Is 'indirect' contact with lead solder safe? - Page 1
Forum section: electronics / beginners

author: jotwerde
author_rank: Contributor
timestamp: November 24, 2018, 06:52:06 am
content: Let's say someone solders with lead solder in a room. He doesn't clean up very well and leaves some solder residue lying on the floor.Then, something is placed on the floor, say, a book, which touches the solder left on the floor/comes into contact with it.Then, someone else grabs the book, which has touched the lying around solder, and reads it, coming into contact with the 'solder/lead-contaminated' book.Now, when touching food without washing hands, is the second person at risk of getting lead into his mouth?This is similar to coughing on your hand when sick, touching a door handle with said hand, someone else touching the same handle, eating without washing their hands and getting the bacteria of the sick one into their mouth.

author: Ian.M
author_rank: Super Contributor
timestamp: November 24, 2018, 07:31:44 am
content: Bacteria and viruses (at least in cells) are alive, they propagate and the population grows exponentially if conditions are favourable.Lead and its compounds are mineral, they don't grow. The question therefore is: How much contamination actually gets transferred to the second person's hands and then ingested, and is it significant in relation to permissible exposure limits?

author: BradC
author_rank: Super Contributor
timestamp: November 24, 2018, 07:33:01 am
content: If you read my books you'll find notes and annotations made with solder. 60/40 will sub as a pencil when you can't find one.

author: Rerouter
author_rank: Super Contributor
timestamp: November 24, 2018, 08:20:22 am
content: From point contact with lead, (e.g. many little balls of solder, scattered on a table, there mostly spheres so only a tiny area makes contact), barely any ends up transferring,As someone who works on circuit boards and solders just about every day with leaded solder, I can say the fumes are much more harmful, Wash your hands before you eat and it will likely not contribute a measurable level even after years in.

author: Leiothrix
author_rank: Regular Contributor
timestamp: November 24, 2018, 10:45:49 am
content: Ugh. Even eating the solder is safer than you might think.The fumes from the flux can be harmful; and are sensitizing so they can cause problems over time.Lead is bad for sure, especially as a child. As an adult you pretty much have to be trying before you'll have a problem. Wash you hands after handling it, don't eat it, you'll be fine.

author: GreyWoolfe
author_rank: Unknown
timestamp: November 24, 2018, 01:26:31 pm
content: Quote from: Leiothrix on November 24, 2018, 10:45:49 amI tend to solder with nitrile gloves on. Keeps hands clean from flux residue also. I am not the cleanest solderer. After I clean up the board, gloves in trash, clean hands, no worries.

author: jotwerde
author_rank: Contributor
timestamp: November 24, 2018, 03:49:19 pm
content: Thanks, everyone.I worried about this quite a bit after reading the manual of a heat gun, which stated that "one shouldn't eat, smoke or drink in a lead contaminated room" and that "lead causes irreversible brain damage". Considering that I solder in my bedroom, this made me a bit anxious and I came to think of this question, as there sure are some lead solder balls I've overlooked lying around in it. Kinda thought I underestimated the danger, one could say. As it turns out, I rather panicked.

author: jmelson
author_rank: Super Contributor
timestamp: November 24, 2018, 04:35:32 pm
content: Lead solder is not all that toxic. A good idea to wash your hands, especially before eating, and to clean up solder residue, especially after using desoldering equipment, that can make a fine dust of it. But, really, people have been using lead solder for centuries, and the amounts used for electronics are quite minimal. Now, lead-lined water pipes are a whole different story.I've been using lead solder for almost 60 years, and not been super-careful with it. As far as i know, I have no effects from that.Jon

author: jmelson
author_rank: Super Contributor
timestamp: November 24, 2018, 04:39:28 pm
content: Quote from: jotwerde on November 24, 2018, 03:49:19 pmAHH, that is different! Heat guns are used by idiots to remove lead-based paint from houses. That is a totally different form of lead compound, NOT just lead and tin. It is much more easily absorbed by the body in that form. I say idiots, because if they are not idiots going in, they WILL be after using a heat gun on lead paint indoors. So, this is totally different than soldering.Jon

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: November 24, 2018, 06:26:19 pm
content: Good grief, if lead was as deadly as anthrax, all air pistol users would be dead within days, don't you think?I handle hundreds of .177 pellets WITH NO GLOVES on the weekends!Oh no!!!

