The rumor that WD-40 is kerosene-based has been around a very long time, and I'm surprised at the number of times that that's still stated.
But FWIW, the product was Stoddard solvent when I looked up the MSDS info quite a few years ago.
Stoddard is the reason that it's a reasonably good solvent for cleaning away lots of different types of grime.
WB ......... metalworking projects