How Long To Boil Water

How Long to Boil Water To Get Rid of Bacteria

Aside from using water filters and tablets to purify your drinking water, boiling it seems to be the more usual thing to do. But have you ever asked yourself how long you should boil water to kill harmful bacteria? Does it only take 5 to 10 minutes or more?


There are quite a number of articles posted on the internet that claim you should boil water for at least 5 to 20 minutes for to destroy waterborne pathogens and man-made pollutants (such as bacteria, protozoa, viruses, metals, chemicals and possibly pharmaceuticals). These impurities can only be eliminated at high heat temperature. However, The World Health Organization (WHO) notes reaching 158°F/70°C of water temperature will get destroy these unwanted water impurities after one minute. Here at Prepper Base, we like to err on the side of caution, especially when it comes to our water. We personally think it’s best to boil for at least 5 minutes.

A Little Science Behind How Long To Boil Water

When water reaches its boiling point at 212°F/100°C, we presume that it will be safe drinking water as nearly no organism can survive at that temperature. Regardless of that, the Centers for Disease Control (CDC) still recommends adding one more minute after the water has boiled to ensure cleanliness.


The only tricky part in the process is that boiling point may vary depending on the altitude. The 212°F/100°C boiling point only applies to sea level and the higher you are above sea level, the boiling point drops at approximately one degree per 500 feet. Ideally, at 5000 feet above sea level, boiling point drops to 203°F/95°C and higher at 10,000 feet boiling point drops to 194°F/90°C. Therefore, Centers for Disease Control (CDC) recommends adding three more minutes after the water has boiled at altitudes about 5000 feet or so.

Final Thoughts

Boiling water might not be the most glamorous thing, but clean water can mean the difference between life and death. If you don’t have a purifying straw or bottle and you end up in a survival situation, it’s going to be trouble. Knowing how long your need to boil your water in order to purify it becomes a skill you will need to know in order to survive. So learn how long you need to boil water in order to kill bacteria and be prepared for whatever situation comes your way.