Attorney General Bonta Leads Multistate Comment Letter Supporting EPA Finding on Leaded Aviation Gas

Wednesday, January 18, 2023
Contact: (916) 210-6000,

OAKLAND – California Attorney General Rob Bonta, leading a multistate coalition of 12 attorneys general, today submitted a comment letter to the Environmental Protection Agency (EPA) supporting its proposed finding that emissions from the combustion of leaded aviation gasoline (avgas) in piston-engine planes cause or contribute to air pollution that endangers public health and welfare. If finalized, the long-overdue finding will require the EPA to promulgate lead emission standards and regulations for piston-engine planes under the Clean Air Act, and require the Federal Aviation Administration (FAA) to establish aircraft fuel standards that are consistent with these aircraft lead emission standards. In the comment letter, the attorneys general urge EPA to swiftly finalize its proposed finding and commence its rulemaking process to protect the public – especially environmental justice communities situated near airports for piston-engine planes – from exposure to lead air pollution.
“Piston-engine airplanes are the largest source of lead air pollution in the nation, and consequently, communities living, working, and going to school near airports are bearing the brunt of their toxic emissions,” said Attorney General Bonta. “We’re encouraged that the EPA is taking this first important step toward protecting the public from lead pollution from these airplanes. But in order to protect our residents from lead pollution, we urge the EPA to swiftly finalize its proposal and move forward with a rulemaking to set emission standards that do right by our communities and protect public health.” 
The negative health impacts of lead exposure are well-documented. Short-term and prolonged lead exposure can cause memory loss, nausea, fatigue, and increase the risk of developing hypertension, heart disease, kidney disease, and infertility. Lead exposure is particularly dangerous for children, whose developing brains and nervous systems are more sensitive to its damaging effects. The impacts of lead exposure in children include behavioral issues, reduced IQ, slowed body growth, and a predisposition to depression, anxiety, or high-risk behavior. There is widespread scientific consensus that there is no safe level of lead exposure for children.
The coalition has a vested interest in protecting their residents from lead emissions from piston-engine airplanes. Leaded avgas is the only remaining lead-containing transportation fuel, and its combustion is the single largest contributor of airborne lead emissions in the United States. Piston-engine planes powered by leaded avgas released more than 930,000 pounds of lead in 2017 and are responsible for nearly three-quarters of total lead emissions nationwide.
General aviation airports that service these planes are often located near densely populated metropolitan areas, communities impacted by environmental hazards and risks, and residential areas near homes and schools. These emissions are a significant health risk for the more than 16 million people living and 3 million children going to school within one kilometer of an airport. California has 452 general aviation airports that service piston-engine aircraft, which are responsible for 83 percent of the state’s lead emissions. Of these, 111 lead-emitting airports are located in environmental justice communities, where residents are already exposed to excessive levels of ozone, fine particulate matter, and other pollution sources. 
Much, if not all, of the lead emissions from piston-engine planes could be avoided. In 2014, the FAA launched the Piston Aviation Fuels Initiative (PAFI) to speed up the “deployment of the most promising unleaded replacements,” but despite FAA’s certification of various unleaded fuels, including two recent fuel replacements suitable for nearly all piston-engine planes, these unleaded aviation fuels have not successfully penetrated the market.  Less than three percent of U.S. airports that service piston-engine planes sell unleaded alternatives.
In the comment letter, the attorneys general support EPA’s proposed finding and urge the agency to swiftly issue a final endangerment determination and initiate a rulemaking to regulate lead emissions from avgas. In the comment letter, the attorneys general argue:

  • States have a vested interest in protecting their residents from the public health harms associated with exposure to lead pollution from piston-engine planes that use leaded avgas;
  • Leaded avgas is a significant and preventable source of airborne lead pollution; and
  • EPA must swiftly finalize its proposed finding and address the serious public health and environmental justice harms posed by avgas in a rulemaking for aircraft lead emissions.

Attorney General Bonta and the California Air Resources Board are currently leading multistate litigation challenging the EPA’s ineffective standards regulating greenhouse gas emissions from airplanes.
Attorney General Bonta is joined by the attorneys general of Connecticut, the District of Columbia, Maryland, Massachusetts, Minnesota, New Jersey, New York, Oregon, Pennsylvania, Vermont, and Wisconsin in filing the comments.
A copy of the letter can be found here.

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