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> The new tape cartridge media, also called 3592 70F, uses Strontium Ferrite particle technology. If anyone else is wondering if this is radioactive, it likely

> The new tape cartridge media, also called 3592 70F, uses Strontium Ferrite particle technology. If anyone else is wondering if this is radioactive, it likely isn’t. > While natural strontium (which is mostly the isotope strontium-88) is stable, the synthetic strontium-90 is radioactive and is one of the most dangerous components of nuclear fallout, as strontium is absorbed by the body in a similar manner to calcium. Natural stable strontium, on the other hand, is not hazardous to health.

PaulHoule 3y ago
In fact, small amounts of strontium seem to be good for your bones https://www.webmd.com/osteoporosis/strontium-treatment-osteoporosis https://www.webmd.com/osteoporosis/strontium-treatment-osteo...
- chaps 3y ago
  Erm, that webmd article you linked is for strontium, not strontium ferrite -- Sr vs SrO6Fe2O3.
  - BenjiWiebe 3y ago
    Not saying strontium ferrite is good for you, but remember that when we talk about sodium intake or iron intake or whatever, that includes multiple different forms of those, not including the pure metal. That article actually mentions two different forms of strontium and hints at others.
    - chaps 3y ago
      That's fair and I was curious if the same thing would happen here. But this definitely isn't my domain :) In any case, here's a lovely FDA safety data sheet of strontium ferrite. It... uh.. apparently doesn't cause pain when rubbed into the eyes of rabbits and guinea pigs. No LD50 tests were taken for the sheet though, so that's bittersweet I guess. https://www.advancedenergy.com/globalassets/non-resource-library-assets/sds-documents/strontium-ferrite.pdf https://www.advancedenergy.com/globalassets/non-resource-lib...
  - ImPostingOnHN 3y ago
    that might be because the post they responded to was also talking about elemental strontium: > While natural strontium (which is mostly the isotope strontium-88) is stable, the synthetic strontium-90 is
  - Dylan16807 3y ago
    Someone that's worried about radioactivity is talking about the atoms. And so is the webmd article. Zero mismatch.
adrian_b 3y ago
Natural strontium not only is not radioactive but it is one of the elements with the most stable nuclei (compared to their neighbors), together with barium, tin and lead, because they have "magic" numbers of neutrons or of protons. Because of this, strontium is one of the most abundant elements in the universe, among those that are heavier than the elements of the iron peak, i.e. among the elements that cannot be produced by fusion, in stars. There are various living beings which use either salts of strontium or salts of barium for their skeletons, instead of the more common salts of calcium (because the salts of Sr and Ba, especially the sulfates, are less soluble than the corresponding salts of Ca). In magnetic tapes, either barium ferrite or strontium ferrite are preferred to ferromagnetic metals that have been used in the past, because they already are oxides, so they cannot be oxidized by the air, which enables long lifetimes for the magnetic tapes, of at least thirty years.
- quakeguy 3y ago
  Awesome reply, thx!
- dylan604 3y ago
  >In magnetic tapes, either barium ferrite or strontium ferrite are preferred to ferromagnetic metals that have been used in the past, because they already are oxides, so they cannot be oxidized by the air, which enables long lifetimes for the magnetic tapes, of at least thirty years. This was very interesting. I quit paying attention to tape formulations decades ago, but even when paying attention, I only knew of the names vs actually knowing this level of detail.
- bhewes 3y ago
  I second quakeguy, great reply; love seeing material science on HN.
tzs 3y ago
If you knew you were going to exposed to nuclear fallout could you ingest a lot of natural strontium to minimize the amount of strontium-90 your body could absorb?

PaulHoule 3y ago

In fact, small amounts of strontium seem to be good for your bones https://www.webmd.com/osteoporosis/strontium-treatment-osteoporosis https://www.webmd.com/osteoporosis/strontium-treatment-osteo...

chaps 3y ago
Erm, that webmd article you linked is for strontium, not strontium ferrite -- Sr vs SrO6Fe2O3.
- BenjiWiebe 3y ago
  Not saying strontium ferrite is good for you, but remember that when we talk about sodium intake or iron intake or whatever, that includes multiple different forms of those, not including the pure metal. That article actually mentions two different forms of strontium and hints at others.
  - chaps 3y ago
    That's fair and I was curious if the same thing would happen here. But this definitely isn't my domain :) In any case, here's a lovely FDA safety data sheet of strontium ferrite. It... uh.. apparently doesn't cause pain when rubbed into the eyes of rabbits and guinea pigs. No LD50 tests were taken for the sheet though, so that's bittersweet I guess. https://www.advancedenergy.com/globalassets/non-resource-library-assets/sds-documents/strontium-ferrite.pdf https://www.advancedenergy.com/globalassets/non-resource-lib...
- ImPostingOnHN 3y ago
  that might be because the post they responded to was also talking about elemental strontium: > While natural strontium (which is mostly the isotope strontium-88) is stable, the synthetic strontium-90 is
- Dylan16807 3y ago
  Someone that's worried about radioactivity is talking about the atoms. And so is the webmd article. Zero mismatch.

adrian_b 3y ago

Natural strontium not only is not radioactive but it is one of the elements with the most stable nuclei (compared to their neighbors), together with barium, tin and lead, because they have "magic" numbers of neutrons or of protons. Because of this, strontium is one of the most abundant elements in the universe, among those that are heavier than the elements of the iron peak, i.e. among the elements that cannot be produced by fusion, in stars. There are various living beings which use either salts of strontium or salts of barium for their skeletons, instead of the more common salts of calcium (because the salts of Sr and Ba, especially the sulfates, are less soluble than the corresponding salts of Ca). In magnetic tapes, either barium ferrite or strontium ferrite are preferred to ferromagnetic metals that have been used in the past, because they already are oxides, so they cannot be oxidized by the air, which enables long lifetimes for the magnetic tapes, of at least thirty years.

quakeguy 3y ago
Awesome reply, thx!
dylan604 3y ago
>In magnetic tapes, either barium ferrite or strontium ferrite are preferred to ferromagnetic metals that have been used in the past, because they already are oxides, so they cannot be oxidized by the air, which enables long lifetimes for the magnetic tapes, of at least thirty years. This was very interesting. I quit paying attention to tape formulations decades ago, but even when paying attention, I only knew of the names vs actually knowing this level of detail.
bhewes 3y ago
I second quakeguy, great reply; love seeing material science on HN.

tzs 3y ago

If you knew you were going to exposed to nuclear fallout could you ingest a lot of natural strontium to minimize the amount of strontium-90 your body could absorb?