Quick Answer
Boil water for at least 1-3 minutes to kill bacteria and viruses, and for 3-5 minutes to kill Giardia and Cryptosporidium. The boiling time may vary depending on the altitude and the type of water.
Understanding Boiling Point and Altitude
When boiling water at high altitudes, the boiling point is lower due to the reduced air pressure. To ensure proper boiling, it’s essential to adjust the boiling time accordingly. At altitudes above 6,562 feet (2,000 meters), add 1-2 minutes to the boiling time for every 1,000 feet of altitude gain.
Boiling Time for Various Contaminants
Boiling water for 1-3 minutes is sufficient to kill most bacteria, viruses, and protozoa, including E. coli, Salmonella, and Rotavirus. However, to kill Giardia and Cryptosporidium, which are more resilient, boil water for 3-5 minutes. For a more reliable purification method, consider using a combination of boiling with other techniques, such as filtration or disinfection.
Ensuring Water Safety
When using boiling as a purification method, ensure that the water reaches a rolling boil, and maintain it for the specified time. Use a thermometer to confirm the water has reached a minimum temperature of 160°F (71°C). After boiling, let the water cool before consumption to prevent scalding.
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