Suppose there were a class of technologies called millitech: science and engineering that could be measured in millimeters, from say about a tenth of a millimeter to 100 millimeters — in any dimension. That includes hairs, paper, pebbles, marbles, anything you can hold in the palm of your hand, anything less than 4 inches thick no matter how long or wide it is.
This would be, frankly, an insane classification on which to base regulations of whatever technology you had in mind. We regulate hair from appearing in our food in restaurants; we regulate cell phones from operating on the wrong frequency; we don’t legally regulate golf balls but the USGA does. Regulating hair and 2-inch steel plate the same because they were both “millitechnology” would be nuts.
Similarly, the ridiculously broad term “nanotechnology” is a monumentally silly basis for regulating things. Nano-powders and particulates are substances — regulate them according to their toxicity, residence time in the atmosphere, biodegradability. Something real.