I was cleaning out a chemical storage closet at work. A hydrogen chloride container leaked out onto some iodine containers. I picked one up (bare handed) and sat it down in the grass. About thirty seconds later, I noticed the steam boiling up from around the bottom of the container. This is about 45 seconds worth of contact.
Depends on the concentration, but usually not something you want on yourself.
I know. I’ve worked with it myself, and I once accidentally inhaled a small volume of it.
A-Level chemistry, innit.