Understanding the Transition to Unleaded Aviation Gasoline: A Primer (2026)
Chapter: Introduction
Introduction
This Primer is intended to provide airports with concise answers to eight key questions related to the transition to unleaded aviation gasoline, based on the latest information available at the time of its preparation in January 2025.
The Primer addresses the following eight questions:
- Why are airports transitioning to unleaded aviation gasoline?
- What are governments and agencies doing to support the transition to unleaded aviation gasoline?
- What are other organizations doing to support the transition to unleaded aviation gasoline?
- What is the status of unleaded aviation gasoline?
- What steps do airports generally have to take to provide unleaded aviation gasoline?
- What are the opportunities and challenges for airports in providing unleaded aviation gasoline?
- What other actions can airports take to reduce lead-related issues?
- What resources are available to help airports transition to unleaded aviation gasoline?
Why Are Airports Transitioning to Unleaded Aviation Gasoline?
Lead is a well-known pollutant that can cause a variety of adverse health impacts. Lead can enter the body through inhalation, diet (including consumption of food grown in lead-contaminated soil), hand-to-mouth ingestion of contaminated dirt, drinking water contaminated by lead in plumbing systems, and the ingestion of house dust containing residues of lead-based paints (Sy et al. 2024).
Concerns about the adverse health effects of exposure to airborne lead resulted in its classification as an air pollutant pursuant to the Clean Air Act in 1976. This was followed by the requisite enactment of a health-based National Ambient Air Quality Standard for lead in 1978, which was updated in 2008.
During the 1970s, the primary source of airborne lead in the United States was the combustion of leaded gasoline in motor vehicles. The phaseout of leaded gasoline use in motor vehicles began in the mid-1970s with the introduction of catalytic converters on new vehicles and was completely banned after December 31, 1995. Lead emissions from other sources have also been reduced over time, leaving leaded aviation gasoline as the largest current source of airborne lead emissions in the country.
Aircraft operating on leaded aviation gasoline emit lead particles from their exhaust systems into the air. However, the relevant lead exposure pathways include not only inhalation of aircraft exhaust emissions, but also consumption of food grown in lead-contaminated soils around airports or ingestion of dirt or dust from those soils.
