Household Chlorination
Disinfecting drinking water at home with a measured dose of chlorine.
What is it?
Household chlorination adds a small, measured dose of chlorine (liquid, tablet, or generated on-site) to water to inactivate pathogens, leaving a residual that guards against recontamination.
Why does it matter?
It is inexpensive, provides a protective residual that filters do not, and scales well in outbreaks and emergencies.
How does it work?
Chlorine oxidises and disrupts microbial cell components. A correct dose leaves a free chlorine residual that continues to disinfect water in storage.
Who benefits?
Communities in cholera outbreaks, emergency responses, and anywhere recontamination during storage is a major risk.
Who may be disadvantaged?
People who dislike the taste or smell may stop using it; households dosing incorrectly get either no protection or unpleasant over-chlorination.
What evidence exists?
Chlorination is one of the most studied interventions, with strong evidence against bacterial and viral pathogens; protozoa like cryptosporidium are notably resistant.
What tradeoffs exist?
Chlorine is ineffective against some protozoan cysts, and reacts with organic matter to form disinfection by-products; dosing turbid water needs pre-filtration.
Common misconceptions
More chlorine is not better — overdosing is unpleasant and wasteful, and chlorine does not remove sediment or chemical contaminants.
What you can do next
Compare with filtration (which removes protozoa and turbidity but leaves no residual) and consider combining a filter with chlorination.