The FDA has issued a pair of challenges to encourage the development of new approaches to medical device sterilization. The first challenge focuses on identifying alternatives to ethylene oxide (EO) sterilization methods. The second seeks input on reducing EO emissions.
The agency warned of possible medical device shortages in March following the abrupt closure of a Sterigenics EO plant in Willowbrook, Ill. The device sterilization industry also faces new regulations from the U.S. Environmental Protection Agency. The EPA published proposed amendments to the National Emissions Standards for Hazardous Pollutants in the Federal Register in February. The EPA’s proposal seeks comment on the science-based health risk of EO.
The EPA’s last formal rule governing EO came out in 2006. Ten years later, the agency changed the sterilant’s classification from “possibly carcinogenic” to a determination that long-term exposure could cause elevated risks for certain cancers, including non-Hodgkins lymphoma, myeloma, lymphocytic leukemia and breast cancer. That change prompted protest from the sterilization and medtech industries.
The possibility of stricter regulations on EO could hit the medtech industry hard, as it is used to sterilize 56% of medical devices, according to AdvaMed. The trade group has been meeting with the EPA, and the industry has also been working on alternatives to EO for years, AdvaMed chief lobbyist Greg Crist told Medical Design & Outsourcing.
The medtech industry has also been researching methods of reducing and removing EO emissions, including wet and dry scrubbers, catalytic and thermal oxidizers, and water barriers, as EO is water-soluble, Crist said.
“The point is to show that there are various control technologies employed in our plants throughout the country to meet federal standards but also state standards, such as New Jersey, where the ceiling is much higher,” he added. In the wake of the Sterigenics plant closure, Illinois instituted a new, tougher EO emissions law as well.
Ethylene oxide is a colorless, odorless gas primarily used in the production of several industrial chemicals, the most notable of which is ethylene glycol, according to the U.S. Occupational Safety and Health Administration. It is popular for medtech sterilization because it works at low temperatures and can penetrate device packaging, speeding the process and keeping costs down.
Current alternatives to EO include nitrogen dioxide, another low-temperature, gaseous sterilization method, and vapor-based peracetic acid, according to an industry expert who requested anonymity. Another low-temperature option, gamma sterilization, can alter the chemical makeup of some devices, making them brittle and discoloring them, according to David Gilbert, EO sterilization consulting study director for Nelson Laboratories. Gamma may also compromise some electronic components’ functions, he added.
Medtech sterilization method selection depends on several factors, including material compatibility, process availability, processing location, physical device attributes, legacy regulatory approval, processing volume, speed to market, cost and regulatory registration within the countries in which the medical device or products are to be distributed and used, according to the Gamma Processing Industry Alliance. Once a sterilization process is selected, it must be validated and approved by the FDA.
Changing the sterilization method for a device can be costly and take many years, the alliance said in a 2017 white paper. Risk aversion in healthcare markets and the complexities of securing FDA approval for devices that have many previous iterations have prompted the medtech industry to stick with traditional methods such as EO and gamma radiation, the group said.
Sterigenics said in June that it has applied for Illinois state permits to upgrade emissions controls at its Willowbrook plant, which had sterilized thousands of devices daily until its Feb.15 shutdown. The plant had sterilized 594 types of devices, including sutures, clamps, knives, stents and needles and its shutdown sent medtech makers — particularly smaller and mid-sizes companies — scrambling for different sterilization sites. Sterigenics is also continuing its lawsuit against the state, seeking to reopen the plant.
Meanwhile, the FDA has set a deadline of October 15, 2019 for submissions to its two challenges.
“It’s just one of those things where it’s a wait-and -see,” Crist said of the EO regulation scenario. “We’re making the case and we’re talking to folks, but we’re not getting any indication of much of anything. That’s about wall we can do right now.”