What Materials Cannot Be Autoclaved?

What Materials Cannot Be Autoclaved?
Authored By Tom Toi

Autoclaves are one of the most important devices when it comes to sterilisation. By generating highly-saturated steam, autoclaves can kill all types of microorganisms, including the peskiest spores.

However, there are still do’s and dont’s when it comes to what you can and cannot autoclave. This is particularly important to consider especially if you want to ensure a safe working space.

If you want to learn more about what materials you can and cannot autoclave, let’s explore this further in this article.

Acceptable Materials For Autoclaving

When it comes to autoclaving instruments, it is important to ensure that they are compatible with the high heat and pressure environment created within the autoclave.

If you are not careful enough, this can lead to some serious health and safety hazards that could have been avoided in the first place. As such, here is a list of what objects you CAN autoclave:

1). Glass

Generally, the only type of glass that you should be placing in an autoclave is Pyrex or Pyrex type materials. However, usually, the vendor or manufacturer of the glass product may indicate if the glassware can be autoclaved or not.

In spite of this, even Pyrex glassware can explode in an autoclave. However, this is only if it contains a certain volume of liquid and the container is closed tightly. As a general rule of thumb, you should never autoclave liquids in a closed container.

What Materials Cannot Be Autoclaved

2). Polypropylene

Polypropylene is an inexpensive resin that is capable of withstanding autoclaving temperatures. These containers are generally available in various shapes and sizes running from bags, trays, and pans.

The bags must be open so that the steam can penetrate it. It is recommended to pour a small amount of water into the bag before autoclaving so that heat transfer can be more sufficient.

3). Latex or Vinyl

Generally, these items can melt inside of an autoclave and combustion is possible. However, if it is placed inside an autoclavable biohazard bag with a steam setting as waste items, then they will melt slightly but not combust to fire or smoke.

Biohazard bags inside autoclaves often come with latex or vinyl safety gloves along with paper and plastic culture plates. Therefore, some melting may be possible with these items. 

4). Paper

Paper can only be placed inside of an autoclave as a waste item contained inside a clear or red biohazardous autoclave waste bag. In the “dry setting,” you should never sterilise waste containing paper. Make sure you use the “wet” setting to prevent fires from breaking out.

5). Metals

Most metals found in laboratories are already designed to withstand extreme conditions and sterilisation. While there are few exceptions, the majority of metal objects are autoclavable. 

Small cages for animals can even be autoclaved. However, make sure to extract liners, plastics, and other items that can possibly combust.

6). Plastic Pipette Tips and Culture Plates

Some tips are plastic while some are high-density polyethylene. The degree to which it will melt depends on the autoclave’s setting, material density, and the plastic-type. 

Pipette tips should only be autoclave as waste inside an appropriate biohazard bed. They must also always be sterilised on a steam producing setting.

What Materials Cannot Be Autoclaved

Unacceptable Materials For Autoclaving

Of course, while there are acceptable materials for autoclaving, there are also unaccepted materials for autoclaving. It is important to caution yourself against these materials in order to avoid accidents or hazards from occurring. 

As a general rule of thumb, you CANNOT autoclave materials that are contaminated with solvents, radioactive materials, volatile or corrosive chemicals, or items that contain mutagens, carcinogens, or teratogens. Here is a shortlist of materials NOT to autoclave:

  • Radioactive materials or materials that may have been contaminated by radiation
  • Combustible, volatile, or flammable liquids
  • Liquids sealed in a container
  • Materials that are contained in a way that touches the interior surface of the autoclave


When it comes to autoclaving materials, you should always carry out the utmost caution possible. Hazards such as explosions, fires, and more can occur if you are not careful with the material that you wish to autoclave.

MES Medical Equipment Services has been Australia’s leading provider of autoclaves and other medical equipment and equipment services since 1952. 

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

Our products range from sterilisation, dental systems, dental imaging, electrosurgical equipment, medical consumables,  dental lasers, and equipment service maintenance.

We sell only top of the line equipment and machines produced by the leading manufacturers in the world. Our integrity and standards are your guarantees!

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

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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