Lead Fumes let's settle this.

[mroliver77]

Over the years I have seen guys say that one needs to be carefull of the lead fumes given off by molten lead. There were various authorities also that claimed bunk on this. I did some searching and from all I could find there are no fumes from lead unless it is very very hot. I was reading Glens F's book and he referred to lead fumes. He is often mentioned as THE authority on casting. So does anybody know for sure and can this be documented?
TIA
Jay

[Trey45]

Lead must boil to produce fumes. Lead isn't boiling at casting temperatures. That's all I know, and all I care to know about it.

[Marlin Junky]

I'd also like to know the facts but until I do, it's better to be safe than sorry. I understand that the vapor pressure of molten lead is virtually non existent at normal casting temperatures; however, while fluxing, perhaps lead oxide particles may become airborne... perhaps that is Glen's concern. Since he is a chemist, I would tend to heed his advice with respect to adequate ventilation. I've never had my blood checked specifically for Pb.

MJ

[sffar]

My understanding is that there are no fumes from casting lead, and so I don't worry about that. But when fluxing, and certainly when smelting/alloying there are impurities and obvious fumes from smoke that is seems prudent to keep upwind of, or ventilate to get rid of. Maybe those are the kind of fumes Glen F. is referring to.

[462]

This has been discussed before. In one thread, a member with the appropriate credentials said that lead fumes are non-existent below 1200-degrees Farenheit. I have read this, elsewhere, too.

[jsizemore]

When folks were posting pix of their indoor casting enclosures, I started an internet search of the vaporization question (at least in my mind). I found that lead starts to vaporive at about 1600*F but lead oxide starts at 820*F. Since our tin-pb alloys start to oxidize at 750*F, at least the tin, then it doesn't seem to be any stretch of the imagination that some lead oxide is also taking place. So I've kept my casting temp below 700*F (usually 650-675) and kept the melt fluxed and covered. I cast when and where I took a notion.

Then I read about the arsenic. Uh-oh, now I messed up casting anywhere. Well, arsenic sublimates (means goes from solid to gas without a liquid state in between) at 1137*F. I'm ok there but then I remember that there has to be an oxide version since it always seems to happen. Sure enough, arsenic oxide. Well it vaporizes at 869*F.

So I seem to be safe. At least with what I'm aware of. Haven't made up my mind about casting without a hood inside.

[lwknight]

Almost all heavy metal poisoning cases are related to ingestion.
Do not chew on window sills of old buildings.
Do not put anything into your mouth ( gum , tobacco , supper ,etc ) after handling lead till you thoroughly wash your hands with soap and water also using a scouring pad helps a lot.

[deltaenterprizes]

Lead dust was the source of the lead I ingested by breathing it that caused my lead level to rise to 37 mg/dl. I was going through 3000 lbs every 2 months.
The source was a bullet collator that had a slot in the bottom of the bowl nose high. Once this was identified as the source and a dust collector was mounted to catch particles instead of letting them go airborne my level dropped quickly. I also had 3 automatic casters running in the same room at the same time with 40 lb pots on each one with vent hoods over the machines.

The lead dust was the problem, not fumes.

[Jim]

MSD for lead

See section 9.

[lurch]

I'm no chemist, but I look at it this way. The amount of vapors put off from a liquid are primarily determined by the vapor pressure of the liquid in question and the pressure at the surface of the liquid. The vapor pressure of a liquid is dependent on temperature of the liquid. For lead the vapor pressure in the molten state has been determined and can be seen here:

http://www.powerstream.com/z/vapor-press1-big.png

Say for example that the melt is at 1000*F - in excess of any reasonable casting temperature. That translates to about 538*C or 811*K. From the chart, the vapor pressure of lead at that temperature is on the order of 0.0000001 (10^-7 in case I miscounted the 0's) atmospheres. Boiling would be a vapor pressure of 1 atmosphere. With a vapor pressure that low, the amount of lead vapor coming off the melt is extremely small and what does come off I have been told (posted here somewhere I believe) is fairly well constrained to the area near the surface of the melt, but again, I'm no chemist.

Another perspective can be had based on what standards are at my workplace (major semiconductor manufacturer). In the labs, the safety folks are completely anal about everything, to the point of absolute ridiculousness in some cases. Lead exposure is one of the top priorities. The soldering iron temperatures are all checked and confirmed to be at most 800*F to limit exposure to vapors for a person soldering eight hours a day, five days a week, for their entire career. If there was any potential for measurable lead exposure at this temperature the maximum iron temperature would be lower - guaranteed. This is higher than most all casting is done and I don't think many folks spend that much time with their lead pot.

