I don't want to derail Dena's thread about this too much, so if this leads down a long discussion, I will split the thread and move this to the reef discussion forum.
This is a very common question when people first hear about Palytoxins. I think the short answer is most zoa's don't contain this, and those Paly's that do... well it is harmless unless you do something silly like eat them.
A slightly longer answer is, like all "poisons", it depends on the person. Some people are severely allergic to bee stings, some aren't.