Why The 2030 Deadline For Unleaded Avgas Is Final

Much has been written about the ongoing development of unleaded avgas and the plan to have general aviation transitioned completely to unleaded fuels by 2030.

A number of General Aviation News readers have protested, saying the amount of lead in 100LL is so small as to be inconsequential. Others, having watched government in action, are confident the 2030 deadline is more of a suggestion, rather than a hard date for the end of 100LL.

I understand that sentiment. I worked at Chevron for 38 years, including several years managing an unleaded avgas investigation effort. I had a boss who intoned, “Unleaded avgas is the fuel of the future! And it always will be…” The implication, of course, is that we’ll never actually get there.

After 38 years of FAA development work, it’s certainly understandable why you might think it’s never going to happen. But this time, it’s different.

Why This Time is Different

Let’s start with some history: In compliance with the Clean Air Act of 1970, the EPA began a phasedown of lead in mogas (motor gasoline for automobiles) in the late 1970s. By 1995, lead was gone from the corner service station. However, given concerns about feasibility of effectively replacing lead in avgas, and the comparatively smaller impact (about 1/500th the annual volume of mogas), action on avgas was deferred. Following the law, the EPA continued to pursue evidence-based regulation to reduce lead in the environment from all sources. By 2010, it had been very effective. In fact, avgas now represents ⅔ of all lead air emissions.

So we’ve seen an enormous decrease. Why is this remaining historically small contribution a concern? The problem is that there’s no safe level of lead. Scientists have been unable to demonstrate that even a minuscule lead exposure doesn’t cause some damage, particularly to developing nervous systems in humans less than five years old. This damage is irreversible and lifelong.

Again, following the law, the EPA made a 2023 finding of endangerment that emissions of lead from piston-engine aircraft pose a significant risk to public health and welfare. The regulatory process is slow but steady, and 2030 has been set as the sunset for lead in avgas. To reinforce that, Congress included firm language in the FAA Reauthorization Act of 2024, giving the FAA no wiggle room on the 2030 date.

But, come on, the current administration is more sanguine about such issues. Couldn’t they delay this? Certainly they might try.

But there are a significant number of folks very concerned about the impact of lead on children living near airports and recent judicial decisions make it clear the courts are no less inclined to observe the law than historically. Given the advocacy for children’s health, and letter of the law of the Clean Air Act and the FAA Reauthorization Act, administrative attempts at delay are unlikely to be effective.

Forget About The Politics

Even if a government delay might be arranged, there are indications that TEL, tetra-ethyl-lead, which gives 100LL its desirable anti-knock quality, won’t be available after 2030.

Why not? There’s a single remaining TEL manufacturer in the west, Innospec. Innospec has been watching world events unfold, and has announced it plans to stop making TEL in the 2028-2029 time frame, with inventory available to support leaded avgas blending until the sunset date of 2030.

But couldn’t Innospec be convinced to delay its decision?

That is unlikely.

First, a little bit about the TEL manufacturing process. TEL comes from the reaction of metallic lead alloyed with sodium to form a reactive sodium-lead alloy. This alloy is then bubbled with ethyl chloride (chloroethane) gas in a controlled reaction vessel. The process itself is not just toxic, but corrosive, and the reaction equipment is of finite life, limited by corrosion allowances.

It is very likely that Innospec’s statements about stopping the production of TEL by 2030 are based on its estimates of remaining corrosion allowance in the equipment. Periodically, significant investment is required to replace or renew that equipment. It wouldn’t make economic sense for Innospec to make that re-investment with the end of TEL in sight.

How about TEL supply from Russia or China? It’s unknown if Russian TEL facilities are still operational, and doing business with Russia is problematic at present. China makes some TEL, but the samples I’ve seen — and remember, these are their bragging samples they’re using to try to solicit business — are of very poor quality. U.S. avgas blenders are unlikely to accept the liability of such a poor-quality supply.

TEL is extremely toxic and is treated with enormous respect in the refining industry. Quality supplies are coming to an end and no new quality supplier is likely.

That means whether or not the EPA is successful in outlawing lead use in avgas, there’s unlikely to be TEL available to continue blending avgas past 2030.

What does that mean for GA?

It’s time to prepare for whatever changes might be necessary to use approved unleaded avgas to keep ‘em flying.