Invidium was an element with many uses, although very dangerous if handled inappropriately. This element was an almost permeable substance used in biological containment vessels for operations involving a type of virus culture. It was not normally detected by standard scans, could exist in a nitrogen-oxygen atmosphere, and could alter the molecular structure of glass. It was one of only five substances with these criteria. The substance became inert below −200 °C.
In 2366, the USS Enterprise-D was transporting a shipment from the Mikulaks when Lieutenant Reginald Barclay broke a container. Lieutenant jg Duffy and Miles O'Brien were handling the container and were unknowingly contaminated with invidium. Through them, the substance then began wreaking havoc on different ship's systems, including causing the replicators to malfunction, causing a drinking glass to melt in Duffy's hand, and, more seriously, the matter/antimatter injectors had become physically jammed, almost destroying the Enterprise. Cooling the injectors allowed them to come back online.
The engineering team realized the Mikulaks still used invidium and took appropriate measures to repair the damage caused to the ship. Afterward, the ship was decontaminated at Starbase 121. (TNG: "Hollow Pursuits")