The Illinois Environmental Protection Agency on Friday issued a permit to Sterigenics to begin construction to update emissions controls at its Willowbrook medtech sterilization plant.
For the plant to reopen, Sterigenics must submit plans for emissions testing and air monitoring to the state EPA. It also must provide the state agency with certification from each device’s manufacturer that ethylene oxide (EO) processing is the only available sterilization method for that device.
The state EPA abruptly shut down the Willowbrook plant in February, citing excessive emissions of the sterilant EO, a colorless, odorless gas known to cause cancer. The plant sterilized millions of medical devices annually — 594 types of devices, according to the FDA, including sutures, clamps, knives, stents and needles — and its closure left medtech companies scrambling for alternatives and the FDA concerned about shortages.
The construction permit allows Sterigenics to begin emissions control upgrades on one of its two EO plants in Willowbrook. Required improvements include installing a permanent total enclosure, capturing all ethylene oxide emissions from Willowbrook I, and installing additional air pollution controls to reduce emissions by 99.9% or to 0.2 parts per million.
Emissions will be limited to 85 pounds per year. This compares with Sterigenics’ reported annual emissions from 2006 to 2018, which ranged from 2,840 pounds to 7,340 pounds per year, according to the state EPA. The Willowbrook facility emitted approximately 380 pounds of EO per year when it was most recently operating, according to the company.
Sterigenics declined to comment on when construction at Willowbrook would begin or end. The updates will have to comply with Illinois’ strict new emissions law that requires demonstrating 100% capture of all EO emissions. A copy of the final construction permit is available on the Illinois EPA’s website, here.
“This is the first step in a lengthy process, and only following strict testing and monitoring requirements would the facility be permitted to operate,” said Illinois EPA director John Kim in a news release. “As we move forward, the Illinois EPA will continue to provide technical guidance to legislators as they draft further legislation to strengthen their initial law.”
EO is popular for medtech sterilization because it works at low temperatures and can penetrate device packaging, speeding the process and keeping costs down. The FDA issued a pair of challenges in July 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 did not immediately respond to an inquiry about the number of responses it has received.
Current alternatives include nitrogen dioxide, another low-temperature, gaseous sterilization method, and vapor-based peracetic acid. 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.