The Tin-Whisker Menace

An anonymous reader writes "Fortune has an article about how the recent environmental push to completely eliminate lead from electronic components and wiring may eventually lead to the next Y2K problem of slowly-growing tin whiskers short-circuiting equipment.""

Comments

It's those idiot greens again

[PedanticSpellingTrol]

This probem is one of the reasons we use lead in solder, it's only reappearing now that the EU is pushing for all new electronics sold to be lead-free. Frankly, I'd like to see everyone keep using lead and just stop selling to europe. That'll teach 'em.

Re:It's those idiot greens again

[PornMaster]

How about just teaching kids to avoid licking circuit boards?

Re:It's those idiot greens again

[Space Coyote]

Yeah, they'll have to replace some electronic equipment now and then, perhaps. And all because they don't want to poison themselves with lead. Silly Europeans.

But you go, USA, put lead back in everything, just to be the rugged individualists you are and show the rest of the world.

Hell, do you think Ancient Rome would have taken any crap from anyone else criticizing them for their lead pots? Exactly. USA! USA!

Re:It's those idiot greens again

[Vegeta99]

it's more disposal than consumer protection... tons of lead in a landfill isn't good

Re:It's those idiot greens again

[lachlan76]

Yeah, but, now, there's a hell of a lot of other stuff in the landfills.

Not to mention that you don't want this to be happening on your mission-critical server.

Re:It's those idiot greens again

[jmichaelg]

I hired a contractor to remodel my kitchen a few years back. I did some of the easier jobs such as wire the switches and plumb the sink drains. I was putting together a list of parts I'd need for the sink when the contractor told me the following story about a new development on the north side of town.

The plumbing inspection happens before the sheetrock goes up so any plumbing errors are easy to spot and repair. The permit inspector was on the last house where the plumbers were just cleaning up. The inspector spotted a discarded solder can and picked it up. As he handed over the empty to one of the plumbers, the inspector said,
"Boy that solder is really good stuff!"
To which the plumber said, "Yeah, it's a little more expensive but it flows really smoothly."
The inspector replied, "It must be the lead that makes it flow so smoothly. But you know, it's too bad that you're not allowed to use lead solder any more. You're going to have to start over." And with that, the inspector ticketed every house in the subdivision.

I ended up using plastic plumbing.

Re:It's those idiot greens again

[amembleton]

Tons more lead free electronics isn't a good thing for a land-fill either. If electronic devices, don't last as long then more will be dumped onto landfills, albeit leadfree.

Re:It's those idiot greens again

[trburkholder]

OK, I'll feed the troll.

Lead is a neurotoxin; children exposed to lead are at risk of developmental delays, reduced IQ, learning disabilities, hearing loss, reduced height and hyperactivity. Levels above 10 mcg/dL (about 100 ppb) are considered to be a health risk to children. Adults are at risk of anemia, nervous system dysfunction, kidney problems, hypertension, decreased fertility, and increased level of miscarriages.

It used to be that the biggest source of environmental lead was automobile exhaust, followed by lead paint. In the late 1970's 14.9 million children in the US had elevated blood lead levels. This figure declined to about 300,000 in the US CDC's 99-00 survey. Banning lead paint in 1978 and leaded gasoline's phase out starting in 1975 removed the sources of exposure.

In adults, levels above 24 mcg/dL are considered elevated and mostly come from workplace exposures, such as demolition, recycling and manufacturing. The number of adults with elevated blood lead levels has also been declining.

The problem with adult exposure is that without proper industrial hygiene, the lead comes home with them, providing a route of exposure to their children. 2-3% of children with elevated blood lead levels are exposed in this way.

Lead in manufacturing is an expense since exposure has to be managed. But, if you don't control it at the source, then you have to try and manage it in the waste stream which is much more expensive and difficult. Given the population density and the emphasis on recycling in the EU, lead exposure through this route is a decreasingly acceptable risk to the population.

P.S. The EU is the largest economy in the world so you tell your directors that you don't need that market anymore!

Re:It's those idiot greens again

[lgw]

Well, yes, that's obvious isn't it? Billions of dollars in research, and no one thought of that?

The problem is: no one understands quite why lead prevents tin whisker formation, so it's hard to find a replacement that you *know* works. Texas Insrtuments has ten years of development on this, and has a solution that "looks good"; evryone else is behind that. Lead alloys have a 50 year track record, however, and the new apporaches just don't have the field data yet.

