Is Radium Lume Really That Dangerous?

Many vintage watches have radium lume on the dial and in the watch hands. It’s a big part of the overall appearance and the charm of these vintage watches, especially when the lume has changed into that attractive vintage yellow/brown color.

However, all over the internet are scary stories about radium, radioactivity, and potential dangers.

Is radium lume that dangerous, or is it a tempest in a teapot?

A bit of history

In 1898, Pierre and Marie Curie discovered radium when they found out that the mineral uraninite was still radioactive after they’d removed the uranium.

Radioactivity was new and exciting. They had no idea that it was potentially dangerous. People thought that it was healthy, and it was included as an ingredient in many products. Those products even included drinks and creams.

Is radium lume really that dangerous
Radior cream, because every woman deserves a beautiful glow

Watchmakers discovered that they could mix the radium with paint to create a paint that glows in the dark.

In the early 1900s, the dials and hands of nearly all timepieces were painted with this radioluminescent paint.

Almost all of the workers were women, and they were told that the paint was harmless. They pointed their brushes on their lips to create a fine tip for the delicate work.

Several of the women got seriously ill and sued their employer for having contracted an occupational disease. These women are known as the Radium Girls.

The case was settled in 1928, and since that time, radium dial painters were provided with protective gear. Most importantly, they were forbidden to point the tip with their lips, and they avoided to ingest or inhale the luminous paint.

Eventually, safer options were discovered, and the use of radium was discontinued in the 1960s.


Radium has a half-life of 1600 years. That means that the old radium on your watch dial and in the hands doesn’t glow anymore, but it’s still radioactive.

It emits two types of radiation; alpha radiation and gamma radiation.

Alpha radiation

97% of the radiation is alpha radiation, also known as alpha particles.

These particles have such a large mass that they can only travel for a few centimeters, and they’re quickly absorbed. The watch crystal and the watch case(back) absorb all the alpha particles while wearing the watch.

The particles also can’t penetrate the epidermis, so the skin absorbs them without entering the body.

Alpha particles are highly dangerous inside the body, though, because it kills and mutates cells. That’s why those poor radium girls got sick. They licked their brushes with luminous paint hundreds of times a day and ingested radium every time they did so.

Gamma radiation

3% of the radiation is the penetrating gamma radiation. Unlike alpha radiation, this type of radiation won’t be stopped by paper or plastic, and it also penetrates the skin.

Tests have shown that a radium dial emits approx. 10uSv / hr. That means that you’ll have been exposed to a full day’s worth of background radiation in about 20 minutes. This is almost exclusively gamma radiation because the alpha particles will have been blocked.

Decasing, removing the hands and dial, and vice versa shouldn’t take more than 30 minutes. That means you’ll have been exposed to approx. a day and a half worth of background radiation as a watchmaker. While that’s not entirely safe, it’s also not an immediate cause for concern.

What you might not have realized is that you’re exposed to the same level of radiation when you’re wearing the watch because gamma radiation requires a massive shield (a thick layer of lead, for example) to be absorbed. You’ll be more exposed because you’ll likely wear a watch for more than 30 minutes at a time.

So, it’s not only the watchmaker who’s affected by the gamma rays but also the wearer.

Is radium lume really that dangerous?
Dial with radium of a Tiega watch


The gaseous decay product of radium is radon.

According to the United States Environmental Protection Agency, radon is the number one cause of lung cancer among non-smokers. In other words, it’s a severe health hazard. It also comes from natural sources and occurs as background radiation.

However, radon could only pose a threat in watches that are airtight, like divers. Many of the older dress watches are barely dustproof, so there’s no way that gas could have built up.

If you suspect that radon might have built up over time, carefully remove the crystal in a well-ventilated room and let it cool down for a while.


The use of radium was discontinued since the 1960s. Omega stopped using radium around 1963.

Immediately after, substances like promethium and tritium were used as a luminous material, and they’re still being used today.

Nowadays, Super-LumiNova, which is entirely non-radioactive and non-toxic, is the most used lume in watchmaking.


As you can see, radium isn’t completely safe. That’s why the use of radium was discontinued in the 1960s.

But it’s also not as life-threatening as many claim it to be. Not a single factory worker got sick after they started wearing protective gear and stopped licking their paintbrush.

The biggest risk is inhalation or ingestion of radium because alpha particles are harmful inside the body. Aged lume has often dried out and turned brittle, so that’s certainly a risk when you want to relume the hands, for example.

What do you think of those old radium dials and hands? Let me know in the comments below.

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44 thoughts on “Is Radium Lume Really That Dangerous?”

  1. Gamma radiation is not so dangerous as you have written. The photons go through the body like pistol bullet through a fishing net.
    10 feet thick of concrete wall stops 50% of gamma photons.
    Gamma radiation in lumę goes in every direction so wearer gets ca 10-20% of this 10 uSv/h.
    At 30,000 feet pilots, passengers get ca 4 uSv/h cosmic gamma radiation.
    Long distance pilots get more gamma on the fly, and they don’t die early. Well, unless in a catastrophe.

