Boiled water is one of the safest ways to make water potable and free of disease-causing microorganisms. But how long does that safety last once the water has cooled down? Let’s take a look at some key questions around how long boiled water stays safe to drink:
How does boiling make water safe to drink?
Boiling water kills or inactivates pathogens like bacteria, viruses, and protozoa that can cause illness. Boiling brings water to a high enough temperature (212°F at sea level) to kill pathogens that cause diseases such as dysentery, typhoid, and cholera.
Why does boiled water eventually become unsafe to drink?
While the boiling process kills pathogens, it does not remove all microbes and does not add anything to stop microbial growth after cooling. Over time, remaining spores and microbes in the water can multiply and recontaminate it.
What factors influence how long boiled water stays safe?
The length of time boiled water stays safe depends on a few key factors:
– Initial quality of the water: Water that is dirtier or contaminated to begin with will become recontaminated faster than cleaner water.
– Container hygiene: Boiled water stored in a dirty container can pick up pathogens that shorten its safe storage time.
– Ambient temperature: Warmer temperatures allow microbes to multiply faster. Storing boiled water in cooler places prolongs its safety.
– Handling: Introducing hands, utensils, etc into the water can contaminate it with bacteria and viruses.
How Long Does Boiled Tap Water Stay Safe to Drink?
For relatively clean tap water that has been boiled and stored properly, here are some general guidelines on how long it stays safe to drink:
At Room Temperature:
– In a clean, sealed container: 1-2 days
– In an open container: 6-8 hours
Refrigerated:
– In a clean, covered container: 3-5 days
Frozen:
– Ice made from boiled water: indefinite if frozen solid
So if you boil tap water and keep it refrigerated in a tightly closed bottle or jug, it should retain its safety for drinking for up to 3-5 days. Keep in mind that higher ambient temperatures may shorten this timeframe.
What About Boiled Bottled Water?
Bottled water that has been commercially disinfected and sealed should stay safe at room temperature for:
– 6 months to 1 year – if unopened
– 1-2 weeks – if opened and resealed
If boiled bottled water is then refrigerated in a clean container, it can safely be stored for:
– 2-4 weeks
So commercially purified bottled waters have longer shelf lives than boiled tap water. But once opened, their storage times are similar.
How Long Does Boiled Untreated Water Stay Safe?
If boiling minimally contaminated water like from lakes, rivers, or streams, here is how long it will stay safe:
| Storage Time | At Room Temperature | Refrigerated |
|---|---|---|
| In clean, closed container | 16-24 hours | 1-2 days |
| In open container | 4-6 hours | 8-12 hours |
As you can see, boiled but untreated water has much shorter safe storage times compared to treated tap water. This is due to higher contamination levels to begin with.
What About Heavily Contaminated Water?
For heavily fouled, contaminated water, boiling provides the shortest protection:
| Storage Time | At Room Temperature | Refrigerated |
|---|---|---|
| In clean, closed container | 6-8 hours | 8-12 hours |
| In open container | 1-3 hours | 3-6 hours |
As you can see, heavily contaminated water becomes unsafe to drink much more quickly. This shows the importance of starting with the cleanest water possible when boiling.
How Can You Tell When Boiled Water Goes Bad?
While keeping track of timelines can help estimate when boiled water stays safe, your senses and simple tests can also indicate when it’s time to boil again:
Sight:
– Cloudiness or particulate matter indicate microbes are multiplying
Smell:
– “Off” odors like rotten eggs or sewage suggest dangerous contaminants
Taste:
– Bitterness or unexpected tastes means don’t drink
Testing:
– Test strips that measure chlorine can verify loss of sanitization
– A UV purifier light can detect microbe growth through fluorescence
Trust Your Senses
If boiled water exhibits foul sights, smells, or tastes – then it’s safest not to drink it. Your senses are designed to detect potential biological contamination. So heed what they tell you.
How to Keep Boiled Water Safe Longer
If you want to preserve boiled water’s safety for longer periods, here are some tips:
Start with cleaner water
– Use the cleanest water possible – ideally commercially purified water.
Store in sanitized containers
– Bottles and jugs should be washed thoroughly before use.
Limit opening container
– Each time a container is opened, more microbes can enter.
Keep water cool
– Refrigerate or keep boiled water cool as possible.
Use within recommended time
– Don’t store for longer than suggested time periods.
Re-boil as needed
– If in doubt, re-boiling water renews its safety.
Advanced Options
For longer term storage, additional steps can be taken:
– Adding hydrogen peroxide or bleach helps prevent recontamination
– UV treatment systems remove microbes from stored water
General Rules on Storing Boiled Water
Based on the information provided above, here are some good general guidelines on boiled water storage:
| Type of Water | Room Temperature | Refrigerated |
|---|---|---|
| Tap | 1-2 days max | 3-5 days |
| Untreated | 16-24 hours | 1-2 days |
| Heavily contaminated | 6-8 hours | 8-12 hours |
| Commercially bottled | 6-12 months (unopened) 1-2 weeks (opened) |
2-4 weeks |
The cooler you can store boiled water, the longer it will stay safe. But do not rely on timelines alone – use sight, smell and taste too. When in doubt, re-boil!
Conclusion
To summarize key points:
– Boiling makes water safe by killing pathogens but does not prevent recontamination over time.
– How long boiled water stays safe depends on initial water quality, storage method, temperatures, and handling.
– General guidelines are: tap water 1-5 days, untreated water 16-48 hours, heavily contaminated 6-12 hours.
– Refrigeration extends the safe storage time of boiled water significantly.
– Senses, testing, and adherence to timelines helps determine when re-boiling is needed.
Following proper procedures allows boiled water to remain safe for drinking for reasonable periods. But when in doubt, re-boiling water is the best way to re-sanitize it and remove any lingering pathogens.