When disinfecting water with unscented chlorine bleach, how many drops are needed per gallon?

When using unscented chlorine bleach to disinfect water, the widely accepted practice is to add 8 drops per gallon. This amount is effective for making water safe for consumption by killing harmful bacteria, viruses, and protozoa during emergency situations.

The rationale behind using 8 drops is based on achieving sufficient concentration of chlorine to ensure proper disinfection without imparting an overly strong chemical taste or odor, which can occur with higher concentrations. Additionally, this specific measurement is largely supported by health authorities like the Centers for Disease Control and Prevention (CDC) and the Environmental Protection Agency (EPA), making it a standard practice.

Understanding the correct amount to use is crucial, particularly in emergency preparedness situations, where safe drinking water may be scarce. This standardized approach helps ensure both safety and palatability in drinking water disinfection.