[Noisebridge-discuss] which is more toxic to use, leaded or no-lead solder?

[Kragen Javier Sitaker]

On Sun, Jul 25, 2010 at 10:04:16AM -0700, Lee Sonko wrote:
> I just purchased a spool of this no-lead solder
> (http://www.all-spec.com/products/KWLF27500.html) for the Crucible
> Youth Kinetics program. I've had a few discussions with people about
> the toxicity of using no-lead solder vs leaded solder. Which solder is
> more toxic to work with, especially considering that children as young
> as 8 will be using it?
> 
> 
> Some notes:
> * I've been very pleased with how well this solder works. It flows
> just as well as leaded solder!

Does that mean that it melts at just as low a temperature, say because
it contains a little indium or gallium or something? The main issue I've
read about with RoHS solder is that it needs a higher temperature to
melt, which produces more toxic (but delicious-smelling) fumes from the
rosin.

> * Assume the students wash their hands after using either solder
> * Assume reasonable though not "excellent" ventilation

I don't think RoHS solder has been in wide use for long enough to come
up with a definitive answer to your question. 

Although I'm not a toxicologist, I'd imagine that the drawbacks of
leaded solder would be less serious for adults, whose brains are
undergoing neurogenesis more slowly, if at all.

I'm not aware of any epidemiological studies showing higher lead levels
in electronics technicians, although I haven't looked. I *am* aware of
epidemiological studies showing higher cancer levels in weldors. Given
that leaded solder has been in use for many decades, this probably means
that the health risks of leaded solder to adults are relatively minimal.

No such statement can currently be made about higher-temperature RoHS
solder.