An entertaining article. It's strange to see cadmium described as something obscure that hardly anyone encounters. NiCad batteries were pretty common as well as CdS photo resistors for anyone doing electronics.
Again, the usual "hacker news learns about chemistry" disclaimer must be specified: just because a chemical shares a part of another chemical does not mean that it shares the toxicity of that other chemical.
Chemistry is complex. Biology, even more so. You can't just say "oh, it contains cadmium", and assume that it's bad.
With heavy metals like Cd, it's a good first order of approximation. It's not like flourine that's a vicious oxidiser when it's alone, and so stable the only real issue with it is you can't get rid of it when it's with friends.
I don't disagree at all, but unfortunately, the usual reflex amongst non-chemists is to go far in the other direction: assume that anything containing the toxic thing is evil and wrong. So therefore you get people calling out (for example) ceramics containing CdS glazes, which haven't been shown to harm anyone using them (the finished ceramics, not the glazes themselves).
But of course, even for definitively "toxic" things, one must differentiate between exposure channels. I wouldn't care if I handled a piece of Greenrockite [1], but I wouldn't want to breathe the stuff in powdered form. Same with Cadmium glazes: orange pottery doesn't concern me, but I'd want to be careful if I were handling Cd-containing powdered glazes. You don't want your dry cleaner dumping used methylene chloride in the river, but it's commonly used in decaffeinating coffee.
The reason the author won't work with this particular compound isn't the fact that it contains Cadmium, but rather, that this particular compound has nasty tendencies, in addition to being toxic, that make it particularly dangerous.
Per my sibling comment, I think thought must be given to the likelyhood of distribution of a "channel" or material state, not just the fact that one exists.
Particularly, wood is fairly recognizable, and almost certainly not liable to spontaneously implode into a cloud of dust. Plus, I'm fairly confident it is biodegradable (even in dust form).
Not sure the same can be said for most other materials, such as cadmium, or the parent mentioned naturally occuring compound.
Kind of a digression, but wood dust absolutely does present an explosion risk, when mixed in the right ratio with air. It's a thing that happens, and people worry about it in industrial settings.
> Cadmium is bad news. Lead and mercury get all the press, but cadmium is just as foul, even if far fewer people encounter it. Never in my career have I had any occasion to use any, and I like it that way.
It seems clear that he doesn’t want to work with cadmium, regardless of the compound.
I mean, sure. But then you read past that sentence, and you see that the rest of the article is about this particular compound, and it's unique tendency to explode, form toxic gases when burned, and so on.
I can't speak for the guy, but lots of things are "bad news", colloquially, and yet we work with them in the laboratory as an accepted everyday risk. I am not an inorganic chemist, but I'm pretty certain that they work with far riskier things than inorganic Cadmium on a regular basis.
> used methylene chloride in the river, but it's commonly used in decaffeinating coffee.
Where was it that folks found that decaf coffee was eating into their styrofoam cups (decaf alone), so they concluded that the solvents used during the decaffeination process must have been seeping into the coffee ...
"one must differentiate between exposure channels"
I think this is a mistake, though.
I mean, yes, exposure "channels" are absolutely important, but its the (false) assumption that one "safe channel" lowers the general risk of the other channels being an issue.
Your particular example mentions powder - what happens to the substance after it is crushed in a landfill? Or involved in a high speed collision, exposed to high heat, uv rays, microwaved, etc.
Potential harm should include the risk posed by all channels as a function how likely they are to be in that state. If the likelyhood is at 100% over any "reasonable" period of time, then you don't get to ignore the effects of that "channel".
Worse, if any of the channels are difficult to detect, then the risk should be compounded - I know about wood dust and can both easily see it and am amply aware when it is an issue and can take precautions. I'm not sure I can even identify the material you mention nor would be able to distinguish it from just "normal" dust.
I wasn't criticizing the parent. I was making a general comment -- the reason you see Cadmium-containing compounds in common products is that they're useful, and not necessarily harmful.
Then I strongly advise you change your wording. Without specifically saying it's a warning to future theoretical comments, phrases like 'the usual "hacker news learns about chemistry" disclaimer' and 'You can't just say "oh, it contains cadmium", and assume that it's bad.' come across as direct and harsh counterarguments.
FWIW, it did not came across to me that way. But in the intended way. Maybe a little bit condescending, but still informative, without me feeling negativly insulted as someone knowing way more about computer than chemistry.
Also just about every yellow or orange pigment, like in e.g. oil paint, is cadmium selenide or something in that family, as far as I am aware. Same for ceramics, if you want a nice yellow or orange it's cadmium time.
I remember seeing a cadmium spill on the edges of the sewage treatment plant near where I grew up. I was a nerdy enough kid to recognize it when I saw it.
As an interesting aside, right now bright OLED screens have pretty bad wear characteristics. We do have a cheap solution that would work, but it requires cadmium.
A decade ago or so there was an application for RoHS exemption for the use of cadmium in displays, and their argument was that because coal plants emit cadmium, and because Oled screens with cadmium quantum dots are so much more efficient than backlit screens, that in practice allowing the use of cadmium in screens would reduce total cadmium release into the environment. It didn't pass.
Cadmium was also widely used in the past as a galvanic coating on iron and steel parts to keep them from rusting. And unfortunately when and if it oxidizes, it can become powdery and easily airborne. I mess around with old electronics and it's unfortunately pretty common to encounter on old metal radio chassis and things like that.
Still quite common to encounter elemental cadmium in other contexts, too. I'm around it all the time while working on my race cars where (at least in amateur circuit racing in North America), the use of cadmium-plated "AN" and "MS" fasteners is extremely common. Ditto for aviation.
Mercury is, though, https://en.m.wikipedia.org/wiki/Merbromin - and on the "paints & coatings" side, orange-red and anti-rust often enough used mercury salts as well. Rarely these days, fortunately.
In some ways, it's nice GaN "won" for blue LEDs. CdTe / CdSe would literally have been "twice bad".
