Chlorgase

Chlorgase, or chlorine gas, is a diatomic element with the formula Cl2. It is a pale yellow‑green gas at room temperature with a sharp, distinctive odor and high reactivity.

Industrial production occurs mainly by electrolysis of brine in the chlor-alkali process, yielding chlorine gas, sodium hydroxide, and hydrogen. Chlorine is not found free in nature and is typically handled as a compressed gas or in solutions.

Chlorgase is a powerful oxidizer that reacts with water to form hypochlorous and hydrochloric acids and with many organic compounds to form chlorinated products. It is denser than air and can accumulate in low-lying or poorly ventilated areas, posing inhalation hazards.

Its principal uses are water disinfection and sanitation, bleaching, and as a chemical feedstock for ethylene dichloride and vinyl chloride, which are precursors to polyvinyl chloride (PVC) and other organochlorines. It was historically employed as a chemical weapon in World War I and remains tightly regulated in modern practice.

Exposure to chlorine gas irritates the eyes, throat, and lungs and can be fatal at high concentrations. Handling requires appropriate containment, ventilation, and protective equipment. Because of toxicity and environmental concerns, chlorine production and use are subject to strict safety standards and regulatory controls.