From: Ken Kretchman <kwkretch**At_Symbol_Here**NCSU.EDU>
Subject: Re: [DCHAS-L] Toxic dust handling
Date: June 27, 2012 10:27:41 AM EDT
Reply-To: DCHAS-L <DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU>
Message-ID: <04DF14193E316D44811B9787B948042F2385B57C**At_Symbol_Here**SULFATE.fsidomain.local>

I think this is a very useful discussion. I'm curious about the original mention of silica gel which started this thread. For those of you who may handle this material in bulk, is this silica gel (amorphous silica) expected to be contaminated with crystalline silica which is the toxicity concern ?
Director, Environmental Health and Safety
NC State University
Raleigh, NC 27695-8007

On Wed, Jun 27, 2012 at 9:40 AM, Michael E. Richardson <mrichardson**At_Symbol_Here**> wrote:
Flow Sciences in Leland, NC provides enclosures for just this type of application among others. We have test data from our own testing and third party certifiers that prove the enclosures work to protect product and personnel.

Take a look at this link:

Mike Richardson

-----Original Message-----
From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**MED.CORNELL.EDU] On Behalf Of Ralph B Stuart
Sent: Tuesday, June 26, 2012 12:42 PM
Subject: [DCHAS-L] Toxic dust handling

A question has arisen here about the best practices for handling dusts known to be unusually toxic, such as teratogens or mutagens. It appears from google searches that many academic Standard Operating Procedures recommend using these dusts in a fume hood. This seems counter-intuitive to me, as strong air flows around these dusts would seem to create a housekeeping challenge by dispersing the dust around the use area. This could lead to unnecessary contamination of someone's hands as they work with the material. In addition, the ergonomics of performing delicate operations, such as handling dusts, in a hood can be a challenge due to their one size fits all nature.

Prudent Practices indicates that highly toxic dusts should be used in a hood, but that seems to be rolled up in the same recommendation as for handling gases and vapors. It seems to me that dusts present distinct hygiene challenges from gases and vapors. I wonder if anyone has addressed this issue with specific rules that distinguish between these kinds of chemicals?

Thanks for any information about this.

- Ralph

Ralph Stuart CIH
Laboratory Ventilation Specialist
Department of Environmental Health and Safety
Cornell University


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