Is Your Tape Dispenser Radioactive?

Do you have anything radioactive in your house? Most people will say no, but they are probably wrong. A host of things ranging from glow-in-the dark timepieces to smoke detectors have some amount of radioactivity. But as [Wheeler Scientific] points out, so do some old Scotch tape dispensers. You can watch the video, below.

The dispenser in question is the C-15 which was very common around offices, military bases, and homes for years. They were made up until the 1980s. You have to wonder why a tape dispenser would be radioactive, and [Wheeler] has the explanation.

When you pull tape from the dispenser, you don’t want the dispenser to slide around the desk, so it needs to be heavy. But no one wants to have a giant dispenser nor do you want to pay for one made from a dense metal. So the plastic dispenser contains a ballast to make it heavier. In the case of the C-15 that ballast is thorium-containing monazite sand. A vintage counter shows the radioactivity which isn’t much, of course, but still way less than the ordinary sand used in newer models. You can also see in the video that the material is paramagnetic.

Monazite used to be a primary source of lanthanides but getting rid of the thorium led to alternate sources in the 1960s although it is still used as an ore for thorium. We know some lenses are radioactive. If you want to search your home for radioactivity and you don’t have a Geiger counter, you don’t need much to build one.

26 thoughts on “Is Your Tape Dispenser Radioactive?

          1. Cool!
            Wasn’t aware of that XKCD.
            But no, English is my L2 and I read a few articles on linguistics while researching some quirks of the English language.

  1. Bananas and NoSalt salt substitute are very slightly radioactive from potassium-40, a very-long-lived beta emitter. Brazil nuts tend to concentrate barium, a group IIA element; radium is in the same column of the periodic table and is also picked up. Heavy, glossy paper (oldguys: think Playboy magazine ;-)) often contains barium sulfate which contains tiny amounts of radium. Then there’s vaseline glass (uranium), thoriated tungsten welding electrodes, propane-lantern mantles, granite…the list of consumer items that are radioactive goes on and on. Radioactivity is everywhere! for more examples.

      1. Old, because the internet has made buying playboy stupid.
        Male, because lesbians don’t like the misogynistic objectification of women as sex objects that playboy exemplifies?

        1. @ Dan

          I really didn’t mind at all being classified as old and therefore a reader of Playboy – although I used to mainly look at the pictures. However being classified as stupid because I’m old seems a little bit over the top as well as slightly inaccurate. Go on, just for once admit that you’ve made a mildly silly generalisation. Why not make a few assumptions about black / white / yellow / pink people or red headed people or vegetarians while you’re at it. And, of course finally, how many lesbians have you asked about their attitudes to Playboy? Enough to be statistically significant?

          Toodle pip


          1. Dave, you missed the point of the “stupid” comment: he was commenting that STILL buying playboy in the age of internet porn would be “stupid”, so the people with the strongest memory of the physical magazine would necessarily be older. Your assumption, based on you misunderstanding, even enabled you to call him basically a racist (or as bad as one). While it may have been a mildly imprecise generalization (as generalizations tend to be), I’m not sure how “silly” fits (unless you’re using it to mean “mildly” stupid, which means you’d be the one classifying people as stupid, not him).

  2. >Monazite used to be a primary source of lanthanides but getting rid of the thorium led to alternate sources in the 1960s

    Monazite and bastnäsite are still the primary ores with monzanite still being the more abundant and cheaper source. The production from monzanite was driven out from the west due to environmental protests over the radioactive wastes – it still continues in Asia, Africa, etc. which produce the bigger share of rare-earth metals.

  3. Up to not so long ago, bottled water sold in Italy had a full chemical analysis of the content on the label. This also included the radioactivity, which was never zero. I used to find that quite amusing as a child, and would compare between different brands to see which one was the most radioactive.

  4. There was a dude ten years ago that built an xray machine that was essentially a machine that would peel a giant roll of scotch tape at a constant rate and expose the film. Scotch tape releases xrays apparently.

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