Federal rules require airliner cabin air to be free of harmful or hazardous levels of gases or vapors, and airlines must report certain smoke and fume events. Two major federal reviews, a 2002 National Research Council report and a 2004 Government Accountability Office report, examined cabin air and health. Both called for more research. Here is what those reviews found, and what remains uncertain.
The rules on cabin air
Design rules for transport airplanes require crew and passenger compartment air to be free from harmful or hazardous concentrations of gases or vapors. They also set limits for carbon monoxide and carbon dioxide. (14 CFR 25.831)
Airlines operating under Part 121 must file a Service Difficulty Report when an aircraft component causes smoke, vapor, or toxic or noxious fumes to accumulate or circulate in the cockpit or cabin during flight. Reports for each 24-hour period are due within the next 96 hours. (14 CFR 121.703)
The National Research Council review (2002)
The National Research Council's report on the airliner cabin environment examined aircraft air systems, contaminants and health effects. (Summary)
- It said engine oil, hydraulic fluid or deicing fluid can unintentionally enter the cabin through bleed air.
- It found no exposure data identifying what was in cabin air during these incidents.
- It said no data had definitively linked exposure to these compounds with reported health effects, and that establishing causation is extremely difficult.
- It recommended carbon monoxide monitors in air supply ducts, an air-quality surveillance program and research on engine oil and hydraulic fluid.
On organophosphate compounds such as tricresyl phosphate (TCP), found in some engine oils, the committee said it could not find objective information documenting nerve damage in people exposed on aircraft, but that the possibility cannot be ruled out if exposures were high enough and long enough. (Chapter 5)
The GAO review (2004)
The Government Accountability Office reported that more research was needed on the effects of cabin air quality on passengers and crew. It recommended detailed research plans and expert involvement in that research. (GAO-04-54)
What remains uncertain
- How often contamination events happen and at what levels
- Which compounds are present during real events
- Whether, and how, exposure causes lasting health problems
- How any health condition linked to fume events should be defined and diagnosed
This article draws on the federal reviews we could verify. It will be updated as newer FAA or other federal research becomes available.
If you were affected
Anyone can report an aviation safety concern through the FAA Safety Hotline. If you were on a flight with fumes, our aircraft fume exposure page explains what to document and how a claim may work.
This article is general information, not legal or medical advice, and reading it does not create an attorney-client relationship. Research on cabin air is ongoing, and this article does not claim that any illness was caused by aircraft fumes.
This article is general information about how these cases work. It is not legal advice, it does not create an attorney-client relationship, and no two claims are alike. If something here sounds like your situation, the useful next step is a conversation about the facts.