Small planes are still spewing toxic lead across the US, EPA says

The agency says the more than 220,000 piston-engine aircraft still running on lead fuel are a public health concern under the Clean Air Act.
Small propeller plane flying in a clear sky
Piston-engine small aircraft are the only planes to still use leaded fuel in the US. Deposit Photos

Airborne lead levels in the US have declined an impressive 99 percent since 1980 thanks to Environmental Protection Agency regulations, but leaded gas isn’t gone completely. While large jet aircraft do not use leaded fuel, according to the Federal Aviation Administration, over 220,000 smaller, piston-engine aircraft capable of carrying between two and 10 people still run on leaded aviation gasoline, or “avgas.” 

Today, the EPA took its first step towards attempting to finally phase out air transportation’s lingering lead holdouts with a new endangerment finding announcement highlighting the adverse effects of even minuscule levels of airborne lead. With the new findings, the EPA argues that leaded avgas endangers public health and welfare under the Clean Air Act—and because of this, the US could finally see its first-ever avgas lead limitations.

“The science is clear: Exposure to lead can cause irreversible and life-long health effects in children,” EPA Administrator Michael Regan via the agency’s October 18 announcement. “Aircraft that use leaded fuel are the dominant source of lead emissions in our air.”

[Related: The US can’t get away from lead’s toxic legacy.]

The federal level determination earned support from legislators including House Science, Space, and Technology Committee Ranking Member Zoe Lofgren (D-CA). “[The] EPA’s conclusion confirms what constituents in my district and Americans across the country know all too well—emissions from leaded aviation fuel contribute to dangerous lead air pollution,” Lofgren said via the announcement. She also cited the disproportionate exposure to leaded avgas in many poorer and minority communities near general aviation airports.

Lead’s neurotoxic effects have long been understood, especially its dangers to younger children, as it  negatively affects cognitive abilities and slows physical growth. In 2022, the Centers for Disease Control announced a redefinition of “lead poisoning,” lowering the threshold for toxic exposure from 5 micrograms per deciliter of a child’s blood down to just 3.5 mgs per deciliter. Even with the added stringency, however, the EPA reiterated in its October 18 announcement that there is no evidence of any threshold to fully reduce lead exposure’s harmful effects.

[Related: Leaded gas may have lowered the IQ of 170 million US adults.]

The new avgas endangerment finding does not carry any regulatory or legal weight itself. Instead, it opens the door to a future phaseout of avgas for small aircraft. Last year, the FAA and industry leaders announced their “Eliminate Aviation Gasoline Lead Emissions” (EAGLE) program aiming to “achieve a lead-free aviation system” by 2030. The FAA has already approved usage of a 100 octane unleaded fuel capable of being used by piston-engine aircraft, although the EPA notes it is not yet commercially available. A lower octane fuel is also available at an estimated 35 US airports, with plans to “expand and streamline the process for eligible aircraft to use this fuel.”

As The Washington Post notes, however, the EPA’s and FAA’s attempts to phase out avgas come as Congress considers a long-term reauthorization of the FAA that would all but require smaller airports to continue offering leaded avgas.

“While today’s announcement is a step forward, we cannot be complacent,” Lofgren added on Wednesday. “We must finish the job and protect our nation’s children from all sources of lead.”