Thioacetic acid appears as a clear,yellow liquid with a strong, unpleasant odor. May be toxic by ingestion, inhalation and skin absorption. Irritating to skin and eyes. Used to make other chemicals.Ethanethioic S-acid is a thioacetic acid that is acetic acid in which the oxygen atom of the hydroxy group has been replaced by a sulfur atom. It is a tautomer of an ethanethioic O-acid