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Things I Won't Work With: Dimethylcadmium (2013)
- kens 2y agoAn 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
- 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.
- supertofu 2y agoA consumer report not too long ago found cadmium at unsafe levels in many dark chocolate brands: https://www.consumerreports.org/health/food-safety/lead-and-cadmium-in-dark-chocolate-a8480295550/ https://www.consumerreports.org/health/food-safety/lead-and-... The cacao was contaminated with cadmium from the soil during harvest.
- Bluestein 2y ago> found cadmium at unsafe levels in many dark chocolate brands: That's just bonkers.- PS. Lead too, apparently ...
- MattGaiser 2y agoChocolate production is a mess of child labour, toxins, violence, and poverty.
- teractiveodular 2y ago(2013)
- mhb 2y agoet alia: https://hn.algolia.com/?q=things+i+won%27t+work+with+ https://hn.algolia.com/?q=things+i+won%27t+work+with+
- DylanSp 2y agohttps://www.science.org/topic/blog-category/things-i-wont-work-with https://www.science.org/topic/blog-category/things-i-wont-wo... links to all of Lowe's posts in this category. The How Not to Do It series is also great - https://www.science.org/topic/blog-category/how-not-to-do-it https://www.science.org/topic/blog-category/how-not-to-do-it.
- mech422 2y agoDerek Lowe's stuff is awesome - Probably the most famous 'stuff I won't work with' is 'sand won't save you this time' ... 1) https://www.science.org/content/blog-post/sand-won-t-save-you-time https://www.science.org/content/blog-post/sand-won-t-save-yo... edit: full index here: https://www.science.org/topic/blog-category/things-i-wont-work-with https://www.science.org/topic/blog-category/things-i-wont-wo...
- brenns10 2y ago(warning: pedantic comment) "et alia" is used to refer to "the others (people)" whereas "et cetera" is used to refer to "the others (things)". So you'd use "et cetera" to refer to the other posts. But if you were writing a list of authors you might end with "et al." to indicate that there are more. I know correcting somebody's Latin usage is really pedantic even by HN's standards. I'm only saying it cause I find it interesting and want to share, not because I want to correct you :) https://en.m.wikipedia.org/wiki/Et_cetera https://en.m.wikipedia.org/wiki/Et_cetera
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- Ekaros 2y agoAre dimethyls with wrong sort of metals all really nasty stuff? Just wondering as dimethylmercury is also nasty stuff.
- ta988 2y agoIt seem so, but it is a bit more complex in reality https://pubs.acs.org/doi/10.1021/acs.organomet.7b00605 https://pubs.acs.org/doi/10.1021/acs.organomet.7b00605
- zdragnar 2y agoMethyl groups play heavily in organic chemistry. As an organic compound, it allows otherwise fairly inert metals to be easily absorbed into body tissues and interfere with the chemical processes therein. To take mercury for example, you can stick your hand in a vat of elemental mercury and be fine. A few drops of dimethylmercury on your skin can be fatal.
- Bluestein 2y ago> A few drops of dimethylmercury on your skin can be fatal. Sounds like a state actor's weapon of choice ...
- deleted 2y ago[deleted]
- Ekaros 2y agoOnly if your agents are ready to commit painful suicide... Dimethylmercury can pass through gloves...
- Bluestein 2y agoNasty stuff.-
- btilly 2y agoMy ex knew the woman who discovered that by accident. https://cen.acs.org/safety/lab-safety/25-years-Karen-Wetterhahn-died-dimethylmercury-poisoning/100/i21 https://cen.acs.org/safety/lab-safety/25-years-Karen-Wetterh... has the story. A few drops on the outside of the latex gloves was enough to kill her. Maybe she would have survived if she'd changed the gloves immediately? Regardless, she didn't do that, and so didn't survive.
- deleted 2y ago[deleted]
- cperciva 2y ago[I]ts odor is variously described as "foul", "unpleasant", "metallic", "disagreeable", and (wait for it) "characteristic", which is an adjective that shows up often in the literature with regard to smells, and almost always makes a person want to punch whoever thought it was useful. No need to punch them; if someone has been exposed to enough dimethylcadmium to describe its odor as "characteristic" they probably don't have long to live...
- stavros 2y agoI'm sure the author knows this, and wants to punch them anyway.
- gtmitchell 2y agoA generation ago or two ago, it was common for chemists to use taste and smell as a tools for qualitative evaluation of chemical compounds. So older scientific literature is full of all sorts of knowledge that was obtained in ways that are shockingly unsafe by modern standards, including gems like the taste of all sorts of poisons and how large quantities of plutonium are warm to the touch.
- thrw9358767 2y agoA friend’s dad recognised cyanide during a chemistry exam by tasting it. (He survived and passed the exam.) The task was to say what each of n substances given were in a short enough amount of time, filling out a report. I’m not sure if they still give cyanide to students during exams. That was communist Poland.
- cperciva 2y agoHe's lucky that he could smell it! About 1/3 of the population lack the gene -- including my grandfather, who discovered this when performing an industrial reaction with cyanides and being alerted by someone at the other end of the room yelling that he could smell cyanide.
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- lifeisstillgood 2y ago>>> Cadmium compounds in general have also been confirmed as carcinogenic, should you survive the initial exposure. I have heard of gallows humour, but its the gallows sarcasm that gets me :-)
- fortran77 2y agoCadmium used to be all around us in Nickel-Cadmium batteries, and in Cadmium Sulfide "electric eye" photoresistors, that lower their resistance when exposed to light, and increase their resistance in darkness. (https://en.wikipedia.org/wiki/Photoresistor https://en.wikipedia.org/wiki/Photoresistor). Its probably a good idea to avoid drilling, sanding, or filing things that may have Cadmium in them if you're dismantaling old electronics, lets you inhale it.
- rbanffy 2y agoI can't believe I have to say this, but please don't eat batteries. ;-)
- wiml 2y agoIt's still reasonably common as an anti-corrosive plating on metal hardware.
- tim333 2y agoIt sees to make one of the most cost effective solar cells but I think they only use them in commercial projects rather than on roofs.
- deleted 2y ago[deleted]
- throw156754228 2y agoGreat discussion following the article in the comments. Bunsen was a legend.
- Bluestein 2y agoI noticed. Also a good read, the entire comment section :)
- gizajob 2y agoNice to see the word “floof” in a Science article
- fch42 2y agoI love reading the "things I won't work with" series ... a shame it's no longer being added to. Just curious: why did Derek Lowe stop writing these ?
- mattmaroon 2y agoPerhaps he’ll work with almost everything so he ran out.
- Bluestein 2y agoWikipedia seems to put 2017 as the stopping point for his collaboration with the publication. He went elsewhere.-
- DylanSp 2y agoHe's definitely still blogging on Science, he just hasn't posted any Things I Won't Work With entries in a few years.
- petereborn 2y agoI prefer Derek's previous thing he won't work with: Satan's Kimchi. https://www.science.org/content/blog-post/things-i-won-t-work-dioxygen-difluoride https://www.science.org/content/blog-post/things-i-won-t-wor...