I wonder how many of you knew this . While surfing the internet today I found this bit of information .
Many people , including myself , thought that you needed to boil water for a number of minutes - at least 3 or maybe even 5 or 10 minutes - to make it safe to drink . Not true , it takes 0 minutes . The time it takes for the water to reach a full boil is enough .

The center for disease control seems to think otherwise.

http://wwwn.cdc.gov/travel/contentWaterTreatment.aspx

Where did you get your info from?

I'm not so sure. I've stepped into a fire and I survived. If I'd have stood there for 3 minutes I might not have.

or am I just being an ass this time?

I can be wrong, but my memory of my science and oother classes is telling me that water cannot get hotter than boiling and remain in the liquid state. As you add heat to boiling water, the heat turns the water into vapor, i.e. steam.

But otherwise, yes, it makes a lot of senses that water once at boiling has already killed all of the organisms need to be killed, if boiling it for one minute is also good enough. However, once I had it boiling, I'd give it that extra minute, just to make sure, provided I was nto concerend about my supply of fuel.

I believe that Chris K. posted that into about a year ago.

"The center for disease control seems to think otherwise."

I suspect that the information is aimed at the 'lowest common denominator' of intelligence. If they didn't say to boil it for a minute, some dork holding a Bic under a cast iron pot would figure that two minutes of that should be good enough. The boiling gives people a definite point to aim for.

Sue

Hey,

I remember a water safety rhyme that went "Big Bubbles, No Troubles". I seem to remember that once you get most water (not the seriously polluted stuff) to a rolling boil, its OK. It has worked for me in the past.

Mike

I think this is the first time I'm playing devil's advocate with myself!

http://www.survivaltopics.com/survival/how-long-do-you-need-to-boil-water/

Another good article which supports Susan's theory (and has a bunch of other good info about water too):

http://grandpappy.info/wwater.htm

I think one of the most important elements when looking at boiling times is Altitude. At sea level 1 minute of a rolling boil is acceptable, but 3 minutes is recommended. At elevations above 2000m (5000’) then 3 minutes is required and 5 minutes is recommended. The difference is just a 'fudge factor' because in wilderness conditions things go wrong and a little more time is better than a little less and everyone option on a rolling boil may be a bit different as well. Don't take chances boil your water for at least 3 minutes.

Hi Hacksaw,

Altitude will also play a factor, the boiling point temperature of water gets lower the higher the altitude.

http://en.wikipedia.org/wiki/Clausius-Clapeyron_equation

This is crucial, as prolonged boiling of water, or water that is boiled twice, drives off the dissolved oxygen in the water, making the tea taste flat . There can sometimes be a fine point between a decent cup of tea and bacterial infection at high altitudes. Thats why a pressure cooker is a good idea at altitude.

People who live at high altitudes, like Tibetans, drink their tea while it is bubbling with boiling. Many Tibetans who moved to India suffered serious burns when they drank their boiling tea at sea-level.

I've heard that it's impossible to boil and egg on Mt. Everest because the water won't get hot enough at a boil to cook the egg.

Just an observation from the peanut gallery...the whole boiling water (how long / how hot etc.) has been discussed multiple times in various ETS Forum threads over the last several years. A forum search should reveal several threads. Additionally, check out the following:

1. Look in the top right corner of your screen and use the "Where do you want to go on ETS?" menu, then select "Skills & Technique" from the drop down menu. Then click on the "GO" button and scroll down the resulting menu to find "No substitute for water" and click on that link in which Doug mentions that a continuous rolling boil is not needed.

2. Also, do a googlesearch for "SODIS" and you will find an amazing amount of information (150k hits in my check moments ago) on the subject.

This is something that we should all consider when we are in need of water. Hope this helps out.


Regards, Comanche7

SODIS will only work at certain latitudes. From 15N to 15S is optimum, but 35N to 35S can work under certain conditions.

Sue

the best take i heard on this--from a Dr--was that the little
nastys in the water are "programed" to reproduce at our body
temp..at 98.6 they start to unzip their DNA..with nothing
around them except H2o they just keep unraveling into the
harmless base chemicals they are made from..the stuff that
survives in really hot water--like at Yellowstone Park--does
not have us on their food chain..

