Trilithium resin is a highly toxic and explosive compound produced as a waste by-product of matter-antimatter reactions, whose only useful application is as a weapon. However, storing and moving it is a highly delicate process and requires specialized equipment. In 2368, a group of weapons dealers led by Kelsey attempted to steal trilithium resin from the warp core of the USS Enterprise-D while it was undergoing a baryon sweep at Arkaria Base. They were stopped by Captain Jean-Luc Picard. (TNG: "Starship Mine")
When introduced into an atmosphere, trilithium resin acts as a biogenic weapon and is lethal to humans (but not Cardassians). Two hundred kilograms of trilithium resin is enough to make a planet uninhabitable to humans for 50 years. Captain Benjamin Sisko poisoned the atmosphere of Solosos III with trilithium resin in 2373 in response to Michael Eddington's use of cobalt diselenide. (DS9: "For the Uniform")