Too bad the OP's question led to degeneration of this thread so quickly, but it is a serious subject. You won't find the health hazard information on a SDS, so let's back up. Engineered nanomaterials, carbon nano tubes/fibers/particles, call it what you will, is incredibly hazardous to inhale. It won't kill you like cyanide gas or other instant death, but it will kill you nice and slowly like it's mineral cousin asbestos. Someone said above that it's the particle size that matters, and they were absolutely correct. The aerodynamic diameter of engineered nanomaterials generated during sanding and machining is in the 2.5-minus micron range, meaning it is respirable into the alveolar gas-exchange region of the lung. A lot of electron microscopy research has also shown that they meet the definition of a NIOSH fiber, where fibers exhibit a length greater than 5 microns and an aspect ratio of 3:1, prompting the need for asbestos controls to protect worker health. Fibers and particles smaller than the NIOSH definition are known to be generated when working with these materials, and the long term health effects are not completely understood.
So if you like the idea of dying slowly in front of your family by coughing blood and mucus from your lungs and sucking oxygen from a bottle, that's okay- it's your life. If you don't, you can try a few things. Wear a P-100 HEPA respirator. Sand and machine carbon nanomaterials using water wet methods. Clean up with wet wiping and vacuuming. Do the work outside. Take the hazard seriously.