Radium in Vintage Watch Dials

Youtube Video I took of me measuring a vintage Lord Elgin watch using a Civil Defense Geiger Counter

In the old days, people did not appreciate the risks of radioactive material as we do today, as this crazy old TV commercial will clearly show you. This is not to say that all radioactive materials are imminently dangerous and that radiation is not present everywhere. Radiation comes from surprising sources: Your granite countertops, your smoke detector. Certain fruits and vegetables. Radiation is everywhere, and there are different forms of it, but radium is indubitably a risky substance that requires some caution. Whether you are a collector or a restorer of vintage watches, it’s good to have a baseline understanding of the facts and risks of dealing with vintage watches that used radium. But not panic about it either.

How Radium in Vintage Watches Came to Be:

The very first glow-in-the-dark substances really did glow. Like torches. The luminous stuff we have today in glowsticks and watch dials is fairly wimpy compared to what was. And unlike modern compounds, the old stuff did not “go out”. It continued to glow for long amounts of time. Verily, soldiers during WWII were instructed to tape over their glow-in-the-dark watches at night as not to give away their position. That’s how bright and long-lasting they were.

Why was this? Think of your old CRT television set. (Not your flat screen TV, but your clunker fishbowl TV you relocated in front of the treadmill in the basement). The inside of that TV is coated with phosphor, and phosphor glows when it is hit with electrons. That is the magic of early Television in a nutshell: An electron beam shoots out from a magnetically controlled yoke and hits the phosphor screen in the front, causing it to glow bright.

This technology was inspired in no small part by radium dial watches. The principle is identical: Phosphor is illuminated by electrons. Where do these electrons come from? Not your wall outlet as in the case of your television, but from the element Radium. The breakdown of Radioactive substances releases energetic particles into the air.

My Vintage Watch doesn’t Glow. Does this mean it’s radium free?

Absolutely not and this is the crazy part: Phosphorous burns out over the years. Manufacturers ceased using Radium in the 1960s. That was 50 years ago. The life on Phoshorous for all these watches was never intended for more than 20 years. Today all of these watches no longer glow (you can see some faint sparks under a jewelers loupe for some still). But the radium is still there. And the half-life on radium is 1600 years. The Phosphorous is disintegrated but the radium is still factory fresh!Though to look at the dial you may not even guess it ever was meant to glow.

Telltale signs of Radium
Telltale signs of radium in a watchThe trick is to look for blotchy marks on the dial that look like rust. Or burn marks on the plastic crystal. If you see a halo around the numbers, that means radium did its job bombarding the vicinity of the paint for decades until it left a shadow. In many cases, an old watch forgotten in a drawer will still show the hour and minute it last ran, because the hands burned marks into the plastic from being in the same position for years.

Lovely. Is my Vintage Bulova gonna kill me then? 

In a word, Not likely [edit] but there are some concerns to be aware of. [my revised opinion as of 2/12/17) The radiation from a radioactive dial is of the heavy alpha emission variety (slow moving helium atoms that are stopped by your skin) and at very low amounts. It’s not at all like gamma emissions which are the stuff of post-apocalyptic fear (and your dentist’s visit). It is only problematic if you inhale or ingest radium, which as long as its behind glass, is really hard to impossible to do. [edit] Several readers pointed out the decomposition of radium to radon gas, which is cause for concern as it fills up the entire room regardless of being cased. Concentrations depend on a variety of factors, obviously probably best not to surround yourself with too many radium dials if this is concerning. 

And even then your death from direct exposure is still not a statistical certainty. This was the tragic case of the Radium Girls. In a time with absolutely no industrial regulation 4,000 of these women were taught to sharpen their radium paint brushes by licking them (a technique known as lippointing). Essentially through repeated direct ingestation of radium over the years sickened many and some developed necrosis in the jaw, bone cancer, and death. That is the most extreme case ever. (and some good came out of this dark chapter, as workplace safety laws came into existence as a result.)

Because inhalation or ingestation is a concern, you should only worry if your watch dial is exposed from having the case broken. And the way you deal with that situation is to immediately bag it up in a ziploc bag, wipe down immediate surfaces with a wet paper towel, toss it, and wash your hands.  You want to avoid touching the dial. But even if you do touch the dial, just wash it off. All you want to do is minimize the chance of radioactive dust spreading that you might inhale.

How prevalent is this problem in vintage watches?

As a restorer and collector, this is my unscientific assessment: Any watch made before 1960 has a 1 in 5 chance of having radium, with the greatest propensity being in sportier military-inspired watches (small size, round faces, wide numbers) from the late 40s to early 50s. This has been my observation measuring every project I have gotten using a geiger counter.  (a Civil Defense beauty. Victoreen CDV-700 made in the 1960s. It was meant for measuring radioactivity in food storage!). As a rule, I measure every watch I work on because appearances are deceptive. Even the white faced tank watch with the gold indices might have radium dots embedded at the end of the chapter marks)

What precautions do you take as a restorer?

