The IDLH ( immediately dangerous to life or health) for Xylene is 900 ppm.
The IDLH for toluene is 500 ppm, and
naphtha isn't much better.
So yeah i agree inhaling solvents is bad.
However xylene and toulene are aromatic hydrocarbon consisting of a methyl group and a benzene ring, basically they are metabolized from a benzyl alcohol to benzoic acid in the body and then hippuric acid for urine excretion.
n-Hexane is eventually metabolised in 2,5-hexanedione, which is neurotoxic causing polyneuropathy. Of course large amounts of just about any solvent in the system will cause health issues from organ damage to CNS issues etc but theses are different compounds that are metabolized differently and therefore have different/ more severe health effects than one another. Which is why n-hexane should be treated with extra caution, especially it's vapours as it is metabolized directly into a neurotoxin.
I think from a safety POV the amount of n-hexane in shellite and the potential neurotoxic effects should be more widespread and known.