 Complete the following phrase:  Chlorine is a relatively common gas in industry with a variety of uses. It is used to disinfect water as well as being a part of the sanitation process for sewage and industrial waste. Chlorine is also used as a bleaching agent during the production of paper and cloth. Many household cleaning products, including bleach, contain chlorine. Given the volume and ease of chlorine for industrial and commercial use, exposure could occur from an accidental spill or a deliberate attack. The National Institute for Occupational Safety and Health recommends that a person wear splash proof goggles, a face shield and a respirator mask when working in the vicinity of chlorine gas. Because chlorine is a gas at room temperature, most exposure occurs via inhalation. Exposure may also occur through skin or eye contact or by ingesting chlorine-contaminated food or water. Chlorine is a strong oxidizing element causing the hydrogen to split from water in moist tissue, resulting in nascent oxygen and hydrogen chloride that cause corrosive tissue damage. Additionally oxidation of chlorine may form hypochlorous acid, which can penetrate cells and react with cytoplasmic proteins destroying cell structure. Chlorines odor provides early warning signs of exposure but causes olfactory fatigue or adaptations, reducing awareness of exposure at low concentrations. With increased exposure, symptoms may progress to labored respirations, severe coughing, chest tightness, wheezing, dyspnea, and bronchospasm associated with a decrease in oxygen saturation level. . Severe exposure may result in changes in upper and lower airways resulting in an acute lung injury, which may not be present until several hours after exposure. A recent chlorine gas leak in Pune, India, landed 20 individuals in the hospital. Though that was an accidental exposure, chlorine gas has been used as a weapon of warfare since World War I, most recently in 