Chlorine dioxide is a disinfectant. When added Chlorine Dioxide Powder to drinking water, it helps destroy bacteria, viruses and some types of parasites that can make people sick, such as Cryptosporidium parvum and Giardia lamblia. The Environmental Protection Agency (EPA) regulates the maximum concentration of chlorine dioxide in drinking water to be no greater than 0.8 parts per million (ppm). http://www.zhaoguangroup.com/chlorine-dioxide-powder/