Basic Concepts of Steam

Fourth post in series, "Autoclave Sterilization Basics"

Let’s test your steam IQ. What’s the white smoke called that comes out of your tea kettle? What’s the difference between evaporation and condensation? We will answer these questions and more, as we introduce you to some basic concepts in the water cycle and familiarize you with words like vapor and steam. (Goggles and gloves not required.)

Water Vapor & Evaporation

First, let’s go back to basic science. The molecule H20 has many names, depending on its physical state. As a solid, we call it ice, as a liquid, we call it water, and as a gas, we call it vapor. Vapor is really diffused water molecules that appear as fog or mist. When water is heated, the molecules in the water vibrate and some of them escape into the air, thus becoming water vapor, or the gaseous state of water. That’s why we call it eVAPORation. The liquid water becomes a gas known as vapor.

Boiling & Steam

Now, if we continue to heat the water it will reach boiling point, which is about 100℃ (at sea level). Rapidly boiling water makes a bubbling noise due to all the intense evaporation, and you can see big bubbles on the surface of the water. At this point the water can no longer maintain its liquid state and quickly evaporates into vapor. You may have noticed that if you put a pot of water on the stove to boil and forget about it, when you come back later, less water is left in the pot as much of the water will have evaporated.

Boiling & Steam - Sterilization Basics - Tuttnauer

Steam is a specific kind of vapor that is only produced through boiling. And when steam is created, it also expands. Each liter of water that is boiled will expand to 1600 liters of steam!


Whereas evaporation is the transformation of liquid water to gaseous water vapor, condensation is the opposite: it is the transformation of vapor back into liquid water. As we said above, when water evaporates, it expands 1600 times larger in volume to become steam. When it condenses, it compresses back into tiny droplets of water. And we call those those tiny droplets of water condensation.

Condensation - Sterilization Basics - Tuttnauer

Tea Time

Here’s another way to think about evaporation and condensation. When you boil water in a tea kettle, you know that the water has reached boiling point when the kettle whistles and white smoke starts coming out of the spout. That smoke is not actually steam but rather vapor (though most people would claim it is steam). Steam is an invisible gas, unlike water vapor, which appears as a mist or fog. In the image below, look closely at what’s coming out immediately near the spout. At first you don’t see anything; that’s the steam. And then after the steam are the small white billows of smoke, which is actually the steam condensing back into water vapor (due to contact with the air). In other words, the water inside the tea kettle boils, evaporates in the form of bubbles and comes out of the spout as steam. Then when the steam makes contact with the cold air outside the tea kettle, it quickly condenses back to tiny droplets of water, which you see as water vapor.

Steam is invisible - Tuttnauer - Sterilization BasicsSteam is invisible. That is what is coming out near the spout. The steam turns to white smoke as it hits the cooler air, which we see as water vapor.

Steamy Science Condensed

Let’s review. We learned that water has three states: ice is the solid state, water vapor is the gaseous state, and water is the liquid state. When water is heated it evaporates, which means it turns into water vapor and expands. At 100℃ it boils, thus rapidly evaporating. And at boiling point, the invisible gas of steam is created. The opposite of evaporation is condensation, which is when water vapor condenses back into tiny droplets of water. Those drops of water are called condensation.

Join us in our next post as we apply our understanding of steam to the autoclave. We will answer the following important question: why is steam the best sterilization agent for the autoclave?

(Post based on Sterilization of Medical Supplies by Steam by Jan Huys. Credit for image of boiling water.)


Sterilization and Infection Control News Update - April 2016

Once again, we've collected for you sterilization and infection control news items that we found to be interesting. Enjoy them!


More Hospitals Set Up Sterilization Facilities in Saudi Arabia

Arab News – 13 March, 2016

The Ministry of Health (MoH)  of Saudi Arabia has intensified its efforts to set up more sterilization departments in the Kingdom’s hospitals under its national program for equipment sterilization which was flagged off five years ago.

Read More


Renovation Benefits Schriever Dental Clinic, Patients

Schriver Air Force News – 17 February, 2016

The Schriever Air Force Base Dental Clinic completed a renovation in December which brought the instrument sterilization process up to the highest Air Force standards, creating a three-room Central Instrument Processing Center and a streamlined cleaning process.

Read More 


West Arkansas Hospital Reopens after Undergoing Sterilization

Fox 13 – 17 March, 2016

A West Arkansas hospital reopened its operating rooms after closing them for sterilization. The hospital closed its operating theatres after a deadly disease was discovered there.