    1. It’s not just me that writes that. Several institutions, including the US Environmental Protection Agency state the very same thing. By the way, preliminary studies do seem to confirm that pilots have a lower average life expectancy than the general population as a result of their profession. By about 3 or 4 years.

  2. I recently bought a Seiko 62MAS diver. It’s from 1966 or 1967. I noticed that lume still glows somewhat in the darkness. Does anyone know if Seiko was still using radium in 1966? After reading some articles I’m a little hesitant to wear the watch now.


    Update on the Gubelin: My curiosity led me to purchase a geiger counter and it arrived today. I checked all the watches as well as some Radium hands I have and found out that the Gubelin is pretty hot. It was about 70 CPM so there isn’t any doubt about it containing Radium. I also have 6 military pocket watch hour hands. They were pretty close to the Gubelin at 66 CPM but that was all six at once. I did one further experiment putting the hands and the Gubelin right together and put the meter right on them. The count went over 100 CPM and the chirping alarm on the meter went off! Needless to say, I boxed everything up and put it in a cabinet in the basement. At this point, I am very grateful for the article and now I know you really have to exercise caution with older radium timepieces. Thank you for the article!

    1. Wow, thanks for the update. I didn’t know that it was THAT bad. Yeah, timepieces with radium look great, but I’m much happier wearing a modern piece with Super-LumiNova.


    I recently purchased a Gubelin Ipsomatic watch. I’m pretty convinced the dial has paint with Radium. Usually there is a “T” at the bottom of the dial when Tritium is used and this watch doesn’t have any letter at all. There also is a different quality glow between Radium and Tritium. I’ve noticed the Tritium gives a more steady glow of whitish light while the Radium tends to lightly flicker and have a green tint. Under a magnifying glass, the Radium paint can give the appearance of a lightning storm from the multitude of little individual flashes. It is quite mesmerizing! I’ve read that these flashes are actual individual electrons exciting a chemical that reacts to the alpha particles emitted from the Radium.
    So the point of all this is that the dial on this Gubelin is really quite bright. It glows with more intensity than radium hands made for military use that I also have. I don’t have a rad meter but my guess is this dial is really cooking with some serious radioactivity.
    Do you or anyone else know any back story with the Gubelin Ipso dials? I’d be very curious to find out if there is any anecdotal information about this. Since this dial is more intense than anything I’ve yet seen, I thought it would be of interest to the readers of your article.
    Thank you,

  5. Nice article, I want to buy a dirty dozen military watch with radium lume which made in 1945. Do you know Which kind of radium is? Will it be safe after I let watchmaker to remove the radium? Thank you

  6. Mister Freeze

    I personally feel that the occasional wearing of radium dial watches is safe and presents no real danger. Especially the ones with small amounts of Lume from the 50s and 60s. However, I would not be Comfortable wearing them on a regular, daily basis.

    Also, most of the radiation goes out the front crystal and only for about 6” or so. The radiation at the back at the wrist is only about 10% this level. So as long as you aren’t sleeping with it under your head or wearing it in a pocket, the actual levels are pretty negligible, maybe 10x background radiation.

  7. Thank you for the very informative article. What about a Tritium dial watches? Are they safe? I bought a NOS watch by CWC. The seller claims that it was produced back in 1990s. Is Tritium in a watch safe to wear?

    Thanks in advance

      1. Thank you for your reply.

        I have been observing a watch that I want to purchase that gives me sleepless nights. Omega Ranchero.

        The watch is an original and has already lost its lume in the hannds.

        The radium is still present on the dial.

        Do you think that it wold pose a real threat to my health if I wanted it to be my daily driver?

        Thank you

  8. Did Bulova use radium in its watches and if so, when was that practice discontinued? Would my grandfather’s 1967 Accutron contain radium?

    1. Yes, Bulova did use radium. I don’t know when they stopped using it. Probably around the early/mid-sixties, just like Omega. If you really want to be sure, you’ll need to test it with a Geiger counter.

  9. Hi,
    I have an 60s omega seamaster with what i guess is radium on the hands, nothing on the dail. If I let some watchmaker to clean the hands from radium will the watch be secured from gamma and radon? Or is other parts of the watch contemitated?Or have you tested what the diffrent will be?
    Maby some still there but it will be so low radiation and radon so its safe?

    Kind regards

    1. Hi, I think that the watch will be safe to wear afterward. However, every watch is unique so you’ll need to test that particular watch. Are you sure it’s radium? Omega stopped using it around 1963.

      1. Omega started using T SWISS T marking at the bottom of the dial around the time they switched to Tritium (hence the T’s), so if that can’t be found there and the watch dates to early years of 60’s chances are there’s radium. BTW I have one other brand vintage watch that looks like there’s only lume on the hands but under blacklight the glow reveals tiny dots in the index markers as well, unnoticeable in daylight.

