Cholic acid

Cholic acid as a crystalline acidic substance secreted by the humanoid liver.

When Chief Engineer Geordi La Forge and Lieutenant Barclay were analyzing a corrosive organic solvent in a Jefferies tube, La Forge mentioned there were high levels of cholic acid enzymes which were dissolving a Bulkhead and Conduit. Upon completing a Biospectral analysis, the solvent was later learned to be that of Lieutenant Worf's venom, as he was spraying it throughout the ship after becoming infected with Barclay's Protomorphosis Syndrome.