Lets not get carried away though - something with a low concentration of HF is very unlikely to kill you (unless you drink loads of it/inject yourself with it etc). With normal precuations (goggles and rubber gloves) it's perfectly fine to use. Plus the mag wheel cleaners with HF in them work bloody well!
Concentrated HF is tremendously dangerous stuff - it will eat straight through your skin and gets into your bones and can kill you very quickly. Chemists have died from spilling HF onto themselves - even jumping under an emergency shower / bath won't stop HF burning through you if it's concentrated enough.
Polyglycol-ethyl ester is classified as non-hazardous because (funnily enough) it's not hazardous. In fact poly-glycols, and polyethylene glycol are common industrial chemicals.
Check out your shampoo ingredients for a list of interesting chemicals - most contain methyl or chloro isothiazolonone - biocides known to cause sensitisation on skin contact if concentration is high enough!
Anyway...back to the petrol part of the thread!
I found this good article which gives a bit of insight into petrol chemistry
http://www.chm.bris.ac.uk/motm/leadtet/leadh.htm
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