Wednesday, June 1, 2016

Process Wednesday: huh, that's a lot of "NEVER"s

Via a random Googling, I happened upon Dow's "Dow Answer Center" with a few helpful suggestions for handling acrylic acid:
While some of these are certainly understandable (gee, thawing acrylic acid with steam seems like a terrible idea), some of them (don't deadhead a pump with acrylic acid in it) is obvious only with some hindsight (if you're not used to dealing with pumps in the plant, anyway.) 

It's funny to me how safety literature is mostly of the "polite suggestions" variety, with strong words ("always", "never") reserved for material that has some pretty remarkable consequences. Considering that a random Googling of acrylate accidents reveals quite a few of them (including a plant explosion in Georgia that injured 6 and killed 1), following the 10 "NEVER"s seems like a good idea. 

13 comments:

  1. It's also a lot of exclamation points!!!!!!!!!!!! (although I have more!)

    I'm glad to see that their site has links explaining why these "polite suggestions" exist, rather than just having them as arbitrary rules.

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  2. Funny thing about acrylic acid is that at 4 degC it forms a nice eutectic, with lots of pure crystalline material and a small remaining volume of liquid rich in inhibitor. Best thing a lazy grad student can do to poison a polymerization is to use that liquid. :D

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  3. I suspect the use of the term Never in chemical handling may be prompted by legal CYA however knowing how combinations of cavalier and ignorant chemists can be dangerous at times the strong wording could actually have an impact on most. I am darned sure less educated technicians and plant operators are more likely to pay attention. The Nevers are defined often by real world unfortunate incidents just like to Georgia plant explosion.

    Without following up on John's links my other guess is that polite suggestions mean less know about the consequences and risks so uncertainty as to degree is modulated.

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  4. The Iron ChemistJune 1, 2016 at 12:00 PM

    Great, now all you have to do is hire people who can read, understand, and remember simple directions.

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  5. Reminds me of the "10 Do's and 500 Don'ts of Knife Safety" from The Simpsons.

    "Don't do what Donny Don't does".

    https://simpsonswiki.com/wiki/The_10_Dos_and_500_Don'ts_of_Knife_Safety

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  6. I would rather have this than most MSDS, which don't really help differentiate the really bad chemicals from the relatively safe ones.

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    1. I agree. Once as part of a training session, we were given the MSDS's for methyl methacrylate and methyl mercury from the same supplier. They were remarkably similar -looking at first glance, despite one being "standard laboratory chemical" bad and one being "tiny mistake and you die" bad

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    2. Anon2:19 here. I think the best bet for determining how bad a chemical might be is the number of layers of packaging it comes in.

      Sodium chloride - open shipping box, take out bottle.
      Bad chemical - open shipping box, take out can, open can, take out bag, open bag and dump out absorbent material, open smaller can...

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    3. Anon I see your point yet not sure how accurate such a rule of thumb for degree of danger based on shipment configuration might be since not very well standardized or possibly enforced, both throughout different vendors and even from same suppliers. While I know chemicals get assigned DOT coding to define minimum requirements there is still apparent interpretations plus variability in how to meet those regulations. There have been occasions where I have opened reagents that I would have expected much greater care and protections implemented and on the other end received a few innocuous materials so over the top I wondered if the people who prepped the shipments were high on something or attempting to play (im)practical jokes.

      Your basic point about MSDSs is largely true since frequently more than worthless. There are reliable reference books (e.g. Prudent Practices, Brethericks) that can act as good general guides if purchasing something unfamiliar that has limited useful details in MSDS.

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  7. I'm a bit confused and would love to learn from someone more familiar with acrylates (I thought I was familiar with acrylates until reading this list). Why would adding a radical inhibitor, oxygen scavenger, or storing under inert gas be a bad thing? Why would mixing with oxygen (or sparging with it) be a good thing, when I usually expect that to be an invitation for radical polymerization?

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    1. VTJ: This is true of most vinyl monomers, not only acrylates. The inhibitors require oxygen to work. Conversely, uninhibited monomers must be kept oxygen-free for the reason you state. See: http://www.styrenemonomer.org/2.4.2.html

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    2. Thank you for that clarification.

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