Paxton and Whitfield makes jam jars of PVC plastic because...  

I don't count myself an...
I don't count myself an expert on this matter. I do think based on what I've learned, it's often an unnecessary plastic to use. The health effects can be detrimental, due to chemicals leaching. Environmental concerns also to leaching, pollution, and a life span of hundreds to thousands of years. Plus difficult to recycle. I'm sure a web search will produce far better info.
Personally, I avoid vinyl products whenever I can. I stick to glass, metal and stoneware products whenever cooking and storing food. Looking at getting new windows, and avoiding vinyl clad ones, opting for aluminum clad.
It's not the .000005ppm I'm concerned about, it's the sum total of every chemical we are exposed to. This includes the product, the production of product, production of materials, and all waste from the entire chain. That .00005 starts to look uncomfortably dangerous wouldn't you say?