What is the minimum contact time required for satisfactory chlorine disinfection?

The minimum contact time required for satisfactory chlorine disinfection is 30 minutes. This duration is critical because it allows chlorine to effectively kill harmful pathogens present in water or on surfaces by ensuring that there is enough time for the chlorine to interact with microorganisms. During this contact period, the chlorine works to penetrate the cell walls of bacteria, viruses, and other pathogens, ultimately leading to their inactivation or death.

Shorter contact times may not provide sufficient opportunity for the chlorine to eliminate the pathogens effectively, leading to the risk of waterborne illnesses or surface contamination. Therefore, adherence to the 30-minute contact time standard is essential for ensuring safety and effectiveness in water treatment and sanitation processes.