Friday, September 18, 2015

Handling nitric acid requires caution, from cradle to grave

I have seen far too many pictures like this one at Reddit, where a graduate student added some waste HNO3 into a bottle* with some ethanol. Result: explosion and a broken window. Here is a direct link to the pics.

(Isn't there some sort of lockout/tagout system that should be set up with every experiment with HNO3?, i.e. opening a bottle of nitric requires the locking out of all waste containers in a certain radius until the waste is properly disposed of?)

UPDATE: *That he did not know contained ethanol. 

9 comments:

  1. That was awesome to read. And well-cited. Thanks for this.

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  2. In this situation it seemed however that the researcher was well aware of the risks and proper safety disposal. Locking out other waste containers would not have helped as the issue was with EHS improperly leaving EtOH in the container after dropoff.

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  3. When I was in 8th grade, I was asked by an earth science teacher to make some nickel nitrate for a demonstration he was going to perform in class the next day (involving dimethylglyoxime, IIRC). We didn't have any nickel salts in the stockroom, but I had some nickels in my pocket along with a 4 liter bottle of concentrated nitric acid on the stockroom shelf.

    We didn't have a hood in the school, so I took the material outside, dumped some HNO3 into a beaker and threw some nickels into it. Nitrogen oxides are not your friend! The breeze outside took some of it into a classroom with open windows.

    That was first, but by no means the last, classroom that was evacuated by your truly... :-) But in the 60's. no one got excited and called Homeland Security on budding chemists.

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  4. Ditto when trying to make FeCl3 from nails, hydrochloric acid, and nitric acid. Fumes were heavy as they flowed out the window and I managed to get up and a stool and keep my head above them. I did get an instant "tan", though. I can confirm that there was no Homeland Sec in the 60s.

    Orange patient: What?
    Dr. Gregory House: You're *orange*, you moron!

    Oh, well....

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  5. Woah...Kinda cool to be on chemjobber...even if for less than stellar reasons...

    I was a second year graduate student when this happened. I was well aware of what nitric acid does to organics and thought I had taken the proper precautions. Had I capped the bottle tightly, I doubt I would have had any warning that it was about to blow. Later, we managed to find the mangled wreck that was the top of the bottle and the cap was about half way on. I think that gives some idea as to how violently and quickly the reaction proceeded. Looking back, part of the problem was at the time, the safety training on handling nitric acid waste consisted of "don't mix it with organics". That was it. 1st week of graduate school. Between moving across the country, starting school, teaching, class, etc etc it's not surprising that things like this happen. I knew HNO3 would react with ethanol, but I didn't know the specifics. I didn't know there was an incubation time to this reaction. I also trusted EH&S to do their job and give us cleaned and empty waste bottles. Luckily no one was hurt and this really changed some of the safety protocol at the University I was at. This was not the first waste bottle overpressurization at this school resulting in an explosion and sadly, I doubt it will be the last.

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    Replies
    1. I clarified my post a little.

      Also, glad to hear that you're all right.

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  6. LOTO - No.
    Nitric Acid Management Program - Yes.

    I get 5-10 calls per year resulting in nitric acid mismanagement. They are the all the same story. Waste bottle capped for the night and moved to the central accumulation area (or not). Day crew comes in at 7-8 AM and finds a huge mess where the organic solvent waste used to be.

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  7. "(Isn't there some sort of lockout/tagout system that should be set up with every experiment with HNO3?, i.e. opening a bottle of nitric requires the locking out of all waste containers in a certain radius until the waste is properly disposed of?)"

    No.

    just stop the retarded process of keeping waste in non-venting glass bottles.

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  8. Had a couple of nitric acid accidents at UIUC. That's what happens when you have an organic group notorious for safety failures. The latest here was caused by stupidity/lack of knowledge combined with fear of reporting what was happening to their colleagues, instead hoping it would all go away. Which it did, taking the glass from the fume hood with it.

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