I wash my hands after handling electronics, regardless of whether I think they're leaded or not. If I only ever handled clean electronics then my only concern would be ingesting heavy metals, but I also handle burned/failed and elderly electronics too.
You should wash your hands after handling electronics, but its lead content is largely irrelevant. The lead generally stays where it is. However, flux, seepage from capacitors, and various breakdown products from ageing components can be quite nasty.
It's supermarket trollies that really bother me...
My bench only has MY dirt on it.
BT
I know guys that use lead-free when they aren't required to for fear of lead.
LOL, the flux in the lead free stuff is far worse than leaded+rosin
What are our sources for all of this information?
The first question is kind of funny. Only after handling lead, but for example never after a visit to the toilet?
I wash my hands when they are visibly dirty, and when I know I have touched something that I would never put my mouth on.
And when I am about to handle something that must not get dirty fingerprints.
I don't think I have ever washed my hands after using leaded solder or using my old equipment full of wonderful leaded solder, if they're not visibly dirty.
I guess I just forget.
It's far worse inhaling the flux fumes in my opinion, than getting a minuscule amount of leaked electrolyte on your tongue.
For those that do not know, the taste is quite bitter. Like denatured alcohol... :p
I do appreciate the humor on this thread, including taking the word "only" literally, and also about washing the hands before smoking cigarettes.
I also would like to see some more sources for some of this information. I'll probably do a little studying here and there on some of the things mentioned above, and I'll share links if I find them useful.
I thought this stackexchange answer was very thorough:
http://electronics.stackexchange.com/a/19086/83333(The top answer, with 53 votes).
This was a good paragraph:
Rosin cored solder fume is a well established respiratory sensitiser, and is one of the main causes of occupational asthma in Great Britain. Colophony fume is generated at temperatures above about 180 C, well below the temperatures associated with soft soldering. So significant concentrations can be evolved. The higher the temperature, the more fume is generated. The lead free solders introduced since the Restriction of Hazardous Substances Directive was implemented in 2006 tend to have higher melting points than the traditional lead:tin types. So, ironically, the elimination of lead for environmental reasons has led to a potential for increased exposures to a potent asthmagen in the workplace.
https://diamondenv.wordpress.com/2011/01/06/lead-exposure-during-soldering/
What are our sources for all of this information?
Have you learned nothing? This the internet!
Nobody needs actual sources for information, 'trusty' meters don't need checking or calibrating, and no person has ever actually derived practical benefit from something they learned on a degree course.
The following page had some neat info that I'll quote below:
http://store.curiousinventor.com/guides/how_to_solder/kind_of_solderIt also was well referenced.
Lead boils at over 3000 °F, and in most cases soldering tips should be kept below 750 °F, so it is highly unlikely that gaseous lead is present in the fumes. The fumes are actually from the flux boiling, which still isn't great for you--many of the chemicals found in cigarette smoke are found in flux fumes: formaldehyde, toluene, alcohols, and hydrochloric acid to name a few. Most of the public health literature indicates that asthma is the major health risk from soldering fumes (not cancer or lead poisoning). When acquired, it is permanent and can cause hyper sensitivity so that even small amounts of fumes bring on attacks. Surprisingly, scientists have not been able to determine what exactly in the fumes cause the health defects, nor what amounts are harmful. Yet, the British health department has set exposure limits of .05 mg/m^3 over 8 hours and .15 mg/m^3 over 15 minutes. I believe these limits have been shown to provide a safe work environment and also one for which the necessary systems / filters are financially reasonable.
The conspicuous lack of emphasis on lead poisoning in all the research done by the UK health department implies that these particles are of little concern.
It had a link to a Weller page that said that lead-free solder fumes are more toxic and require better ventilation, but the page doesn't seem to exist at that address anymore.
For those who want scholarly justification try some of the following.
http://jama.jamanetwork.com/article.aspx?articleid=256412This is a widely cited paper on the epidemiology of lead poisoning. In the first page summary (which is free) are several pertinent facts about lead poisoning.
https://www.cdph.ca.gov/programs/olppp/Documents/medgdln.pdfGood summary of health effects, ingestion paths and efficiencies. No direct information on typical exposure in electronics work.
http://www.aafp.org/afp/1998/0215/p719.htmlThis has a list purported to be the industries most associated with overexposure to lead. Electronics use of solder is not on the list, but there is no quantitative evidence backing the list.
http://www.hse.gov.uk/statistics/causdis/lead/lead.pdfThis shows blood levels in industries which Britain regards as significant exposures to lead. You can put the information together to show that even in the worst industries (smelting lead for example) exposures are marginally acceptable. Electronics does not show explicitly in the list, though it may crop up in the "other" category.
After reading through these and others I remain convinced that solder is low on the list of hazards we face. Don't eat it. Don't sweep your bench onto your meal. Staying away from the flux fumes will keep you safe enough from the lead vapor.
AFIK the main reason for removal of lead from electronics was primarily an attempt to keep lead out of the water table from landfill. While it is a good thing to reduce exposure to harmful substances often the risks are grossly overstated by people who don't have the full facts. I love in a house built in the 1930's and the water company will not replace the lead pipes that supply water to the house because the amount of lead is considered within safe limits.
