A simple field test for presence of Jet fuel in your Avgas is to take a fuel sample (which you do anyway, right?), and after checking for water (make sure you check color against a white background and odor, 'cause a strainer full of water only held against the sky looks just like 100LL), sediment, etc, pour some on a paper towel (color doesn't matter).  The Avgas quickly evaporates; the jet fuel takes much longer and leaves behind an oily residue.  It will have a similar effect to what the towel looks like if you set down a can or bottle of something that had oil on the bottom.

 

By the way, although probably not healthy, if you get the fuel on your skin, the Avgas evaporates quickly, which cools the skin, and leaves behind no "slickness" ... pure jet fuel will not cool the skin and it will leave the oily feeling.  I don't know what concentration would have to happen to detect presence of jet in avgas - this may only work for a very high concentration.

 

excellent question...

 

Jim McIrivn

Lancair instructor,

210-275-7780