Halogen Free PCB
Halogen free PCBs still aren't that common and all of the bugs aren't worked out of the systems yet, but they are starting to show up here and there. I suspect that like RoHS a few years back, we will be seeing more and more as time goes by.
If you do feel the need to try out a Halogen free PCB, our experience here suggests that they are more sensitive to moisture than standard FR-4 and are a bit more brittle. That might be an issue when de-panelizing boards or when putting a lot of mechanical stress on a pcb.
An article in "Future Circuits International" suggests that some of the replacement flame retardant chemicals may have other environmental risks too, but I guess that seems to be the case with just about everything we pull up these days to replace something that is a known hazard.
Anybody with some good practical experiance here, feel free to chime in.
No matter where you go, there you are