RE: Waste landfills "safe for PVC disposal"

["Pete Thomas" <P_Thomas2@csi.com>]

The usual source of vinyl chloride is thought to be chlorinated solvents
which undergo biological degredation. The PVC industry would be very happy
if PVC could be made to revert to VCM. This would open up the possibility of
feedstock recycling. Unfortunately it breaks down to HCl which is much less
attractive from a recycling point of view.

Pete Thomas

> -----Original Message-----
> From: dioxin-l@essential.org [mailto:dioxin-l@essential.org]On Behalf Of
> Alan Watson
> Sent: 04 October 1999 22:49
> To: Multiple recipients of list DIOXIN-L
> Subject: Waste landfills "safe for PVC disposal"
>
>
>
> Does anybody know where the vinyl chloride gas comes from if not from PVC?
>
snip
>
> The research involved simulating landfill conditions in the
> laboratory and taking samples from actual landfills in
> Italy, Germany and Sweden.  According to the project
> summary, the results "allow the prediction of long-term
> behaviour of PVC products under these conditions for
> centuries".
>
> A principal conclusion of the research is that the PVC
> polymer itself is resistant in landfill conditions and does
> not break down to produce vinyl chloride monomer, the
> polymer's toxic building block.  The presence of vinyl
> chloride in landfill gas therefore does not come from PVC,
> the researchers conclude.
>
> The scientists did find some release of PVC additives,
> however, especially during the transition phase that
> landfills undergo from their early "acidogenic" state to
> the more stable "methanogenic" state.  In particular, the
> project revealed that the plasticiser DINA could leach out
> of PVC cables in significant quantities.
>
> Release levels of other plasticisers, as well as
> stabilisers, were reported to be lower, however.  For heavy
> metals and organotins stabilisers, levels in leachate were
> found to be "very low and…usually attributable to surface
> wash-off".  The scientists also estimated that PVC items
> contribute only 5% of lead and less than 1% of all zinc in
> landfills.
>
> Contacts:  ECVM (http://www.ecvm.org), tel: +32 2 676 7443.
>
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