Rigid PVC is used in construction for pipe, doors and windows. It is also used in making plastic bottles, packaging, and bank or membership cards. In a fire, PVC-coated wires can form hydrogen chloride fumes; the chlorine serves to scavenge free radicals and is the source of the material's fire retardancy.
Chlorine, in one form or another, is added to most swimming pools, spas, and public water supplies because it kills bacteria that cause disease. Many people also use chlorine to bleach their clothes. Large paper and pulp mills use chlorine to bleach their products. Chlorine is a greenish-yellow poisonous gas. Dechlorination is the process of removing the free and combined chlorine residuals to reduce residual toxicity after chlorination and before discharge. Sulfur dioxide, sodium bisulfite, and sodium metabisulfite are the commonly used dechlorinating chemicals. Activated carbon has also been used. Also, if your Free Available Chlorine level is less than 2.0 ppm, use a chlorine shock to bring the levels up and keep the pool sanitized. Start-Up and Close-Down: For winterized pools, opening the pool is the first time of the year that pool shock is used, after the water chemistry is balanced. This helps oxidize particles, kill bacteria and Before this, fluorine salts, known as fluorides, were for a long time used in welding and for frosting glass. The element is used to make uranium hexafluoride, needed by the nuclear power industry to separate uranium isotopes. The early chemists were aware that metal fluorides contained an unidentified element similar to chlorine, but they Note: This page deals with the practice of continuously adding chlorine to water, not the occasional use of chlorine to disinfect wells, pipes, and other water system equipment. Why water systems continuously add chlorine to their water. Many public water systems add chlorine (a process known as "chlorination") to their water supply for the purpose of disinfection. Bleach, solid or liquid chemical used to whiten or remove the natural color of fibers, yarns, paper, and textile fabrics or to remove discoloration. Bleach is also used as a disinfectant because of its microbicidal properties. Chlorine and sodium hypochlorite are examples of chemicals commonly used as bleaches. DDG0D.