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[[Image:Ceramic candle filter.jpg|thumb|right|150px200px|Diagram of a ceramic candle filter]][[Image:filter in use.jpg|thumb|right|150px250px|Man using the ceramic candle filter]]Boiling is considered the world’s oldest, most common, and one of the most effective methods for treating water. If done properly, boiling kills or deactivates all bacteria, viruses, protozoa (including cysts) and helminths that cause diarrheal disease. Pathogens are killed when the temperature reaches 100 degrees Celsius. In high-lying areas, where the boiling temperature of water can be as low as 80 degrees Celcius, a longer boiling time is necessary to kill all pathogens.
Boiling is considered the world’s oldest, most common, and one of the most effective methods for treating water. If done properly, boiling kills or deactivates all bacteria, viruses, protozoa (including cysts) and helminths that cause diarrheal disease. Pathogens are killed when the temperature reaches 100 degrees Celsius. In high-lying areas, where the boiling temperature of water can be as low as 80 degrees Celcius, a longer boiling time is necessary to kill all pathogens. Boiling is arguably the oldest and most commonly practiced household water treatment method, and it has been widely promoted for decades. Organizations recommend boiling both for water treatment in developing countries and to provide safe drinking water in emergency situations throughout the world. Although boiling time recommendations vary significantly, from 0-20 minutes, to make water safe for consumption the water simply must reach the boiling point of 100°C. However, studies in developing countries have documented incomplete inactivation of bacteria in boiled water. This disparity between the laboratory and field results is attributed to users not heating the water to the boiling point and/or recontamination of boiled water in storage. To date, there have been no peer reviewed studies assessing the health impact associated with boiling water, although some case-control studies in cholera outbreaks have noted boiling as being protective against cholera.
==Suitable conditions ==
Boiling is applicable in area with a good fuel supply, a cultural tradition of boiling, and where water is stored safely after boiling.
{{procontable | pro=
- Simple <br>
- Socio-cultural acceptance of boiling for water treatment, particularly in tea-consuming cultures
- Easy and very effective
| con=
- Inefficient <br>
- CO2 emission
}}
==History and social context==
==Suitable conditions ==
Boiling is applicable in area with a good fuel supply, a cultural tradition of boiling, and where water is stored safely after boiling.
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==Technical specificationConstruction, operations and maintenance==
====Operation====
Almost all households have the equipment required to boil water.
====Manufacturing====
Needed materials are fuel (e.g. wood, charcoal, biomass, biogas, kerosene, propane, solar panels, electricity, a pot and a lid. Labour is needed for the regular collection of some fuels (e.g. wood, charcoal, biomass).
There is potential for burn injuries; caution should be maintained around stoves and fires and when handling hot water. Cause of respiratory infections associated with poor indoor air quality; improved stoves can be used to reduce illness and death from indoor fires and stoves.
====Treatment Efficiency====
====Maintenance====
Pots used for boiling may need to be replaced.
====Manufacturing====
Needed materials are fuel (e.g. wood, charcoal, biomass, biogas, kerosene, propane, solar panels, electricity, a pot and a lid. Labour is needed for the regular collection of some fuels (e.g. wood, charcoal, biomass).
There is potential for burn injuries; caution should be maintained around stoves and fires and when handling hot water. Cause of respiratory infections associated with poor indoor air quality; improved stoves can be used to reduce illness and death from indoor fires and stoves.
====Estimated Lifespan====
There is an on-going requirement for fuel. Pots used for boiling need may need replacement.
==CostCosts==
{{Treatment_Cost
==Country Field experiences==
==ManualsReference manuals, videos, and links== ==Movies==[http://www.cawst.org CAWST (Centre for Affordable Water and Sanitation Technology)]
==Acknowledgements==
==External Links==
[http://www.cawst.org CAWST (Centre for Affordable Water and Sanitation Technology)]
==Footnotes==
This article is based on a factsheet from [http://www.cawst.org/ Centre for Affordable Water and Sanitation Technology (CAWST)], which is gratefully acknowledged.
==References==
*<cite>Centers for Disease Control and Prevention (2009). Household Water Treatment Options in Developing Countries: Boiling. Atlanta, USA.</cite>
*<cite id=WHO>World Health Organization. [http://www.who.int/entity/household_water/resources/emergencies.pdf Household Water Treatment and Safe Storage Following Emergencies and Disasters: South Asia Earthquake and Tsunami]. Available at: [www.who.int/household_water/en/]</cite>
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