[decktech]

From what I was told, lead-free solder has a large amount of flux in it to make it half-way usable. Unless you're licking your fingers after soldering with leaded solder, you may be doing more damage to your lungs with the lead-free stuff than you're doing to your body with the leaded. But I'd love to see the numbers on this.

[badsock]

I've looked into this, but I'm torn. In my mind the most compelling arguments against lead-free are: of the studies of factory workers who work every day with lead/tin solder, they couldn't find elevated blood lead levels; and that the fluxes in lead-free solders are both more exotic (i.e. less studied for adverse health effects) and a greater proportion of the solder.

The danger of absorbed lead is clear, but it's not a straight line from there to lead-free solder. Furthermore, the process that resulted in the EU (mostly) banning lead solder seems to be based more on the precautionary principle than any evidence of health or environmental damage from solder specifically. Added to that is some definite PR misinformation floating around - it's been hard for me to come to any conclusions.

[willyt]

The EU regulation is about preventing lead contamination of the waste stream.

[cmatteri]

I believe it contains on the order of twice as much flux, but I can't find a source for that at the moment. So I don't think flux fumes are much more of a concern than with leaded solder (for which you should have good ventilation or a fan). I did have a ball of solder shoot towards me when I was first getting a feel for it, so you definitely need safety glasses, though I understand this can occur with leaded solder as well, and you want to wear glasses anyways to keep clipped leads out of your eyes.