Ethylene Oxide Sterilization for Medical Devices

While ethylene oxide is an effective cleaning agent, its use is limited to certain types of medical devices. Its use as a sterilization agent in sterile packaging requires that a gas-permeable package is used to prevent the ethylene oxide from escaping. Despite its limited use in medical sterilization, it is an excellent alternative to traditional heat sterilization methods. It is safe to use and is not known to cause cancer.

ETO is a Powerful Cleaning Agent

Ethylene oxide, or ETO, is a widely used gas sterilant. First prepared in 1859, it is often used to manufacture polyester fibers. It has since evolved into a popular medtech disinfection method, accounting for nearly half of device disinfection processes. ETO has several benefits over alternative cleaning processes. It can penetrate plastic and packaging, and can sanitize complex product configurations.

However, the ETO industry has been largely unresponsive to the EPA’s findings regarding ETO. The EPA released new monitoring data in summer 2018, and lawsuits quickly followed. However, an ETO ban would have an enormous impact on the healthcare system, causing widespread shortages of critical medical devices. If such a ban were to occur, patients’ lives could be at risk. Recently, ETO was the topic of a public hearing by the FDA’s advisory committee, which will discuss the issue further.

The EPA is working with industry to reduce emissions of ETO into the outdoor air. The agency is also reviewing existing Clean Air Act rules for these industries to identify early reduction opportunities. EPA is also conducting new studies on the background levels of ETO in the air and investigating new technologies and methods for measuring ETO. Currently, the EPA is the only agency regulating ETO emissions. If this change is made, it will have a profound impact on the microbial levels in the air.

Industrial ETO Sterilizer
Industrial ETO Sterilizer

It does not Cause Cancer

The EPA and the Food and Drug Administration disagree on how to regulate the concentrations of ethylene oxide in treated water. Both are working on parallel avenues to limit public exposure. Concerns over airborne ethylene oxide have been raised by communities near medical sterilization plants in Michigan, Georgia, and Willowbrook, Illinois. In each of these locations, residents and senators raised concerns about the safety of the devices. The EPA’s findings in February 2020, however, did not change the FDA’s position on the topic.

The EPA based its assessment on computer models and concluded that the concentrations of EtO in the air may increase the risk of cancer. It did not, however, identify any cancer-causing levels at any particular location, but the U.S. Environmental Protection Agency cited an air toxics assessment conducted at a facility at 11308 W. Collins Avenue in Lakewood as a potential site for further study.

It is an Alternative to Traditional Heat Sterilization Methods

Liquid chemical sterilants are an alternative to traditional heat sterilization methods for sterilizing medical devices. While this method is effective, it does have its limitations. It is not compatible with other methods of sterilization. This new process is not suitable for all types of devices. For instance, a device may only be sterile if it is used only for reprocessing.

Another alternative to traditional heat sterilization methods for medical products is ETO gas sterilization. This process involves exposing devices to a mixture of EtO gas and nitrogen gas. The process takes approximately two to three hours, and is best suited for devices that cannot withstand a temperature of over 60 degrees Celsius. Some medical devices may not be acceptable for this method, however, if they contain embedded batteries or electronics. Additionally, ETO is a flammable petroleum-based gas, which makes this method unsuitable for some devices.

Dry heat sterilization uses high temperatures to kill microorganisms by oxidation and cell bursting. In contrast, moist heat sterilization destroys microorganisms by applying high pressure to a container. Medical products and devices commonly undergo this process. Hot air ovens, mixing tanks, and rubber devices are among the many pieces of equipment that can be sterilized using moist heat.

It Must be Sealed in a Gas-permeable Package

The choice of secondary packaging is critical when using Ethylene Oxide sterilization to protect medical devices. The package must be robust enough to withstand shipping and maintain its integrity over time, such as two years. Moreover, the package must be easy to read and contain clear instructions. Packaging must also meet all standards of safety and microbial barriers. Its material must be safe and effective, and the machinery used in manufacturing the package must produce consistent results.

For ethylene oxide sterilization to be effective, the packaging material used in the device must be gas-permeable. This is a challenge, as a large amount of paper prevents the ethylene oxide from reaching the device. Large amounts of paper prevent ethylene oxide from reaching the device, thereby limiting its effectiveness. A gas-permeable package is the best solution in most cases.

Hospital Sterilizer- Best for Sterilization of Critical Medical Supplies
ETO Sterilizer