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When soldering, I have on a few occasions, used my teeth to hold a strand of solder while my hands were busy. I do not do this frequently, but sometimes I forget that solder is made of lead and I instinctively use my mouth.

How bad is doing that for my health? Is it very dangerous?

I use manly lead based rosin-core solder.

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I would certainly stop doing this. I'm not a doctor, but the Wikipedia article and numerous extra warnings about heavy metal poisoning suggest that it's quite dangerous, and you don't need a terrible amount of it to have to worry about your health. – helloworld922 Aug 26 '14 at 6:09
The flux isn't terribly great for you either. – Ignacio Vazquez-Abrams Aug 26 '14 at 6:12
If lead poisoning gets bad you can see often it as a blue line along the gum, with bluish black edging to the teeth, known as Burton line. By the time you get that far you are already in Big Trouble. – user32885 Aug 26 '14 at 7:42
Stop doing this before it makes you too stupid to stop doing this. – Olin Lathrop Aug 26 '14 at 11:46
(Technically most solders are radioactive, due to the carbon-14 in rosin flux and as an impurity. Also in your body.) – Ignacio Vazquez-Abrams Aug 26 '14 at 15:08
up vote 17 down vote accepted

It's a question of bio-availablity, which is facilitated by acids and lead that is more "absorbable" when it is in certain compounds. Certainly Lead accumulates in tissues but even sub toxic doses would take years to accumulate. The Romans used lead based wine mugs because the acidic wine would dissolve the lead which apparently made the wine more palatable (sweeter). No one is willing to do the taste test of that one, that certainly would be unethical for a tester to ask someone to do that. It took the Roman years to get to toxic levels.

As long as you weren't chewing down on the lead and having a good floss with it, it is very likely that very little transferred into your system. I know this because I have myself had blood tests. The Dr. told me it was unlikely that they could detect anything as the lead tends to be gathered into tissues and does not tend to be available in blood. the next option was a biopsy which is more dangerous that any possible lead given predicted exposure.

TLDR; don't worry about having done this, but don't continue.

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The Romans and later also recorded some significant ailments that we now know were the result of lead poisining. It's not necessarily true that they all got away with this, just that they didn't make the connection. In some places, the treatment for such ailments was actually lead oxide (called litharge back then), which of course made things worse. It wasn't until 1 1/2 millenium later that a german doctor made the connection between wine consumption (which was lead tainted) and a outbreak of colic. – Olin Lathrop Aug 26 '14 at 12:00
Most people in Roman times, if they made it to age 15, were probably in the ground by age 45 or so. Life expectancy at birth was only 20 years compared to 81.4 years (Canada) or 78.7 years (USA) now richardcarrier.info/lifetbl.html – Spehro Pefhany Aug 26 '14 at 14:08
This is the best answer because the toxicity of lead isn't an issue until it enters the blood. Metallic lead alloys, even if consumed and passing through the digestive tract, are hardly absorbed. The common lead poisoning people experience is through organic lead compounds such as lead oxides previously used to make white paints white. Otherwise it's not very dangerous. I still wouldn't recommend it - lead based solder is not food grade, and likely has other chemicals in the flux (assuming flux cored solder) that should not be consumed. If you need a "third hand" use tools designed for it. – Adam Davis Aug 26 '14 at 14:27

Heavy metals don't really flush from your system, they accumulate- so its probably a really bad idea. I try to use helping hands or blutac or piles or desk clutter to hold my bits and pieces in place. I have also seen people stab components into old erasers and other bizarre things.

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Also, tidy up - there should be enough space to put down a piece of solder on your bench when you're working. – Pete Kirkham Aug 26 '14 at 8:38
@Pete: Agreed. The more cluttered your desk, the more likely you are to injure yourself. Snipping leads or close soldering - protect your eyes and your lungs (flux smoke is very bad for you)! One of the guys at work got a snipped lead in his eye - very unpleasant. – carveone Aug 26 '14 at 10:14
@PeteKirkham That is definitely the leading problem lol. – Nikita240 Aug 26 '14 at 14:06
"its probably a really bad idea" So you don't know the answer to this question, just a guess? – Adam Davis Aug 26 '14 at 14:30
I think "its probably a really bad idea" is a perfectly valid answer, although it could use an apostrophe. – TDHofstetter Aug 26 '14 at 19:09

Good solder is only 37% lead, but I still wouldn't be doing that. As well as outright lead poisoning, there could be subtle effects below the poisoning threshold. If it drops your IQ by 10 points would that be acceptable?

Edit: As @Blrfl says, loss of mental acuity is a common symptom of lead poisoning. It's not clear that there is a threshold below which lead is safe, especially for kids.

Really, "there is no safe level of blood lead in children," said Christopher Portier, of the Centers for Disease Control and Prevention. He heads the agency's environmental health programs.

Also, if you don't care about your body, please think of the electronics- your viscous organics-laden spittle and drool won't do much for the integrity of the joints.

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Can you cite that it has ever been expected to have any effects relating to dropping IQ? I can't cite that eating apples doesn't drop IQ, so should I stop eating apples? – Oxinabox Aug 26 '14 at 11:36
@Oxinabox: Loss of mental acuity is a common symptom of lead poisoning. – Blrfl Aug 26 '14 at 13:27
Blrfl: You might want to suggest that as a edit then. it is a statement worth referencing. – Oxinabox Aug 26 '14 at 13:33
" As well as outright lead poisoning" Are you asserting that chewing metallic lead alloy will cause lead poisoning? Can you please provide a reference or citation for this assertion? – Adam Davis Aug 26 '14 at 14:31
@SpehroPefhany Pure lead is significantly more bioavailable than the 67% tin 33% lead alloy commonly used in electronics. When you say 50% greater what you're talking about is an increase from 0.87 ug/dl to 1.27 ug/dl. While many advocate zero tolerance for any non-essential lead exposure, the CDC's health guidelines are still 10 ug/dl. Digesting pure lead pellets doesn't cause you to go anywhere near the max, so putting solder in your mouth for a minute isn't dangerous. – Adam Davis Aug 26 '14 at 16:49

Although your exposure to lead poisoning may not be too great, if you are a young person and do it frequently, it could become significant. Even if the probability turns out to be very small, there is no need to settle for "small exposure" when you can easily keep it at zero!

What I do, instead of holding the solder with my teeth, I hold it with any pair of objects I have on hand - pliers, hammer, blocks of wood, etc. Obviously, if you have (or get) a "parts holder" it would be easier and much better to do the soldering.

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