Cumbria & Lancashire Health Protection Unit: Boil Water Advice - Further Information. Last updated 30th June 2003.
Contents
General Notes
How long do I have
to boil the water for?
What about
brushing teeth, ice cubes, bathing and washing up?
Are pets affected?
Can I use water
filters or water purification tablets instead of boiling?
Should
drinks vending machines be used?
I am a dialysis
patient. Can you offer advice?
Does the boil
water advice have any implications for swimming pool operation?
I am a dentist.
How can I protect my patients?
I run a bar/restaurant.
What precautions should I take?
I am a food/drink
producer. How can I protect my products?
General Notes (back to top)
The following has been put together
to address many of the "public health" questions that
people ask when their home or business has been issued with Boil
Water advice. This advice is usually given in order to protect
the community from becoming ill due to contamination of the water
supply with germs. The exact risks vary depending on the source
of your water and the technical problem that has occurred, but
frequently the main concerns relate to cryptosporidium and giardiasis.
Factsheets on these germs are available
elsewhere on the site.
Q.
How long do I have to boil water for?
(back to top)
A. It is sufficient
to bring the water to the boil and then allow it to cool.
Using an electric kettle is fine.
Q.
What about brushing teeth, ice cubes, bathing and washing up? (back to top)
A. Brushing teeth -
use cooled boiled water for brushing teeth.
Ice cubes - if you made ice cubes prior to the boil water notice,
discard them. Make ice cubes with cooled boiled water or
fizzy drinks.
Washing and bathing - it is quite safe to wash and take a bath:
the route of infection is by swallowing the water. Only
bathe your child if you can be sure they do not drink any of the
bath water.
Washing up - dishes can be washed using boiled water, but it is
probably sufficient to rinse washed dishes with boiled and cooled
water before they are dried. Dishwashers are unaffected
if used on a hot wash cycle.
Q.
Are pets affected? (back to top)
A. As household pets
can become infected with Cryptosporidium, it is advisable to use
water for them to drink that has been boiled and cooled.
Q.
Can I use water filters or water purification tablets instead
of boiling? (back
to top)
A. Domestic filters
should not be relied upon unless they are designed for the purpose
of removing micro-organisms (ie not just designed to improve palatability).
Please refer to the manufacturer's brochure if in any doubt.
Domestic filter cartridges may trap contamination, and in particular
care is required in hygienic disposal of these. Water purification
tablets are not recommended as an alternative to boiling.
Q.
Should drinks vending machines be used? (back to top)
A. Use of drinks for
dispensers is not recommended unless the water is heated to at
least 70°C for 5 minutes. Ideally, they should be turned
off and disconnected from the water supply. When the water
supplies are back to normal, the machine should be cleaned out
before re-use, and any filters replaced as recommended in the
manufacturer's operating manual. Care should be exercised
in the handling and disposal of filters in case they are contaminated
with Cryptosporidium. Refer enquiries about whether machine
can achieve 70°C for 5 minutes to machine manufacturer.
Do not use cold drinks from vending machines.
Q.
I am a dialysis patient. Can you offer advice? (back to top)
A. Cryptosporidiosis
is a gut disease and there is no risk of contracting it during
dialysis. However, you should boil your drinking water as
directed. If you have any other concerns please contact
your dialysis administrator.
Q.
Does the boil water advice have any implications for swimming
pool operation? (back
to top)
A. Swimming pools are
not normally considered to pose a risk during incidents such as
this, and closure is not considered necessary. It is important
that people who are symptomatic should be advised not to use public
swimming pools.
Q.
I am a dentist. How can I protect my patients? (back to top)
A. Precautions should
be taken to minimise the ingestion of drill bit cooling water
and mouth rinses should be made from boiled water that has been
cooled. Dentists will normally have a separate tank feed
for drill water, and in such circumstances the mains feed can
be turned off and alternative safe supplies added directly (prepackaged
bottled water). As far as we are aware, the British Dental
Association does not offer specific advice on this matter; the
Centers for Disease Control in the United States has some information on their website which may be
of relevance.
Q.
I run a bar/restaurant. What precautions should I take? (back to top)
A. All water for drinking
and food preparation should be brought to the boil and cooled
as necessary. Bottled water may be used as normal.
Fizzy drink dispensers should not be used unless they can be adapted
to use sources other than tap water. Washing up should be
carried out in water which has been heated to 70°C for 5 minutes
or from prepackaged bottled water. And allowed to cool, or in
a dishwater which heats to 70°C. Ice making machines
should be disconnected but ice may be made from water which has
been brought to the boil and cooled.
Q.
I am a food/drink producer. How can I protect my products? (back to top)
A. If an alternative
water source is not available the mains water should be treated
at the point of use by means of an appropriate filtration system.
Only micro straining filters capable of removing particles down
to 1 micrometre in diameter should be used. Filters in this
category include reverse osmosis units and those labelled "absolute"
1 micrometre filters. Care should be taken in handling
and disposal of used filter cartridges. Your local authority
Environmental Health department will be able to give further advice.