In the mid-70's my first job out of college was at a research chemical place out in the industrial park a few miles from the UF campus, which had actually been founded by one of my professors back in the 1950's.

We were fluorine and silicon chemistry leaders, and there was even a bulk tube-trailer of elemental fluorine parked on the site, rendering us un-insurable.

One time it was pentafluoropropionic anhydride day. This is some agressive stuff, and had to be handled in a disposable glove bag under an inert nitrogen atmosphere.

It had to be flame-sealed into special glass bottles because it would eventually escape from any other type of closure.

When it comes into contact with moisture or humidity, it separates into two short-chain PFAS molecules that are still notably acidic and tend to bond to living tissue and not let go.

The acidic form was more widely available and was handled in regular drums, and I guess you could say it was quite a bit milder as a bad actor.

There was an operator who had left his gloves on top of a drum and a number of grams of fluorinted acid had gotten into them before he put them on again later. There was a delayed reaction but his hands did start burning after a while, fortunately this stuff was mild enough that his hands did not even fully dissolve.

But you can't wash it off and it keeps burning for years until you get accustomed to the pain. The scarring alone was painful to look at.

Anyway they put a brand new student model mechanical balance into the glove bag with the world's only kilo of the anhydride and weighed it into portions. It was possible to watch the paint peeling off the scale in real time and the corrosion process proceed to destruction. The glove bag and the scale were then discarded.

Out in the pit with everything else.

The temporary closures were then flame-sealed under a hood, and I get to pick two of the smallest ones for the analytical lab, one to test and the other to hang on to unopened.

Well they don't always seal, and upon inversion a couple micro-drops flew out and hit me on the shoulder and the hip, soaking right through the fabric and basically evaporating before long without doing visible damage. It did start to burn after a while but it mostly felt like a couple mosquito bites. Small red spots did show up along with the irritation which faded quite a bit over a few months but it took a few years before it could easily be forgotten.

In following decades though, the same red spots would re-appear if I was over-exerting myself and almost feeling like I was going to get heat stroke or something, yep, there they were still.

No surprise when I found out that Gainesville industrial park was an EPA Superfund site decades ago.

Now it's also been a couple decades or more since one of the most brilliant workers I had in Texas, later moved to an oilfield services group where they were injecting rare kilos of as many different short-chain perfluoroalkyls as they could, and using them as tracers to determine subsurface formation characteristics, when the different compounds could later be detected in the producing wells across a vast field.

Perfluoroalkyls are really inert and not acidic at all, but they are forever and they were thought especially good for geological tracing for that reason.

My associate became a specialist in a type of fluoride-specific ultra-trace detailed analysis that was more sensitive than what they were doing before.

Fluorides are a bitch.

Nobody's fault but mine.