In order to fix a very small part of the lead problem, any electronics you buy going forward have a non-trivial risk of suddenly failing a few years down the road. Including life-critical equipment.

How many lives saved by eliminating a very small percentage of environmental lead? (Lead in electronics is tightly bound; no evidence that is can get into the water table.) How many lives lost due to sudden system failure? What bothers me is: no one making these laws cares about such analysis.

Re:It's those idiot greens again

[jabuzz]

Second? The Euro zone is perhaps the second largest economy, but the EU is bigger than the Euro zone. For example it does not include the U.K. which is the third/forth largest economy period (it about the same size as Germany and the two jocky for position). It is my understanding that the total E.U. economy is now larger than the U.S.A.

Re:It's those idiot greens again

[harrkev]

Have you ever seen inside a typical chip? The die is bonded to a ceramic carrier, and wires are then bonded to the chip. And those wires are also "pretty damn this." So, thickness is not really an issue here. If a whisker can handle 1mA, that is enough to screw up a signal line.

And for what it's worth, I have a MSEE and design digital electronics for a living.

I wonder...

[SharpFang]

how hard would it be to put -everything- on chip?
I mean, yeah, stuff remains modular. One module, one chip. A motherboard consisting of a central "motherboard chip" (containing both bridges, IDE circuitry, bus drivers, all the "integrated hardware" etc), plus slots for all the rest of the hardware, single-chip graphics card, single-chip RAM dice, etc. Just reduce the role of PCB to a board where slots are being located and connected to the central chip, no more batteries of capacitors, network of resistors, hundreds of small chips... Just load everything into one (even big) IC, add some radiator/cooler, and get rid of space and soldering problems.

Re:I wonder...

[notany]

This is whre progress is going. For example Prof. David Patterson (inventor of RAID and first MISC instruction set computers) has been trying to do this many years. See IRAM

There is some practical problems.

1. Low yield. Failure rate grows with bigger chips. Makes them more expensive.
2. Harder to make. Different prosesses for making memory and logic (this has been done already of course).
3. Heat problem. It's easier to cool separaate chunks of prosessor, graphics processor and memory.
4. Upgrading. New usb spec, make new mask. Upgrade graphics prosessor, make new mask. New mask for every memory configuration. Uh.

We may get close eventually. Practicality may dictate that we end up with 1-3 chips per home PC. Maybe optical connections between.

My time estimate for this to happen is 10-30 years from now.

Re:I wonder...

[bbrack]

SOC work has already reached this point for many electronics devices - cell phones are about the highest level things that I can think of that can currently be built from a single IC This is also being seen in the processor market, especially on the server side, where chips can be significantly more expensive, with things like memory controllers, network controllers, etc being put on-die on a lot of next generation processors The main problem is that combining all these parts into a single chip raises the cost out of the range that the typical consumer would consider. Since every new process node provides an ~50% reduction in die size, and assuming defect densities are fairly constant, it is conceivable that prices would be low enough to make it to the mainstream market sometime late in the 45nm or early in the 35nm generation (~3-5 years)

No

[Sycraft-fu]

All other factors aside, the reason that Y2K would have been the problem that some alleged is that all the failures would happen at the same time. If something fails, even something major like a powerplant, it's a problem not a catastrophe. It would only be a catastrophe if lots of tem, or worse yet all of them, failed at the same time.

So supposing this problem is as stated, it'll just lead to higher failure rates of electronics. That's not a catastrophe, just something we'll have to deal with, either by changing the methods used or simply by increasing the rate at which we replace devices.

paint finish?

[silence535]

Where is the problem in making a final layer of paint finish on the tin circuitry?

Lead on the cirquit boards is a huge sleeping environmental problem and those who are tempted to shout 'tree higger' now might want to inform themselves on the potential lead hazards first.

-silence

Re:paint finish?

[bombadillo]

those who are tempted to shout 'tree higger'

Looks like you combined to very commonly used words by bigots.

Re:paint finish?

[einhverfr]

Paint reduces the issue of whiskers, but it does not eliminate the problem completely.

Also lead is used because it is suitable for keeping the melting point low for electronics soldering, but other metals also inhibit the formation of whiskers. This leads to a number of interesting questions:

1) How much lead is required to inhibit whisker formation? Is it possible to use a "very low lead content" solder instead of a "lead free" solder and avoid both problems?

