The question of radioactivity in alloys

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SVB

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Feb 19, 2022
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Hi all!
Perhaps a question from the tinfoil hats section :D
Please develop my concerns about the dangers of wearing knives that contain Molybdenum, Vanadium and Tungsten.
For example CPM S30V contains: Molybdenum 2,0% and Vanadium 4%. CPM 20CV contains: Molybdenum 1%, Vanadium 4% and Tungsten 0,6 %.
But Sandvik 14C28N contains Molybdenum only 0,55 % and contains phosphorus and sulfur within acceptable limits
Molybdenum, Vanadium and Tungsten are radioactive element (contain one radioactive isotope).
I understand that in food, everywhere in the world there is a natural radioactive background.
I'm not a pro in chemistry or physics, nor is I a fan of conspiracy theories, I just want to understand the topic :)
 
Nothing to worry about. Everytime you go outside on a sunny day your standing in front of the a giant fusion reactor. If you live in a brick house those bricks emit radiation and so do many other things in our day to day lives. I think health concerns typically come from a very high level of exposure over a short period of time.
 
It's my understanding that the vanadium and tungsten content in knife steels is as carbides. Not the same as a free element. In any case, don't worry about it. I'm not a nukular physicist either, but I know that "radioactive" doesn't necessarily translate to dangerous. Even U-238 (the most common naturally occurring isotope) isn't really dangerous to touch.* The radioactivity that might exist in a knife blade probably wouldn't trip a giger counter; no more than other common objects things cat litter or bananas, anyway.



*Uranium is extremely toxic if ingested, as are many metals, but not because of radioactivity.
 
The very worst that'll happen after years of exposure will be that you'll develop a blond crewcut and huge muscles and start spouting one-liners from Army of Darkness, while blasting alien scum with a variety of guns. 😄

iu


In all seriousness, I know there can be concerns in the smelting and manufacturing of various metal alloys, but I don't think there's any risk to the end user worth talking about. 👍
 
The levels of radiation coming from the metals in our knife steels is extraordinarily low.

For example, bananas are many times higher in levels due to their containing radioactive potassium.

It doesn’t matter if it’s a free element or not—elements will still radiate—but those found in knife steels have such low levels that it’s hardly worth mentioning.
 
The level of radioactivity in common blade steels is so low as to be a non-existent issue. It's the difference between CMBR( Cosmic Microwave Background Radiation), the standard frequency of the universe, as compared to a Type 1-A supernova, one of the more energetic events in the cosmos.

Take your tinfoil, smooth it back out a little, and save it for a rainy day. Your concerns are little more than high thin clouds on an otherwise sunny afternoon.....
 
If you just want something real to worry about, without the tinfoil stigma, long-term chemical exposure is far more damaging than radiation concerns, for almost everyone, except those living near Chernobyl, or Fukushima.
My own personal exposure to chlorinated hydrocarbon solvents and lead, from 40 years in the electronics industry, along with cholinesterase inhibitors used in industrial insecticides from a summer as an Orkin termite
technician, are far more concerning to me than radiation, from any source...
 
It's all about relative risk. Note also that it does not matter if it is a carbide or in elemental form, the radioactive decay is the same. But for the elements that you list:

Molybdenum is about 9.74% Mo100, but it is a beta emitter, which won't even penetrate your skin.
Tungsten is 99.88% stable isotopes, so there is no real risk there.
Vanadium is 99.75% stable isotopes.

Step outside on a sunny day and you will get far more ionizing radiation that you will from your knives. Then add in the normal background from the soil and rocks under your feet (and incorporated into concrete and other construction materials) and all bets are off.

If you only knew what is in the water you drink (tap and bottled are the same, unless they are run through an RO or ion exchanger). I work in a lab that tests drinking water, and I have seen a lot of samples of drinking water that I wouldn't touch. There is an area in the Sierra foothills near where I live where there is a lot of uranium in the water, making it up 50 times the safe limit. There are many places around here with a lot of arsenic. Add to that the decades of pesticide use, which shows up in the water. And now we are just beginning to get a grasp of the magnitude of the PFAS contamination in groundwater that is found in drinking water all around the country - if your drinking water comes from sources that are less than a mile from an airport of any size, including small private airfields, and military airfields, I would be very concerned. I recently saw the results for a city that has 34 drinking water wells, and 31 are contaminated with PFAS.

People get all worked up about things. After Fukushima, the government announced that radiation from Fukushima was detected on the west coast of the US. I got a lot of calls from panicked people who thought they were going to die and wanted their water tested. It turns out that the level detected was about 1/80,000 of our normal background radiation.

It's all about relative risk. The same people who were in a panic about Fukushima radiation on the west coast of the US probably smoke, drive fast, text while driving, eat a poor diet, and don't exercise. Go figure.
 
Don't worry about it, (unless you are in California. Without exception, everything in California, from the food you eat, water you drink, the ground and grass, cloth, air, sun, shade, the car you drive, motorcycle/scooter/bicycle you ride ... everything known is known to cause cancer and/or birth defects by the state of California) Your glow in the dark watch and alarm clock hands have much higher radiation levels, and are completely harmless.
According to the tour guide at the Cordova, IL. nuclear plant, the alarm clock with glow in the dark hands puts out less radiation than a single unused 1 inch fuel cell nodule (which can safely be held with a bare hand, he demonstrates.)

As others have pointed out, you are exposed to higher levels of background radiation every instant of your life than what the knife blade would expose you to.
Less than any organic material, would be my guess. (remember: They can measure the radiation of Carbon 14, present in all organic matter to determine the approximate age of the item.)
 
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afishhunter said:
As others have pointed out, you are exposed to higher levels of background radiation every instant of your life than what the knife blade would expose you to.
Click to expand...

In other words, you should probably COVER yourself with knives to shield and protect yourself from everything else around you. :D Danny Trejo comes to mind....

KR7Iorq.jpg
 
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The one non-synthetic unstable Molybdenum isotope (100Mo) has a half-life of 7.1x10^18 years (7.1 quintillion years). Tungsten's one naturally-occurring radioactive isotope has a half-life of 1.8 quintillion years. For Vanadium, it's 1.5x10^17 years.
 
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For those of us who start getting dizzy at a million: how big are those numbers?
 
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