 
Oxalic acid H2C2O4 is
an organic acid that is a white, odourless crystalline solid that forms a colourless solution in water. Oxalic acid is about 10,000 times “stronger” than the acetic acid in vinegar.
Oxalic acid is used as a cleaning agent to remove rust and mineral stains. It is commonly found in rust removers, stain removers, and wood cleaning products. It is also used to remove calcium deposits in the wastewater treatment process. Oxalic acid occurs naturally in many foods, including fruits, vegetables, nuts, and whole grains. Spinach is a particularly large source. One of the main health concerns about oxalates is that they can bind to minerals in the gut and prevent the body from absorbing them. 
The Oxalis houseplant, or Wood Sorrel, is known for the sour taste of its flower stems, which is due to oxalic acid. Oxalic acid is common in the plant kingdom because it is repellent to herbivores.
Excessive ingestion of oxalic acid or prolonged skin contact can be dangerous. |