We used to have multiple sources of lead in fairly high doses particularly from leaded fuel, but now most sources of lead exposure have gone, fuel, paint, plumbing are all lead free now and children aren't sucking on miniature lead soldiers any more. My personal take on it is that a typical hobbyist use of lead solder and components isn't going to have any significant impact. However in order to comply with safety rules the lead solder we sell has to carry advice to wash your hands simply because we live in a world where the lawyers are in control.
Chances are that the cleaning products that you use to try and keep yourself and your home clean and smelling 'nice' are causing you more harm. Volatile organic compounds in fragranced products have been shown to cause damage to DNA.
Lead doesn't turn unto vapor until over 1600C, temperatures never reached soldering.
No, lead can exist
only as a gas/vapour above its boiling point (2022K, 1746C) but that doesn't mean that lead vapour doesn't exist below that temperature. Just as water vapour exists between its freezing point (strictly triple point) and its 100C boiling point.
I can't find a phase diagram for Lead or a Lead-Tin eutectic alloy that extends high enough in temperature to show the vapour phase, but it's there. I can tell you that the melting point of lead is 600K (327C) and the vapour pressure of lead is 1 Pa by 978K (705C) and keeps going up until it reaches ~100kPa at boiling point. If you compare the vapour pressure with that of any of the gases that make up air (including water vapour) it's pretty clear that the absolute quantity of lead vapour that could drift off into the air from molten solder at temperatures compatible with life is tiny but to say it doesn't exist is, strictly, incorrect.
I spent too long at school and university in laboratories to have anything other than an instinctive handwashing reflex if I've been involved in any activity that might conceivably, possibly resulted in me picking up anything one might describe as contamination. Microbiology labs are the best training for this - it's not the possibility of contaminating yourself that matters so much as that you might contaminate what you're working on and render your efforts to date worthless.
So electronics attracts no more or less handwashing, for me, than any other activity.
About the same amount as after any other activities. You are far more at risk from bacteria, greases, resins, and any number of other things than from the lead.
Idiots. You missed idiots from the list, by far the most dangerous thing in my opinion.
Lead fear, like radioactivity fear is promulgated by folks who have no idea what numbers are, or how to use them. Since they don't have this tool the choices become binary. It is either good, or bad. Lead which is bad when put into the air by the ton as a byproduct of combusting leaded gasoline, or in paint which might be a problem for anyone who actually eats the paint gets translated into "Lead is bad".
I'm pretty much convinced that the harm done to your health by worrying about the things people, particularly the Daily Mail
1, tell you to fear as threats to your health does more harm than all the ostensible threats put together.
[Editted to add:] I can smell the Hasselback potatoes baking in the kitchen over which I have just poured a mixture of
- Olive oil - apparently supposed to make me live forever.
- Butter - apparently this will kill me.
- Rosemary - full of Volatile Organic Components which surely are the devil incarnate
As to what the Daily Mail would have to say about the sausages, peas,
Italian carrots and gravy that is going with these I dread to think.
1 The Daily Mail is a tabloid, right wing British daily national newspaper catering to the middle aged of middle England which can't go a day without publishing a headline that "X causes cancer", or some other left field, baseless, and marginal health claim or health fear. Political rather than medical problems are all blamed on immigrants and foreigners (Daily Mail code for anyone who's not got pasty white middle English skin). Substitute your local equivalent.
One of my first jobs involved the installation of antenna masts and prior to the advent of silicone sealants we used a bitumen based product called Ormonoid, black as tar it was and nobody instructed me to use a stick when applying it so I used my hands instead, sticks like shit to a blanket.
I recently patched some pavement with a similar product that contained asphaltum. Not only was it extremely sticky, but it also smelled like cat piss. I resorted to using naphtha to clean it off my hands.
There are antiseptics made of coal tar ("ichthammol") which while looking very similar are actually not that sticky.
Maybe medical people were worried that pregnant ladies were soldering and eating the lead in solder? I am a guy and I worked with leaded solder all my life and I never got lead poisoning because I never ate the stuff. For many years copper water pipes were soldered together with leaded solder and nobody got lead poisoning. My drinking water comes from a lake that has lead down there and nobody is poisoned.
By the way, you can get poisoned by silver also. Yet it's used for utensils; in fact I just spent a few hours polishing a bunch. No signs of poisoning yet...
By the way, you can get poisoned by silver also. Yet it's used for utensils; in fact I just spent a few hours polishing a bunch. No signs of poisoning yet...
I believe this is different because it takes a much higher intake of silver to get poisoned. People die every year in the USA from drinking too much water too, but generally it would be very difficult for someone to be able to drink that amount without trying hard. Whereas with something like lead, we know that children can get seriously harmed by it from playing in contaminated dirt and not washing their hands before eating. The amount of lead on their hands is miniscule and invisible, yet it still poisons them.