2) What is the environmental cost of having the other electronic components sitting in land fills? How does this compare to the lead? Given the possibility of electronic damage from short circuits, how does this impact possibilities for component recycling?

3) Are there any other metals that might work for doping the tin? I know that the noble metals have extremely high melting points (Gold is close to 2000F), so despite being soft they are unsuitable for such alloying, and metals like aluminum might add undesirable characteristics. So what are the metallurgical alternatives?

4) Are there any possibilities of alternate delivery methods which don't require the low melting point? What about amalgams or the possibility of conductive resins?

Tin whiskers eh?

[bildungsroman_yorick]

Obviously to fix the problem we need some amalgamation of courage and heart in electronic form pronto. Is there any engineers here whose work includes hiding behind curtains and appearing to his co-workers in giant green mask form?

Good job...

[JaredOfEuropa]

... you lot just slashdotted NASA.

"The page cannot be displayed. There are too many people accessing the Web site at this time."

Duplicate story

[emj]

Same story as 6 month ago Zinc Whiskers Cripple Colorado's Computers. There's a PDF there that explains it all as well. They are pretty little whiskers, that can only be observed if examined very closely in the right environment.

sealant

[confusion]

Surely a bath in some sort of sealant post production would eliminate this problem? Finding a way not to seal up the connection points would be a challenge, though.

Then again, this problem doesn't work out so bad for the hardware manufacturers, now does it?

Jerry
http://www.syslog.org/

Re:sealant

[PornMaster]

I think you'd also have to consider things like the heat-insulating properties of the sealants. That whole law-of-unintended-consequences thing. Would suck to solve the tin whiskers problem, but have your CPU fail because of overheating.

Re:sealant

[twrake]

From the following artical Sealant may be a solution.

http://physics.about.com/od/condensedmatter/a/soft metalwisker.htm

Soft Metal Wiskers

from AIP Physics News
AIP Physics News Update #711
Soft-metal whiskers, tiny metallic protrusions that grow like hair from soft metals, are a problem that can cause electronic short circuits leading, in some cases, to the failure of heart pacemakers, avionic relays, and satellites. What to do with the unwanted whiskers---and, in the first place, understanding how they form---is a problem that's been around for fifty years. Now, researchers at Drexel University have arrived at what they think is an explanation for the cause of whiskers and a potential method for alleviating them. Basically, the whiskers form because of reactions between oxygen and the soft metal such as tin or indium. The reaction results in a volume increase that pushes the whiskers out. The whiskers that form do not have to break off in order to be troublesome; sometimes they cause mischief merely by bridging two neighboring electronic pathways that are supposed to be insulated from each other. The Drexel scientists believe that an oxygen-barrier coating on pertinent surfaces should prevent whiskers from developing. (Barsoum et al. Physical Review Letters, 12 November 2004)

Re:sealant

[GoRK]

It's not really a bath, but you can use conformal coatings to protect PCB's against this and other maladies such as high humidity, salt water spray, etc. I tend to spray down most PCB's I produce myself as they have no solder mask to protect the bare traces otherwise.

Re:I don't get the connection

[InternationalCow]

I quote from a most informative pdf (get it here):
"A tin whisker is a single crystal of tin that grows spontaneously from a surface a pure tin. They are typically only a few microns (?m) in diameter but can grow to lengths of more than 10 mm (though lengths on the order of 1 mm are far more common) [NIST Website, 2002]. Tin whisker growth is spontaneous, not relying on external influences of current or electrolytic action, more commonly associated with mechanisms like "dendritic" growth, conductive filament formation and electromigration. While early studies believed that tin recrystallization (which occurs at 50 deg C) played some role in whisker formation, recent studies have reported as much, if not greater, propensity for whisker formation at temperatures as low as room temperature [NASA Web Site, 2002].(....)Conventional wisdom attributes tin whiskering to internal stresses in the pure tin layer, with a primary source being the compressive stresses caused by electroplating. However, tin whiskers have also been reported from surfaces where tin has been applied by methods other than electroplating. In the presence of compressive stress, whiskers are extruded over time, as a stress release mechanism. Many factors may contribute to the stress in the plating, including intermetallic formation, thermal expansion mismatches, corrosion of the substrate, and externally applied forces such as bending, lead forming and application of pressure. Defects such as scratches and nicks have been reported to magnify the effects by causing local stress concentrations and possibly providing openings in any protective surface oxide layers. In fact, these external factors may cause whiskering in samples that may otherwise be resistant to the phenomenon. For example, tin whiskers have been observed to form on tin finished surfaces that had been exposed to hot oil dip to fuse the tin (a known mitigating process) [Cunningham and Donahue, 1990]. Adding a trace amount of another element (i.e. Pb or Bi) has been shown to reduce the tendency of plating to grow whiskers."

