Oxalic acid is an organic compound with the formula C2H2O4. Some call it “crab acid” due to its appearance. Oxalic acid crystals technical are a white, crystalline powder that is commonly used in various industrial applications. It is primarily used as a reducing agent, bleaching agent, and chelating agent in the production of various chemicals, including dyes, pharmaceuticals, and metal cleaning agents. Additionally, it is used in the food industry as a preservative and acidifier. Oxalic acid crystals technical are also used in the cleaning and restoration of wood and stone surfaces, as well as in the removal of rust and stains from metal surfaces.