Medical autoclaves are pivotal tools for ineffective infection control in a medical facility. From GP clinics, and hospitals, to research laboratories, there is hardly a place where instruments needn’t be sterilized. Also known as steam sterilizers, autoclaves have proven to be a must-have piece of equipment for various healthcare and industrial sectors.

What does an autoclave do?

An autoclave is essentially a machine that uses high-pressurized steam or plain heat to kill dangerous bacteria, contagious viruses, fungi, spores, etc., on any item that is placed inside it. The items that can be sterilized are often medical tools or containers that are exposed to harmful germs and bacteria. The articles are then heated to a regulated sterilization temperature for a set period of time. The combination of moisture and heat in applying high-pressure steam results in the destruction of the protein structure of the bacteria and viruses. Hence, the term “autoclave” in the medical industry is synonymous with a steam sterilizer.

Invented by a French-born physicist Denis Papin in 1679, the early prototype of an autoclave has found itself being a pressure cooker. However, a century later, a French microbiologist Charles Chamberland created a modern version of an autoclave that has been modified into the medical autoclave sterilizers used today.

The science of disinfection tools and equipment for medical purposes has long been practiced. As the inventions of more sophisticated machinery started coming in, disinfection and sterilization were applied thoughtfully in 1881. Robert Koch’s research on the effects of using hot air and steam as an agent of disinfection was ground-breaking in the industry. The clinical demonstration of how moist heat (steam) can penetrate deeper into the microscopic level and perform far better disinfection than dry heat was both exclaimed at and applauded! This led to the launch of medical autoclave technology to make its way into sterilization procedures across the healthcare industry. It was called the first pressure steam sterilizer to manipulate the outcome by measuring the temperature in the chamber drain line (thermostatic trap).

While the world was still grasping at the marvel of controlling air pressure and verifying the temperature, autoclave technology was already in the further development phase. By 1958 there was a pre-vacuum cycle and a steam-flush pressure-pulse in 1987, and revolutionary science became a foundational principle for new autoclave technology to evolve into the modern-day sterilization processes in hospitals and other industries.

How does an autoclave function?

As stated before, autoclaves are commonly employed in healthcare settings to sterilize medical devices. The functioning is rather simple and can be compared with how one works with an oven. The items needed to be sterilized, placed inside the tray, and closed before turning the machine on. On the technical side, the articles are put inside a pressure vessel or the chamber. Once everything is in place, there are three additional factors on which successful steam sterilization in an autoclave depends: time, temperature, and steam quality.

These requirements are achieved by three phases of an autoclave functioning:

• Conditioning Phase (C) – In this phase, the air that restricts the sterilization process needs to be removed from the chamber. In the first phase of the sterilization cycle, this action is known as conditioning. In dynamic air removal-type steam sterilizers, the air is often extracted with a vacuum system. Alternatively, a series of steam flushes and pressure pulses can also be used to achieve the results. Lastly, gravity-type sterilizers utilize steam to displace the air in the chamber and force the air down the sterilizer drain.
• Exposure Phase (S) – After the success of the first phase, when the air is removed, the sterilizer drain then closes to let the steam into the chamber. This causes a quick escalation of both the pressure and temperature inside to a predetermined level. This means that the cycle has reached the exposure phase and the tools inside the chamber only need to be kept in there for a set time for them to be completely sterilized.
• Exhaust Phase (E) – In the final stage of the disinfection process, the sterilizer drain is opened, steam is removed, letting the vessel depressurize, and the articles in the load dry. In all the phases of sterilization, the quality of steam is elemental in ensuring microscopic success at disinfection. Therefore, the steam used for this process needs to be composed of 97% steam (vapor) and 3% moisture (liquid water).

What is an ideal temperature range for a medical autoclave sterilizer?

When the recommended ratio of steam to moisture is maintained at 97:3 strictly, the chances of the steam being superheated or dry fall low. Hence, typically recommended temperatures for steam sterilization are 250° F (121° C), 270°F (132°C), or 275°F (135° C). This ensures that all harmful microorganisms are killed as the tools and equipment are kept in the chamber for the set timer (according to the size of the machine and the load in the vessel), and the perfect disinfection is achieved.

What are the main types of autoclaves used in the industry?

There are mainly industrial autoclaves and medical autoclaves. Both have their own unique distinction, and their application often overlaps in different sectors.

Primarily, industrial autoclaves can be found in manufacturing plants where some parts and materials may require disinfection before assembly. For instance, autoclaves are employed in the manufacturing of pressure-treated woods and specialized rubbers used in the tires of many vehicles.

Additionally, autoclaves play a pivotal role in scientific research, such as in pharmaceutical and lab testing, where the tools, equipment, and other items are constantly exposed to many a potent mixture of chemicals, bacteria, viruses, etc. Here, they work more than just sterilizing the equipment; rather, they sterilize the liquids used in laboratory environments as well.

On the other hand, medical steam sterilizers have a coveted space in the healthcare industry. One can find a vertical autoclave in essentially every hospital today. They are used to sterilize heat and moisture-stable items like surgical instruments, implanted medical devices, surgical drapes, linens, etc.

Choosing a medical autoclave sterilizer for your facility can be tricky, given the choices in the market. Hence, the best approach is to educate yourself on the device and understand what you need from it. Then, reach out to our team at Genist Technocracy and let us assist you in finding the right fit for your sterilization requirements!