Given these two reference points, I am very comfortable not worrying about lead vapors while casting. That said, I do use decent ventilation to carry away smoke from fluxing operations and am careful about cleaning the crud out of the pot when it becomes necessary. The dust produced can contain lead oxide and it would not be good to breathe this. No food or drink is allowed while casting and I always wash up afterwards. Others can do as they so choose.

[Rockydog]

The only person I've known in my entire life that had lead poisoning issues was a bridge sandblaster. This was in the 1970s and he was blasting off paint that contained lead from the 40s and 50s. At that time Personal Protective Equipment was sorely lacking. Probably a bandana around his nose. At any rate dust was the cause. I worry more about the lead styphenate dust in my used tumbler media than fumes from lead. Fumes from other sources while casting/smelting are a different story. Breathing smoke from stick on WW tape, valve caps etc. can't do one any good. RD

[cbrick]

I emailed a heads up to this thread to Glen. Be interesting what he has to say if he responds.

Rick

[cbrick]

I worry more about the lead styphenate dust in my used tumbler media than fumes from lead. RD

Yep, same here.

Rick

[geargnasher]

+1 on the tumbler dust, that's the biggest concern for most of us. The physical nature of lead precludes the average caster from being exposed to "vapors" at normal casting temperatures, although some particulate dust will abound in the casting area, if you're curious how much, get some color-indicating wipes, it will surpise you how much lead contamination is on the surfaces around a well-used casting pot. I think most of this "dust" is carried into the air with soot from fluxing smoke, and some settles around the casting area. If it were vapors and light enough to exit the pot, it would be on the ceiling, not on the table.

Gear

[BOOM BOOM]

HI,
Several threads have addressed this subject.
Do a thread search if you need more info than is already stated above. The info listed here alone should calm your concerns.

I have been casting since the late 1960"s, & have never had lead poisoning. Follow the points listed above & you will have no problem.
One point has not been made.

When smelting to refine your TW it is the other **** rubber,gum, plastic paint fumes that are more likely to do you harm. Smelting/Refining produces more varied & potentially harmful vapors/fumes than casting ever did.

[lwknight]

I second the " Staying out of the smoke" for sure. There is no telling what is getting burned inthe smelting pot. Could be some really wicked chemicals reacting there.

[Glen]

Lead does not have to be boiling to create fumes, just like water doesn't have to be boiling to evaporate. Molten lead does have a very real vapor pressure and it can get into your system if you are casting without adequate ventilation. More importantly, if you are casting with WW alloy, which has a small amount of arsenic in it, there are certain oxides of arsenic that boil well below typical casting temperatures, thereby insuring that they will boil off and be easily inhaled. Be smart, use good ventilation. Casting without good ventilation is simply nominating yourself for the Darwin Award.

PS -- I agree about the lead styphnate residues...

[leadman]

My bll went up last year so I bought a couple of lead test kits to locate the source. These are the ampules (sp) that you squeeze to release the test fluid onto the cotton swab.
I never set my lead pot temp. for over 800' and smelted in a different area.
I found lead when I swabbed the wood around my lead pot up to a line about 3" on my side of the pot. This was wood fresh from HD that I built my "casting closet" out of. I tested some leftover scraps of this wood and they tested negative for the lead. I had been using a fan behind me but when I found where the lead was I installed a 20" box fan on the far side of the pot to pull the fumes away from me.
I attached a piece of aluminum to my shirt on my chest that I tested for lead, then cast for about 3 or 4 hours. When I restested there was no lead on the plate. The box fan tested positive for lead after the casting session.
I was an OSHA certified hazardous waste worker for awhile while working for a major city and if I would have found this in a workplace it would have cause for some clean-up and changes.
There is also a warning in Lyman's 3rd Edition manual about lead dust in the casting area.

Test kits are simple and easy to use and run from about $10 to $20. If you want to know if there is lead in your casting area buy a kit and test it.

[JIMinPHX]

Lead does oxidize in common atmosphere, at normal casting temperature. I can see the oxide scum form on the top of the melt. The stuff that worries me, is oxide powders getting up into the air. From what I've read, lead oxide powder is more toxic than lead itself. Oxides of antimony & arsenic are bad characters too. I don't know about tin.

Perhaps, if you cover the top of the melt with borax, or charcoal or some other substance, & use a bottom pour pot, it might help to keep that stuff under control. I cast from an open top pot, so that's not my situation.

As far as I know, casting should be done in a well ventilated area. If someone can authoritatively prove that to be bunk, that would be good news to me. I would like to be able to have an indoor casting area when it's 110F+ here in Phoenix. In the mean time, I'll keep casting outdoors & upwind of the pot.

[maglvr]

I'll worry more about all the mercury the school science teachers poured in our palms, for us to play with!