Read More


Delhi Government Plans Steps to Ensure Proper Disposal of Bio-medical Waste

The Indian Express – 20 March, 2016

Concerned about disposal of bio-medical waste being generated in the capital, the Delhi Pollution Control Committee (DPCC) and the environment department of the Delhi government may soon involve more private companies in the process.

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Weighing Rigid Containers against Sterilization Wrap in War on Infections

HealthCareBusiness – 24 March, 2016

A recent scientific study published in the American Journal of Infection Control (AJIC) found that certain sterilization packaging systems, used to maintain the sterility of surgical instruments from the time of sterilization until use in the OR, may also not be doing an adequate job.

Read More 


Design as if your Life Depends on It

Today's Medical Development - 25 February, 2016

The design of medical devices can mean life or death – for the product and, if flawed, a patient.

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2nd Cape Breton Tattoo Artist Used Improper Sterilization

CBC News - 11 March, 2016

A second tattoo artist in Cape Breton has been found to be sterilizing his tools improperly, leaving open the possibility of blood-borne illnesses transferring from one client to another, according to the Nova Scotia Health Authority.

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Sterilization of mosquitoes helps in the control of the Zika virus outbreak



Who is to blame for Superbug DeathsBrazil Attempts to stop Zika Virus by Sterilising Mosquitoes with Gamma Rays

International Business Times – 23 February, 2016

Global nuclear watchdog International Atomic Energy Agency (IAEA) has reportedly stepped in to help Brazil fight the Zika virus outbreak by sterilising male Aedes mosquitoes with gamma rays, which will prevent the spread of the virus.

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Zika Outbreak: What You Need to Know

BBC News – 13 April, 2016

The World Health Organization has declared the Zika virus a global public health emergency. It is suspected of leading to thousands of babies being born with underdeveloped brains. This article includes complete information about the infection.

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FDA issues Guidances and inspects producers of medical devices in order to find sterilization anomalies



Who is to blame for Superbug DeathsFDA Announces Updated Guidance for Devices Labeled as Sterile

Orthopedics Tday – 19 February, 2016

The FDA recently announced the issuance of a guidance document to update and clarify information regarding the sterilization process that sponsors should include in the 510(k) submission for devices labeled as sterile.

Read More


Duendoscope ToolFDA Reaffirms Endoscope Washer Recall After Company Tries to Correct Devices

RAPS – 24 February, 2016

The US Food and Drug Administration (FDA) has reiterated its recall of Custom Ultrasonics' automated endoscope reprocessors (AERs) after the company had proposed to correct, rather than recall the AERs, which FDA rejected as the devices fail to adequately wash and disinfect endoscopes.

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FDA Warns SureTek on Sterilization, QC Issues

Mass Device – 16 March, 2016

The FDA issued a warning letter it sent to single use device reprocessor SureTek Medical earlier this month over issues with the company’s cleaning and validation processes.

Read More


Disclaimer: The views and opinions expressed in the referenced articles and blog posts are solely those of the original authors and other contributors. These views and opinions do not necessarily represent those of Tuttnauer, the staff, and/or any/all contributors to this site.


The Age of Sterile Processing

Weston “Hank” Balch, director of Sterile Processing Operations at KentuckyOne Health, asserts in the following article that we are now living in the Age of Sterile Processing.

It’s hard to believe that as far back as 3,000 years ago the Ancient Egyptians had already figured out how to preserve their dead by using antiseptics like pitch and tar, a process we call mummification. From Ancient Egypt to today, we have come a long way in understanding how to use chemicals and medical tools to treat the human body -- most remarkably, now we can actually cut into a living person in order to heal him.

From clamps and crude saws on Civil War battlefields to seemingly sci-fi surgical procedures like non-invasive remote-controlled robots that can extract tumors through your belly-button, we have truly made a huge leap in surgical instrumentation. But what’s possibly more impressive are the changes taking place right now in the Sterile Processing departments -- the teams who are responsible for these innovative surgical instruments. Here are five reasons why you’ll agree that we are living in the Age of Sterile Processing.

1. Governments are committed to lowering the amount of Hospital Acquired Infections (HAIs) The Affordable Care Act of 2010 made clear the United States government’s intention to reduce the rates of Hospital Acquired Infections. The bottom line is, that for the first time, under the ACA, Medicare and Medicaid reimbursements became directly linked to a hospital’s quality of care, and that includes the incidents of patients who acquire infections during their hospital stay. Obviously we all know the importance of hospital staff following proper hygiene, but in addition to that, the single biggest way we can actively prevent HAIs is to ensure proper sterilization of all surgical instrumentation. Though it’s true that there are other ways to acquire infections during a hospital stay, it’s difficult and time-consuming to zero in on the particular type of microorganism and how it is being transmitted. In contrast, preparing completely sterile trays of instruments for our surgeons will go a long way in preventing the spread of HAIs. Recently the US government has been pouring billions of dollars into infection control -- as well as our counterparts overseas -- and therefore, Sterile Processing departments are sure to be at the heart of this effort.

