Oxalic acid is widely used as a cleaning agent, particularly for removing rust and stains from various surfaces, including metals, fabrics, bathrooms, kitchens, and hard surfaces. In the textile and leather industries, it serves as a mordant in dyeing and bleaching processes to improve color fastness. It is also employed in beekeeping to control varroa mites, a common pest in hives. Additionally, oxalic acid is utilized in the production of pharmaceuticals as an intermediate, and as a reagent in analytical chemistry for precipitating rare earth elements and other analyses. In wood restoration, it helps bleach and restore the natural color of aged wood. It is used in water treatment to remove unwanted minerals and metals, in paper recycling to eliminate ink and coatings, and occasionally as a catalyst in plastics and polymer production. While not typically a direct additive in food processing due to toxicity concerns, it is used for equipment cleaning in the food industry. However, it must be handled with care due to its corrosive nature.