When Electronics Get Five O'Clock Shadow

I looked around to get a feeling for how dangerous tin whiskers really are. Apparently, tin, zinc, and some other metals can form metal whiskers up to 1-2 mm long over the course of months to several years. Alloying (eg, with lead) is one of several ways to reduce but not prevent whisker formation.

In the Risks Digest, I see only two mentions to metal whiskers (and a third to ferret whiskers . So it appears that the problem is relatively rare (or perhaps rarely diagnosed/reported accurately).

Looking around, I found a article/presentation (appears to be on or after 2002) that focuses on the dangers of tin whiskers in military electronics and appears to be worth a close look. One thing that was disturbing was that a lot of electronics was being switched to pure tin and that many of the parts suppliers (the article claims one half of those surveyed) weren’t aware of tin whisker formation. NASA, who “prohibits” the use/presence of pure tin surfaces still had “1-2% pure tin parts” enter their satellite systems at some point (date not specified).

The ecological dangers seem overrated especially when compared with lead-acid batteries. From the paper:

Note: In the EU starting in 2006 – Electronic Solder (0.49%) will be banned, but Lead Batteries (80%) will be exempt. Reason: “cars can not run without batteries but the electronics industry can manage without lead .” (Chart is based on Consumption) [chart came from "Advancing Microelectronics", Sept/Oct 1999, pg 29, vol 4]

[...]

Note: EU exempts lead acid batteries from the landfill, but prohibits consumer electronics from disposal. (Chart is based on Lead containing Discards as a Weight Percent) [EPA, 1998]

From the chart refered to in the second quote, consumer electronics seemed responsible for 4.4% of lead leachate in US landfills, but batteries were responsible for 48.1%.

This seems to me to be a gross imposition on the electronics industry without a good reason. If lead is really that bad, then they should regulate more sternly battery producers, who are the prime consumer of lead and producer of lead tainted waste.

I think the electronics industry was just a target of opportunity. A considerable portion of the political side of the Green movement seems driven by ideology rather than practical considerations. Perhaps they need to demonstrate that they are “improving” the environment via imposing regulations on industry and commerce. Ie, a politician who does nothing may fall out of power.

Also glancing at the table of EPA contributors to lead leachate, I see three items ahead of consumer electronics, namely, batteries, CRTs, and glass/ceramics. The first two are virtually untouchable from a Green point of view because they already serve an ideological function. The lead-acid battery is still a decent choice for an electric car and for a storage system for home based power systems. Meanwhile the lead in CRTs (cathode ray tubes in TVs and computer monitors) shields millions of people from the CRTs’ electromagnetic field radiation (including a small amount of soft X-Rays, I understand). I believe that the lead is required in CRTs to meet existing regulations on EMF emissions. The category of “glass and ceramics” may be regulated. It is only modestly larger than consumer electronics.

So politically, electronic devices are among the largest categories of lead sources that can be regulated more with relatively little consequence.

I think you hit the tin whisker on the head, Karl. I realize that we all have blind spots when it comes to our political idealology. One goal I have for 2005 is to examine mine closely. The EU’s blind spot, however, could be extremely hazardous to the environment and the environmental movement. It would seem to me that in the long-term, dealing with the real dangers of lead from all sources would give environmentalists more credibility and elicit better cooperation. But maybe I’m just an idealist.