Mah cat has tin whiskers

[BadDoggie]

Oh wait, mah mistake. He has twailve.
</drawl>

woof.

wither the tin-foil hat?

[close_wait]

This is just a government conspiracy to bypass tin-foil hats! Everyone knows that it's the 2% lead content which actually blocks the mind-control rays....

Heavy Metal!

[Nikkodemus]

Oh man, this song could be sooo big!

Tin Whiiiiiiiiiskers
They cancelled IT Class
Tin Whiiiiiiiiiskers
They come from Satan's ass..

Hairs of the Devil, items of no good repute
If the grow to a certain lenght, the PC's can't compute!

Tin Whiiiiiiiiiskers

(guitar solo)

(reprise)

Forget tin Whiskers, Nanotechnology will kill.

[d3nali]

The issue with tin whiskers is that they are so small and invasive. Next to this problem however nanotechnology will make it look trivial.

The small particles being produced with nanotechnology concepts will enable it to invade and affect the body in ways that connot possibly be handeled by todays technology or our immune systems.

I'm all for technology but we need some protections before a company starts spewing these waste/production nanoparticles off into the enviroment in order to save in producing costs for that lastest flat screen tv using carbon nanotubes.

Temperature cycling

[NoseBag]

When I worked in the E-Warfare division of (deleted) we ran into this issue whenever we used brass prototype packages to house circuits. The cause of the whisker growth (in brass) was the repeated temperature cycling (TC) of the package. Apparently in the presence of the TC, the tin in the brass preferentially crystalized out of the brass in whisker form and pushed out of the sides. Kinda neat, actually, except for the occasional power supply short. We found that a solid nickel-plate or copper-plate fixed the problem nicely.

Mad Tin Disease?

[handy_vandal]

All other factors aside, the reason that Y2K would have been the problem that some alleged is that all the failures would happen at the same time. If something fails, even something major like a powerplant, it's a problem not a catastrophe. It would only be a catastrophe if lots of tem, or worse yet all of them, failed at the same time.

Tin Whiskers are less like Y2K, more like Mad Cow -- an insidious, slow-growing disease that consumes our neural infrastructure.

-kgj

Let's talk reality here

[Sycraft-fu]

The lead in solder accounts for a very, VERY tiny percentage of the lead we use and dispose of. It's a really stupid thing to be targeting since there are much bigger problems. It's like worrying about a basket of dirty laundry when your entire floor is covered in garbage. You aren't fixing a problem worth solving.

Now these tin whiskers aside, this sucks for people who like ot do electronics work at home. The only solder blends that are easy to work with contain lead. A 63/37 Sn/Pb or 62/36/2 Sn/Pb/Ag blend is what you need for a low melting point and nice, clean, easy application. The non-lead solders are much harder to work with since they need much higher temperatures. Easy to burn out a component if you aren't careful.

Now compare the amount of lead I use to make an electronic device (like 25-30% of a tube the size of my pinky, that's less than 40% lead and wound such as to use less than 30% of the space in the tube) to a lead-acid car battery, which all cars have and are replaced about once every 5 years.

The no lead in circuts is a wonderful example of environmentalists going after a non issue and fucking things up for people. Yes, lead is a problem, it can contaminate water tables and lead poisoning is NASTY. However the small amount of lead used on PCBs is NOT the problem, and getting rid of it just creats MORE waste by creating electronics that die faster.

Re:Let's talk reality here

[Waffle Iron]

The lead in solder accounts for a very, VERY tiny percentage of the lead we use and dispose of.

It seems to me that the whole lead issue is addressed very erratically. The solder in a circuit board is a huge problem, but anybody can go down to Wal-Mart and buy a tin of airgun pellets containing about a 1/4 pound of pure lead and spray it all over their back yard. Lead encased in computer monitor glass is a huge crisis, but nobody talks much about 36-inch TV tubes, and if you shop for wine glasses some of them brag about the the fact that they contain 24% lead.

It seems to me that all the focus goes on new types of products, while many old products that use lead are ignored.

Re:Let's talk reality here

[ChrisMaple]

Actually, lead in batteries will also be banned in a couple of years,

In automobile batteries? Get real. There's no suitable replacement available.

