The bonding of structural steel has become an issue in our area as well. I think the wording could be worked with for clarity.

1. It does not say the frame of an entire building. I have seen (especially in residential) portions of the framing to be ofmetal and portions to be of wood.
I think the 2 keys here are "may become energized" and "Exposed Structural steel", not one or the other, but both items have to be present at the same time.
In the residential buildings I mentioned, most of the time the steel is concealed at final construction, so it becomes a moot question. Otherwise how would one make the connection "accessible" [Linked Image]

Pierre Belarge