The ingestion/breathability table might be more restrictive. Like, elemental Sulfur is perfectly fine but probably unpleasant to lick. Contact dermatitis likely but not life threatening.
Breathing elemental Sulfur is also going to result in contact dermatitis -inside the lungs. Which is going make a really bad day.
Not moisture but reactive molecules. (I mean, many forms probably do still absorb a good bit but) I forgot the exact chemistry but "activated" means chemically reactive. It binds with all sorts of reactive molecules, like toxins and many other things.
By that logic you could argue that you're always licking carbon since your tongue has a lot of carbon in it. But I think the carbon has to be pure for it to count. If it's in a compound molecule it's void