ARDMORE – Ethylene oxide has been used to sterilize medical equipment for about four decades. According to the Food and Drug Administration, it is the only method available for many medical devices without damaging them. About half of all sterile medical devices in the United State are treated with the chemical each year.

LEMCO Ardmore has been providing this type of sterilization since the 1990s and is the local part of an industry now being scrutinized because of health risks associated with ethylene oxide. The Environmental Protection Agency on Tuesday, Oct. 18, held an open house to answer any questions about ongoing studies of ethylene oxide emissions from that Ardmore facility.

“It’s really just to inform the community and talk to the community,” said Jeff Robinson, a manager with the EPA’s Region 6.

The open house was the next step in the agency’s effort to monitor pollution and inform the public of potential dangers. Sustained exposure to ethylene oxide has been found to cause several cancers, including non-Hodgkin’s lymphoma, myeloma, and lymphocytic leukemia, according to a 2020 EPA risk assessment.

The Ardmore facility is one of about 100 such facilities across the country and the only one in Oklahoma currently being further examined by the federal agency. Robinson estimated there are about a dozen similar facilities across the EPA’s Region 6 and said LEMCO Ardmore was fairly standard among them.

Most of the questions posed by the public during the open house primarily focused on exposure, health risks, and the facility itself. Organizers estimated about 20 people had visited the open house on Tuesday evening.

An EPA program in 2016 updated the cancer assessment for ethylene oxide and characterized it as carcinogenic to humans if inhaled. Late last year, the agency announced LEMCO Ardmore was among 29 facilities nationwide that would be required to extend Toxics Release Inventory (TRI) reporting requirements.

“The EPA determined there is a population of approximately 25,712 within a five-mile radius of this facility, including approximately 1,800 children under five years old. The EPA also estimated there are at least 11 schools within a five-mile radius of the facility,” reads a December 2021 document from the EPA.

Risk assessment information provided at Tuesday’s open house was based on information from July 2022. Robinson said the agency relied on self-reported data from facilities and uses it to compile a human exposure model.

“That model factors in meteorological data for a given area, it factors in emissions and what we know about those emissions from a given facility, and it projects a risk once you run the model. For ethylene oxide, it typically is rather localized,” he said.

The model provided by the EPA shows a risk gradient surrounding the facility near Oklahoma Highway 77 just south of U.S. Highway 70. The highest risks in the sparsely population section of the county are immediately surrounding the facility, where two cancer cases could develop if 10,000 people were exposed to the air 24 hours per day for 70 years.

Robinson said that the EPA is required by the Clean Air Act to regularly reevaluate industrial sectors to determine if residual risks are still posed by emissions. These evaluations, done roughly every eight years, can help reduce or even eliminate risks posed by air pollution.

“That’s actually the process of what we’re doing right now. We’re doing a risk technology review and evaluation, and potentially we will propose new rules in the coming months for this particular sector,” he said.

If and when new rules are proposed for the industrial sector, further hearings and open houses would be held for public review.