I disagree. Above 5000 feet, yes, boil for longer. But if you are below 2500 feet, don't waste the time of the fuel. Pretty much everything that can hurt you dies at 180F, you hit that before things boil at the altitudes most of us live at.

Special cases are just that, special. "Don't drink the water" is a special case that exists at sea. *shrugs* Keep the special cases in mind, but don't make them SOP.

No, you are being a multi-celled life form. If you are a single cell life form, if that one bursts, you are done. For us, it is "just" a burn, not insta-death.

LOL! For some reason I love that line.

-Blast

Having caught Giardia once, I will boil water at least a minute if I can't treat it or filter it before I drink it.

I don't recall their names, but I think there were a couple other nasties out there that required a rolling boil for a bit longer.

In most cases, if I have a source of heating the water, I can get it to a boil and keep it there long enough.

Y'all do what you think is best for you. I've learnt my lesson.

Watching Les, he always gets his raw water boiling for a while. That together with my own experiences is gospel to me.

Actually what happens is tha protiens break down at about 160 to 180 degrees. Fortunatelly this is juat about the boiling point of water on the top of Mt. Everest. So it is safe to bring the water to a full boil at any elevation and the water is safe. The ony eception to this is the thermophiles found in Yellowstone and some deep sea trenches but I do not think any of these are pathogens.
cheers

Protiens break down at about 160 degrees F which is just about the boiling point on top of Mt Everest. So you can boil an egg in theory, though I know of anyone that has tried this but I do know someone that has hit a golf ball off of the top of Everest.
cheers

Big bubbles = no troubles.

the reason you boil water longer is to allow for impurites to settle out of the water sure the water may be safe from any parasites but there are impurities in water that may make you sick

I seriously question the validity of that statement. Please provide a reference that corroborates your claim. In my experience, raising the temperature of water tends to allow more impurities to go into solution, which would preclude separation by settling. I know of very few substances that precipitate out of solution as the temperature increases, unless you are referring to evaporation, in which case you would be losing clean water to the atmosphere, and concentrating the solution to the point that it exceeds the saturation point.

I don't think crypto spores can reliably be destroyed just by bringing the water to a boil. It takes some time at high heat to break down the spore compared to just trying to denature some "naked" protein. I think crypto is the primary reason for maintaining the boil for some time.

Keep in mind that the size of the container, the amount of water in the container and the surface area (or better yet the amount of contact area the bottom of the container has with the heat source) will determine when the water is adequately “mixed” to reach killing temperatures for pathogenic organisms and parasites. That is why many references say a “rolling boil”/large bubbles, indicating there is sufficient mixing of the water to reach killing temperatures in all parts of the container. A very deep pot/cup with only small bubbles may have water at the surface, which has not reached high enough temperatures to kill certain organisms.

Recognizing that most pathogenic bacteria are likely killed when the water reaches a rolling boil, most steam autoclaves (steam under pressure is far more efficient at killing, then boiling) operate at 250 F (well above 212F) under 15psi and the minimum autoclaving time is 15 minutes (although this is in part to allow steam to access all parts of the chamber).

I can tell you from personal experience, we use chemical (and biological indicators) integrator strips, which start to measure a given/standard heat (250F) over time. The use of chemical change tape (you may see these on surgical supply packs or other medical devices and supplies), which changes as soon as the given/standard temperature (250F) is not a valid indicator of sterilization. I have run studies in which autoclaving (at 250F under 15psi) for up to 10 minutes was insufficient to kill indicator bacteria (spore forming rods – a heat resistant Bacillus species), despite the change of the indicator tape.

Also keep in mind there is both heat labile (easily destroyed by heat) and heat stabile (resistant to heat inactivation or denaturing) bacterial/fungal toxins (proteins). When one is heating food/water, one is not only attempting to kill the living organisms, but also the toxins (both exo and endo) produced by the bacteria, both living and dead). It is possible the references to boiling water longer then either a rolling boil or for 1 minute are taking the presence and heat resistance of any bacterial toxins that might be present. While I have never heard of bacterial toxin poising from water (food – definitely yes), I guess it could be possible if there were a lot of organic material supporting bacterial growth.

