The United States phased out the use of leaded gasoline for automobiles in 1996, but many small aircraft continue to run on it. That’s worrying to some public health experts, because lead is a potent neurotoxicant, and leaded aviation gas is now the nation’s leading contributor to airborne lead pollution. And studies suggest that people who live near or work at airports can have elevated lead levels in their blood. As a result, for years advocates have been pushing the aviation industry to get the lead out of aviation gasoline, or avgas.
Last week brought a milestone in that effort. The Center for Environmental Health (CEH), an advocacy group based in Oakland, California, announced a legal settlement with 30 companies that sell or distribute leaded avgas in California, bringing closure to a long-running lawsuit that had been closely watched within the small-aircraft community. Under the settlement, the companies must sell the lowest lead fuel that is commercially available in sufficient quantities, warn the public about the danger of lead exposure through signs posted at airports and notices sent to nearby residences, and pay a total of $550,000 in penalties and legal costs.
“We’re really optimistic that it will make a transition [away from leaded avgas] occur,” says Caroline Cox, CEH’s research director. It’s a shift, she says, that “should have happened back when they transitioned cars away from leaded gasoline.”
Lead is added to avgas to prevent engine knock, which can pose safety problems during flight. Avgas is the last remaining leaded transportation fuel in the United States, where about 167,000 mainly small piston-engine aircraft use it, according to the Federal Aviation Administration (FAA). (Commercial planes and many business jets use unleaded jet fuel.) About 480 tons of lead from avgas were released to the country’s air in 2011, more than half the total amount of lead released that year, according to the Environmental Protection Agency. In 2013, the agency found that two out of 17 airports where lead emissions were monitored exceeded its air quality standards for lead, both of them in California.
Phasing lead out of automobile gas, along with banning it in household paint and other measures, is credited with a striking decline in U.S. children’s average blood lead levels since the 1970s. Lead emissions to the air from avgas are far lower than past emissions of lead from automobile gas. Still, a 2011 study showed that children living within a kilometer of airports in North Carolina where planes use avgas had higher blood lead levels than children living farther away. A 2013 study showed that aircraft maintenance workers at airports that sold leaded avgas had higher blood lead levels than workers at airports that did not.
CEH initiated legal proceedings in May 2011 under California’s Safe Drinking Water and Toxic Enforcement Act, also known as Proposition 65. The state is home to more than 200 airports serving small aircraft, but CEH targeted companies operating at 23 of the busiest ones that are located near population centers, Cox says. Some in the industry worried the suit would mean an end to avgas sales and the grounding of 37,000 avgas-using aircraft in California, which the settlement avoids.
Ray Richmond, general manager of Crownair Aviation in San Diego, says the lengthy legal wrangling hurt his company, costing tens of thousands of dollars, including legal fees and more than $7000 in penalties imposed by the settlement. Richmond says the main beneficiaries seemed to be attorneys rather than the environment through any reductions in fuel lead content and that companies like his actually have little control over what fuels they can offer. “I’m glad it’s ending,” he says. “The impact for us is it’s a lot of money to spend on something that we don’t think solves the real problem.”
Alternatives to leaded avgas exist for many planes, but they are not widely available at airports. Roughly three-quarters of U.S. aircraft that run on avgas could use ordinary premium unleaded auto gasoline, provided it is ethanol-free. But only about 100 U.S. airports offer it—a small fraction of the nearly 20,000 in the country. The settlement requires the avgas distributors to offer this fuel—called mogas—to any airport-based avgas seller in California that requests it, subject to several conditions.
Another alternative is a kind of avgas known as 100VLL, for “very low lead,” which has a maximum lead content 19% lower than that of standard avgas and is usable by the entire avgas-burning fleet. It, too, is rarely sold and is unavailable in California. Cox says she is optimistic the settlement will help bring the fuel not just to California but also nationwide by creating demand. “Our hope is because we have all these airports in California that are committed to buy it as soon as it is available that that creates a market demand and a company will start providing it,” she says.
The aviation industry has long held that the best solution is a single unleaded replacement fuel that will work for all aircraft now burning leaded avgas. The avgas market is so small, industry officials say, that it will never make economic sense to sell more than one fuel at airports serving avgas customers. FAA, with broad industry support, is working to identify an unleaded avgas replacement. In 2011, the agency announced a goal of making one available by 2018, but a recent press release stated only that testing of candidate fuels would be completed by then.
Although he expressed satisfaction with the terms of the settlement, Mark Willey, CEO of Napa Jet Center, a defendant in the suit, says he and others interested in reducing the lead content of aviation fuel will likely have to wait for FAA’s replacement, settlement or no settlement.
Ultimately, a federal regulation mandating a nationwide transition to unleaded fuel is what’s needed, says Marcie Keever, legal director of Friends of the Earth in Berkeley, California, an advocacy group that was not involved in CEH’s lawsuit. Nevertheless, Keever says the settlement is a step in the right direction. “It helps us get on the road towards making unleaded available and making people aware that there’s a possibility to go unleaded,” she said.