Talking story is my favorite part of EHS! I’ve spent a lot of time working in the semiconductor industry. It uses some terrible chemicals, one of which is hydrofluoric acid, HF. HF is awful. Exposure to moderate amounts usually doesn’t do anything. Not immediately. Without treatment, a very painful burn will appear about 24-36 hours later, as if by magic, due to liquefaction necrosis: it dissolves your tissue into a jelly. Small burns just hurt a lot, big burns can result in abscesses.

It has a very high affinity for calcium, so a single large exposure can result in cardiac arrest due to it binding the calcium in your blood. Chronic exposure to low levels can lead to it leeching the calcium out of your bones, resulting in bones collapsing or simply dying. This is very painful.

Despite it being scary, it’s dead simple to work with: don’t get it on your skin. If you do, wash it off, slather on a calcium gel, and it’ll likely be like nothing happened.