Eliza, not the smell I got hanging round the photocopier, then. But I have had the idea that gunpowder, since it includes sulphur, would smell a bit of SO2. Sharp, cuts up your nose, clean smelling.

In terms of electron orbits, ozone, O3, and SO2 are similar, as oxygen and sulphur are close in the periodic table. I don't know if that would make the smells similar, though.

Penny