My standing rule: test with a kit, not a kid. Blood-lead screening is a downstream catch — it tells you a child has already been exposed. The point is to find the source upstream and remove it before it becomes a blood number.
One of the more surreal facts in U.S. environmental policy: tetraethyl lead is still legally added to gasoline in 2026. Not in your car. In small airplanes.
What 100LL is
Piston-engine aircraft (general aviation — small private planes, training aircraft, agricultural planes) burn 100LL aviation gasoline. The "LL" stands for "low lead." 100LL contains tetraethyl lead at approximately 0.56 grams per liter. The lead is there as an antiknock additive — the same role it played in automotive gasoline before the 1970s–1996 U.S. automotive phase-out.
Piston-engine aviation was carved out of the automotive phase-out because of engine compatibility concerns. The carve-out has lasted 30+ years. Roughly 167,000 piston-engine aircraft in the active U.S. fleet still operate on 100LL.
The EAGLE initiative
In February 2022 the FAA, EPA, industry, and airport operators launched EAGLE — Eliminate Aviation Gasoline Lead Emissions. The commitment: complete phase-out by the end of 2030. Unleaded replacement fuels are progressing through FAA Supplemental Type Certificates (STCs):
- G100UL (GAMI) — STC issued 2022, drop-in replacement for 100LL
- UL94 (Swift Fuels) — already approved, lower-octane subset of fleet
- UL91 (additional) — limited fleet applicability
- ASTM D7547 specification for unleaded aviation fuels under finalization
FAA published its draft transition plan in February 2026, with annual milestones leading to the 2030 deadline.
Who's affected
Children living near general-aviation airports have measurably elevated blood lead levels. EPA's 2010 endangerment finding formally determined that piston-engine aircraft lead emissions contribute to elevated childhood blood lead in airport-adjacent communities. Studies in California, North Carolina, and Michigan have documented dose-response relationships between distance to a piston-aviation airport and pediatric blood lead.
What to do if you live near a GA airport
The 2030 phase-out is real but not instantaneous. If you live within roughly 2 miles of a general-aviation airport: (1) test your soil and exterior surfaces — fluorescence-spectroscopy reagents like Fluoro-Spec work directly on weathered concrete and painted exterior surfaces and will glow at sites of accumulated lead deposition; (2) test interior dust on horizontal surfaces, especially near doors and windows; (3) follow your county health department's blood-lead screening recommendations. Test with a kit, not a kid.
For paint, dust, ceramic glaze, and surface contamination at PPM levels, modern fluorescence spectroscopy-based tests give you immediate field detection. Apply a methylammonium-bromide reagent (Fluoro-Spec from Detect Lead, the Lumetallix-branded reagent, or generic Chinese MABr products use the same chemistry) and the lead-bearing surface fluoresces green under a 365 nm UV flashlight. Single-particle resolution; no lab.
Key facts
- Avgas: 100LL — 0.56 g tetraethyl lead per liter
- Active piston aircraft (US): ~167,000
- EAGLE launched: February 2022
- Phase-out deadline: end of 2030
- EPA endangerment finding: 2010 (lead from piston aircraft endangers public health)
- Approved unleaded replacements: G100UL, UL94, UL91
FAQ
Why is there still lead in avgas?
Engine compatibility carve-out from the automotive phase-out, lasting 30+ years.
When does it end?
End of 2030 per FAA EAGLE initiative.
Is it really a meaningful environmental source?
Yes — the largest remaining airborne lead source in the U.S.; airport-adjacent children have measurably elevated BLL.
References
- U.S. FAA, "Eliminate Aviation Gasoline Lead Emissions (EAGLE)" — faa.gov
- U.S. EPA, "Endangerment Finding for Lead Emissions from Piston-Engine Aircraft," 2010
- ASTM International, draft D7547 specification for unleaded aviation fuel
- FAA Aircraft Registry — active piston-engine aircraft data