Hi Archie,

I posted a note several weeks ago explaining this test. PVC
isn't damaging the chips. It's the plasticizers. What she
didn't tell you was that this test gives false positive results
sometimes. There are many elements and compounds that will
complex with copper (like the copper chloride she mentioned)
and will burn green that have no chlorine in them. There are
also other colors that can appear in the flame. For example,
lets say there is a compound in the plastic that causes the flame
to burn red. This red color may be more intense than the green color
and lead you to believe that no chlorine is present when in fact it
is. It may also burn green due to a different element or compound and
make you believe there is chlorine present which in fact it is not. That
is the false positive part.

It's an okay test but VERY limited in sensitivity. That's why chemists
rarely ever use this method for identification.

Katie