My mother has a story - and some significant scars to back it up, about her time employed in the 70&#x27;s at Litronix moving wafers from between the stepper, furnace, etching, etc in the era where you could still be in the same room as the wafer.<p>As this was the 70s, &quot;occupational safety&quot; didn&#x27;t mean the same thing as it does today, so apparently the etching was done <i>by hand</i>. This involved putting on three layers of heavy gloves and dipping boats of wafers in some type of etching acid. My mother wasn&#x27;t sure of the contents, but knew it involved extremely concentrated acids, which were shipped in daily because the couldn&#x27;t be stored more than a few days in the glass bottles (!!!). As she described it, the HCl and HNO3 were easy to identify when you worked with them, because they cause intense burning - and scaring - if you splashed any on your arm.<p>At least one of the etching steps, though (maybe all? I&#x27;m not sure) used concentrated HF.<p>So this went fine, until my mother took off her gloves one day... and aw bone. Didn&#x27;t even notice it. She sat with her hand under the DI faucet suggesting someone should probably call an ambulance. The paramedics wanted to amputate her hand immediate (on site). Instead, they were talked into trying to estimate how much acid actually actually made it&#x27;s way to her hand, and spent the afternoon injecting various things to try to neutralize the HF.<p>Fortunately, it must have been a very small amount of acid, as she made a full recovery, albeit with a nasty scar on her finger. It wasn&#x27;t even the worst thing that happened to her - she was a <i>lot</i> more concerned the day she discovered someone had used several full storage shelves (total an entire wall wide, floor to ceiling) to store the &quot;empty&quot; nitric acid bottles that were still full of very-nasty fumes. Shelves, that were a few feet from the (full) liquid O2 tanks. That warranted an immediate call to OSHA... from another building.<p>The industry is a <i>lot</i> safer than it once was.