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.
The business that we responded to with a person who had a serious HF exposure and ended up losing his arm... was a place that treats hazardous wastes and converts them into innocuous substances that can be disposed of. The victim was someone who had many years of experience working with Hydrofluoric Acid and other chemicals that must be handled very carefully.
It reminded me of my many years working in a lumber mill. Most of the more experienced guys that I worked with were missing fingers. I chopped my fingers up pretty good once when I tried to pull out some wood debris that had stopped the machine and my fingers came into contact with a moulder side head that was still spinning. All it takes is a second of inattention and bad things can happen.
At least when you hack up a body part the damage is fairly easy for doctors to see and understand, when you have a serious chemical exposure depending on who is giving treatment... there is a good chance that they may not have a good understanding of what is taking place inside your body. If the person I referred to had received appropriate and timely treatment he most likely would not have lost his entire arm.