Chlorine is used in treating drinking water, swimming pools, hot tubs.etc, to kill bacteria and other microorganisms. It is also a building block for PVC and numerous other chemicals such as antifreeze, pesticides, refrigerants, and anti-knock compounds. As sodium hypochlorite, or bleach, it is widely used as a disinfectant and in bleaching. Mixing bleach with other cleaning agents, such as ammonia, can expose children or the elderly to dangerous gases... Full Text