Why Is An Autoclave Stronger At Sterilising Than A Microwave?

Why Is An Autoclave Stronger At Sterilising Than A Microwave?
Authored By Medical Equipment Services Admin

Autoclaves and microwaves are both technical devices that are used to sterilise medical equipment and tools.

However, they vary in their techniques and effectiveness in their sterilisation processes.

In this article, we’ll be talking about exactly what each device is, how they both differ from each other, and why the autoclave is a more powerful sterilising apparatus compared to the microwave. 

What Is Sterilisation?

Before we talk about autoclaves and microwaves, it is important that you first understand exactly what sterilisation is.

Sterilisation is the process of eliminating all kinds of living forms of microorganisms along with spore forms.

This can take place through physical, chemical, or mechanical means, and produces an object that is 100% safe for the human body. 

Sterilisation processes that are performed correctly do not change, alter, or damage the properties of the equipment or object that is being sterilised.

So, What Is An Autoclave?

An autoclave is a device that comes in various shapes, sizes, and functions and is typically used to sterilise surgical equipment, pharmaceutical items, laboratory instruments, and more.

To put it simply, they function similarly to a pressure cooker because it boils instruments above the boiling point and uses steam power to kill bacteria, germs, and spores that cannot be killed by boiling water and other chemicals. 

There are different kinds of autoclaves like medical autoclaves, dental autoclaves, and laboratory autoclaves, but they all more or less serve the same purpose.

How Does A Microwave Differ From An Autoclave?

Microwaves are commonly used to disinfect objects such as soft contact lenses, milk, dentures, and urinary intermittent-use catheters.

Unlike an autoclave which uses steam, microwaves make use of radio-frequency waves which causes water molecules to vibrate and produce friction in order to generate heat and ultimately kill germs. 

However, they are a bit more limited than an autoclave in some ways. For example, microwaves can only be used with compatible objects that do not melt. 

In addition to this, microwaves often do not evenly distribute energy over the instruments, which means the object will not be sterilised evenly.

This means that some parts of the object will be dry and other parts of the object will be wet. 

Efficient microwave sterilisation is often dependent on different circumstances and conditions.

For example, the condition of the object such as how much water is present determines how evenly the microwave can disinfect the object.

Likewise, microwave power is another factor to consider, as this can affect the effectiveness of the sterilisation process.

Because of this, microwaves are typically not recommended to be used for the sterilisation of medical devices. 

In What Ways Is The Autoclave Better Than The Microwave For Sterilisation?

The autoclave has a more intricate structure in comparison to the microwave.

It is a hermetically sealed and heated tank with thick walls so that it can perform high-pressure processes with higher temperatures.

It is because of this that water vapour condensation can occur which can release more energy in order to completely kill harmful microorganisms.

So, instead of using radio-frequency waves to sterilise, autoclaves use steam sterilisation.

This process is known to be fast, effective, and environmentally friendly.

It also does not yield much waste and can sterilise liquids as well, which makes steam sterilisation the go-to sterilisation process for many health care facilities and centres. 

Moreover, autoclaves can also be used in industrial settings to sterilise parts and materials such as specialised rubbers and pressure-treated woods. 

Because of its structure and scope of functions, autoclaves are better devices to perform stronger sterilisation processes in comparison to microwaves. 


While microwaves do perform a degree of disinfection and sterilisation, they are quite limited and are not generally recommended especially in the medical environment and setting.

This is because of the possibility of uneven energy distribution, which renders parts of the object in question to still be infected.

On the other hand, autoclaves perform a more comprehensive job of sterilising an object or instrument.

Due to its technical structure, it can generate high pressures and high temperatures to completely eliminate microorganisms.

Moreover, the steam also generates more energy that can add to the effectiveness of the sterilisation process.

As such, autoclaves are widely used in both medical and industrial settings and are important in maintaining safe and clean instruments used in both fields. 

If you are searching for the best autoclave supplier in Australia, then look no further than Medical Equipment Services Australia

We were originally established in 1952 in order to provide electro-medical products to healthcare professionals across the country. 

The company (Medical Equipment Services) was acquired by Medical Equipment Australia in 2009. Since then, we have also expanded into the dental industry. 

For all your medical and dental supply requirements, please call us today on 1300 342 013 or contact us through our website.

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