Avoiding the PCB Bandwagon

In response to Chrys Shea’s column on halogens and halides, a note of correction: I think the abbreviation PCB (in the context used) is for polychlorinated biphenyls, not bisphenols.

My real interest in writing, however, is to question whether we are getting worked up over nothing, as we did with lead-free. Nearly two years after RoHS, I doubt anyone can show a statistical improvement in the safety of our environment. I still have lots of lead in my life – try the battery in my car. I’m probably 1000 times more at risk from servicing the battery than I ever would be from the assemblies in my consumer electronics. I handle lead every year when my family does our annual Thanksgiving Day shoot (with live guns and lead-tipped ammo) – more than I’ll touch in a lifetime in the electronics industry.

An article published a few years back shared my attitude about the tilting at windmills that characterizes RoHS and many of our other environmental escapades. The author noted there might be [italics mine] some small advantage to removing halides and halogens from our products – in contrast to removing lead, which is just about an environmental draw. But even that small benefit assumes a really ugly compounding of “what ifs” and “supposes.”

OK, so we might have to be careful recycling assemblies, so as not to incinerate them at conditions where dioxyns are produced. With the movement afoot to have companies accept discarded products for recycling, I suspect we can manage to avoid making the nasties. It’s one thing to have a board here and there end up in the trash, and quite another when you manage tons and tons of refuse, all of similar construction and requiring similar, careful disposal.

Shea also mentions the presence of these halogens and halides in a fire can produce toxic gases. Just how much equipment will produce enough fumes to be of consequence? Even in the fully decked-out home – several computers, printers, home entertainment devices, etc. – we are talking about a pound or two of actual PCB material (not counting components, etc.). And in the most tragic fire, it is not all going to go up in smoke simultaneously. In a small, closed room, there might be enough to be hazardous. But vented to atmosphere (and I’m assuming that the house is a total loss here), we aren’t going to present as big a hazard as some other materials that burn: carpets, drapes, clothes, household chemicals, even the plastic cases on the products that house the assemblies.

I’m not jumping on the bandwagon on this one. If there is a technically superior way of making PCBs (not the biphenyl kind) and assemblies that avoids the use of chlorine, bromine, fluorine, etc., then great, let’s do it. I’m not suggesting we stop trying. But until there is a recipe that is, in all important ways, better, let’s not get too worked up over halogen windmills.

David Odenwalder