When I was a teenager, my chemistry teacher had a gallon of the stuff (one of his favourite gags was, “Hand me that jug of mercury”). There were other places that it could be found. It was understood that mercury required care in handling, etc. I have some that I use in a manometer for synchronizing carburetors.
Nowadays, I hear reports of school being shut down because of someone discovering a bottle of mercury on school grounds, and people going into hysterics over it. Is it just hype? insurance problems?
How dangerous is this stuff (in liquid form) really?
Nowadays in industry people go to pretty extreme measures to avoid contact with it and, especially, contact with its vapor. I’d expect a dropped thermometer to bring a team of specialists who would close off the area and work on cleaning it up.
This stands in sharp contrast with my own experiences playing with a prized toy, a bottle of several pounds (maybe 5) of mercury, when I was 10 to 15 years old. I’d amalgamate bits of copper by rubbing mercury into them in my hands. I’d use it to make electrical connections, tilt switches and the like. By the time I was 12 I had figured out that I could melt solder in a tablespoon clamped in a vice and held over a bunsen burner, and then mix in mercury and cool the mixture to create a marvelous silvery paste whose texture depended on mix ratio and cooling rate. I’d do this in the little workshop in the basement of our house, which basement had no windows, and which house had no HVAC (baseboard water heat and no air conditioning). There must have been negligible air turnover in there. Sometimes if I got the solder too hot, when I added the mercury it would boil rapidly and make a big blue cloud, spattering mercury and molten solder all over and making a big mess.
By the end of this time period there was none of the mercury left - and I never used any of it elsewhere, all of it having gotten “consumed” in the little shop.
I don’t know of any permanent effect it had on me. Clever Dopers will now go off and read my other posts, trying to decide for themselves.
It can be pretty hazardous, depending on the circumstances. I found two MSDS’s on elemental mercury that classify it as a level 3 or 4 health hazard on the HMIS scale (0=no hazard, 4=Deadly). Here are the links:
http://www.bethlehemapparatus.com/Hg_MSDS.pdf
Is the stuff’s just sitting in a bottle, it’s not a danger to anyone. If it gets in the water supply, your screwed.
It can be pretty hazardous, depending on the circumstances. I found two MSDS’s on elemental mercury that classify it as a level 3 or 4 health hazard on the HMIS scale (0=no hazard, 4=Deadly). Here are the links:
http://www.bethlehemapparatus.com/Hg_MSDS.pdf
Is the stuff’s just sitting in a bottle, it’s not a danger to anyone. If it gets in the water supply, you’re screwed.
Liquid mercury isn’t really toxic per se, but the vapor is highly toxic. Mercury has a very high vapor pressure at room temperature, so a spill can release a substantial amount of vapor. Mercury is very poorly absorbed if ingested, but the small amount that is absorbed can still be quite toxic. It can also be absorbed through the skin. (For more information see this MSDS.)
I can imagine that high-school chemistry teachers some time ago might have treated mercury as being more fun than dangerous, but it’s probably not like that now, and it’s certainly not like that in research labs. There are still a lot of practical applications for mercury – in manometers, in vacuum lines and pumps, and in thermometers – but mercury is always used with great care. Often glass containers with a lot of mercury are placed in beakers full of sulfur – if there’s a spill, the mercury reacts with the sulfur to form (I think) mercuric sulfide, which minimizes the vapor released. Labs also have a ‘mercury sponge’ that can be used to absorb spilled mercury, then contain it within a plastic capsule.
Anyway, the danger is real and well-appreciated by people who work with mercury. When I dropped a thermometer in a lab and spilled a few mL of mercury, there was a panic to find sulfur. We couldn’t find any, so someone had to get some from the stores in the basement. I’m not sure why there wasn’t a mercury sponge.
When I was a kid I had a small vial of mercury that I used to play with with my bare hands, and I turned out perfectly norbal.
I’ll add to the mercury-isn’t-as-immediately-dangerous-as-the-MSDS-may-lead-you-to-think-crowd. Heck, the government lets us eat limited quantities of it in fish.
Twice in my previous position, though, we’ve called to call in an emergency, industrial hygeine company because someone spotted a drop of mercury. It’s a big deal. It closes down assembly lines and causes thousands of dollars in losses. Is it a health threat? Not all all – I literally mean a drop. But, the MSDS is the MSDS, and industrial hygeine is industrial hygiene, so that’s just the way it is.
At school, in our chemistry classes, the teacher used to allow us to roll liquid mercury around in our hands.
