really no trigger is considered "reef safe" it is all by trial and error. Some people get luck with niger's, my opinion I wouldn't really try it but if your heart is set on a trigger (because they are beautiful fish). They say and I have friends that have blue throat triggers in there reef with great success. Maybe look into those. Just my .02
In regards to the Blue Throat, it is classified as "With Caution" in regards to reef's, so if you wanted to try one, this probably be the one to try... But again, remember its "With Caution"
In my case, my Blue Throat Trigger has never nipped at any coral.