I was on a HAZMAT team for several years. There are many substances that can kill you through absorption. One of the scariest that I came into contact with was Hydrofluoric acid. If you had a hole in your gloves and a small amount was absorbed through your finger tip it can cause unbelievable damage to your body surprisingly without causing much discomfort to your finger tip. Because of Fluorines affinity for calcium it can do severe damage to your bones even in very small quantities. One person at a local business we responded to had to have his entire arm amputated after what seemed to have been a minor exposure. But he was lucky because a Hydrofluoric acid exposure can also cause a person to go into cardiac arrest.
There are some refineries that use HF in their alkylation units. I won’t set foot in one, even with PPE. The semiconductor plants are scary enough.
It doesn’t cause discomfort in your fingertips because it destroys the nerves. I once had to change a sensor in a HD tank. I was wearing protection but as I was getting cleaned up one of the workers said those weren’t the right gloves for the job. When we got the gloves off my hands were wet but you couldn’t tell if it was sweat or HF. They took me to the hospital, which was supposed to have data sheets for every chemical we used but they couldn’t find one for HF. Their solution was to let me sit there for a few hours to see if my hands started to melt. When I didn’t show any symptoms they sent me home.
I have worked as an industrial hygienist in several refinery turnarounds. HF is really scary. I’ve seen several guys permanently scarred after explosions. The treatment with Calcium Gluconate is extremely painful, getting tatooed in the burn sites. Also destroys lung tissues if you inhale fumes. Forms a scale on equipment that is really nasty.
And yet HF is used in dentistry, for example. Recently had some work done and the dentist used HF to etch the tooth before cementing in the new inlay. Of course that was only some <10% HF gel product. (I remembered enough about concentrated HF from my undergrad chemistry studies that I asked whether it was a good idea to put that stuff in my mouth and he then explained it’s just a diluted gel.)
I used HF in a chemistry lab. We were warned repeatedly of the dangers you described. Nasty stuff. It will even dissolve glass.
I did some hazmat training at the fire college, there was one substance they said that makes your lower jaw melt, forgot what it was, sounds like it’s similar to the hydroflouric acid though.
That’s why I don’t want that stuff in my water (fluoride).