Comment by kragen

Comment by kragen 3 days ago

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Sevensor said they would like to make Etsy moms using HF to frost shot glasses reread the MSDS for HF. This would only benefit them if MSDSes were reliable guides to the risks of working with different materials. Unfortunately, as evidenced by my example, they are not. Therefore, the Etsy moms, having reread the MSDS, might reasonably dismiss the information contained in it, unfortunately failing to protect themselves against the very real dangers it poses. Furthermore, given the astounding lack of thought evident in the NaCl MSDS, it is reasonable to guess that many MSDSes you find for HF will propose "safety" measures that are actually counterproductive, such as wearing gloves.

I thought all of this was obvious from my comment.

sevensor 3 days ago

You don’t wear gloves when you work with HF? You are banned from my lab. 8 mil nitrile. Always check for cracks and pinholes before use.

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  • pedvide 3 days ago

    Part of my PhD involved lots of fluoride synthesis using HF. I always used gloves (changing them very frequently). My advisor never used them for the following reason: if a droplet of HF lands on your glove you won't notice, but HF will go through the glove. If it lands on your bare hand chances are you'll notice it and wash them immediately. I could never follow his advise, but I did change gloves pretty much every step in the synthesis just in case.

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    • sevensor 2 days ago

      I’m definitely in the frequent glove change camp. And PSA for anyone reading this, latex gloves are worse than useless for protection against HF. But hopefully anybody working with HF already knows that.

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      • kragen 2 days ago

        The MSDS at https://www.nano.pitt.edu/sites/default/files/MSDS/Acids/Hyd... doesn't specifically mention to avoid latex, so it wouldn't be a useful source of information on this point. One of the four times that it mentions gloves, it does specifically specify "neoprene" (not latex nitrile), and the other three times, it doesn't say anything. Even though neoprene is strongly HF-resistant, rereading the MSDS is probably going to be worse than useless to the Etsy moms.

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  • kragen 2 days ago

    Conventional wisdom is to not wear gloves when working with HF, as pedvide points out. It may not be to your advantage to ban people like pedvide's advisor from your lab, especially if at some point they're refereeing your papers—though, at least from my point of view, there should be no such personal-offense considerations involved, it would be unsurprising if someone were insufficiently detached for such a personal snub to prejudice them against you.

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    • sevensor 9 hours ago

      My teaching lab was for undergraduates who were etching oxide off of silicon wafers in a big old tub of hf. We’d have them wear a big thick apron and massive gloves; this is not an occasion requiring dexterity, and it’s one with a high potential for inadvertent splashes. We never had an exposure in the years I was there, although a grad student in a research lab got careless and took a cold, rusty shower.

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    • kragen 2 days ago

      to not prejudice them against you.

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