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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
by kens 2y ago
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.
- Bluestein 2y agoIndeed. In fact, a recent participant around here spoke of dealing with huge amounts of such batteries on a daily, professional basis.- They were pretty common.-
- jaggederest 2y agoAlso 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.
- timr 2y agoAgain, 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.
- Dylan16807 2y agoThe comment you replied to does not say or imply anything about toxicity.
- timr 2y agoI 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.
- Dylan16807 2y agoThen 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.
- lukan 2y agoFWIW, 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.
- wisty 2y agoWith 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.
- timr 2y agoI 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. [1] https://en.wikipedia.org/wiki/Greenockite https://en.wikipedia.org/wiki/Greenockite
- guyomes 2y ago> I wouldn't want to breathe the stuff in powdered form. This makes me think of wood dust being dangerous to inhale [1], despite wood being a perfectly safe material for furniture at home. [1]: https://en.wikipedia.org/wiki/Health_impacts_of_sawdust https://en.wikipedia.org/wiki/Health_impacts_of_sawdust
- rbanffy 2y agoRegolith is also considered safe, but that’s only because it’s about one light-second away.
- fortran77 2y agoI would guess that kens has a great deal of background knowledge.
- deleted 2y ago[deleted]
- hvs 2y agoOn the plus side, it's a step up from the general public's: "X is bad because it contains chemicals!"
- apothegm 2y agoIIRC the author works in pharmaceuticals. I would be unsurprised to learn that cadmium is rarely used in the production of medications.
- fch42 2y agomaybe not Cadmium. Mercury is, though, https://en.m.wikipedia.org/wiki/Merbromin 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".
- Jeema101 2y agoCadmium 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.
- Tuna-Fish 2y agoAs 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.
- teuobk 2y agoStill 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.