Chlorine, a chemical element, is a yellow-green gas at room temperature. It is an extremely reactive element and a strong oxidizing agent. Despite its reactive nature, controlled application of chlorine is fundamental to modern society. Its pervasive role extends across various sectors, making it an an indispensable component for maintaining public health, ensuring clean water, and enabling the production of countless goods.
Purifying Our Water Supply
Chlorine plays a significant role in ensuring the safety of drinking water and recreational water sources. When introduced into water, chlorine compounds, such as sodium hypochlorite or calcium hypochlorite, react to form hypochlorous acid (HOCl), which is the primary disinfecting agent. This acid works by penetrating cell walls of microorganisms, disrupting essential components for their survival and reproduction. This process effectively inactivates harmful bacteria like Salmonella and E. coli, as well as viruses and protozoa, preventing the spread of waterborne diseases such as cholera and typhoid.
In municipal water treatment plants, chlorine is added to disinfect water on a large scale before it reaches homes and businesses. This ensures a continuous barrier against pathogens throughout the distribution system. Similarly, swimming pools rely on chlorine to kill bacteria, viruses, and other microorganisms that can cause infections, while also preventing algae growth and breaking down organic debris. Maintaining specific chlorine concentrations is necessary for effective disinfection.
Maintaining Public Health
Beyond water purification, chlorine’s application in disinfection and sanitation is important for public health. Household cleaning products, such as bleach, utilize chlorine-based compounds like sodium hypochlorite. These products act as powerful oxidizing agents, effectively killing a wide spectrum of bacteria, viruses, and fungi on surfaces.
In hospitals and healthcare settings, chlorine-containing solutions are used for sterilizing equipment and disinfecting surfaces to control the spread of infections. Chlorine also contributes to food safety by being used in processing facilities to wash fruits and vegetables, disinfect food contact surfaces, and prevent contamination in meat and poultry. These applications collectively help control pathogens and maintain hygiene across various environments, reducing the overall burden of disease.
A Foundation for Modern Products
Chlorine is a fundamental building block in the chemical industry, serving as a raw material for many products. Approximately one-fifth of the chlorine produced globally is used in the manufacturing of polyvinyl chloride (PVC), a versatile plastic. Chlorine plays a role in PVC’s structure, providing durability, strength, heat resistance, and a smooth, non-porous surface, making it ideal for pipes, window frames, and other construction materials.
Chlorine chemistry is also important in the pharmaceutical industry, where it is used in the synthesis of many medications. It can be incorporated into drug molecules or used as an intermediate in their production. About 85-88% of top-selling drugs use chlorine or chlorinated compounds in their manufacturing processes, including those for diabetes, high blood pressure, and cancer. Chlorine is also used to create various solvents, refrigerants, and to purify silicon for solar panels.