Also, I just wanted to mention that the common argument that "I've done such-and-such for years, but it hasn't harmed me" isn't good science, since lots of people can say the same thing about smoking cigarettes as well. My grandpa chain-smoked every day of his adult life and lived happily and healthily until the age of 95. I used to be a smoker for years too, and noticed no negative consequences on myself, but that doesn't mean that smoking is safe nor that it doesn't harm other people.
I don't think anyone here was relying on such arguments as their sole evidence, and I think it's still useful to share information like that, but it should be used with the rest of the available evidence.
Whereas with something like lead, we know that children can get seriously harmed by it from playing in contaminated dirt and not washing their hands before eating. The amount of lead on their hands is miniscule and invisible, yet it still poisons them.
Do you have a reference for that? How do "we" know that such is the case?
Whereas with something like lead, we know that children can get seriously harmed by it from playing in contaminated dirt and not washing their hands before eating. The amount of lead on their hands is miniscule and invisible, yet it still poisons them.
Do you have a reference for that? How do "we" know that such is the case?
The topic of childhood lead poisoning is non-controversial, with every major health organization in the world agreeing on the causes and effects. Of course this doesn't mean that the information they're asserting is correct, but that does give me freedom to say that "we know" this, since there is a general consensus on the data. It's similar to saying that "we know" cigarettes are harmful.
Since there are countless studies and references that show how harmful lead exposure is to children, it feels silly to make a list of them. But here's one from the World Health Organization that is a good summary:
http://www.who.int/ceh/publications/leadguidance.pdfHere is a quote from that document about what I wrote above, but please read the entire document before complaining about this specific quote:
Ingestion is the most common route of exposure to lead for children. Once
lead has been swallowed, it enters a child’s body by absorption from the
gastrointestinal tract. Children’s innate curiosity and their age-appropriate
hand-to-mouth behaviour result in their bringing lead-containing or leadcoated
objects, such as contaminated soil or dust, to their mouth, and
thus greatly increase their risk of exposure.
Would anyone like to provide some sources that say it's safe for children to ingest lead? Good luck finding them.
[Editted to add:] I can smell the Hasselback potatoes baking in the kitchen over which I have just poured a mixture of
- Olive oil - apparently supposed to make me live forever.
- Butter - apparently this will kill me.
- Rosemary - full of Volatile Organic Components which surely are the devil incarnate
Shame on you, you forgot the garlic
The topic of childhood lead poisoning is non-controversial, with every major health organization in the world agreeing on the causes and effects. Of course this doesn't mean that the information they're asserting is correct, but that does give me freedom to say that "we know" this, since there is a general consensus on the data. It's similar to saying that "we know" cigarettes are harmful.
From the context of your comment you made it sound like lead is a major environmental hazard that children everywhere will become exposed to. Yes, lead ingestion is harmful, but I don't believe the average child playing in average dirt will become exposed to lead poisoning.
I went off and put together the following chart using various sources. There are flaws in some of the sources and assumptions, but I think it is close to correct. The point is that vapor pressure is not the critical factor, as that determines the equilibrium. We never reach equilibrium in our labs. The evaporated lead cools immediately and has no effect on whether more lead comes out of the joint. The graph is based on evaporation rate, and plots the amount of lead put into the air per second for a typical solder joint. If all of this lead were transmitted into you it would be the dose you get from soldering. But only a fraction of that will end up in you, depending on your ventilation, size of lab, how close your face is to the work and many other factors. Your lifetime limit on lead collection to keep your blood below the accepted range is pretty tiny, about 20 milligrams. Using values from the chart and assuming that all of the evaporated lead ends up in you, if you keep your iron cool (350C), you can solder for about half a million hours before getting your 20 milligram dose. Hard to do in one lifetime. If you really run your iron hot (550C) you need to pay attention to ventilation and other hygiene practices as the dose could be achieved in under 20 hours of soldering.
This is all consistent with the anecdotal information most people here have related. If there were a extremely serious problem with this lead exposure there would be many reports of problems. Not like the cigarette case where there are huge numbers of observed lung cancers to go with the admittedly large number of people who live a long life of smoking with minimal problems.
@CatalinaWOW: Thank you so much for your helpful and informational posts. I just wanted to note, (not that you were accusing me of this), that I don't personally think the lead-solder case is anything like the cigarettes case, and that whenever I had mentioned cigarettes it was for contrast. I completely agree with you that the lead-soldering case is opposite of the cigarette case, since the bulk of the evidence shows that soldering with lead is generally safe.
I think it's very evident from the information shared here that the biggest danger when soldering is from inhaling the fumes from the flux. Some people took that to mean that lead poisoning isn't a problem in this country, which I disagree with, since the WHO document I linked to says the damages from lead poisonong in the US cost society over $40 billion per year. But obviously most of that poisoning is from other sources besides solder, and it seems that even the official health organizations recognize that.
I think this was a high quality thread, and I thank everyone for their contributions.
One final note. All of the literature indicates that lead is far more dangerous to juveniles. The recommended exposure levels are at least a factor of four lower, and the consequences of minor poisoning are more severe. Those raising or advising children (cutoff is a little unclear but definitely for the under 10 group, probably should carry on to 17 or more years) should use extra care on solder exposure.