Re: question

[DrBillC <DrBillC@aol.com>]

  Some facilities that electrolyze brine to make chlorine and caustic soda use
  mercury electrodes.  About 14% of the capacity in the US is this way, a larger
  percentage in Europe.  Some chlorine made over mercury electrodes probably
  goes into production of ethylene dichloride (EDC).  When EDC is made in the
  balanced process from ethylene and chlorine (97% of US capacity) then cracked
  to vinyl chloride monomer (VCM), and then the VCM is purified,  if there were
  any mercury left from chlorine made in this process, it would not distill
  over.  Thus, with very little to no mercury in the VCM there would be very
  little to no mercury in the PVC resin.
  
  For the acetylene process used by Borden the same holds true about
  distillation of the monomer.
  
  To my knowledge there are no additives currently in use with PVC that contain
  mercury.
  
  However, Sam is right.  80+ percent of the mercury in the environment arises
  from combustion of fossil fuels.  Thus, there is mercury all around you, and
  most things are likely to contain a little from this source.
  
  Bill Carroll
  Chlorine Chemistry Council