author: Vtile
author_rank: Super Contributor
timestamp: November 24, 2018, 10:05:18 pm
content: Yes. People are jumping on the wall with the lead these days. Mind you the gasoline were leaded in the days even then most people weren't zombies in their 20s.

author: d_brennen
author_rank: Newbie
timestamp: November 24, 2018, 10:59:47 pm
content: As AvE always says, filter the smoke through a cigarette. And wash your hands

author: jack-daniels
author_rank: Contributor
timestamp: November 24, 2018, 11:33:10 pm
content: Quote from: jotwerde on November 24, 2018, 06:52:06 amYou definitely don't want to watch this then!

author: Ian.M
author_rank: Super Contributor
timestamp: November 25, 2018, 12:00:08 am
content: Lead pipes are safe enough as long as you have hard water and don't drink or cook with water from the hot tap. The video doesn't mention iron pipes which are by far the commonest for the incoming supply in old properties. Running a litre of water will flush out 8m of 1/2" pipe, so its a good idea to run a couple of litres from the kitchen tap before use if it hasn't been run that day, even for plastic pipes. Don't drink from taps that don't have a direct mains water supply - cold header tanks are a breeding environment for all sorts of nasties and if poorly maintained tend to have dead rats and/or pigeons in the bottom!

author: basinstreetdesign
author_rank: Frequent Contributor
timestamp: November 25, 2018, 12:52:31 am
content: Quote from: jmelson on November 24, 2018, 04:35:32 pmYeah, I've been using lead solder for a few decades and it hasn't affected me at all! (cough)But I always wash my hands after working at the bench. I do the cooking in our house so its pretty mandatory. But to say eating it has no immediate affect is a stretch. When Canada was young and the old Hudson Bay company was in the trapping business, they operated out of "camps" where their furs were warehoused and traded. If some kids got rambunctious the camp doctor would give their parents a lump of lead for the kids to chew on! It seemed to settle them right down!

author: cdev
author_rank: Super Contributor
timestamp: November 25, 2018, 01:57:41 am
content: I wonder if sulfur soap or EDTA-soap would be better than regular soap for washing up after soldering? EDTA binds metals. And thiols like lipoic acid, as well as sulfur-containing amino acids may help bind some metals.Both tend to dry out the skin a bit more than most soaps.

author: Rerouter
author_rank: Super Contributor
timestamp: November 25, 2018, 02:36:23 am
content: The soaps not much of an issue, just most people don't wash there hands wellhttps://worldwide.saraya.com/expertise/public-health-hygiene/hand-hygiene-in-public-settingsHave a look at the Wash part

author: jotwerde
author_rank: Contributor
timestamp: November 25, 2018, 08:14:59 am
content: Just for clarification, when you all say 'wash your hands before eating', do you mean 'wash your hands before eating if you handled solder' or 'generally wash your hands before eating even if you haven't handled solder, because you've got solder lying around'? Taking the example from above, should the one who took the book wash his hands, even though he just touched the book and may not know that it's touched solder?Quote from: jack-daniels on November 24, 2018, 11:33:10 pmFeeling brave yesterday, I watched it. Aside from loosing consciousness twice while watching, I'd say I'm fine.Just joking.

author: Mechatrommer
author_rank: Super Contributor
timestamp: November 25, 2018, 08:56:53 am
content: i think i have brain damage from lead poisoning. you name it, inhale fume, direct contact and chewing. luckily it doesnt taste good.sarcasm offbut seriously i think i have brain damage because lately i have tendency to buy higher BW stuffs from ebay, where's that TEA thread?

author: Rerouter
author_rank: Super Contributor
timestamp: November 25, 2018, 09:05:09 am
content: Mechatrommer, If the bandwidth is under 40GHz, then your still fine. once you have to apply correction curves for the characteristics of your probes, you start going mad.

author: tggzzz
author_rank: Super Contributor
timestamp: November 25, 2018, 09:21:23 am
content: Quote from: Ian.M on November 25, 2018, 12:00:08 amPrecisely; beat me to it.For 30 years I've lived in a house with lead pipes between the street and the internal stopcock. When I moved in I had the lead content measured as 49ug/l, just under the legal limit (limit is now 10ug/l). After running the cold water for 1 minute to clear out that pipe, the lead content was undetectable.Hence for any cooking/drinking purposes I have run the water for 1 minute, and I was perfectly happy to bring my daughter up here.I also keep tin/lead solder paste in my fridge, inside a syringe, inside a sealed plastic bag, inside a sealed plastic box.I handle lead/tin solder whenever I do some soldering.I do wash my hands after any such activities, but I'm not paranoid about it.

