This standard describes sulfur dioxide, a compressed, nonflammable liquefied gas, for use in the treatment of potable water, wastewater, or reclaimed water to remove excess residual chlorine. It can be referenced in documents for purchasing and receiving sulfur dioxide and can be used as a guide for testing the physical and chemical properties of sulfur dioxide samples. The stipulations of this standard apply when this document has been referenced and then only to sulfur dioxide used in the treatment of potable water, wastewater, or reclaimed water.