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Monday, November 2, 2009

Possible Increased Combustible Dust Explosions Due to the Increased Industrial Use of Nano Powders?

NANO POWDERS

The interesting thing about nanopowders is the particle size and surface area, making them appear at first glance potentially highly combustible similar to vapor cloud or hybrid mixtures, but they also tend to agglomerate. Particle size, shape, charge, concentration, humidity etc. all affect agglomeration. Consequently, agglomeration (and de-agglomeration in testing) can throw off combustible testing results!  Another interesting note is that the finer the particle, the lighter and higher it will travel and settle, so dust collection (and therefore protection - fire, explosion and personal) becomes even more important.


On our Linked-In network The Combustible Dust Forum, Robert Dumbrowski at Nanoview Associates asked the following question:Possible Increased Combustible Dust Explosions Due to the Increased Industrial Use of Nano Powders?


Rachel Brutosky, at Nilfisk-Advance America did some research and found this from the EPA:

* Nanomaterials present a safety concern for potential fire and explosion because data show that decreasing the particle size of combustible materials may increase the risk for explosion.
* For many particles, the explosion risk appears to plateau at particles sizes on the order of tens of microns.
* However, some nanomaterials are designed specifically to generate heat through the progression of reactions at the nanoscale; this too may present a fire hazard that is unique to engineered nanomaterials.
* The ability of nanomaterials to become electrostatically charged during transport, handling, and processing introduces a unique explosion hazard when dealing specifically with nanopowders.
* Their tendency to charge has been found to drastically increase as particle surface area increases.
* As a result, their large surface area may become highly charged and become their own ignition source if the powder is dispersed in the air.

 

Jon Barrett at Interior Maintenance Company offered some insight and presented some resources for safe handling of Nanopowders:

 

http://findarticles.com/p/articles/mi_qa3816/is_200601/ai_n17178887/pg_18/

http://www.hse.gov.uk/research/hsl_pdf/2004/hsl04-12.pdf

http://www.iop.org/EJ/article/1742-6596/170/1/012037/jpconf9_170_012037.pdf?request-id=3c82e2a7-3a1d-4a92-8681-0c8dbd2cd036



Our good friend John Astad at Combustible Dust Policy Institute had several pertinent comments, and had just returned form an IH conference in Canada where several topics on Nanoparticles were discussed, but nothing on fire and explosion characteristics!


In conclusion, as this subject continues to be developed, and nonopowders are more widely utilized in production, safety will become more important then ever.

1 comment:

  1. That's a good idea Jeff, providing a summary of this important topic for everyone that didn't view the original discussion on the LinkedIn Combustible Dust Forum

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