The risk assessment of CNT has been specialised between different types of CNT for many years. The reason Australia's regulatory approval is taking so long is because they have had to run testing on their own variety. And as I have shown, the testing proved using EdenCrete as safe.
"SAFE HANDLING AND USE OF CARBON NANOTUBES
MARCH 2012
Acknowledgement
This document was developed by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in support of Safe Work Australia’s Nanotechnology Work Health and Safety Program. CSIRO has lengthy experience in working with carbon nanotubes. The document was prepared by Mr Greg Haywood (Manager - Health, Safety and Environment, Materials Science and Engineering, CSIRO).
The document has been reviewed by Safe Work Australia’s Nanotechnology Work Health and Safety Advisory Group and Nanotechnology Work Health and Safety Measurement Reference Group, and by other stakeholders both within Australia and overseas. Thanks go to Professor Joe Shapter (Flinders University), Dr Vladimir Murashov (US National Institute for Occupational Safety and Health, NIOSH),
Dr Miriam Baron (German Federal Institute for Occupational Safety and Health, BAuA), Dr Henri Heussen (Arbo Unie) and Mr Jeremy Allan (WorkCover NSW) for their comments"
"NIOSH (2010) reports that currently there are no studies reported in the literature of adverse
health effects in workers producing or using CNTs. However use is not yet widespread,
and there can be a long latency before the development of disease. The concern about
worker exposure to CNTs arises from results of animal studies, showing adverse lung effects
including pulmonary inflammation and fibrosis.
NIOSH (2010) also reports that animal studies have also shown asbestos-type pathology
associated with exposure to longer, straighter CNT structures. Mesothelial tumors have been
reported in a susceptible strain of mice after intraperitoneal injection of longer MWCNTs (10-
20 μm in length) but not by short MWCNTs (<1 μm in length)."
Current evidence suggests that all CNTs should be treated as hazardous, unless evidence
suggests otherwise. However, it is important to understand if they are fibre-like and thus
present fibre hazards and to understand other potential hazards associated with their
production or handling. This is the focus of Step 1.
Answering the following questions can assist in identifying these hazards.
1.1 Carbon nanotubes characterisation
What types of CNTs are being used; single-walled or multi-walled?
Thicker, stiffer CNTs may be more likely to be fibre-like
What quantities of CNTs are being used?
The greater the quantity used, potentially the greater the exposure risk
Are the CNTs loosely or tightly bound together?
CNTs, and particularly SWCNTs, can be very tightly bound together. They readily
agglomerate and aggregate. A very large clump of CNTs may be less hazardous than
loosely bound CNTs because:
Loose CNTs may be able to penetrate deeper into lung tissues
Loose CNTs may be fibre-like and cause pathogenic responses
Are the CNTs modified or functionalised, or coated with a chemical? Is this chemical
hazardous?
Functionalisation may make the CNTs more biodegradeable and hence less hazardous.
The chemical coating on the CNT may also be hazardous"
The manufacture of EdenCrete is an enclosed, continuous, automated process. There is no risk whatsoever to workers.
(20min delay)