Re:Let's talk reality here

[lambadomy]

I think you're missing the point when it comes to the lead issue. I'm sure plenty of greens are trying to get lead batteries banned or replaced, it just hasn't happened yet. Maybe electronics companies need better lobbiests. Either way, while I understand your frustration, your post does give a good example of something just as aggrivating to the greens: the idea that it is pointless to protect ourselves from small things when there are big, more dangerous things. The small things are still bad! And do you really think no one is trying to protect us from the bigger things? It can't all change overnight. Other people in this thread bring up other lead-laden products, but the point is that they probably all should be either changed, or have a good way to be recycled.

As a side note, I was under the impression that part of the reason for this lead ban in solder was due to the fact that recycling or removal of the lead to keep it out of landfills was nigh impossible, unlike other lead products where the lead is easier to seperate.

Re:Let's talk reality here

[fermion]

I am a reasonable well off white person is not really concerned about the things that the bleeding heart liberals complain about. Even though I have worked in manufacturing, i was mostly in a clean office while the poor white and minorities were the ones exposed to the chemicals, albeit in small doses that were likely not harmful, even after many years. I never had to live next to the factories that dumped the chemicals into my drinking water, even though the levels were probably dilute enough not to matter. If I worked with dangerous chemicals, i did so in a lab environment where there were no production issues forcing me to cut corners that might risk my health. I used chemical in personal quantities, and was seldom if ever exposed to the industrial quantities that many poor white and minorities are exposed to.

As such it makes little sense for me to suffer the mild aggravation of having to use lead free solder, or acetone instead of trichloroethylene, or perhaps, god forbid, drive a car that get better than 20 miles to the gallon. After all I have air conditioning so I do not have to breathe the air. I have water filtration so I do not have to drink straight tap water. My kids have clean play grounds to they do not get exposed to the toxic sludge in that the poor kids play in.

In fact there is no reason why i should not just starting getting into the American spirit and get an obedient wife, some servants, and watch my property cut down the sugar cane. Why we ever gave poor and colored people any power at all is a mystery to me. Fortunately our president and congress will fix that mistake.

Re:Why are they mentioning Y2K?

[fozzmeister]

because there is a lifetime for every component, it would be reasonable to expect a reasonably static rate of growth of tin wiskers, and it will therefore prolly take a set amount of time for them to grow between components and short (at least in particular types of products.

Forinstance if AMD started manufacturing the AMD64 3200+ and got the substitues wrong, they would all start failing at rougly the same time, taking down all computers that are built using them.

It's not such a date of failure but the inference is they will prolly all fail at similar times

Other Brands?

[polyp2000]

I've always bought tins of whiskers for tiddles, should I switch to another brand - He's never been too keen on kit-e-cat. How will this affect my cat ?

Nick ...

Re:Whatever.

[Shipwack]

A "leaky capacitor" can be identified by the foreign material seeming stuck to it on the outside of the capacitor, almost like glue, but not sticky. A less extreme sympton of a bad capacitor is a bulge in the sides or top. Really big capacitors (used in high power electrical applications)or older (20+ years,maybe?)capacitors actually have liquid inside, so the sign of leakage might be a stain on the circuit board or chassis.

A capacitor can be identified by the letters "uF" (which stands for "micro-Farads", which capacitors are measured in) after a number. They tend to be either cylendrical, with the leads coming out of the bottom circular base, or "plate shaped", with the leads coming out of the edge.

Re:nope, greens are still idiots.

[dougmc]

Yeah, how did humanity ever survive the dark ages of the early 1900's when we didn't have some fucking nanny-state telling us not to use something ...

To be fair, the average life expectancy back then (1901) was like 49 years. Now it's 77 years (in the US, anyways)..

Granted, much of the increase is due to better medical care, but much of it's due to knowing things about hygene and the like that we didn't know back then. At one point, plates and the like had lots of lead in them, and people ingested lots of lead from this and it caused them to live shorter lives.

But now that I know about the tin whiskers, I want lead in my electronic circuits! I wonder which is worse for the environment -- a stereo with no lead that gets thrown in the landfill after breaking after 10 years, or a stereo with some lead in it that lasts 20 years before breaking and getting thrown away ...

Re:Whatever.

[mrbcs]

The machine will crash at random. You can change ram, cards, chips and it will still crash often. (not just windows )You will see the seeping caps inside.

