As distasteful as the thought may be to most people, drinking purified urine is recognized as a survival tactic in an emergency situation.

In fact, NASA engineers use recycled urine as a way to ensure astronauts have a sustainable water supply if they get stranded in space. The cost of transporting water to space travelers if they need emergency water is cost prohibitive and would take way too long. So engineers are developing a sophisticated urine purification system.

NASA is using forward osmosis which filters urine, shower, and other water through a semi-permeable membrane, which effectively strains the contaminants out of the water.

Of course, you would likely not have such a sophisticated purification system at hand in the event of an emergency. However, it is nice to know that admirable people like astronauts are willing to drink filtered urine and hygiene water.

It is generally advised by health professionals that you should not drink urine, but if you must drink it do so a maximum of 3 times, and only if there is no alternative water supply. In other words, it is a last resort water supply. However, anyone would admit that it is better to drink urine than die from dehydration.

The guidelines are as follows:

• Only drink purified urine unless it is a matter of life or death
• If you are unable to make a solar still, use water purification tablets as a minimum purification step
• Do not drink the first urine in the morning, as it is usually the most concentrated flow of the day in terms of body toxin content
• DO NOT try to collect urine contaminated by sewage because it is way too dangerous to your health
• Only drink your own urine and never drink another person’s urine.
• Do not tell people you drank your urine because they will not be impressed in the least, even if it is an emergency
• Once again, only drink purified urine a maximum of 3 times

There are very good reasons why the amount of urine you drink should be limited Urine is approximately 95% water and 5% waste elements. The waste elements are just that—substances your body does not need. These substances include potassium, chloride, sodium, nitrogen and calcium. Sodium attracts water in cells, which is why you cannot drink salt water. Too much sodium will lead to dehydration, while too much potassium can interfere with your heart functioning.

Urine may also contain traces of medications or other substances that you do not want to put back into your body.

When a disaster occurs, there is also a good chance you may be at risk of dehydration already, if you’re desperate enough to consider drinking your own urine. When the body is dehydrated, urine contains less water which means the waste elements make up a larger percentage of the urine’s composition. This may sound like a list of reasons designed to stop you from drinking urine.

However, it is important to understand the limitations of urine as a source of emergency water. If you know other ways to obtain fresh water, you are less likely to succumb to the temptation to drink more urine. In fact, unpurified urine should only be drunk in the most severe emergencies, when there are no other options for obtaining water.

Urine can, and always should be, purified before drinking it. The easiest way to purify it is to distill it or process the urine through a solar still. This will eliminate most contaminants, including solids. A solar still is the most efficient low-fuel usage choice, as you will learn in the next sections on purifying water. A distiller requires a particular setup and heat and can require a lot of fuel to produce the heat. If you are considering drinking your own urine, there is an excellent chance that you are unable to set up a distiller, so the best option for purifying urine is a solar still. In the next chapter, you will learn how to purify urine or water using a solar still.