Radiolysis
From Memory Alpha, the free Star Trek reference
Radiolysis is the dissociation of molecules by radiation - either through the impact of high-energy α and β particles emitted from unstable radioisotopes, or by the action of high-energy electromagnetic waves such as gamma radiation.
The Takret were a humanoid species that were naturally immune to radiolytic isotopes, whereas Human contact with the isotopes will cause death within three minutes. (ENT: "The Catwalk")
The neutronic wavefront encountered by Enterprise (NX-01) in 2152 was saturated with radiolytic isotopes. The catwalk and sickbay were the only two locations on the ship that were able to protect the crew from exposed to the isotopes. (ENT: "The Catwalk")
Kemocite was described as "some kind of radiolytic compound." (ENT: "The Shipment") The Enterprise (NX-01) was able to track a specific shipment of kemocite by its radiolytic signature. (ENT: "Twilight")
