To qualify as a disinfectant, a compound must kill or inactivate what percentage of contaminants?

To qualify as a disinfectant, a compound must demonstrate its efficacy in killing or inactivating 99.9% of contaminants. This high percentage ensures that the disinfectant is effective against a broad spectrum of pathogens, including bacteria, viruses, and fungi, which are critical in maintaining a safe and sanitary environment, especially in pool settings.

The requirement of 99.9% effectiveness is based on standards set by health and safety authorities and reflects the need for rigorous sanitation measures to protect public health. It is not sufficient for a disinfectant to only partially inactivate contaminants, as even a small number of surviving pathogens can pose health risks. This is crucial in the context of pools, where water is continuously circulated and can easily harbor harmful microorganisms.

While lower percentages like 90% or 99% might indicate some level of effectiveness, they do not guarantee the high level of disinfection necessary for safe public use. The requirement of 100% effectiveness, although ideal, is not feasible in practice. Hence, the standard of 99.9% strikes a balance between practical efficacy and safety in disinfection protocols.