Well, it was over 30 years ago, but what it smelt like to me was dust, like an old shed or basement, and hot metal, like one of those engineering workshops where they use machines to cut and shape metal.

We had to wear sealed suits and air filters to run new cables into a section of a telephone exchange that had asbestos sludge/paste sprayed on the walls as fire retardant, spent a week or so working in the asbestos area.