[mrob]

Agreed. This, not lead fumes, is the real danger of leaded solder. You can't hand solder reliably without cleaning the iron, but both of the common cleaning techniques (damp sponge and brass wool) inevitably break the soldier into tiny balls, which bounce and roll all over the place. They can get caught in clothes, and from there they might end up getting into food. With the safe dose for lead being zero, I don't think it's worth the risk.

[trhway]

During my elementary school years (beginning of 198x USSR) the lead was a go to material for a lot of things - using campfires we melted the lead out of Navy cables and batteries (from the Navy dumps), no gloves, no masks, and made a lot of things out of it - toy action figures/soldiers for example, weights and weighted hooks for fishing, bullets for DYI guns, gear for some games, etc. (I'm a drop-out from PhD. program at a top Russian Math school - didn't see money in it and thus went into programming, so i guess the few IQ points i lost due to lead (i score usually about 130) is what caused such poor judgement :)

[foldr]

None of those activities pose the same risks as soldering using leaded solder, for the reasons given above. You are unlikely to end up ingesting significant quantities of the lead.

It's probably worth emphasizing that this is risk with home soldering, where you're likely to eat and solder in relatively close proximity, and without being completely rigorous about changing your clothes and vacuuming up every last spec of dust.

Lead free solder works fine, so there is really no reason to take even a small risk if you are soldering as a hobbyist.

(And yeah, it's probably a small risk. By all means use leaded solder if you think the slight additional convenience outweighs the small risk of significant lead exposure.)

[trhway]

During 6 and 7 grade i was at electronics hobby club where beside soldering of new stuff we also did a bunch of desoldering too as the main source of electronics components where the PCBs pulled out from the pieces of missiles/torpedoes/etc at the Navy dumps. There was no any "safe handling" procedures wrt. lead. Granted though that washing hands before eating has been ingrained in me (and as far as i saw - in my friends too) from the early childhood.

Don't get me wrong - I'm not arguing about un-safety of lead. I'm just wondering how things can be different when one knows vs. when one doesn't know. Statistically speaking a bunch of people i knew though the childhood/school should have some lead damage. Many of them went to become military/Navy officers (growing on a Navy base biases your choice that way, i also did an attempt to go to military officers college). As my childhood was pretty typical for that time in USSR, I wonder what systemic effect missing few IQ points by a large number of people can have.

[foldr]

I'm not quite sure what your point is. Of course we know that people can do lots of soldering using leaded solder and not suffer any obvious harm. It's not an enormously risky activity. It just seems pointless to take the risk when you don't have to.

[CamperBob2]

Bioavailability of metallic lead is practically nil.

[foldr]

Eating lead is the worst case scenario when it comes to lead poisoning. Yes, your body will manage not to absorb much of the lead. But you can't seriously be suggesting that lead is safe to eat!

I'm not sure if maybe you were misinterpreting 'end up in food' in the post you're replying to. The GP isn't talking about the lead getting into the soil and then indirectly into the food supply. They're talking about the scenario where some little balls of solder are literally inside the sandwich you're eating.

[CamperBob2]

I don't know anyone who would recommend eating while working with lead solder. At some point, common sense has to come into play.

Fortunately, common sense is enough. Metallic lead simply isn't that toxic in the grand scheme of things.

[foldr]

As has been repeatedly said, the problem is that small balls of solder can persist in your home environment, which makes it difficult to be sure that you’re not eventually eating them. For example, solder balls caught in your clothes or hair can fall off and land in food or drink that you’re preparing. It’s very difficult to quantify how likely this is to happen, but it’s not that outlandish of a possibility.

Now of course you could be really careful about changing your clothes and washing after you solder. Then again, you could also just use lead free solder, which works fine.

[CamperBob2]

Or you could cite some reproducible statistics indicating that this actually happens in real life, in quantities that affect human health and development rather than mass-spectrometry plots.

Fact is, there was never any actual science behind the RoHS prohibition of lead solder. Not while lead-acid battery production was still permitted, certainly. The same people who thought it was a good idea to do this also thought it was a good idea to shut down all the nuclear plants in Germany because of something that happened at an unrelated facility in Japan. We're not allowed to argue with them because reasons.

[foldr]

We are not discussing the question of whether leaded solder should be banned, but the question of whether it is advisable for hobbyists to use it in a home environment. RoHS prohibitions on leaded solder have nothing to do with concerns about the safety of home soldering.

I'm not sure why you think that the absence of relevant safety data argues in favor of using leaded solder for home soldering. Surely one should err on the side of caution. I use unleaded solder myself without problems. Why then would I want to take on the additional risk of using leaded solder? It's worth noting that there is no known safe dose of lead ("there is no lower threshold to the dose-response relationship below which lead exposure is treated as safe" [1]). If you are spraying little balls of lead around your home environment, it's obvious that there is a non-zero risk of eventually ingesting some of them. People aren't doing scientific studies to prove that because it comes under the heading of the "bleedin' obvious" :)

Of course everyone can make their own decisions here. If you really want to use leaded solder then go ahead. What I don't quite understand is why some people react so strongly to the precautionary advice to use unleaded solder.

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4961898/