In a single family residence, the space between two floor joists is enclosed with a galvanized steel sheet and is used as a return air duct for the furnace. Can a low voltage cable that is not rated for low-smoke be routed along the face of each of these wood joists within the enclosed spaces? Why, or why not?

In a single family residence, the space between two floor joists is enclosed with a galvanized steel sheet and is used as a return air duct for the furnace. Can a low voltage cable that is not rated for low-smoke be routed along the face of each of these wood joists within the enclosed spaces? Why, or why not?