When purchasing sterile laboratory products, you will notice that there are different types of sterilisation methods. Two of the most common methods are gamma sterile and ethylene oxide (EtO) sterilisation and the common questions surrounding these two types are which, if any, is better and what are the main differences.
Let’s first take a look at gamma sterilisation and when it is used. This type of sterilisation is an irradiation process where the product is exposed to gamma rays. This type of method is efficient, effective and relatively simple. It is a common sterilisation process as it is predictable and is able to repeat time and time again with accuracy.
Gamma sterilisation uses gamma rays that are emitted from a radioactive isotope source in order to kill any living organisms. Packaged products are subject to the sterilisation process as gamma rays have the ability to pass through packaging and the actual product itself via electromagnetic waves. This results in the packaged product being sterile and provided this package remains sealed, it will remain sterile. After the sterilisation is complete, products are able to be shipped immediately, thus, increasing the overall efficiency of this method.
Ethylene Oxide (EtO or EO) Sterilisation
The other common sterilisation method is EtO sterilisation which is used for products that are sensitive to radiation. EtO is a type of gas and the process involves exposing the products to the gas at a specified temperature, relative humidity, and pressure for a controlled amount of time in order to ensure proper sterilisation has taken place.
As EtO is a toxic gas which is highly explosive, organisations must comply with strict usage guidelines. Upon completion and when the EtO gas is removed from the sterilisation room, the room then needs to be treated to remove all traces of EtO through a degassing process.
Which method is best?
When asking which sterilisation method is best, you need to identify a range of variables to determine which is best. There are many more sterilisation methods available other than gamma and EtO but most sterile packaged laboratory products fall into one of these methods. EtO sterilisation is known as the most universal sterilising method due to the fact that it can be used with almost all laboratory products including plastic and heat-sensitive materials. This makes EtO a very appealing sterilisation method. It is important to note that both methods work very well and usually the manufacturer will choose the most appropriate method based on the products they are sterilising. It is up to the individual to check the test methods that you are using to confirm if EtO or gamma is recommended for your processes.