yes they are. But not right away. If i were you i would soak them in one part bleach to 10 parts water over night. Then let rinse very well in warm water. After that take it out and let it air dry. If you still smell the bleach rinse over again until you dont smell anything. Then its ready to be placed in. Thats how I have done it in the pass and it worked for me unless someone else has their own opinion or better methodology. But anyways, happy and health reef keeping.