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