The Ethylene Oxide Sterilization is the key for thermo-sensitive products sterilization


The pharmaceutical industry is doubtless, one of the most important sector worldwide and in constant evolution in terms of laboratories, research centers...

The development of this sector has been very strong for several decades, in several aspects like the medical sector.
Such an evolution has had an important impact on the instruments and products used at hospitals and pharmaceutical companies such as prostheses, implants, packaging... using new technologies and innovative materials. An important aspect to take into account during a life of instruments, objects or pharmaceutical and medical products, is a perfect sterilization.


Why is sterilization of pharmaceutical and medical products so important?

Medical devices sterilized by EtO processThe sterilization allows the elimination, or rather a great reduction of the biological load that can have the utensil or instrument.

In other words, it is the elimination of virus, bacteria and other microorganisms that are present inside or on the surface of pharmaceutical and hospital utensils / objects such as syringes, gloves, saline bags...

The importance of a correct sterilization in the pharmaceutical sector as well as hospital sector is essential for its success and its correct functioning. On one hand at the laboratory level to get right results, and on the other hand at the hospital level in order to prevent having patient complications.

Different methods of sterilization are available and they had to adapt themselves to the arrival of "thermo sensitive" products. The evolution of the pharmaceutical and medical sectors has given rise to new products such as: prostheses, implants and also products with new characteristics thanks to the composition of materials like resin, rubber, plastic...

That is why sterilization process also had to evolve at the same pace as the instruments and products in order to guarantee on one hand total sterilization, and on the other hand to complete integrity after the sterilization of the so-called thermo sensitive products.


What are the thermo sensitive products and/or materials?

They are called "thermo-sensitive" materials or products that are sensitive to changes in temperature, or that do not resist heat such as: cameras, gums, some plastics, optical instruments...

These types of products are becoming more and more common, but they do not withstand the high temperatures that could bring a traditional steam sterilization cycle.

That is why low-temperature sterilization processes had to be developed.

Some of the processes are gas type like ethylene oxide or hydrogen peroxide. Others are radiation type such as gamma or beta radiation for example.

Each process has its advantages and drawbacks, and may be more or less appropriate to a determinate product, depending on the characteristics of the materials to be sterilized.

One of the most important process and usually used for its high efficiency, is ethylene oxide (ETO) sterilization.


What is ethylene oxide?

ETO Ethylene-Oxide gas

It is an odorless and colorless gas that allows to sterilize and destroy microorganisms, penetrating and propagating into thermo-sensitive products, including porous and difficult-to-reach materials without deteriorating the materials of the sterilized products.


Its advantages are the following one:

  • Propagation in the folds and inaccessible places of the element to be sterilized.
  • Go through the membranes of the wrappings containing the elements (ex: the polyethylene film).
  • It can depirogenate the dead cells.
  • Sterilization between 25ºC and 60ºC (low-temperature) guaranteed the non-deformation or the non-destruction of the elements to be sterilized.

The ethylene oxide is very effective for thermo sensitive materials, which cannot be sterilized by traditional methods like steam sterilization.


What to know about the ethylene oxide sterilization process?

The ethylene oxide gas (ETO) has great advantages but it is also necessary to know that it is explosive, carcinogenic, mutagenic  and toxic as well, so it must always be used with great security, working with sterilization equipment that ensure the safety of personnel, machine, and environment. This is for this safety reason that a stringent normative appeared in Europe on July 2003, called ATEX (2014/34/UE).

The importance of a good optimization of the sterilization process is essential, so it is crucial to find the most appropriate relationship between the variables: gas concentration, humidity, exposure time and temperature.

The ethylene oxide sterilization process can be divided into 3 main phases which are:

Know How Ethylene Oxide Sterilization process

  • Conditioning or preconditioning.
  • Sterilization.
  • Ventilation or Aeration.

In order to make the sterilization process optimal, there must be an adequate relationship with the 4 keys variable mentioned above. So we should keep in mind that the design, manufacturing, commissioning, installation and validation of the ethylene oxide (EO) sterilisers have to be performed by a team of professional.

They are special machines, with a customized design in order to fulfil the customer needs, and require a deep know-how and a perfect control over the entire ETO sterilization process in order to obtain improved results and to comply regulations, especially in terms of safety.

Thanks to a huge experience in Ethylene Oxide sterilization, RSD® has all the knowledge about the entire ETO sterilization process to propose turnkey projects. Many important customers already trust on us, like BBRAUN, Merck Millipore, etc. The collaboration with the recognized company Inoxtorres for equipment manufacturing and installation makes that our projects always end up with success.

For further information, please contact us.



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