"Test Tubes" at the Nanoscale
Tubular nanomaterials such as carbon nanotubes can indeed have diameters roughly 10,000 times smaller than the width of a human hair. Hair is typically tens of micrometers wide, while nanotubes have diameters on the order of a few nanometers.
But calling a nanotube a “test tube” without qualification is misleading: a carbon nanotube is a material/nanostructure, not ordinary laboratory glassware for routine chemical experiments. There are separate experiments with “nanotubes” or nanoscale test tubes—tiny cavities or channel structures; for example, Guinness describes a laboratory test-tube experiment about one-thousandth the width of a hair. So the scale comparison is plausible for tubular nanostructures, but both “test tube” and the exact ratio depend on the object being described.