author: jotwerde
author_rank: Contributor
timestamp: November 25, 2018, 02:24:53 pm
content: Quote from: tggzzz on November 25, 2018, 09:21:23 amThis may sound stupid, but is there any particular reason for storing the solder in your fridge?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: November 25, 2018, 02:36:18 pm
content: Quote from: jotwerde on November 25, 2018, 02:24:53 pmSolder paste lasts longer in the fridge

author: tggzzz
author_rank: Super Contributor
timestamp: November 25, 2018, 02:38:46 pm
content: Quote from: jotwerde on November 25, 2018, 02:24:53 pmSolderpastefor SMD components contains liquid flux and has a shelf life. Being cooler extends the shelf life, but I wouldn't want to use that technique where repeatability is required.

author: jotwerde
author_rank: Contributor
timestamp: November 25, 2018, 02:49:06 pm
content: Quote from: tggzzz on November 25, 2018, 02:38:46 pmI noticed that you wrote paste, excluding it from my question was a typo.Just asking cause there's no hint to keep it cool written on the one I've got.Thanks for the info.

author: wraper
author_rank: Unknown
timestamp: November 25, 2018, 02:49:53 pm
content: Quote from: jotwerde on November 25, 2018, 02:24:53 pmMost solder paste have 6 or 12 month shelf life when refrigerated. At room temperature they may degrade to the point of not being up to spec in just 1 week. Many remain sort of okayish even if you store them at room temperature but some become completely useless in just one month. There are a few solder pastes that a rated to be stored at room temperature, though.

author: wraper
author_rank: Unknown
timestamp: November 25, 2018, 02:53:44 pm
content: Quote from: jotwerde on November 25, 2018, 02:49:06 pmProbably you got some cheap crap then where they did not even bother to mention it. If it's from ebey, then even weight written on the label is most likely twice of actual contents.https://docs-emea.rs-online.com/webdocs/0545/0900766b80545a75.pdfQuote

author: janoc
author_rank: Super Contributor
timestamp: November 25, 2018, 04:07:50 pm
content: Quote from: jotwerde on November 25, 2018, 08:14:59 amI thought that washing hands before eating anythingregardlessof what you have been handling before is common sense that is being taught to toddlers already? There areway worsethings around you can get if you don't wash your hands than lead. Such as salmonella, E. coli (yay toilets), listeria, hepatitis, etc.Lead is really the least of your concerns - lead is a problem only if you ingest it long term (e.g. because you have lead paint or pipes) because it accumulates in your body and will slowly poison you. E. coli from poorly washed food or because you don't wash hands after using the loo can kill you overnight.So if you follow basic, common sense, practices when dealing with food, lead from soldering will never even come into picture. You are literally worrying about nonsense with that book example.I would only suggest that if you have small kids around, make sure they can't get to your solder - small kids like putting stuff in their mouth and licking leaded solder is probably one of the few ways how the lead could get in one's organism from anything soldering related.And if you are wondering why all this RoHS stuff banning lead in electronics is around when it is so safe - it is because most of the electronics ends up in landfills (unfortunately) and the lead (and cadmium and other nasty stuff) can leach out of it into soil and ground water. Where it will accumulate and poison us over time. So it is prudent to avoid that. Those regulations aren't there because handling leaded solder is dangerous.

author: 6PTsocket
author_rank: Regular Contributor
timestamp: November 26, 2018, 07:10:21 pm
content: Quote from: Alex Eisenhut on November 24, 2018, 06:26:19 pmAs a kid, I used to practice at an indoor rifle range. The guy that ran the place had partial paralysis of his hands from all the lead he sucked up. Of course, that is far more exposure than most ammo users are likely to see. As for solder, I have been using 60/40 for many, many years and seem to have gotten away with it but that may be just my opinion. LOL!!Sent from my SM-G900V using Tapatalk

author: janoc
author_rank: Super Contributor
timestamp: November 26, 2018, 08:11:18 pm
content: I would add one more thing for the OP - if worried about lead in solder, why not use lead-free solder? Those were explicitly designed to avoid this problem.