I implied a question in my Mar. 12, 2013 post about the recent announcement from the US National Institute of Occupational Health and Safety (NIOSH) concerning a carbon nanotube toxicity study. I indicated some curiosity about the length of the multi-walled carbon nanotubes studied in this latest research. Coincidentally, Dr. Andrew Maynard (Executive Director of the University of Michigan Risk Science Center answered this implied question in his Mar. 14, 2013 posting about the study (on Andrew’s 2020 Science blog),

The carbon nanotubes in this study were inhaled multi-walled carbon nanotubes with a predominantly long, straight fiber-like morphology.  Mice were exposed at a level of 5 mg/m3 for 5 hours per day, over a 15 day period.

It’s well worth reading Andrew’s posting for the context he provides about the research and for links to further information.

For anyone who wants the short story, multi-walled carbon nanotubes (predominantly the long, straight fibre-type were used in the study) when combined with a known cancer-initiating chemical are more toxic than plain carbon nanotubes. The study has yet to be published but the results were discussed at the Society of Toxicity’s 2013 annual meeting.

Happily, he also provides this charming video (part of his Risk Bites video series) describing carbon nanotubes and their ‘infinite’ variety,

Thank you Andrew for clearing up some of my longstanding questions about carbon nanotubes.

Happy weekend to all!