While chlorine is often associated with swimming pools, when used in moderate amounts, it can make water potable by eliminating bacteria and viruses. Chlorine is widely used in purifying water at municipal levels, making water safe for drinking for a city’s population.

Bleach, the common term used for household grade Chlorine, is typically sold at 4% to 6% chlorine concentration and is what you’d use to disinfect water for safe drinking. The active ingredient in any Chlorine product is Sodium Hypochlorite; how it’s used is dependent on its concentration.

How Much Bleach Should I Use?

When using household bleach, use 2 drops for every liter of water or 8 drops for every gallon of water. Let it stand for 30 minutes before drinking. This amount of time allows the chlorine to work (Scientific American, 1998).

Treating water this way is great if you get your water from a tap that is sourced directly from the earth, or if you are out camping and run out of bottled water and are force to gather water from a natural source. Be sure to always use unscented bleach.

Chlorine is effective against bacteria and most viruses. Norovirus, an intestinal disease that causes diarrhea, is particularly resistant to chlorine and will require the water to sit twice as long instead of the standard 30 minutes before consumption. Giardia, a parasite with a protective coating, will survive in chlorine treated water for 45 minutes before its safe to drink.

Water Purification Tablets

Chlorine can also come in the form of pre-dosed tablets which would be dropped into a container of water and allowed to sit for 30 to 45 minutes while the chemical begins to destroy the pathogens. Water purification tablets are very convenient for those who are traveling overseas or hiking in the wilderness. The convenience of not having to measure the amount of liquid chlorine and being able to carry the lightweight tablets in a backpack have allowed these tablets to gain much popularity among campers, backpackers, humanitarians, and those traveling to areas where clean water is questionable. Read our article on water purification tablets for a detailed guide on how they work and which brands to use.