Obviously 100LL is risky. It's got lead in it, so there's going to be some danger. But is it possible to not get lead into my system when I start flying?

It is, for obvious reasons, something I wish to avoid. I want to learn to fly, but after reading the SDS for 100LL, I'm pretty worried. Here are the hazard and precaution statements for 100LL:

  • H225 Highly flammable liquid and vapour.

  • H304 May be fatal if swallowed and enters airways.

  • H315 Causes skin irritation.

  • H336 May cause drowsiness or dizziness.

  • H361d Suspected of damaging the unborn child.

  • H373 May cause damage to organs through prolonged or repeated exposure through inhalation.

  • H411 Toxic to aquatic life with long-lasting effects.

  • P202 Do not handle until all safety precautions have been read and understood.

  • P210 Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.

  • P260 Do not breathe mist/vapours.

  • P273 Avoid release to the environment.

  • P280 Wear protective gloves/protective clothing/eye protection.

  • P301+P310 IF SWALLOWED: Immediately call a POISON CENTER or doctor/physician.

  • P331 Do NOT induce vomiting.

  • P303+P361+P353 IF ON SKIN (or hair): Take off immediately all contaminated clothing. Rinse skin with water/shower.

  • P308+P313 IF exposed or concerned: Get medical advice/attention.

Some of that is common sense, but that's a lot of very concerning information. How can I avoid contact? It seems like there's not really a good way around it, but I'm really concerned and I want to balance minimizing risk with still being able to fly.

Can anyone offer some advice?

  • 20
    $\begingroup$ How different is this from the warnings for the 87 octane gas we pump into our cars routinely? $\endgroup$
    – Ralph J
    May 20, 2021 at 13:50
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    $\begingroup$ If you look at any hydrocarbon fuel you'll see very similar warnings, including unleaded gasoline. Avgas has some more aromatic hydrocarbons than regular mogas but you still wouldn't sniff or drink mogas. $\endgroup$
    – GdD
    May 20, 2021 at 16:49
  • 2
    $\begingroup$ Fun fact: gasoline was originally a byproduct of kerosene manufacture that oil companies didn't know what to do with. One of the things they marketed it as was a hair tonic! $\endgroup$
    – GdD
    May 20, 2021 at 16:52
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    $\begingroup$ Lead can be absorbed through consumption and breathing, but generally not absorbed through the skin. If you're breathing avgas or drinking it, you have bigger problems. Also, the body sheds lead. Lead poisoning occurs when you consume more lead than the body can shed. $\endgroup$
    – gwally
    May 20, 2021 at 17:35
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    $\begingroup$ Everything in those warnings relates to the gasoline, not to the lead content of 100LL. They almost certainly would be exactly the same for ordinary automotive gasoline. As has been said, the poison is in the dose. Certainly anyone who has done a reasonable amount of auto mechanics over the years has had plenty of contact with small amounts of gasoline, with no ill effect. $\endgroup$
    – jamesqf
    May 20, 2021 at 17:58

1 Answer 1


If you don't crawl underneath and breathe in the exhaust fumes from the engine, you'll be fine. If you do crawl underneath and breathe in the exhaust fumes, you'll be dead from carbon monoxide poisoning long before any harmful effects from the tetraethyl lead combustion byproducts in the fuel.

While you don't want to ingest lots of lead, that won't really happen being around airplanes with engines running. The old saying in toxicology is, "The poison is the dose", and whatever dose you get from casual exposure is too microscopic to matter.

My advice, as an old-timer who likes a clean world as much as the next guy, is don't become so hyper-sensitized (by mostly media coverage) to environmental exposure to chemicals that you can't enjoy life. It's not worth it.

  • 8
    $\begingroup$ I've never been concerned about getting avgas on me - again, the poison is the dose - but on the other hand, it's pretty stinky, and the smell is hard to get rid of, so wearing nitrile gloves while draining sumps, if only to keep the smell off your hands, makes sense in any case. $\endgroup$
    – John K
    May 20, 2021 at 13:59
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    $\begingroup$ There is a non-trivial risk of getting avgas on your hands while fueling or sumping, but just wash your hands ASAP, and in particular don’t touch anything you’ll eat or drink until you do. $\endgroup$
    – StephenS
    May 20, 2021 at 17:52
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    $\begingroup$ @MD88Fan Worst case, keep a pack of wet wipes in your flight bag, in an resealable bag. $\endgroup$
    – StephenS
    May 20, 2021 at 22:29
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    $\begingroup$ @StephenS Granted, while those do help somewhat for cleaning stuff off of your hands, their primary purpose is killing/deactivating germs. The alcohol is very effective at killing germs, but not so effective at removing avgas from your skin. Better than nothing, of course, but not as good as actually washing your hands. $\endgroup$
    – reirab
    May 20, 2021 at 22:35
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    $\begingroup$ The poison is the dose but lead is a cumulative poison. The dose is today's nanogram and yesterday's nanogram and all the nanograms absorbed over a lifetime. Over fifty years that would be 18 micrograms. Since (I just looked it up) 14micrograms/dL of blood is not alarming in a child, I wouldn't worry about it. $\endgroup$
    – Peter Wone
    May 21, 2021 at 8:10

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