I would also welcome some information on this.

The Wikipedia article http://en.wikipedia.org/wiki/Polyvinyl_chloride isn't bad, but I think it may contain a lot of input from industry sources who want to put the product in a good light. For example, it seems a bit surprising that dioxin emissions from incineration should be unaffected by the amount of PVC in the waste.

PVC is made from vinyl chloride monomer, identified 30-40 years ago as a carcinogen. Sounds bad, but the chemical industry uses lots of toxic materials and - with a few spectacular exceptions - generally takes steps to protect workers when a risk is identified. So this doesn't make PVC special. Of course, the petrochemical industry as a whole has substantial greenhouse gas emissions, and PVC production must be responsible for a share of those. I don't know the figures. If you want to avoid petrochemicals altogether, you'll have to go back to cables insulated with paper, cotton and rubber.

Most of the concern about PVC in use, relates to plasticisers rather than PVC itself. That's an issue for cables, but obviously not for unplasticised (rigid) PVC in windows, guttering etc. The risk to humans from electrical cables must be small compared with the risk from PVC in medical equipment where it may be in direct, prolonged contact with body fluids. The EU is phasing out the most hazardous plasticisers.

There are firms which claim to be able to recycle all the plastic in cables, as well as most of the metal. That keeps it out of landfill for the time being, but the reclaimed plastic material is low-grade, e.g. surfaces for horse riding. See http://www.universalrecyclingcompany.co.uk/cable-recycling.php

Until I see some convincing evidence that PVC is causing harm, I am inclined to take the view that every kilogram of PVC is a kilogram (approx) of petroleum diverted away from use as fuel. That's to say, it represents a couple of kg of greenhouse gases that weren't emitted. Not very convincing, I know...

it depends what the insulation material is, but yes that's the reason it's often specified in eco houses.

PIR insulation shouldn't be a problem according to this manufacturer anyway, but I think EPS, XPS and maybe PUR do need LSOH

>>If electrical cables are installed in contact with the insulation there should be no detrimental effect to the PVC coatings of the cables, whereas other types of insulation may cause issues.

http://www.ecotherm.co.uk/about_us/faq.aspx

Thanks for your comments.
I still haven't been able to find any convincing evidence that the use of pvc cables (as opposed to LS0H) in domestic dwellings carries a greater risk to health or the environment. I'd also like to think that when they reach the end of their service life in say 40-50 years time they'll be 'properly' disposed of rather than just being burnt!