This! Working on a small scale, say 40 mm wafers, you’ll be dealing with small amounts of HF - approximately 250 ml. But. There are two problems with HF: firs

This! Working on a small scale, say 40 mm wafers, you’ll be dealing with small amounts of HF - approximately 250 ml. But. There are two problems with HF: first, it doesn’t give a burning sensation like other acids, so there is a tendency to discount the seriousness of a major spill once you get past the shower off stage. Second, it is rapidly absorbed transdermally and causes an insidious necrosis, but, more importantly, it can affect blood potassasium balance and cause heart failure after some delay. While the emergency rooms on the peninsula are aware of the risk and the treatment, that may not be the case in rural Iowa. So do the homework, have a supply of gluconate on hand, and get to the emergency room right away (with the msds) if you wet, say, more than 50 sq cm of skin with HF. Not all people are susceptible, but EKG monitoring is essential following major bodily contact. Always wear gloves, and test them. Since HF doesn’t give a burning sensation, it’s easy to get a small puncture and an HF burn. I remember one older tech who was lax about this and he lost fingernails over time. He would joke about soaking his hand in a bucket of water by his bed so he could get to sleep. Pioneer days!