I wouldn't get worked up about this. I watched the programme, it was a typical "shock, horror, probe" tabloid type effort by a journalist who I suspect didn't really understand in depth what they were delving into. They were very vague about what they measured and gave absolutely no numbers, just some impressive looking plots in glorious technicolour with big spikes in yellow/red, ooooh dreadful isn't it? VOCs can include dangerous carcinogenic compounds like benzene and formaldehyde. Well yes, but how much of these did you measure, total mass and/or concentrations?
Certification will have required certain levels of the regulated pollutants to be met under the test cycles used, it's all closely specified. What they were referring to as VOCs will come under the HC measure for emissions. It's no surprise that a warm diesel will produce lower spikes of VOCs than a cold start petrol engine, consider the fuel used. From what I could tell they drove the cars around on an undefined route, so whatever they measured won't correlate to any certification measurement.
If they are prepared to document exactly what they did and what they measured, and how that compares to either legal levels or safe levels, it can be assessed and evaluated, otherwise it's just chatter.
When you refuel a petrol car, if you let a couple of drops of petrol fall on the forecourt it will amount to a spike in VOCs. High, low, dangerous?
(Edit - just examples of other things to not get worried about - fruit juice can contain arsenic naturally, and apple seeds contain cyanide. Is it an issue? Tobacco smoke is one of the most dangerous mix of carcinogens we regularly get exposed to. Alcohol drink anyone?)
