Melgar
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Why is acetonitrile considered a hazardous material?
I see data sheets all the time saying it's "EXTREMELY HAZARDOUS", and yet I could easily take a shot of it and be just fine. (LD50 is something crazy
like 2g/kg) Is it due to the fact that if it burned, cyanide vapors could be released? Doubtful, because that's true of anything that's made up of
hydrogen, carbon, and nitrogen, plus acetonitrile burns completely and easily when there's enough oxygen for it to do so.
Until proven otherwise, I'm going to assume that some dumbass in congress heard acetonitrile's alternate name, "methyl cyanide" and thought "holy
shit, it's like a combination of meth and cyanide, how could it NOT be dangerous!?"
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clearly_not_atara
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Maybe it has to do with corrosion/complexes forming with metals? I know it complexes Pd/Ag/Cu so it probably complexes some other metals too. Also if
it self-condenses (upon reaction with a base or possibly a metal like Mg? At high temperature?) the product is cyanoacetone imine which I think can
release cyanide more easily.
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phlogiston
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Burning is not necessary, it is also metabolised to cyanide in your body.
If that were a large problem, you'd expect the LD50 to be lower though. Are you sure about it? Could it be that the value you mention is for a
non-human species that is more resistant to it?
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"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer |
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Deathunter88
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Quote: Originally posted by Melgar  | I see data sheets all the time saying it's "EXTREMELY HAZARDOUS", and yet I could easily take a shot of it and be just fine. (LD50 is something crazy
like 2g/kg) Is it due to the fact that if it burned, cyanide vapors could be released? Doubtful, because that's true of anything that's made up of
hydrogen, carbon, and nitrogen, plus acetonitrile burns completely and easily when there's enough oxygen for it to do so.
Until proven otherwise, I'm going to assume that some dumbass in congress heard acetonitrile's alternate name, "methyl cyanide" and thought "holy
shit, it's like a combination of meth and cyanide, how could it NOT be dangerous!?" |
The Extremely Hazardous tag applies to any chemical regardless of their toxicity, if it has other physical hazards. Acetonitrile may not be very
toxic, but with a flash point of 2 degrees celsius and a boiling point of 82 degrees, it would be a class 1B flammable liquid, and thus be considered
to be Extremely Hazardous.
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PirateDocBrown
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Its NFPA is only 2 for Health, but 3 for Flammability.
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BromicAcid
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Remember, LD50 is only a part of the story. Acetonitrile is far from health food. I certainly wouldn't take a shot of it.
| Quote: |
/CASE REPORTS/ The case of a 39-year-old woman, who was found vomiting and confused 7 hr after ingesting 59 mL of nail polish remover (/SRP: probably
nail glue remover not nail polish remover/) containing 99% acetonitrile (4 g/kg) /was reported/. About 12 hr after ingestion, she developed severe
metabolic acidosis, seizures and shallow respiration. Eight hours after ingestion she had a whole blood cyanide level of 3130 ug/L. At 65 hr the serum
cyanide level was 10 mg/L and thiocyanate was 120 mg/L, whereas at 77 hr they were 12 mg/L and 30 mg/L, respectively. She responded to the treatment
with sodium nitrite and sodium thiosulfate. Although she had several relapses, each time she responded to sodium thiosulfate administration. On the
fifth hospital day the cyanide level was 360 ug/L and thiocyanate level 30 mg/L and the patient was discharged on day six.
/CASE REPORTS/ A case of acute acetonitrile intoxication in a 26-year-old man who ingested 40 g of acetonitrile in a suicide attempt /was reported/.
After a 3 hr latent period, he suffered from vomiting, convulsions, coma, acute respiratory insufficiency, severe metabolic acidosis, and two cardiac
arrests. In addition to supportive treatment (oxygen, mechanical ventilation, correction of shock and acidosis), dicobalt EDTA, sodium nitrite, sodium
thiosulfate and hydroxocobalamin were also administered. His clinical course was complicated but he fully recovered 3 months later.
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https://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@te...
I have been told on various occasions that acetonitrile is much more dangerous to people who drink regularly, their bodies apparently generating
cyanide more rapidly,.
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Melgar
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It still seems like the only people who were poisoned by it were clearly suicide attempts or very small children whose parents left
them unsupervised near dangerous chemicals. It hardly seems to justify charging a $25 hazmat fee to ship less than a liter of it, when plenty of
things with similar properties, like ethylene glycol and acetone, don't have the same hazmat designation.
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byko3y
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In my reagion I was shipped with acetonitrile without any hazmat fee. They ship it just like a petroleum ether or ethanol, which are both highly
flammable.
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BromicAcid
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Why is acetonitrile considered a hazardous material? Because it is.
It hits the marks for the definition that has been set fourth for a hazardous material for the DOT (I will be talking US regs since that is what I
know). I figure you are most interested in that criteria since you bemoan the hazmat shipping fee.
Acetonitrile ships as a hazard class 3 (flammable) packing group II (middle of the pack) material. It does not have a poison (6) subsidary hazard
class so that isn't part of the equation. The determination here is based on flammability which is determined quantitatively. You mention acetone
not being the same hazmat designation, actually it has an identical hazmat designation - hazard class 3, packing group II. Packing group for
flammable materials is determined by their flashpoint:
https://en.wikipedia.org/wiki/HAZMAT_Class_3_Flammable_liqui...
Essentially packing group I is the most stringent with III being the least stringent. This determines which sort of box/overpack the unit needs to go
into.
The critical thing with all of this, is that shipping regs are not meant to protect you. They are meant to protect all the people involved with
sending your purchase from seller to buyer. That is why a properly shipped box will have large visible placards on the side. That is why a hazardous
material will ship on a manifest. If the unit falls off a shelf or is leaking the person transporting it should be able to quickly identify the
hazards and respond. If the truck is in a wreck they should be able to look at the shipping papers and see what issues might manifest. This is the
extra level that hazmat shipping provides. And if you're in denial about the flammability hazards then you've never something catch fire from vapors
that had traveled to some far away ignition source.
Sometimes things get muddled because you run into hazardous chemicals all the time in day to day life but don't see special precautions taken with
them. But more often than not those chemicals do come to the distributor as hazardous materials.
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Melgar
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Thanks for answering the question. I figured it had to do with flammability, although for 500 mL, you'd think the danger would be minimal. I guess I
made the stupid mistake of assuming that eBay kept on top of these things; acetone there is listed at prices indicating the shippers clearly aren't
paying hazmat fees. So are plenty of other chemicals.
I'm fully aware that hazmat fees are to protect whoever is transporting the material; to think otherwise would make no sense. My comments about its
toxicity were simply there to rule out toxicity as the reason for the hazmat designation.
The first step in the process of learning something is admitting that you don't know it already.
I'm givin' the spam shields max power at full warp, but they just dinna have the power! We're gonna have to evacuate to new forum software!
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BromicAcid
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Most SDS sheets will list the shipping name at the bottom along with the hazard class so you can do a quick check.
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Melgar
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Yeah, I guess my confusion came from the fact that for some reason, acetonitrile seems to be the only solvent that all sellers seem to be complying
with hazmat restrictions for. That part is still confusing. I can get THF, hexane, and ethyl acetate for a lot cheaper than acetonitrile, and all of
those are similar as far as flammability.
Thinking about it though, diethyl ether is also really hard to find for a reasonable price, but it can be distilled from starting fluid or substituted
with THF, so it's not as important.
[Edited on 6/11/17 by Melgar]
The first step in the process of learning something is admitting that you don't know it already.
I'm givin' the spam shields max power at full warp, but they just dinna have the power! We're gonna have to evacuate to new forum software!
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