Regardless of what kind of racks you have , home built, pro built, all can be a fire hazard. Being diligent and having a case of ocd about you connections and electrical components is key. Inspecting is key. Never band aid fix a potential issue. Also make sure fire extinguishers are in place and smoke detectors are working properly. I put in a sprinkler system in the snake rooms and it was pretty easy to do considering i have a drop ceiling. I have 3 sprnkler heads in the room and 1 in the walk in incubator. Total cost was around 600 bucks and so worth it.