Pyrosulfate
From Memory Alpha, the free Star Trek reference.
A pyrosulfate is a chemical compound containing the pyrosulfate ion, S2O72-, composed of sulfur and oxygen.
In 2152, a Retellian freighter expelled a cloud of dilithium hydroxyls and ionized pyrosulfates into the Enterprise's path, clogging the plasma vents and preventing the Enterprise from engaging its warp drive. (ENT: "Precious Cargo")
