Sterilization is the removal of all life forms and agents from the surface of a material or from a fluid/compound. 

Examples of such agents include:

  • Bacteria
  • Fungi
  • Viruses
  • Spores

Proper cleaning is a very important step for certain businesses that require sterilization on a regular basis.  

Industries that rely on this the most are:

  • Food and beverage industry
  • Pharmaceutical industry 

Not only does proper cleaning keep products safe for people, but it may allow for some products to be used again. Safety and cost benefits are often the reasons that thorough cleaning is so important. 

There are many ways a material can be cleaned. For example, some metal objects can be cleaned with acids. However, for some products this is simply too harsh and may ruin them. Instead, gamma and ethylene oxide sterilization are two of the most common options to choose from. 

So how do they compare? Below you will find out more about both options and what they mean for business. 

Questions we will answer include:

  • How do they work? 
  • Which materials work best with each process?
  • What are the pros and cons? 

With this information, you can better determine:

  • Which process is right for your product
  • Why one process may be better than the others
  • How the pros and cons impact the end result

EO Sterilization

Also known as Gas Sterilization, EO (EO) sterilization is carried out by exposing the material(s) to the toxic and volatile ethylene oxide gas. This is done in a heavily controlled area and within a specific amount of time. In its pure form, ethylene oxide gas is flammable and explosive if it comes in contact with air. As a result, it is usually weakened with inactive gases. Not only does it lessen its toxicity, but also makes it easier to handle. 

The process

Step one:

The material needs to be prepared before disinfection. This is done in a room that meets the following: 

  • Made to heat and humidify the product to a stable temperature
  • Moisture content before it is placed in the chamber 

The cleaning process takes place in a vacuum-tight chamber and when all the air in the chamber is removed, and a set amount of EO ensures proper cleansing is achieved. 

Step two: 

The next step is to add the material that is to be cleaned. During the ongoing process the following is watched closely:

  • Time of exposure 
  • Temperature
  • Concentration
  • Humidity of the gas

Step three: 

Sometimes during the process, the material is softened. To avoid more damage, the product is washed several times at a controlled pressure. 

Additional Information 

EO sterilization is used mostly:

  • In hospitals
  • For plastics
  • For other heat-sensitive materials 

 It is not ideal for materials that absorb gases. Such materials are likely to leach ethylene oxide into future processes, which will ruin the product as a result. 


  • A wide range of materials can be cleaned using this process.
  • Already packed materials can be cleaned using the process because EO can go through cartons and sealed film. 


  • Ethylene oxide may be harmful to people.
  • The process requires the need for more control. 
  • EO is highly flammable. When air is present, it can create its own oxygen. 
  • Possible change in smell or color of the materials.

Gamma Sterilization

Gamma sterilization is done by exposing a material to a controlled dose of gamma rays. The radiation breaks the bond in the microorganisms’ DNA which causes a mutation and ultimately cell death. This is the required process to clean it. 

The Process

Single-step process: 

Materials cleaned using gamma rays do not need to be prepared, and may be put together and packaged before the process. The radiation is applied in a safe and controlled environment

Be aware that a single dose of radiation may take between a couple of minutes to a few hours to clean a product. It depends on the thickness or volume of material. 

Gamma is best for:

  • Acetyls (low doses of radiation)
  • Polycarbonates
  • Acrylics
  • PVDF

It is a commonly used at: 

  • Industrial Plants 
  • Pharmaceutical Companies


  • Gamma is the ideal choice for materials that are stored for a long period of time
  • The process  does not create heat or moisture
  • Less expensive 
  • Cleaner  
  • After the cleansing process, there is no small trace of radioactivity


  • Some materials may be a slightly different color after the process.

Note:  Some plastics perform better after the process is complete. 

Which Option is the Best?

Choosing between EO sterilization or Gamma depends on the type of product being cleaned. However, it is understood that Gamma and EO typically meet the requirements of packaged laboratory products. EO sterilization is a popular choice simply because it tends to be the most versatile since it can be used on plastics and other heat-sensitive products. However, it may have more of a risk with its use. 

To ensure that you’re using the best cleaning process, you should examine the following: 

  • Type of material
  • Heat-resistance level
  • How workers will perform the process
  • Cost 

You’ll want to weigh if the cons of either method could influence how the product is used in the future or how it will impact the workers who use it. 


International Enviroguard, offers  Gamma Radiated products and other protection solutions that help your workers remain:

  • Clean
  • Safe from tox acids
  • Radiation-free
  • Harmful substance-free 

Keep in mind, both processes outlined above require a sterile environment where the processes can be carried out risk- and contamination-free. Check out our list of products to help achieve your sterilization goals.