Inert material
An inert material was any material that was not reactive. Inert materials included inert gases.

In 2267, the 's transporter chief tested the ship's transporters by beaming inert material to Taurus II and back. The material returned in a disassociated condition, and the chief recommended not attempting to beam people down. ()

In 2268, after analyzing the virus with which quadrotriticale stores on Deep Space Station K-7 had been contaminated, Doctor Leonard McCoy determined that the virus transformed into an inert material in the bloodstream, subsequently killing the tribbles by cutting off their nourishment. ()

See also 
 Inert genetic material
Materials