Intel has announced that is has started shipping four halogen-free Xeon processors (series 5200 and 5400). The chips are functionally the same as the previous versions, and they are drop-in compatible.
The Halogen family includes fluorine, chlorine, bromine, iodine, and astatine. “Halogens are highly reactive, and as such can be harmful or lethal to biological organisms in sufficient quantities.” Now, Its not that your CPU is dangerous to you (don’t try too eat it, though), but over the manufacturing of millions of them, it adds up to a lot of halogens. Removing them will no doubt make electronics recycling safer.
– from treehugger