No angles are considered 100% reef-safe. The dwarf angels like the coral beauty, flame etc.. have been kept in reefs without problems, but not always the case. I have a coral beauty and it does not bother a thing. I just rid of my flame angel because it destroyed one of my xenia colonies (it is now coming back great!). You just never know, I think over time they will all look to your corals for a snack between meals.