Sterilization is a critical process for ensuring the safety and efficacy of medical devices. Among the various sterilization methods, Ethylene Oxide (ETO) has emerged as a sterilization method of choice because of its advantages compared with other methods. Due to its potent virucidal, sporicidal, and bactericidal properties, EO is a superb sterilizing agent. In this blog, we will discuss ETO sterilization role, process, regulatory standards and maintaining the integrity of medical equipment.
Ethylene Oxide is a colourless & flammable gas that effectively eliminates microorganisms on medical devices. Its ability to penetrate packaging materials and reach every nook and cranny of complex and heat-sensitive devices. This makes ETO an ideal choice for sterilizing items.
The ETO sterilization process involves exposing medical devices to a carefully controlled environment containing the gas. This controlled environment ensures the eradication of bacteria, viruses, and other microorganisms without compromising the integrity of the devices. The process typically includes preconditioning, gas exposure, and aeration phases, all meticulously managed to meet regulatory standards.
There are three main stages in a typical EtO sterilization cycle:
Cycle time is usually more than 14 hours.
The longest and most crucial stage of the ETO sterilisation cycle is aeration. As previously discussed, substances like rubber and plastics may collect gas, and if this gas is applied to patients, it may cause harmful tissue damage! To eliminate any leftover ETO gas and enable absorbed gas to re-evaporate from the sterilised goods, it is crucial to have an excessive aeration step. At a temperature between 30°C and 50°C, HEPA-filtered air is circulated over the load to achieve this. This aeration treatment is often performed for 48 hours, which causes an extremely delayed instrument turnaround. It is necessary to have a certain infrastructure, including gas-tight ventilation pipes that lead to a catalyst or the roof.
But there are a few benefits. The chamber of an ETO steriliser can be exceptionally large—up to 7 m³. They are frequently used to sterilise large batches of goods that steam sterilisation is unable to achieve. Prior to entering the hospital, gauze and non-woven materials such as disposable gowns must be sterilised. Since steam will deteriorate or distort these materials, ETO is frequently used to sterilise them.
In conclusion, ETO sterilisation needs to be reserved for situations in which no other approach is suitable.
Unlike some other sterilization methods, ETO can penetrate packaging materials. This is particularly advantageous for ensuring the sterility of devices even after they have been sealed in their final packaging.
ETO operates at relatively low temperatures compared to steam sterilization. This makes it suitable for devices sensitive to heat, preventing potential damage during the sterilization process.
While ETO sterilization is highly effective, it comes with certain challenges. The gas is potentially hazardous to human health, requiring stringent safety measures. Residual ETO must be carefully monitored and controlled to ensure it falls within acceptable limits, avoiding any harm to end-users.
Given the potential risks associated with ETO, regulatory bodies have established strict guidelines for its use. Manufacturers must adhere to these regulations to guarantee the safety and efficacy of sterilized medical devices.
This standard specifies requirements for the development, validation and routine control of ethylene oxide sterilization process for medical devices in both the industrial and healthcare settings and it acknowledges the similarities and differences between the two applications.
This standard specifies allowable limits for residual ethylene oxide and ethylene chlorohydrin in individual EO- sterilized medical devices, procedures for the measurement of Ethylene oxide and ethylene chlorohydrin and methods for determining compliance so that the device may be released.
This standard specifies requirements and provides guidance on the enumeration and microbial characterization of the population of viable microorganisms on or in a healthcare product, component, raw material or package.
This specifies the criteria for the test of sterility on medical devices that have been exposed to a treatment with sterilizing agents reduced relative to that anticipated to be used in routine sterilization processing. These tests are intended to be performed when defining, validating or maintaining a sterilization process.
Ethylene Oxide sterilization plays a pivotal role in ensuring that a wide range of medical devices meet the highest standards of safety and efficacy. Despite its challenges, when managed with precision and in compliance with regulations, ETO sterilization stands as a reliable and indispensable method in the arsenal of techniques safeguarding the health and well-being of patients worldwide.
1. Ethylene oxide sterilization of medical devices; A review
2. ISO 10993-7:2008
3. ISO 1135:2014
4. ISO 11737-1:2018
5. ISO 11737-2:2009
Recent Post
Impact of Usability Engineering in Medical Devices
Use of Artificial Intelligence in Medical Devices
Are You Looking For Medical Devices Certifications?
Contact Us