Dead board. I've seen a few ibms and no-name boards with these. Most of the affected capacitors seem to have an x on the top of them. They split apart at the seams and ooze all over the board.

Re: I wonder

[EvilMidnightBomber]

Top ten list of critique openers most likely to get you prematurely killed by an engineer

10. I wonder...
9. I was just thinking...
8. That's great, but what I was really looking for was...
7. You know what would be really cool...
6. Was it supposed to do that?...
5. I'm sure it'll look better by the time you've finished...
4. Would it be possible to...
3. To: Engineering From: Marketing Priority: Urgent
2. Did someone tell you to do it this way?...
1. How hard would it be to...

Re:Plastic is superior in any case

[jmichaelg]

Your suspicion is understandable but the development went up years ago back when plastic plumbing was just taking off.

My best friend owns one of the top plumbing outfits around here. He routinely does the more difficult jobs in Pebble Beach and Big Sur. He also does the bread and butter work in the less expensive areas where cost is the paramount consideration. Years ago, he won a bid on an apartment complex in Marina, a town next to the old Fort Ord land.

To save costs he picked up some plastic pipe from an outfit he had never dealt with but was offering him a really good price on the pipe. Long story short, the pipes started failing about 6 months after the apartments had been occupied - they were all splitting wherever the stress was greatest. The pipe company went tits up as the problem was popping up all around the country. My friend was adequately insured so he didn't lose money replacing the bum pipes but it did cost him as he couldn't take any new work during the time his men were tearing out old pipes. This happened about 12-14 years ago just about the time plastic plumbing was beginning to come on strong.

My friend's experience with the bum pipes circulated and set plastic plumbing back a few years around here. The development didn't want the grief the apartment house owner in Marina had had and so the developer specified metal pipe instead. It is ironic that their schedule got bit by the lead solder but then it's not the first time that a solution to one problem raised another.

Yes, it is.

[MarcQuadra]

Hey there, there's a HUGE difference between pipes made out of lead and a bit of solder with lead in it.

Lead isn't a death-sentence, it can be safely used. I've been drinking from lead pipes and living in lead-painted walls my whole life and never shown elevated levels. My dad is a lead inspector and he says that virtually all the lead poisoning cases are caused by lead paint dust and chips, kids get the dust on their hands and toys and it ends up in their blood.

This sort of demonizing really pisses me off, some of the best materials we had for common uses has been outlawed because of irresponsible use and disposal. Asbestos insulation, lead solder, and asbestos brake pads are all superior at what they do. Hell, my heating bill (gas, in Boston) is about 30% of most of my coworkers because my house is jacketed in asbestos, and as long as I don't fsck with it it's perfectly safe.

Ever notice how often you have to replace brake pads these days? Or how much rusty dust they drop on your rims? That wasn't a problem with asbestos brake pads, they were awesome. I'm still looking to see if I can get my hands on some from overseas (I'll replace them myself or tell my mechanic before he services them).

Lead solder is a dream to work with compared to other materials, it's cheaper, and it lasts much longer. Outlawing it because people illegally dispose lead-containing stuff in landfills is moronic at best.

Ah, the sweetness of lead.

[dustymugs]

So I guess its time to go stock up on lead-tin solder before they pull them off the shelves.

I really do with they'd go after other products with lead, batteries and such, before they go after our electronics. Its not like little kids are licking their parents' spool of solder!

Re:Plastic is superior in any case

[Mattintosh]

Cast iron is better for hot water applications. Ask any HVAC guy or pipefitter. And if you have a pump in the system, don't even think about PVC. A single deadheading will shatter the pipes, and there's a risk of shattering the pipes every time you start or stop the pump, due to the inertia of the water circulating in the system.

Rodney Dangerfield

[4of12]

There are far more dangerous materials in common usage out there, but treated with proper respect they can be used. Bismuth is significantly more toxic than lead, as is cadmium,

I cringe everytime I think of how many Ni-Cd rechargeable batteries get thrown into landfills all over the place, including arid environments where life depends upon the availability of quality groundwater.

I dunno if this is the case everywhere, but my local public waste handling facility has an amnesty day, where you can bring in all those crusty old cans of solvents, paints, pesticides, household cleaners for free. This helps to mitigate the problem of people tossing dangerous chemicals into household trash and not get the proper treatment such chemicals deserve. Or the auxiliary problem of illegal dumping because "taking that stuff to the dump is expensive, dammit!"