I haven't seen anything concrete about dioxins coming from the burning of vinyl chloride. From what I've seen, the known dioxin problem is from the burning PVC,

I haven't seen anything concrete about dioxins coming from the burning of vinyl chloride. From what I've seen, the known dioxin problem is from the burning PVC, which was in bulk cars that were ignited by the derailment (as opposed to deliberately set on fire). FWIW Only one vinyl chloride car was listed as leaking. I would think the alternative was to bring in mobile pumps, new tanker cars, and possibly chillers. And that should probably be made the default standard, rather than defaulting to "controlled" release in an emergent situation.