What is a “boil water advisory”?
In cooperation with the Norwegian Food Safety Authority, the Norwegian Institute of Public Health has published advice on what to do when “Boil water advisory” is announced. Some of the advice may also be useful if the microbial water quality is uncertain for other reasons, for example when drinking untreated water directly from the nature.
You will be notified if the water treatment unit or authorities suspect that the water quality os unsafe. This happens if it is feared that the water contains harmful microorganisms and may cause disease. Boiling kills microorganisms like viruses, bacteria and parasites.
The water should boil for a minute. A kettle will usually bring the water to the boil before switching itself off and this is sufficient. If using a microwave oven, make sure that the water is boiling.
An alternative is to use bottled water.
All drinking water must be boiled
In addition to drinking, you should use boiled water for:
- All foods not cooked or heat treated over 100 °C
- Mixing cordials and other products for consumption
- Coffee. Coffee makers do not boil water, and the water used in the coffee maker must therefore be boiled in advance. Other types of coffee machines should be checked with the suppler.
- Ice cubes
- Rinsing fruit, salad and vegetables that will not be cooked.
- Brushing teeth
Unboiled water can be used for:
- Cooking of food
- Hand wash. Wash hands with soap, rinse and dry afterwards
- Shower and baths. Be careful not to swallow water. Monitor young children.
- Manual dishwashing and dishwasher. When washing dishes by hand, wash the dishes with boiled hot water or dry thoroughly. Detergents with a disinfecting effect are not sufficient.
- Cleaning the house
- Other uses at home
Children should not play with the water from hosepipes or in paddling pools during periods where boiling water is advised.
Background for cooking warning
Only E. coli and intestinal enterococci are sure indicators that water is infected by faeces from animals or humans, and finding these bacteria mean that immediate measures must be considered. Water boiling is one of the possible measures, in addition to the measures that the water treatment plants implement to correct water quality. Water treatments plants will not issue a boil water advisory based on the findings of coliform bacteria, germ numbers or Clostridium perfringens alone.