I have noticed a couple of times a really horrible smell coming from young people smoking, it really seems to linger. I don't think it smells like weed or resin, it seems to have a much more oily smell. Anyway I have confronted my son about smelling of this previously and tonight in trying to help him find his wallet I found a tin with papers and empty wraps smelling of this substance. There was no tobacco in the tin, does anyone know what this is please? He says it is just weed, which I am obviously not happy about but I think it is something more chemical based.