Hi Bob,

If the concentration of a carcinogen is greater than 0.1%,  it must be reported
on an MSDS.  If the carcinogen is no longer in the dye product after all the
steps of synthesis or the the limits are less than 0.1%, it most likely is no
longer a problem.

I think there are only a few manufacturers of dry dyes left.  Us manufacturers
of solutions and chemical products depend on them to supply us with this type of
information.  I can only tell you that here where I work, if even a trace amount
is mentioned by a raw source supplier, it will be on the MSDS.

Rande Kline, HT (ASCP)
Technical Services
EM Science




RSRICHMOND@aol.com on 03/14/2002 08:40:03 AM

To:
cc:   histonet@pathology.swmed.edu (bcc: Rande Kline/EMI/Merck)
Subject:  Re: MSDS access



Rande Kline, HT (ASCP), Technical Services, EM Science notes:

>>If a carcinogen is actually a component of any chemical, it is a
requirement of the manufacturer to list it in the MSDS.<<

But not - I suppose - if the carcinogen were a synthetic intermediate not
present in the final product. Which may be the case with the
sym-dichloromethylether in the Alcian dye synthesis we were talking about. -
Or is it?

Bob Richmond
Samurai Pathologist
Knoxville TN