From the patient gown in a doctor’s office to the surgical kit in open heart surgery, everything used on, in, or by patients and doctors must be sterile. That’s critical to preventing dangerous infection. Sterility isn’t synonymous with cleanliness. Sterile is sterile, period.

Most of us don’t think about that when we go in for a medical procedure. However, medical technology experts think about it constantly. One, they’re in the business of saving lives. Two, they must prove device sterility as part of FDA approval.

One of the most common methods of sterilizing medical devices is ethylene oxide (EtO) gas. A lack of public information about this method persists. That’s why I talked with Dr. Lucy Fraiser, a board-certified toxicologist, about the facts.

Dr. Fraiser explained why EtO sterilization is a common choice.

Other methods, such as steam, would destroy the devices, make them unsafe for patients, or both. EtO works for “critical medical devices that are both moisture- and heat-sensitive,” Dr. Fraiser said.

Consider a single-use syringe for administering a flu shot or COVID-19 booster. Steam heat would melt the plastic. EtO sterilization preserves the device and penetrates the interlocking parts – the plunger and barrel.

Dr. Fraiser pointed out how EtO can penetrate packaging layers. That’s effective and efficient for maintaining timely patient care, helping to ensure hospitals are well-stocked.

“… there are many, many sources of ethylene oxide [in the air] besides sterilization facilities.” 

––Dr. Lucy Fraiser, board-certified toxicologist

Dr. Fraiser described EtO sources in the air.

The substance occurs naturally, such as from decaying vegetation, in addition to its commercial production and emissions as byproducts of lawn mower and fire pit use. EtO’s use to sterilize medical devices is less than 1 percent of all commercial use.

“ … there are many, many sources of ethylene oxide [in the air] besides sterilization facilities,” she said.

She reacted to the EPA’s release of a list of 23 EtO sterilization facilities the agency sees as posing an elevated health risk to local communities.

The agency has used verbal language in community meetings raising alarm among neighbors, in contrast with separate language qualifying its findings as using a worst-case scenario assuming “people living nearby are breathing air containing EtO 24 hours a day for 70 years.” Dr. Fraiser said, “… the problem with that approach is that if the public hears that they’re at risk from facility emissions without hearing that ethylene oxide in the air is already higher than the ethylene oxide that’s contributed by the sterilizers, they are, understandably, going to be more alarmed than if they knew that ethylene oxide was in the air all around.”

The EPA has a job to do. So does the FDA and so does the medical technology field. We all have different functions but our goal is the same: Protecting public health. The medical technology field will continue to inform discussions on EtO with insights into its safe use to protect patients at hospitals and in doctors’ offices nationwide.

Dr. Lucy Fraiser is a board-certified toxicologist with over 30 years of experience. She specializes in air quality health evaluations and has worked in both the public and private sectors. Now, as an independent consultant, she works with clients including local governments with ethylene oxide sterilization facilities in their communities. Dr. Fraiser also has testified before the Illinois House and Senate. She has provided detailed presentations to community members, local regulators, and the EPA on ethylene oxide health effects.

Listen to the full episode of the Medtech POV Podcast.