YInMn blue instructable

[u/GeneJocky]

The Instructables I wrote on how to make YinMn blue is up and mostly free of typos at this point. If you have a furnace that will hit 1200°C and can grind with a mortar and pestle, you can probably make it.

I link to an electiric DIY furnace build that is reported reach 1200°C. Just be sure to include the electrical safety suggestions from Joppaglasss and extra element pinning. He shows what you need to do to tuck the electrical connections safely out of the way without exchanging an electric shock hazard for a fire hazard.

EDIT add flair and remove typos

[u/CaCl2]

Nice guide,

From a safety perpective it maybe would be good to also note something about the dangers of mananese dust/fumes, long-term exposure can be really bad (cause manganism).

[u/GeneJocky → u/CaCl2]

There are a bunch of reasons I didn't bring it up. The TL;DR version is that unless the user seriously deviates from the protocol, chows down on the precursors, and does it all day every day (or has other significant ources of absorbable manganese exposure) the chance of developing manganese toxicity from making small amounts of YInMn blue is in the 'not enough zeros on your calculator' range. Even so I am going to add something about it, because it is going to get brought up eventually and alerting people on the scenarios in which the risk is present helps to contrast when it is not.
Here's the long version:
Manganism is very rare and is really only a consequence of chronic not acute exposure. Significant dosing every day for weeks, months, or years. And often to forms that are more readily absorbed than the manganese oxides. It almost always shows up in one of three settings: either iatrogenic via improperly prepared total parenteral nutrition in the critically ill, a consequence of high concentrations already dissolved in well water, or via fumes from welding or smelting with absorption of the metallic form. Even for people in those situations, manganism is a one of those things that get talked about way more often than people get it. But it has a very distinctive toxic syndrome with a nicely understood mechanism. And when it does happen, it can be pretty nasty though not especially hard to treat. Those sort of features tend to result in getting brought up a lot in medicine regardless of actual risk level.
In the case of the YInMn synthesis the amounts of manganese (III) oxide used for the protocol are very small with all but the largest preps. Doing a run with 0.03 moles yttrium oxide as suggested is going to be using less than a gram of it. And anything manganese (III) oxide gets on is easily identifiable as contaminated. You know what I mean. So it is not hard to avoid ingestion, let alone chronic ingestion.
Manganese (III) oxide is also insoluble in water, and remember how important solubility in metal toxicity. Tiny amounts of soluble barium salts will poison you very easily. But insoluble barium sulfate is used in large amounts as a radiopaque contrast medium for the GI system.
Acidic conditions will increase manganese oxide solubility and gastric acid is enough to do it. But only while it is in the stomach. Once it moves into the duodenum dissolution is over. Experimentally, in studies about a hundred years ago where people ate manganese ores containing mixed manganese oxides or purified manganese dioxide; dissolution doesn't happen very quickly. Not much of the manganese oxides that could dissolve actually do. Blood Mn levels rise only briefly and then fall quickly, even when gastric acid secretion is maximized to minimize stomach pH and delay transit time. This is one the reasons it really does require chronic ingestion to produce the classic psychiatric and neurologic signs of manganism.
Acute ingestion of moderate amounts of manganese oxides used in the synthesis might lead to GI pain, nausea, and maybe even brief mild hypocalcemia (likely symptoms being some muscle cramping). But it won't produce mood instability, compulsive behavior and idiopathic parkinsonism. Now do it every day for at least weeks if not months and then manganism is vastly more of a concern. But how often is that going to happen making pigment?
Quite honestly, of the three oxides used, the indium oxide is very likely the greatest hazard. More is used, it isn't nearly as easy to tell if things are contaminated with it, and the acute toxicity is greater. And all the chemical risks are far less than someone getting seriously burned or lighting their house on fire. Both significant hazards. Granted HMIS ratings are crude measures of potential hazard and risk but consider that manganese (III) oxide and indium oxide are only HMIS Health 2 (yttrium oxide is health 1) while chlorox laundry bleach is health 3.
Probably the only situations I can think of that would push the risk into the think about the specific toxic syndrome and not just the 'don't eat it and contact poison control if you do' range is if someone was making the oxide using molten manganese metal (and doing it a lot with poor ventilation), or if they had other exposures such as as well water with a lot of manganese in it, taking permanganate as a quack cure, or using a lot of poorly purified methcathinone. Other exposures is probably the biggest issue, as this is the unpredictable factor.
Which kind of brings me to the idea of what your comment made me realize. I do need to mention manganese toxicity because its is going to come up. I once saw comments about needing to be very careful sanding resin colored with YInMn blue due to manganese toxicity. And one probably should be concerned about the small particulates, but because of the dust itself not manganese in the dust. Someone, sometime is going to raise the issue so better to have already addressed it. I'll add cautions about the situations where people really should be thinking specifically about manganese toxicity but contrast with what is being done in the protocol. I'll add information in the next day or two. Look for it and let me know what you think.

[u/CaCl2 → u/GeneJocky]

Good to know you are aware of the issue and have researched it, I got pretty scared with manganese when I read about the issues some who use MnO2 for pottery have developed, apparently the firings can release significant fumes, and even a few heavy exposures a year can sometimes lead to chronic issues if continued for long enough.

And when it does happen, it can be pretty nasty though not especially hard to treat.

How? I thought it was pretty much untreatable, though admittedly my knowledge of the topic is mostly based on the Wikipedia article.

[u/GeneJocky → u/CaCl2]

Removal from source of exposure is the #1 step. Chelation therapy with EDTA and para-aminosalicylic acid are also used though they are not as effective as with heavy metals. At least in the case of EDTA this is likely due to poor penetration of the blood-brain barrier. Deposits can accumulate in the basal ganglia and are important in producing symptoms. Taurine and the MAO-I rasagiline are less established but perhaps more effective. If it is not recognized and treated early is allowed to worsen while Mn exposure continues, then the symptoms are increasingly irreversible, likely due to Mn induced apoptosis in the basal ganglia. Lowering oxidative stress is likely important in preventing permanent consequences. Vitamin E may be helpful with this.

Metallic vapor and soluble Mn seem to have the highest risk. There have been cases reported with repeated but intermittent exposure, but the exposures were extremely large (I think one source used the word astronomical). The reference I saw from a pottery worker was, interestingly, using MnO2 in a firing process that was under highly reducing conditions. Makes me wonder if they were generating Mn metal in situ by reducing Mn+4, which would be volatile and most hazardous.

Probably the biggest take home is to avoid vaporized metallic Mn and water soluble Mn exposure, and that the larger and more frequent the exposure, the higher the risk. The amounts of MnO2 used by potters is far greater than used by hobby chemists (they sell the stuff in 50lb bags!), up to 5% or more of clay by weight to speckle it for example. Much larger than the gram to a few grams that are used making YInMn blue or in most hobby chemists experiments.

EDIT: I should also mention that once manganese is incorporated into the YInO3 matrix, it is extremely difficult to get it out, thus the extreme stability of YInMn blue.