as above, and PVC is normally hard (like LP's and pipe, etc...). The soft stuff used all over has added plasticizers (sp?), some of which have been found to be carcinogenic. They leach out, and outgas some.
I seem to recall PVC releasing pretty nasty shit when it's burned, as well, so there are concerns of household waste being incinerated.
IIRC, a few of the plasticizers were banned in the EU.