Clearing the Air: Navigating Toxic Fume Litigation Risk

The current wave of litigation, news coverage, and congressional interest related to alleged “toxic fumes” in aircraft cabins brings with it increased litigation risks to airlines, OEMs, suppliers, and aircraft lessors, among others in the aviation industry. While the issue of cabin air quality and related litigation is not new, recent developments warrant close attention and proactive strategies to manage risk.

Fume events generally refer to events in which contaminated “bleed” air from aircraft engines is mixed with cabin air. In normal operations, hot compressed air that is “bled” off of the engine prior to combustion is fed into aircraft systems, mixed with existing cabin air, and used to maintain cabin pressure.

So-called toxic fume events arise when other fluids (e.g., engine oil, hydraulic fluid, fuel) leak into the cabin air due to a variety of reasons, such as a faulty engine seal. These discrete events are often described as hazy with the odor of old socks.

FAA regulations require that cabin air be “free of harmful or hazardous concentrations of gases and vapors in normal operations” and during “reasonably probable failures” of aircraft systems and equipment. Studies by the FAA, EASA, and industry experts have indicated that cabin air quality on transport category airplanes is “on par with other forms of public transportation and with public buildings and homes,” yet federal preemption arguments based on the FAA’s regulation of aviation safety have not been fully successful in wholly limiting claims.  

Due in part to increased media coverage, a perception that toxic fume events are becoming more common has emerged, which has in turn generated renewed attention from the US Congress. These recent events highlight the exposure of industry participants to potential liability and mass or class action litigation. As the legal—and political—context continues to evolve, it is essential that all industry stakeholders remain vigilant and proactive in assessing their exposure and managing risk.

We highlight below key trends that aviation stakeholders should continue to monitor as they evaluate potential exposure to litigation and best prepare themselves to defend against such claims.

Risks to Airlines, Manufacturers, Lessors, and Suppliers

Given the increasing willingness of courts to permit state law claims to proceed despite federal preemption defenses, the technical complexity of toxic exposure cases, and the uptick in current litigation, it is vital for airlines, OEMs, and lessors to keep a close eye on litigation trends and legislative/regulatory updates. The risks associated with toxic fume exposure are compounded by the evidentiary challenges inherent in these cases, particularly in proving causation.

Class and Mass Actions: A High-Risk Litigation Horizon

Class and mass actions present a substantial and unique risk to airlines, OEMs, and lessors, regardless of the underlying merit of the claims. The evolving trend in favor of state tort claims increases the likelihood that class actions will be filed and may survive initial motions to dismiss, forcing defendants into protracted and costly litigation, including extensive discovery and expert testimony.

Pilots, flight attendants, and passengers have recently filed lawsuits against airlines and OEMs, claiming a variety of injuries allegedly suffered as a result of being exposed to contaminated cabin air including both short- and long-term neurological and respiratory effects.

Prominent plaintiffs’ firms, spurred by recent media coverage, are actively recruiting additional plaintiffs, claiming that airlines and manufacturers have long been aware of the risks of fume events, yet have failed to act to protect airline crew and passengers.

Most litigation to date has been filed on behalf of individual plaintiffs, however, the recent uptick in litigation suggests plaintiffs’ counsel are taking greater interest in this issue and may be looking toward larger class and mass action filings, potentially based on failure-to-warn theories that do not depend on individualized proof of personal injury.

While class certification for mass exposure events, such as those involving multiple passengers or crew across different flights, raises complex challenges regarding commonality and predominance, the mere filing of a class action can result in significant financial, operational, and reputational risks for defendants.

Insurance Considerations

Insurance plays a key role in promoting financial protection and operational stability. As claims increasingly encompass complex allegations of bodily injury, long-term health effects, and regulatory noncompliance, the potential exposure can be substantial and difficult to predict. Adequate insurance coverage helps transfer a portion of this risk, ensuring that airlines, OEMs, and lessors can respond to claims, fund defense costs, and manage settlements or judgments without jeopardizing core operations.

Equally important is the implementation of insurance best practices, including promptly identifying all applicable insurance policies—both current and historical—and carefully examining commercial contracts for indemnity provisions and insurance requirements that may shift or share risk among counterparties. In the event of a claim, policyholders will want to promptly assess policy obligations and provide timely notice to insurers to preserve coverage rights.

These steps can help expand available coverage, reduce out-of-pocket costs, and prevent gaps in coverage. Well-structured and managed insurance programs are not merely a financial safeguard, but a strategy component of broader risk management.

Forward-Looking Considerations

The current intersection of regulatory gaps, evolving judicial approaches, and heightened litigation risks underscores the imperative for airlines, OEMs, and lessors to maintain an active and informed approach to risk management.

Stakeholders should anticipate further litigation and potential regulatory action as awareness of cabin air quality issues grows within the industry and among the public. In advance of a claim, target companies will want to proactively identify applicable insurance coverage. And, in the event of a claim, it will be important to provide prompt claim notice to insurers to preserve coverage, ensure timely insurer participation in investigation and defense, and minimize risk of coverage defenses that could limit or bar recovery under a policy.