Ralph, I believe Moldatherm is a refractory ceramic fiber (RCF) based insulation.  RCF will convert to cristobalite with prolonged exposures to high temperatures.  Cristobalite is a form of crystalline silica, an OSHA regulated carcinogen.  On the other hand, RCF itself is classified as carcinogenic (IARC-2B, NTP-2, ACGIH A2) with a recommended occupational exposure limit of 0.5 fibers per cc.   Consideration should be given to whether friable RCF insulation is made airborne during routine furnace operations. Depending upon the scale of the furnace and its condition, the exposures might be associated with loading or withdrawing samples, or fibers entrained by the hot air.  RCF suppliers and likely OSHA and NIOSH as well provide guidance on strategies and methods for minimizing exposure during equipment servicing. 

Regards,

Joe Damiano, URS / NETL / DOE

 

>>> "Ralph B Stuart" <rstuart**At_Symbol_Here**CORNELL.EDU> 10/12/2012 8:54 AM >>>
Our chemistry department safety coordinator asks this question:
I am seeking guidance on the best practices for furnaces using Moldatherm. We had a group last year report that they were very concerned about possible exposure to this material which when heated to high temperatures becomes Crisobalite...

Has anyone developed specific procedures for addressing this concern in the chemistry lab setting?

Thanks for any help with this.

- Ralph

Ralph Stuart CIH
Chemical Hygiene Officer
Department of Environmental Health and Safety
Cornell University

rstuart**At_Symbol_Here**cornell.edu