I often avoid radium projects as much as I can because of the extra risk they pose when the dial is uncased an exposed. In some cases, I will work on them if I think the project merits it. In this case, I use gloves (you should always use gloves anyway) and an N95 mask. Tools and surfaces are wiped down using rodico and tape, surfaces might be wiped down further with soapy water, and all of this is disposed in plastic bags which are sealed up with more tape.

Do you sell vintage watches with Radium in them?

I trend towards mid-century pieces where the problem is less prevalent…so not many, but yes. And when I do, I identify the presence of radium in the listing because it’s the right thing to do. Also because I own and enjoy such watches myself and treat them with the respect they are accorded and I encourage enthusiasts to buy them with healthy caution and just enjoy them. As I stated, the prevalence of these watches are high. Your grampies and grannies wore them for many years. Epidemiological studies would have turned up a problem if there was one, and certainly among watch repair people. In no way would I ever attempt to minimize any dangers, but just encourage a healthy understanding of them. We all varyingly risky habits, and certainly smoking will kill you faster than an old Elgin.


25 comments on “Radium in Vintage Watch Dials

  1. My dad had an Egiin WW2 wristwatch he gave when I was young. I used to to look at at it very close at night in bed & see what I thought was explosions in green. What do you think .

  2. Steven:
    I have to say that with very high certainty your Elgin had a Radium dial. For one thing, virtually all dials during that epoch used Radium. Moreover, the “explosions in green” as you put it is radioactive decay products striking the phosphor. It’s a random process (which is why radioactive elements are sometimes used in cryptographic applications as a pure random number generator) and visible when closely watched. I wouldn’t over-worry about the exposure you received if the crystal was well-sealed.

  3. Although pure radium produces only alpha particles which will not penetrate the watch crystal, radium decays into many other radioactive isotopes which produce gamma, beta and alpha radiation. Radium paint which is a few decades old will have a lot of these daughter radioisotopes. The beta and more especially gamma radiation will easily pass through the crystal and through the person handling the watch or clock. I think the article needs to mention this.

  4. Stephen: Thanks for mentioning this. This is absolutely true! Moreso, I’ve encountered a handful of watches that were gamma emitters, but I found it to be at barely detectable levels at even the most sensitive setting. While I am not a health professional, my personal assessment is that the greatest health risk continues to come from handling a radium dial outside of the crystal or inhaling dust from an uncased watch, but when undisturbed, the risks are minimal. On the subject of radiation risk, my favorite treatment is this chart put together by Randall Munroe of XKCD: http://xkcd.com/radiation/

  5. Yes, you are right, the amount of gamma and beta radiation is fairly low, certainly from a health point of view. In most cases, it will be relatively harmless unless you decide to sleep with your radium-dial watch every night for several years! I have a 1950s Westclox Baby Ben clock and the gamma and beta radiation from the paint is easily detected using the most basic Geiger counters but even that alone does not present a significant health risk unless you are exposed for a very long time.

    As you also mention, the main concern from a health perspective is contamination from any dust from the paint. Unless you really know what you are doing, it is very inadvisable to dismantle any clock or watch containing radium paint, especially, if the crystal is missing. Radium decays to radon gas which in turn rapidly decays to solid radioactive isotopes which can deposit themsleves on other internal surfaces of timepieces so the entire clock or watch can become radioactively contaminated. Handling should be done wearing gloves and if dust from the paint is present, a suitable face mask filter capable of filtering the smallest particles should be also worn. It should also be done in an area well away from eating areas etc.

    • The comment regarding radon generation wasn’t erroneous, however the statements on its resultant pathway was. Radon is an extreme equilibrium seeker. As such, it will leave the watch/clock in order to reach equilibrium with the environment,be that a drawer, room, building, or the great outdoors. This is why it is so difficult to remediate your building.
      What phosphor would you apply to an old radium time piece for it to function again?

  6. Is there a market or collector out there for radium dials (only)?

  7. I am a little freaked out right now. I have an old Elgin watch of my dad’s on my dresser in a bunch of other jewelry. the case isn’t cracked, I don’t think, but now I want to put it in a ziploc bag and dispose of it. I’ve had it for years and didn’t know it was radium. It does glow in the dark but not very much. I don’t have a radium detector and don’t want to buy one… I also have another antique clock that’s been sitting in storage with other things… how do I dispose of these things, what do I do with them? Have I also exposed the other jewelry in the box with the watch? I wear a watch every day which I just bought, a Bulova new watch but have put it in the box where the old watch is. Have I contaminated it and exposed it? Myself? My pets? I’m freaked out right now. Do I use rubber gloves to put the watch in a bag?

