I heard somewhere that the leads of common electronic components (resistors, capacitors, transistors etc), such as you might buy from your local electronic hobbyist store, are tinned with a lead based alloy. Is this correct? Any help with this query would be appreciated.
Charles L
Historically most components were either tinned or gold plated. The reason was for solderability.
With the recent hysterical ban on lead, I have no idea what the new products are being "tinned" with. Have fun trying to solder to them.
Al
Yes, you are correct.
This is done to increase its solderability with conventional 60/40 lead/tin (or is it tin/lead) solders used in the electronics industry. To the extent of my knowledge, having used it for over 60 years, it does not present any significant health hazard as carbon tetrachloride solvents once did.
I've also used some silver based solders, but mostly on very high-end products like Tektronix Oscilloscopes which generally don't reach the consumer market.
Sometimes you'll find gold plated leads on electronic components. This is to reduce the oxidation, while providing a very solderable surface.
On copper plumbing, the use of lead based solders is now restricted, although many plumbers still use them because the new substitutes are very difficult to work with and produce a water tight joint. Again, I've never heard of a health problem the resulted from the use of lead based solder on copper plumbing. What you want to avoid is PVC water supply plumbing, which has caused documented health problems.
Harry C.
The classic case of lead in water was the grandfather who exhibited signs of lead poisoning when no one else in the family did. Turns out he always drank a lot of water in the morning after it had been standing in the pipes overnight. Lead is also a documented cause of birth defects. All the items I buy from that surplus place in California carry a warning. In the '50s we used to play with asbestos mineral and mercury. Kids would bring mercury to school and we'd coat coins with it. Do that now and they'd have to shut the school down and decontaminate. Richard
And as a result of your experiments with mercury, are you a blithering idiot? I don't think so!
Do you know what a "mad hatter" is? (Aside from "Alice in Wonderland.") At one time, mercury salts were used to in the manufacture of hats. The people who made the hats were exposed on a daily basis to copious amounts of mercury. As a result, they got mercury poisoning.
Now, water is not considered toxic, is it? But if you are exposed to copious amounts of water, where it doesn't belong, like your lungs, you will experience symptoms also.
Moderation in all things is my motto.
Al
Spud, the real question may be what he mixed with that water before drinking it! (Just kidding.)
Realise that there are many things that display the same symptoms as lead poisoning. I'd seriously be curious what an autopsy revealed and if so did it disclose any unusual levels of lead in his body, and what his cause of death was.
The solubility of oxide coated lead in water is normally so low that it cannot produce a health risk. Remember that the Romans used it for the linings of their aquidiucts, some of which are still in use without negative health effect of any note, after over 1,000 years. My home is plumbed with copper pipes that are joined by traditional 60/40 tin/lead based solder, but the amount of exposure of the lead on the joint is so minimal that it cannot be detected on water analysis (which I actually had performed). Lots of copper in the water though, so maybe it's time for society to return to galvanized pipe in the home if someone is overly concerned.
What concerns me most from a health standpoint is that the water supply from the street main to my home is some sort of a black plastic pipe, which may be PVC or HDPE. This supply line is over 100-foot long from the street, and it poses some concern for me since PVC is now resricted from use in water supply line plumbing.
On a more positive note, I'm now 67 and have lived in this house for the past 30 years, and suffered no ill effects. My children are now in their 30s and 40s, also having displayed no ill effects. I've also ingested small amounts of led fumes throughout the past 50+ years from soldering and working with solder pots, still without ever having any ill effects.
I have no doubt that the toxic effects of lead poisoning are now well documentated, but most of the case studies reveal these cases to be based upon small children that for some reason ingested lead based paints containing enormous amounts of lead by by chewing on products containing them, or by workers in industry who absorbed toxic level of lead fumes in the course of their daily work.
In closing, years back I owned a printed circuit board manufacturing facility in which the resist employed was a tin/lead solder plate. For gold plating the contact finger of the circuit boards, a chemical etch was employed to remove the solder coating before a cyanide based gold plating was applied. Curously, anyone that worked with this process was required to have a state lawy imposted blood test for lead, but not for the far more deadly cyanide. Still, no one including myself ever failed that blood test for lead. No one was tested for cyanide, which I assume if it doesn't kill you, is relatively harmless.
Just for the record, the real health hazard in the printed circuit business is not the lead, or cyanide, but organic solvents that we use in the process. Things like trichlorethylene, methyl and ethyl acetate, acetone, MEK, etc. None of these are federally regulated. Many of these are capable of making you feel a bit high or dizzy, then fall into an uncouscious state, with death immediately followiing.
Go figure. To me it's obvious that neither the regulators or the media have any hint of a clue.
Harry C.
Spud, the real question may be what he mixed with that water before drinking it! (Just kidding.)
Realise that there are many things that display the same symptoms as lead poisoning. I'd seriously be curious what an autopsy revealed and if so did it disclose any unusual levels of lead in his body, and what his cause of death was.
The solubility of oxide coated lead in water is normally so low that it cannot produce a health risk. Remember that the Romans used it for the linings of their aquidiucts, some of which are still in use without negative health effect of any note, after over 1,000 years. My home is plumbed with copper pipes that are joined by traditional 60/40 tin/lead based solder, but the amount of exposure of the lead on the joint is so minimal that it cannot be detected on water analysis (which I actually had performed). Lots of copper in the water though, so maybe it's time for society to return to galvanized pipe in the home if someone is overly concerned.
