I don't think that halogens are considered a danger anymore, not since ozone has been declared a polutant. Ozone was listed on the EPA web site as being the most plentiful polutant in Seattle. Phoenix also has high ozone days. I don't get it, maybe the ozone from the whole in the ozone layer is hanging around the cities. But then I also thought that ozone was extremely unstable and disipated quickly, all by itself.
To my knowledge, the problem with halogen [bulbs] was that they caught fire easily.
The ozone, IIRC, is a desirable protective layer around us and there used to be a push for aerosols to be eliminated in favor of sprays as they were frienlier to the ozone.