Polaric ion energy is a highly volatile form of energy based on polaric ion particles. Although polaric ions are capable of generating power on a large scale, polaric ion devices were prone to subspace chain reactions. Such a reaction had the potential of devastating an entire planet, vaporizing all life within a matter of seconds. Polaric ion explosions leave behind high levels of polaric radiation, as well as subspace fractures persisting for hours after the event.
In the Alpha and Beta Quadrants, polaric energy research was investigated, but the destruction of a Romulan research station on Chaltok IV by a polaric ion detonation led to the Polaric Test Ban Treaty of 2268. This agreement effectively halted polaric ion research in the Alpha Quadrant.
One planet in the Delta Quadrant, encountered by the USS Voyager in 2371, was found to be using polaric energy as a planetwide power source. The culture was pre-warp, so contact was not conducted. (VGR: "Time and Again")
In an alternate timeline, the entire civilization of this planet had been annihilated in a polaric catastrope, but it was found that the shockwaves from explosion had propagated into the past, through a subspace fracture. Two members of a Voyager away team moved through one of the fractures and was transported one day into the past, where they discovered that they were the cause of the catastrophe. When they prevented the accident, the timeline in which the explosion occurred was eliminated.