This is a type of sodium salt and a type of sulfurous acid that has a chemical formula of Na2SO3. It is a product of scrubbing sulfur dioxide and it has many uses pertaining to the food industry mainly. For example, you’ll find that this product is used to help prevent dried fruit from discoloring after it has been dehydrated, and it is also used to preserve different meats. It also has use in converting halogens, helping with photography, and educing the chlorine levels in some pools. This product appears as a white solid and is completely odorless to most people.