What concerns me most from a health standpoint is that the water supply from the street main to my home is some sort of a black plastic pipe, which may be PVC or HDPE. This supply line is over 100-foot long from the street, and it poses some concern for me since PVC is now resricted from use in water supply line plumbing.
On a more positive note, I'm now 67 and have lived in this house for the past 30 years, and suffered no ill effects. My children are now in their 30s and 40s, also having displayed no ill effects. I've also ingested small amounts of led fumes throughout the past 50+ years from soldering and working with solder pots, still without ever having any ill effects.
I have no doubt that the toxic effects of lead poisoning are now well documentated, but most of the case studies reveal these cases to be based upon small children that for some reason ingested lead based paints containing enormous amounts of lead by by chewing on products containing them, or by workers in industry who absorbed toxic level of lead fumes in the course of their daily work.
In closing, years back I owned a printed circuit board manufacturing facility in which the resist employed was a tin/lead solder plate. For gold plating the contact finger of the circuit boards, a chemical etch was employed to remove the solder coating before a cyanide based gold plating was applied. Curously, anyone that worked with this process was required to have a state lawy imposted blood test for lead, but not for the far more deadly cyanide. Still, no one including myself ever failed that blood test for lead. No one was tested for cyanide, which I assume if it doesn't kill you, is relatively harmless.
Just for the record, the real health hazard in the printed circuit business is not the lead, or cyanide, but organic solvents that we use in the process. Things like trichlorethylene, methyl and ethyl acetate, acetone, MEK, etc. None of these are federally regulated. Many of these are capable of making you feel a bit high or dizzy, then fall into an uncouscious state, with death immediately followiing.
Go figure. To me it's obvious that neither the regulators or the media have any hint of a clue.
Harry C.
-- As long as you don't carry moderation too far...
I believe it's 60% lead and 40% tin.
Lead is not used much anymore for environmental reasons. A common alloy used for tinning component leads nowadays contains Sn and Ni.
In my teens (35 years ago or so) I saw a friend actually pour the stuff on a cloth and put it up to his nose and sniff it. He survived! I think what saved him was that he lost consciousness so quickly that he didn't breath much in. Remember the aftermath of the death blow to Apollo Creed in Rocky IV? My friend went the same way, eyes rolled back, fell forward on his face (went face-first into a deep freeze) and didn't even attempt to stop himself; he was out like a light. Scary.
Tom
Read up on the history of carbon tetrachloride, because the toxicity issue was a puzzle for many years. For years it was used as an industrial solvent, a standard solvent in every radio and TV repair shop, and even sold as a safe, non-flamable household cleaning agent under the name Carbona Cleaning Fluid.
Most users experience no adverse effects, still other died. For years, no one could figure out what the difference was.
Some bright guy in the 1950s finally solved the mystery and found out what was happening. It turns out that if you had even a small level of alcohol in your bloodstream, the combination with carbon tet was lethal and had no medical cure. I don't recall if if was your liver or kidneys that the combination destroyed. Perhaps someone else here does.
At any rate, rather than banning alcohol, the government banned the general sale and use of carbon tetrachloride.
This made big news in the electronics magazines of the 1950s. Later, trichlorethlene was introduced as a safe replacement for carbon tet but it turned out to be carcinogenic. Later a number of freon solvents were introduced, but not only were they lousy solvents, they were later discovered to pose an environmental risk and banned.
Likely the only general purpose grease and oil solvent available on the market today is unleaded gasoline, which sort of takes us full circle back to the starting line! :-)
Harry C.
Al wrote
Harry C. wrote
Yes I do remember that cleaning fluid, as well as the glass globes that were used as fire extinguishers "toss at the base of flames" Some even had a heat sensitive trigger that would release the carbon tet in a fire. Al, I was always leery of messing around with that mercury so as a result my exposure was limited. Now I just read in Discover magazine that they discovered a genetic marker for sensitivity to mercury. I think that exists with other chemicals too. I worked in the photo industry for many years and always tried to use tongs and rubber gloves in working with methol the developing agent. I met a few old timers who had developed an acute reaction to it. They couldn't be in a building where it was being used without developing a severe reaction.
I grew up on a farm in the west and in the '50s we were using two weed killers. 2-4-D and 2-4-5-T. The first was a broad leaf killer and the
2nd killed everything. I never liked either of them but was particularly afraid of 2-4-5-T. I took a lot of ribbing over my mask, rubber everything goggles etc. but I figured anything that anything that could knock down my mom's roses 50 yards down wind, 5 mph wasn't nice. It was bright orange. Guess what that was called when I saw it on TV in Viet Nam? Now they actually use a chemical to keep the canals and ditches clear of moss. It's so dangerous that the last time I was out there a county guy accidentally sprayed it all over himself. He died. I suppose that's why there are no frogs or toads in those irrigation ditches anymore.Sometimes the hazards are obvious sometimes we're just ignorant. I saw kids at the Buster Brown Shoe store stick everything they could into that fluoroscope they used to check where your toes were in the shoes.
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