general duty of organising, carrying out, and encouraging measures for safeguarding the health of all persons on board an aircraft. These changes are welcome, though in some areas more work is needed to add substance to the organisational outlines.”
Preview from the Boeing – Travel Confidently webpage (contains additional links):
“Our commitment to you
As air travel resumes and restrictions ease around the globe, your health and safety are always our top priority. We continue working across the industry to enhance health safeguards and develop new solutions.”
International Air Transport Association (IATA)
Preview from the IATA – Cabin Air Quality webpage (contains additional links):
“The quality of supplied air onboard an aircraft is much better than most indoor environments. Here are a number of reasons why.
How good is the cabin air?
The risk of transmission in the modern cabin environment is low for a number of reasons: passengers face the same direction, seatbacks act as barriers, airflow is from the top to bottom, and the air is also very clean.
Cabin air is refreshed 20-30 times an hour, about 10 times more than most office buildings.”
Resource: IATA Cabin Air Quality Event – FAQs
Preview from the BBC News webpage – How safe is air quality on commercial planes?:
“Figures from the Civil Aviation Authority (CAA) show that since 2010 they have received more than 1,300 reports of smoke or fumes inside a large passenger aircraft operated by a British airline.
But is there evidence to suggest air quality on flights can pose a serious health risk? We examine the evidence.”
Seventeen former and serving cabin crew are planning legal action against British airlines claiming they have been poisoned by contaminated cabin air.
Workers believe they have fallen sick after breathing in fumes mixed with engine oil and other toxic chemicals.
The cases are funded by the Unite union, but the Civil Aviation Authority say incidents of smoke or fumes on planes are rare and there is no evidence of long-term health effects.