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[Health] Distilled water storage - Printable Version

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Distilled water storage - Kafka82 - 02-02-2022

Stupid question maybe - but thought to do some knowledge share for those who distill water - I have two questions

1) Distilled water by way of producing should be bacteria free? What about other non organic contaminats that might be in the distiller ?

2) What's the best to store if I do prepare batches that last 2 weeks? Do you keep it refrigerated and for how long can be deemed safe?


RE: Distilled water storage - Sleeprider - 02-02-2022

Distilled water is simply one way to separate water from mineral components normally present in potable water. It would separate or kill most bacteria, but it is not a "sterile" liquid as packaged or stored. I'm not aware of any means by which the water would become unsafe. I have always used tap water and just rinsed and dried my humidifier chamber. If you live in a hard-water area where calcium and other minerals are present in the water, then using water filtered by osmosis (Zero Water) distillation or sourced from soft water sources will avoid any problems. In the U.S. most users of distilled water buy it for less then $1/gallon. Melman is the resident expert, and this is his comment in another similar thread:

(08-12-2018, 06:13 PM)Melman Wrote: As a microbiologist, I would not state that it is impossible to acquire an infection from CPAP but the probability is much lower than from other potential sources to which we are routinely exposed.  As has been mentioned, Mycobacterium avium-intracellulare organisms are widespread in fresh water, soil, house dust and even food products (Have you ever seen a soil free potato?). The disease can be acquired by inhalation or ingestion. Sleeprider is correct in saying we are much more likely to inhale the organisms from the shower than CPAP. Although I believe he is incorrect in stating that no aerosol is generated from our humidifiers, it is much less than we are likely to inhale in almost any other activity involving water such as simply running water in a sink, filling a glass for a drink, washing our hands, etc.  It’s virtually impossible to disturb the surface of water without generating an aerosol. We also routinely inhale airborne dust which is known to carry the organisms. So those who are not using CPAP are as likely to have significant exposure to these organisms those who are. Unfortunately, short of living in a sterile isolator with filtered air and sterilized food and water, it is probably impossible for susceptible individuals to avoid exposure.

It is true that steam distilled water should be sterile but only if everything it contacts downstream of the point of distillation is sterile. In the case of inexpensive distilled water purchased at supermarkets and other vendors, it is unlikely that the condensers,  piping, storage tanks, bottling equipment, or the plastic bottles into which the water is dispensed are sterilized or that the operation is conducted in a sterile environment. The cost would be too great to allow a price of $1 or less per gallon. Such distilled water, therefore, will contain a variety of environmental organisms. As I have pointed out in the past, the only commercially available sterile water is sterile water for injection or irrigation which costs $20-25 per liter.

Even if one were to go to the expense of using such water, how would sterility of the humidifier chamber be assured? Simply washing and rinsing it with tap water is likely to result in the presence of environmental organism that may be a threat to immunocompromised individuals.
The only advantage to using distilled water is to avoid mineral deposits. Even if it were to eliminate exposure to potential pathogens it would be ineffectual given the exposure from so many other environmental sources.



RE: Distilled water storage - Crimson Nape - 02-02-2022

Unless you live in an area where the water has a high mineral content, normal tap water will work. The rule is, "if you can safely drink it, it will work in your humidifier".


RE: Distilled water storage - Kafka82 - 02-02-2022

It's safe to drink here but lots of lime scale - water very hard.

My process is use filtered tap water (Zero Water) and distill it - I am wondering how is best to store distilled water because I don't do that everyday of course. I have a plastic jug where I keep the distilled water but I thought over 2-3 weeks it might actually start collecting bacteria. I guess keep it refrigerated might help and probably best to do water production no longer than 2 weeks.

I don't know why but I can't feel totally safe using tap water only - maybe Zero Water filtered is just ok?


RE: Distilled water storage - Kafka82 - 02-02-2022

The other thing I don't understand is - even if I were to use mineral rich water - what woul be the risk for CPAP machine? Scale build up inside the machine and tubing or that would affect just the water tank?


RE: Distilled water storage - Crimson Nape - 02-02-2022

High minerals in your water would just mean that you will need to clean your water tank more often. Using Vinegar will help remove the scale. Water vapor will not carry mineral contaminants. You will only have a scale buildup in the water tank. The buildup is because of the water's evaporation. I guess refrigeration would extend the water. How long has the jugs of water sold in the stores been sitting around?


RE: Distilled water storage - Kafka82 - 02-02-2022

(02-02-2022, 09:47 AM)Crimson Nape Wrote: High minerals in your water would just mean that you will need to clean your water tank more often.  Using Vinegar will help remove the scale.  Water vapor will not carry mineral contaminants.  You will only have a scale buildup in the water tank.    The buildup is because of the water's evaporation.   I guess refrigeration would extend the water.  How long has the jugs of water sold in the stores been sitting around?

yes those in stores are there for ages - but they are kept close so no contamination. I think I will just try to make water more often if I store it. But tempted to use just the ZeroWater filter otherwise. I already clean the tank daily more or less.


RE: Distilled water storage - upsman - 02-02-2022

I found this information helpful from sleepapnea.org.

"Is it possible for a patient to catch an infection from a humidifier? Research says, “no”. In fact, the environment in the heated humidifier chamber under most operating conditions is such that the majority of pathogens are rapidly killed.

Studies show that even if pathogens were able to exist in the humidification chamber, they would not be able to be transported to the patient. The humidity from the chamber is in vapor form, which is too small for a bacteria or virus to travel in!

Passover humidification (both cool and heated) is molecular humidity in that what exits either a cold or heated unit is water vapor or water molecules that are in the .0001 micron size.

Bacteria (.2 to 10 microns) and viruses (.017 to .3 microns) are much larger. Therefore it would be physically impossible for water molecules to transport either bacteria or virus even if the chamber was full of GUNK! In other words, there is NO means of transport.

Heated humidification adds the additional safety net in that it will kill off 90% of the pathogens within 10 minutes of achieving full temperature.

Distilled water is cleaner and lengthens the life of the humidifier; there is no medium for the growth of anything in distilled water. All manufacturers recommend it. Depending on the quality, tap water is not necessarily harmful for use in humidifiers, but well water can be harmful to the chamber if there are a lot of deposits in it."


RE: Distilled water storage - Jeff8356 - 02-02-2022

(02-02-2022, 09:34 AM)Kafka82 Wrote:  - maybe Zero Water filtered is just ok?

The Mrs and I both switched to using Zero Water for our xPAP's. Our tap water is hard and has a fairly strong smell of chlorine.  We were using the cheap distilled water, but have not noticed any difference after switching to just ZeroWater.  No scale buildup, and no odor from the water, nothing growing.
Our humidifiers get washed with soap and water every day or two as part of our routine.

Although ZeroWater has its own expense (filters) I no longer need to store gallons of distilled water around the house.


RE: Distilled water storage - desaturator - 02-02-2022

I would have thought that a lot of the benefit you might notionally get from using distilled water would be lost if you have to store it for an extended period. Unless whatever you're storing it in is completely sterile, and can be kept that way even in daily use, micro-organisms will eventually get in.

I imagine it's true that distilled water will be more-or-less free of the contaminants that would leave a residue in the tank, but I've not found much residue even when filling mine with London's finest tapwater (which is as hard as nails). I keep my humidifier tank full to the "max" line, and replace the water every day. I don't think it ever has chance to get concentrated enough to leave a sediment.

BW, DS