Autre temps, autres moeurs…
According to Dr James Calvert of the University of Denver, the dangers of liquid mercury are greatly exaggerated. He’s got a great webpage about the properties of mercury http://www.du.edu/~jcalvert/phys/mercury.htm
and it even tells you how to build a mercury barometer. (I’m really surprised in this day and age of ambulance-chasing lawyers, he has a webpage about that. And good for him.) Towards the bottom of the page he has a story of how the value of ‘G’ (universal constant of gravitation) was tested in 1995 using 2 cylinders of liquid mercury weighing 7,000 kilograms each. [sarcasm]Wow, those experimenters must have been staring death in the face during every second of that test.[/sarcasm]
The greatest over-exaggeration of mercury’s dangers was on a website ( I won’t post the URL) that claimed Evangelista Torricelli (mercury barometer inventor) died at a young age (39) due to mercury poisoning. Oh and it just so happens that this same site was selling an environmentally-friendly, non-mercury and very expensive barometer. No doubt they sell this barometer because of their concerns about people being driven to an early grave by that dreaded liquid metal of death, :rolleyes:
Incidentally, in another “mercury thread”, I mentioned I was going to build a mercury barometer. I finished it a few months ago - and I lived to tell the tale. 
Mercury ? Shmer-cury !!!
“Mercury’s in the water!” scares seem to pop up every now and again, but the stuff has to come from someplace. How is it mined? Doesn’t it come out of the ground and, presumably, contaminate the water in the area in which it naturally occurs?
I just transferred from a chemical plant that had easily over 1000 tons of elemental mercury. The public’s perception and reality on this issue are quite distant.
There are 3 ways Hg can be absorbed into the body: ingestion, inhaltion, and absorbtion through the skin. Nobody drank Hg at work so the focus was on the latter two.
Having a Hg leak in a cell required immediate action by washing it with water down to the drain the be collected and was recycled back into the process. All exposed mercury equipment was required to have water covering the mercury to avoid it vaporizing. As stated earlier, Hg has a relatively high vapor pressure and leads to high evaporation rates. Having water covering the mercury reduces inhalation dramatically. Any maintanence that had high levels for potential Hg exposure required respirators that are designed to absorb Hg.
Absorbtion through the skin is solved by wearing rubber gloves but that’s not really a problem because nobody ever touches it and worse case would be touching mercury contaminated steel piping or water which isn’t that bad.
Mercury levels is monitored through urine samples and is monitored closely.
I’ve personally been exposed to more Hg that any thermometer breaking and have suffered no ill side effects. I know over a dozen people working with Hg for 5 to 30 years with Hg and haven’t had problems.
Most recent cases of Hg exposure come from labs with work with dimethylmercury. this has no comemrcial application and has the highest absorbtion through skin (even rubber gloves). I’m too lazy to google the research on dimethylmercury at the moment.
The public needs to understand 2 things about Hg. 1) Its a naturally occuring element that can’t be destroyed and is present everywhere. 2) The primary “polluant” source of Hg in the environment is from burning coal in power plants.
I played with Mercury for many years.
Also I worked for 32 years in the petrochemical business. Almost everything we produced or used in the process was on EPA’s Hazardous Chemicals list.
I’m still here in excellent health.
But yet some groups of people living miles from the same plants complained that the plant made them sick.
They had some good lawyers.
:eek:
msmith537, I think you were just whooshed.
On occasion you’ll read how the ocean has a zillion tons of gold in it. The gold gets washed out of the hills into the rivers and out to the tuna. It hadn’t occurred to me (until now) that mercury would follow the same route.
How is that a gag? I don’t get it …
Andrew T
Since mercury has a specific gravity of 13.55, a gallon of it would have a mass of 51.3 kilograms or 113.1 pounds.
If you are used to handling gallon jugs of water (about 3.8 kilograms or 8.3 pounds), you are in for a big surprise.
Many an index finger was lengthened by that joke…
One of the obligatory safety warning stories I heard repeated several times was the dimethylmercury story: someone in a lab once got a single drop of dimethylmercury on their glove, and died several days later because a fatal dose of dimethylmercury had gotten through the glove.
Incidentally, dimethylmercury is the reference compound for mercury NMR. NMR samples are often treated with a trace amount of a reference material to establish a baseline peak on the spectrum to be given a zero value. The table I was given stresses that samples for mercury NMR should not be treated with the reference compound because it is highly toxic, and that one should trust the value in the table instead.
I also have an anecdote about a research group doing work with mercury – I think it was for vacuum lines – where everyone began to suffer from mercury poisoning. The head researcher, rather than discontinuing his studies, documented the effects of his mercury poisoning until he died. I forget who it was.
A natural source of mercury is volcanos… which we can’t do much about. So even if we eliminated all the power plants and other man-made sources of mercury it would still be in the environment.