Hi Archie,

This simple test is used to detect the presence of halogens (i.e.
chlorine, fluorine, Iodine, etc....) To detect chlorine in an
organic compound, such as PVC, you do just what you mentioned. If
chlorine is present, it will produce a green flame. It's a good
simple test....unfortunately it will also produce false positive
results. The presence of other compounds such as cyanide (the only
one I can think of right now...) and others will also produce a green
flame. If it's pure PVC, that wouldn't be a problem. But since
I don't know what is in the plasticizer, can't be sure that the
test is showing positive for chlorine. For example, another type
of plastic may burn green that isn't PVC depending on what other
chemicals are used in the process of that plastic.

Katie