  8. What phosphor would you apply to restore the glow to a radium timepiece?

    The comment regarding radium decay to radon, while not inaccurate, is misleading. Radon is an extreme equilibrium seeker. As such, it will move from the interior of the timepiece to the room, to the building interior, to the great outdoors to achieve equilibrium. Thus, you have the same contamination worry on your floor, as you do in your timepiece, as your house. This is why radon remediation is difficult a d expensive.

  9. I have a Russian military watch purchased new in New York during the early 70’s. could those have radium in their dials?

  10. I was wondering if westclox baby bens have radium in them

    • If made before the late 60s (when old legacy stocks of radium paint would have dwindled for manufacturing purposes) its probable. If it doesn’t glow at all but obviously looks like luminous paint that’s gone mottled or dark, that’s a sign. Radium and phosphor go together, and the phosphor is finite. If it glows brightly, it could be another substance.

  11. Hi
    What do you think of radon?
    I read that they did a test with 15 pocket watches and 15 wristwatches in a room. They reached concentrations of 3000 Bq / m3.
    This data is reliable. We are talking about highly unsafe concentrations with a probability of cancer.
    The radon escapes from the glass or the watch case, is this so?
    Thanks and congratulations for your article

    • I know that it’s a secondary product of concern, but I didn’t imagine a situation where it might create unsafe concentrations in an enclosed space. I’d love to see the study. The first question that jumps out at me are the conditions of the space itself. Airflow, insulation, humidity, etc. If it’s a room full of airplane gauges, I can see that. If it’s an old wristwatch or two, I’d be a little surprised at the prospect of a significant risk. But not discounting it at all.

      I try not to keep many radioactive dials in my own workspace, but it’s a worthy question. I might have to spring for a radon kit and report back.

  12. I have some Westclox Military Dials from the 1960’s. They do glow and I am concerned because the package in which they were stored does have some burn marks on them. I am assuming they are Radium. What is your advice?

    • Hello Fred:

      If there are burn marks on the package you have every right to be concerned, especially if the burn marks approximate the orientation of the dial and appear nowhere else with regard to the contents.

      A geiger reading will tell you for certain. You want to ensure however, that the model reader you get is sensitive, and can detect alpha and beta emitters. The one I use is a Victoreen CDV-700. You can get these on Ebay. Otherwise, there’s probably more contemporary models floating around online.

      Short of getting a definitive reading, you have a few options. Get rid of them, or keep them taped up inside a decent gauge plastic bag in an area of your home or office where you don’t spend too much time and is well ventilated. Storing them in this way won’t completely eliminate the risks, just mitigate it.

      • It’s worth noting that the CD V-700 is absolutely incapable of detecting alpha particles. It can detect gamma with the probe window closed and beta with the window open. The mR/Hr scale is inaccurate with the beta window open though – you can only use the CPM scale. The dose rate calibration is only correct for gamma with the window closed. It’s still a great, simple Geiger counter though. I’ll never give mine up.

  13. should anyone need to know if they have a radioactive time piece who does not have access to a radiation detection meter, i have some suggestions:

    see a jeweler, many have meters

    see a pawn shop, many have meters

    see a university or high school physics department, many have meters

    see a fire department, many have meters

    see a hospital nuclear medicine department, many have meters

    see a scrap yard/ landfill, many have meters

    see a nuclear power plant, all have meters

    go to nukeworker.com and inquire if any health physics/radiation protection personnel live in your vicinity, many have meters

  14. Phosphorus was not used in radium dial paint. The paint consisted of zinc sulfide mixed with a very small amount of radium 226. The alpha particles emitted by the radium caused the zinc sulfide to glow, but eventually the constant bombardment destroyed the zinc sulfide crystals and the dials ceased to glow. Radium 226, however, has a half-life of about 1600 years, so today it’s just about as radioactive as the day the watch dial was painted. I have a Westclox Glo-Ben pocket watch that was the first radium dial model sold by Westclox. It was made between 1918 and 1928, so it was probably painted by one of the unfortunate Radium Girls at the Radium Dial Company in Ottawa, Illinois, since Westclox was their largest customer. I own a modern digital Geiger counter which measures about 80 microSieverts per hour at the face of the crystal. This would be gamma radiation produced by the radium decay chain, since alpha particles cannot penetrate the crystal or watch case. The main threat from a radium dial would be if you were to open up the watch and inhale or ingest small flakes of loose paint from the dial. The human body mistakes radium for calcium and deposits some of it in the bones, where the alpha radiation destroys bone marrow, which eventually can result in anemia, bone degradation and osteosarcoma (bone cancer).

  15. I inherited a ladies bullova watch made in the early 1960s. Should I be concerned about radium?

    • Difficult to say. (1) You need to establish if it was in fact from the early 1960s. (2) If it’s a cocktail style watch, there’s less a chance. (3) Paint stocks lasted well into the 1960s. The Bulova’s that I have encountered from that era have mostly not had radium though. The ones from the 1950’s absolutely do, depending on the model and Bulova liked to use very tiny hour mark dots of radium which are easy to miss.

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