What does the term “free chlorine” refer to?

The term "free chlorine" specifically refers to the chlorine molecules in water that are not combined with other substances and are available to effectively kill bacteria, viruses, and other pathogens. This free chlorine is essential for maintaining safe and sanitary swimming conditions, as it plays a critical role in the disinfection process.

In contrast, chlorine that is bound to other chemical compounds is not considered free because it is not available for disinfection. Chlorine that has evaporated or is simply present in higher concentrations does not accurately convey the capabilities of free chlorine in treating and sanitizing pool water. Lastly, while chlorine can cause irritation, this aspect does not define its availability or effectiveness as a disinfecting agent. Understanding the role of free chlorine in water treatment helps pool operators maintain proper sanitization levels, ensuring a safe environment for swimmers.