Oxalic acid is a dicarboxylic acid with the chemical formula H2C2O4. It is a colorless crystalline solid that is highly soluble in water and has a sour taste. Oxalic acid occurs naturally in many plants, vegetables, and fruits, and is also produced by the human body as a metabolic byproduct. It is commonly used in various industrial processes, such as cleaning agents, metal cleaning, and bleaching agents. It is also used in the production of various chemicals, including dyes, pharmaceuticals, and agrochemicals. Oxalic acid is a strong acid and can be highly corrosive and toxic if ingested, inhaled, or absorbed through the skin. It can cause severe damage to tissues and organs, and therefore it should be handled with caution and proper safety measures.