autoclave sterilizer being loaded with packed medical equpment

2. The media are reporting on the dangerous mistakes of Sterile Processing departments It’s obvious to most of us that if price were no object, we would find the best doctor in the country to treat our beloved parent, spouse, child, etc. But what about the best Sterile Processing department? Isn’t the top surgeon in his or her field functioning as part of a whole support team of SP staff who ensure the safety of all the equipment to be used in surgery? In other words, what is a top surgeon without a top SP department? Recently 12,000 pediatric patients at Seattle Children’s Hospital were advised to be tested for Hepatitis B and C, and HIV, after the hospital discovered it was reprocessing surgical equipment incorrectly. There are, unfortunately, too many other individual cases from all over the United States, that are reaching the media and highlighting the real problem of the challenges SP departments face in ensuring that every single medical tray that leaves the department is sterile and ready for the OR.

3. The more complex the surgery, the more complex the instruments and the harder they are to sterilize effectively. It used to be that the job of the Sterile Processing technician was less complex; everything, more or less, was made of glass or stainless steel and was more easily sterilized. Today, we have a sophisticated generation of surgical instruments, including items like titanium-tipped scissors, retractors that come with their own xenon light sources, and ultrasonic cutting devices. The advances in instrumentation are remarkable, with the medical device companies who manufacture these implements promising decreased patient recovery time and cost-savings to hospitals. Joe Leweling, VP of Standards and Development at the Association for the Advancement of Medical Instrumentation (AAMI), elaborates, “Cleaning was once a basic factory job. Now it’s very complex. It takes a lot of steps. It’s more like a laboratory process.” We can only expect the trend of highly specialized, sophisticated surgical tools to continue, and at the same time, our SP departments must rise to the challenge of sterilizing them properly.

medical tweezers used in surgical operation

4. Sterile Processing leaders are recognizing this historic era in the industry. The years 1787-88 marked a time of expectation and excitement as the first states began to ratify the freshly drafted U.S. Constitution. Today, similarly, there is a feeling of anticipation in the air that changes are coming to the world of sterile processing. We are standing at a crossroads, and our leaders realize it. Michael Matthews, Central Sterile Manager at Conway Regional Health System, explains, "Hospitals can no longer act as though CS technicians do not have a dramatic effect on patient care and safety simply because they are not physically present in the surgical suite with the patient."  And the times they are a changin’ for SP technicians who are now required to earn certification in New York, New Jersey, and now Connecticut. There is a real momentum for positive changes to our industry that will help propel us forward to meet the demands of the changing medical scene.

5. SP technicians are shining in their professionalism, expertise, and leadership. It used to be that standard job descriptions for an SP technician may have appeared something like this: high school diploma required or equivalent, no prior experience. But this is changing. As I mentioned above, three states already require certification and more are sure to follow. And now the field is attracting a new population of bright college graduates and multi-certified specialists. With our “triple crown certification” at KentuckyOne Health system, we are making serious gains in equipping our SP team with knowledge of quality and safety practices, as well as raising the professional bar for the whole department. SP technicians and department managers are getting published in leading industry magazines, advancing our causes in the medical world. And we are able to openly discuss what’s happening in our SP departments in meetings of the International Association of Healthcare Service Materiel Management (IAHCSMM), as well as social media platforms like LinkedIn’s Sterile Processing Department Professionals. These outlets allow for networking and the exchange of relevant and valuable ideas.

And the more we work together creatively across the industry, the more we will be able to tackle the challenges unique to this exciting era, the Age of Sterile Processing.


Weston Balch, Director of Sterile Processing Operations at KentuckyOne HealthWeston “Hank” Balch is the director of Sterile Processing Operations at KentuckyOne Health, which includes the 462-bed internationally renowned, high-tech tertiary referral center at Jewish Hospital and the 329-bed, world renowned Level 1 trauma facility at the University of Louisville Hospital. He has built a highly-acclaimed team of well-trained and certified technicians consisting of 65 employees, many with industry certifications and undergraduate and graduate degrees. His publications include Infection Control Today (May 2015) “Certifiably Educated: One Department’s Drive to Serve with Smarts” and Communique (Sep/Oct 2015) “Triple Crown Certification: How One CS Department is Winning the Race for Quality, Safety, and Professionalism,” as well as over 30 LinkedIn Pulse articles that feature creative solutions and novel approaches to relevant topics in the world of Sterile Processing.