I've had a scare with Zoanthids, whic occurred -AFTER- seeing the posts about toxicity.
I was fragging a colony of purple/green Zoanthids (simmilar to those in the gallery of Logical Reef). I had a hunk of the rock actually broken away, but the -mat- still attached the frag to the mother colony. As I was reaching for a pair of steel scissors, i heard SNAP, and felt something hit my eye. It was wet, it was squishy... it came from the zoanthid colony, which had broken by barely shifting.
It burned like -all hell-, at which point I dropped everything into the fragging bucket and rushed to the bathroom to rinse with water (more water, visine, more water... etc). The stinging stopped almost immediately, and I suffered no ill effects. I assume that rather than something toxic getting in my eye, it was something -salty- and foreign. None the less, it scared me.
I've handled zoos with a sufficient amount of open hangnails (salt water does that to me) and have had nothing more than a mild burn from the salt. I suppose it really does depend on what -kind- of Zoanthid, or Palythoa you're dealing with.
To be on the safe side, I would strongly avoid Palythoa (as I do, for more than just that reason) and stick with Zoanthids which are either Aquacultured, or are frags from fellow reefers (if you are greviously fearful of Zoanthid Death). Gloves are a "Good Thing" as well, because you don't get pickled arms... I sware, if I were to add dill to my tank, I could literally pickle my own arms, as much as I stick them in there...
Frankly, there are things way more common, and way more dangerous than a few species of Palythoa. I had two Cone snails in my tank that came in as hitch-hiking eggs. I have the shell of one of them, which is about 3/4" long. Large enough to give me trouble. I've been tagged by a fireworm which -literally- put me on the floor howling, and my Gonipora (yeah, I have one, let's move on) causes a weird stinging and numbness if I accidentally touch it. Not to mention that the Nudibranches which feed on Zoanthids could be to blame for SOME of these incidents... they would tend to have the chemicals in higher concentration, right?
Also, you have to take into account how sensitive a given person is, as to whether they will react violently to a low dosage. A very good budy of mine in Fla cannot stick his arm into his own tank. He is -horribly- alergic to the chemicals corals put off naturally, especially Coralimorphs. He has to wear armpit-high gloves, or he ends up with what looks like massive sunburn, or Psoriosis on his arms. I imagine if he got -any- zoanthid toxin on his skin, he'd be passing out. He recently got out of the hospital after stepping in a jellyfish. I saw the pictures... his whole leg looked like sausage. Not pretty. There was draining involved. Just... gross. But, I'm not telling people that they should run screaming from the beaches... nahh, just him.
Taking all of those things into account... watch your back. Wash your hands, wash your arms. Use a strong soap and hot water. Hell, douse with vinegar to remove stinging cells. Wear gloves if all else fails. Distribute them at reef meetings under the "Safe Zoo Awareness" campaign...
"No Reef-Love if you've got no Reef-Glove"
-Sumbel.
Who is loath to leave things on a sour note in her posts.