Vinegar is acetic acid
https://pubchem.ncbi.nlm.nih.gov/compound/acetic_acid#section=Top
That looks like what a "Stay Fresh" tab would look like ...
(If such a thing even existed for Kerosene)
'Not in ANY way to be considered a Chemist...
But, given what acetic is and it's compounds what I "Think" you're smelling
is the decomposition of either the Kero or the JP
(Or mayhaps The Entrails of Both entrapped in the Tab)
[Boy , I sure can produce the Horse Manure if Facts are lacking !]