what property of PVC means it can not be used for bags?

PVC stands for polyvinyl chloride. it is a polymeric material comprising of Vinyl chloride as a monomeric unit. Vinyl chloride undergoes addition polymerization reaction to form Polyvinyl chloride.

This reaction can be represented as follows

n CH2=CHCl → [CH2-CHCl]n

The polyvinyl chloride has a very stable structure because it does not have any unsaturated bonds. Hence when PVC is released in environment it does not undergo degradation. Infact PVC matrix is left unaltered for several years when released in environment. Due to this PVC is not preferred for making bags