Na2S2O5 – disodium disulfite – is a white or yellowish crystalline powder with a pungent odor. It is also known as sodium pyrosulfite, sodium metabisulphite, and disodium metabisulfite. This compound often serves as a preservative; it increases the shelf life of a product by impeding the growth of microorganisms. In addition, it works as an antioxidant, and as such is utilized in the production of fruit juices, sweets, wine, and beer. Disodium disulfite is sometimes added to hair care and skincare products; for instance, it is a common ingredient in hair dyes. Surprisingly, disodium disulfite can also be used to uproot stubborn tree stumps. It destroys a specific substance (lignin) in the stumps, making them more porous and consequently easier to remove.