Which of the following is the most active of the chlorine sanitizers?

Sodium hypochlorite is recognized as the most active of the chlorine sanitizers due to its effective oxidation properties and its high available chlorine content. This compound is commonly found in household bleach and is frequently used in various disinfection applications because of its ability to quickly kill bacteria, viruses, and other pathogens in water.

When sodium hypochlorite is diluted in water, it releases hypochlorous acid, which is the active form that reacts with and destroys microorganisms. Its rapid disinfection capability makes it suitable for many environments, including food service, water treatment, and sanitation processes.

While the other chlorine sanitizers have their own uses—such as calcium hypochlorite, which is often used in pool sanitation, and chlorine dioxide, which is effective in certain industrial applications—they may require different concentrations or contact times to achieve comparable disinfection levels. Their chemical structure may also lead to slower reactions under certain conditions compared to sodium hypochlorite. Therefore, for applications that demand immediate and strong disinfection, sodium hypochlorite stands out as the most active option.