The health concerns mostly related to air born nano-materials dust. We plan to distribute the product in a way that minimizes these concerns. Current CNT producers reduce this risk by selling their products in solution or pre-dispersed into a host matrix (like plastic) so no dust can be created. Also, morphology plays a big role in health. If the cnts produced look like needles, this is similar to asbestos. Not good. If you produce CNTs that look more like spaghetti, they cannot penetrate tissue and are less of a concern. These are the type that we are focused on.

HSE?

HSE is health and Safety. I'm not sure what the 'E' stands for :)

E = Executive [1]

They're considering the possibility that CNTs pose specific health concerns (kind of like asbestos from what I understand), which would create quite a few regulatory changes in both production and usage.

http://www.hse.gov.uk/nanotechnology/

Environment :)