Uses It is a white solid used in removal of certain kinds of stains, in removing calcium ions from solutions, and in tanning leather. It occurs naturally and is toxic. The metabolism of sugar by many species of mold results in the production of oxalic acid. The most common uses of oxalic acid are in tanning leather and removing rust and ink stains. In stain removal, it acts as a reducing agent uses: Details Other Names: Ethanedioic acid, Oxalic acid (aqueous), Oxalic acid dihydrate Grade: DiHydrate, Technical 99.6% CAS: 144-62-7 Appearance: White granules. Solubility: Soluble in water Natural or Synthetic: Occurs naturally in cabbage, spinach and rhubarb leaves. Recommended Retest or Shelf Life: Storage: Cool Dark Dry, Tightly Closed. Cautions Not for Ingestion. It is not identified as mutagenic or carcinogenic; there is a possible risk of congenital malformation in the fetus; may be harmful if inhaled, and is extremely destructive to tissue of mucous membranes and upper respiratory tract; harmful if swallowed; harmful to and destructive of tissue and causes burns if absorbed through the skin or is in contact with the eyes.