Although, it is interesting that UV water purification devices such as the Steri-pen do not address or take into account any residual bacterial toxins. The MIOX solution might have some inactivation effect on toxins (I really do not know), but certainly filters with charcoal beds and boiling should be considered for water where the possibility of residual bacterial toxins could be present.


Pete

Also the turbulence from boiling will tend to keep things stirred up.

Strange that they don't even mention using chlorine when its the most readily available chemical treatment.

From the WI Dept. of Natural Resources (http://www.dnr.state.wi.us/org/water/dwg/Crypto.htm):
"Treating drinking water using normal doses of disinfectants such as chlorine does not kill Cryptosporidium oocysts. Researchers have found it takes 90 minutes to kill 90 percent of Cryptosporidium oocysts in a water sample treated with 80 milligrams of chlorine per liter of water. Normally, chlorine is applied at about one milligram per liter. Stronger disinfectants, such as ozone, do a better job of killing these protozoans in a shorter time."

From the Center for Disease Control (http://www.cdc.gov/ncidod/dpd/parasites/cryptosporidiosis/factsht_cryptosporidiosis.htm):

"If you are unable to avoid using or drinking water that might be contaminated, then you can treat the water for Cryptosporidium by doing one of the following:
* Heat the water to a rolling boil for at least 1 minute. OR
* Use a filter that has an absolute pore size of 1 micron or smaller, or one that has been NSF rated for "cyst removal."

"Do not rely on chemicals to kill Cryptosporidium. Because it has a thick outer shell, this particular parasite is highly resistant to disinfectants such as chlorine and iodine."

p.s. The CDC says Giardia is also moderately chlorine-resistant but is killed or at least inactivated by boiling.

Sue

MIOX works well against crypto. that's why most municipal treatment plants use it instead of Chlorine now.

The 1 micron filter tip is an important one. Ever looked at filter specs? Very few of them meet the 1 micron recommendation.

Water temperature will not exceed it's boiling point unless under pressure; the boiling point drops as atmospheric pressure drops (e.g. when hiking/camping in high mountains).

I too have heard, "big bubbles, no troubles." The article at http://www.survivaltopics.com/survival/how-long-do-you-need-to-boil-water/ seems to bear this out.

In an urban survival situation, boiling is a dang good idea, although it won't remove chemical pollutants, heavy metals, etc.

In wilderness areas in North America, the water is generally safe to drink without treatment. The majority of girardia cases are generally caused by poor hygiene. Yes, this isn't what is generally accepted, but I've read the studies. However, having read the studies, I continue to treat my water. The cost of treatment is low, but the consequences of being wrong are high -- particularly in a survival situation. My point is this: hygiene, particularly hand washing, is as or more important as/than water treatment.

"...hygiene, particularly hand washing, is as or more important as/than water treatment."

That is probably true, but... what if you're washing your hands with (organically) contaminated water?

Sue

That's a good question. I think if one were to wash thoroughly and allow one's hands to dry completely, that one would be better off than not washing at all, but I don't have anything to back up my guess. I suppose it might vary with type of contamination.

However, I don't normally encounter that situation. When I'm out back packing, I normally wash with treated water. There are also various types of hand sanitizers and baby wipes out there, although soap and water are considered to be the best, and soap and water don't develop antibacterial resistant bacteria.

One item of note: according to Discover magazine, one should scrub one's hand after soaping up for at least 30 seconds before rinsing off. Some friends of mine in the food prep industry say that washing twice at 30 seconds is what they've been taught.

Yes washing your hands is important when handling food for cooking but if the only water available is contaminated rinsing off with that water leaves your hands contaminated so the thing to do is to decontaminate the water. I have read about a doctor working in Africa that only had contaminated water so what he did was to use Potassium iodide in the saturated solution form, by adding ten to twenty drops to this water after about five minutes it was ready to drink.

Now this soulution of potassium iodide is also known as SSKI is probably can be obtained at a drug store, households today don't seem to keep this on hand as they did many years ago when it was known as tinture of iodine to use on scrapes and cuts.

So to sum up if you only have contaminated water to wash with if you had SSKI you could first treat it with SSKI before washing or for drinking.