Everything You Need to Know About Sterile Water

Jul 25th 2018

You’re thirsty, so you go into the kitchen to grab a glass of ice cold water. You turn on the faucet, and as you take that refreshing gulp, do you ever stop to wonder - what’s in my water? Most of us probably don’t give it much thought since the majority of our water sources are purified and safe for drinking. However, when it comes to scientific research and medical purposes, you can’t just use any water resource. You need sterile water.

What is Sterile Water?

Sterile water is water that is free from all microorganisms such as fungi, spores, bacteria, etc. It is used as a sterile, hypotonic, nonpyrogenic irrigating fluid or pharmaceutical aide.

Sterile water is important for medical research, irrigation solutions, and injections to prevent contamination that could be present in everyday water. Tap water cannot be used because there is a potential risk of contaminants such as leaky sewer pipes, or the risk of being exposed to other corrosive metals.

The role of sterile water within the medical field is crucial, especially sterile water for injections, irrigation, and laboratory testing.

Sterile water for injection

Sterile water is used to dissolve or dilute other medicines before they are given to a patient. Once the medication is diluted, it can then be injected into a vein, muscle or under the skin. It is important to know that sterile water itself should never be injected directly into the body. Because sterile water is hypotonic, heavy absorption of sterile water can cause serious adverse reactions or fluid overload.

Sterile water for irrigation

When used for irrigation purposes, sterile water acts as a safe washing solution for general irrigation of body cavities, wounds, or indwelling urethral catheters. It is also used for rinsing or soaking surgical dressings that are in contact with wounds.

Sterile Water vs Distilled Water

Tap water, sterile water, distilled water - so what’s the difference?

As mentioned above, the use of tap water is okay for everyday drinking but not for medical uses due to the risk of contamination. For safer, cleaner options the medical industry turns to distilled water and sterile water.

Though sterile water and distilled water are both used by medical professionals, they are not the same and do not have the same uses.

Distilled Water

Distilled water is created through a combination of steam and condensation. Distilled water is essentially regular tap which has been purified through evaporation. After evaporation, the steam is re-captured through condensation and deposited into a container. It does not contain any minerals such as salt, iron, or calcium. Medical professionals use distilled water to clean medical tools because it does not cause spotting. It can also be efficient in completely removing detergent that has been used to wash off impurities.

Sterile Water

Sterile water for irrigation and injection is a fluid with a PH of roughly 5.7 and used as a solvent to dissolve or dilute drugs. Its primary pharmaceutical purpose is for injection of non-intravenously administered medication and nutrient mixtures, or to clean wounds. It is prepared by distillation. Sterile water’s role in medical research is crucial. Using this water is required in experiments but normal or even distilled water may bring outside bacteria into the experiment. This contamination would invalidate all test results and jeopardize other experiments within the same lab. Therefore, sterilized water is the only acceptable water for laboratory research.

How to Make Sterile Water

A recent article posted by ASHP.org stated there has been a problem in 2018 for hospitals being able to obtain sufficient amounts of sterile water for injection. The FDA has added sterile water to their list of medical supply shortages. While sterile water used for injections or irrigation should always be administered by a medical professional, it is possible to make your own sterile water.

In order to make sterile water, you must have the appropriate supplies. If you make your own sterile water, you must store it in a sterilized container and keep it in a cool location away from the sun. You can sterilize the container by boiling it for 10 minutes.


  • Pressure cooker or hermetically sealed pot
  • Filtered water
  • Stove
  • Thermometer
  • Sterilized container


  • Fill your pressure cooker or hermetically sealed pot with water
  • Place the cooker on the stove and boil it for 20 minutes
  • Sterilization process: Throughout the boiling period, temperature within the cooker must be maintained at 250 degrees Fahrenheit.

Your sterile water is ready! As mentioned above, saving your sterilized water in a sterilized container is crucial. Once cooled, it is best to use sterilized water immediately to ensure it is contaminate free. If stored properly, it can last up to three days.

Important to note: simply boiling water in a pot for 20 minutes or so will kill most infection causing bacteria and may be perfectly useful for drinking purposes; it would however not be classified as sterile water for medical purposes.

Where to Buy Sterile Water

So, what if you don’t have a pressure cooker or the time to make sterile water? You can buy sterile water in person or online from reputable medical/pharmaceutical supply companies. When choosing a medical supply company we always recommend ensuring the quality of their products and how they are shipped/stored.

At Predictable Surgical Technologies we offer both sterile water for irrigation and injection solutions varying in 250ml, 500ml, and 1,000ml sizes.

While there is a vast difference between the water we drink and sterile water, the importance of water itself is invaluable to the medical and research industries. So, the next time you grab a bottle of water or turn on the tap, remember that water plays a crucial role in not only keeping us hydrated and healthy, but saving lives through its cleaning and diluting properties. This article is meant to answer commonly asked questions regarding sterile water. For the proper use and administration of sterile water, you should always consult a medical expert or physician.