  10. In your article you say “gamma radiation. Unlike alpha radiation, this type of radiation won’t be stopped by paper or plastic and it also penetrates the skin.” So is gamma radiation to be avoided?

    Forgive me if I’m mistaken, but I got the impression that despite gamma radiation’s ability to penetrate paper, plastic, and skin, you think it’s safer than alpha radiation.

      1. It doesn’t. That was just what I was wondering, seeing that you mentioned that gamma can pass through skin but never said whether that would be harmful. I’m presuming it would be.

        1. All harmful radiation from watches is gamma radiation because the alpha particles can’t penetrate the crystal and the case. If you’re removing the old lume from the dial or reluming the hands, alpha particles can still be very dangerous if you inhale or ingest some if it.

  11. So, how much ionizing radiation would you expect to be dosed with if you wear a watch with old radium lume?

    1. I don’t know. It depends on the watch and how long you wear it. If someone really wants to know, a Geiger counter would be the best way of measuring it.

      1. Spencer Bittner

        I have a 1946 telechron telalarm jr. alarm clock with radium hands that i use as my normal alarm clock, is that safe?

        1. Marie Curie Skłodowska kept the bottle full of radium next to her bed as a dim night lamp. There was much more radium than in the clock.
          She lived 66 years, quite long for the beginning of the twentieth century.

  12. Sebastian Persson

    You should still be really careful when handling radium watches that does not have any crystal on them. They do release a large amount of beta radiation and most can give off over 100uSv/h when they dont have the crystal over it. I own a lot of radium clocks and watches and one of the watches gives off 67uSv with the crystal on and another clock that I have does not have any crystal over it and it gives off 2130uSv! And thats not counting the alpha radiation. When putting my camera over it it starts to flash from the high radiation so always be careful and it is not recommended to tamper with the paint because it can still be hazardous and contaminate large areas.

  13. My father was a watchmaker. I remember watching him apply new radium to watch hands. As children, my sister and I were always fascinated with how it glowed intently when we held the radium container under light. Recently I came across the little tin with a small a out of radium left in it. What would be a proper way to safely dispose of it?

  14. I want to buy my first radium vintage watch. I’ll only wear it from time to time. What do people recommend..? I can spend about 500€

  15. Read the book “The Radium Girls” and learn that radium is more dangerous than this article claims. It was not only the dial painters that became ill. Even family members (in one case a sister who shared a bed with her dial painter sibling) became ill. READ THE BOOK AND LEARN THE TRUTH. AS ALWAYS, BIG BUSINESS ONLY CARES ABOUT PROFITS, NOT PEOPLE.

    1. I’ve read Kate Moore’s book. It’s not safe, that’s why it was banned. But there’s no need to get hysterical about it. There’s a way to handle it safely with the proper protective clothing and procedures.

  16. Hi,
    Thank you for this article.
    I bought a Steinhart watch one month ago (black military 42 model). It’s said to use “old radium” as lume. Do you know if it’s really made out of radium or is it a like-radium lume to make the whole more vintage?

  17. In 2009 I bought a 100% factory accurate fully restored 1961 (M1) Bulova Accutron Spaceview Alpha 14kt solid white gold from a reputable dealer. The luminous hands were advertised as new old stock . Do you have any experience with these watches to know if Bulova was still using Radium in 1961? It has been a concern of mine for quite some time particularly since I have to open the back of the watch to replace the battery from time to time. I guess I could buy a geiger counter but I was hoping someone might know the answer to this question.

  18. Nice article. Most people are not aware how much 10 uSv/h is. It is equivalent to a dental Xray every hour.
    Do you have any tips to remove the paint from dials without destroying the paint?
    And how do you dispose of the radium?

    1. Hi, thanks. Everybody knows what a dental Xray is so thank you for clarifying. I try to keep away from the dial as much as possible because it’s very easy to accidentally remove varnish or lettering/markings. But if I had to, I’d use a toothpick or cotton swab with some alcohol. I collect tissues and cloths with old radium in a tin and I take it to the recycling point.

      1. Eugene Velednitsky

        I actually disagree with the usefulness of the above comparison. First of all, though many know what a dental x-ray is, they have little or no clear understanding of negative effects from the dose of radiation, nor do they realize that there is a massive difference between the various types of x-rays. For example, a standard chest X-ray has approximately 20 times the radiation dose of a dental x-ray. Secondly, when dose estimates are given for x-ray procedures, they are estimating the actual dose the patient receives, not the amount of radiation emitted from the source. As the particles are emitted from the radium markers in every direction, only a fraction of the total dose emitted is actually absorbed by the person wearing or working on the watch. So, with that stated. I do not personally know the exact dose of the radiation received by the wearer, I can safely say that there is likely a much better way of assessing the safety of it then saying it’s like dental x-rays.

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