a week ago, i was participating in a solder workshop
they told us solder had like 60% tin and 40% lead, so i think its qutie hazardous. (we had to wash our hands after handling it) though it has a low melting point (200 C), im not sure about the boiling point.
it gives off some toxic fumes, and since i had to lean near to the solder to see how well it had soldered, i got a nasty whiff of the pungent smell
and that was with working with a thin wire of solder, trying to work with liquid solder would probably be giving off alot of fumes. also becareful, because solder can splash around. i've had a few on my hands, but they do no lasting harm.