The Rebuttal for Ethylene Oxide

If you’re involved in the development of orthopedic devices (well, just about any medtech), you’ve undoubtedly heard of the concerns regarding the use of ethylene oxide (EtO). Sterilization facilities have closed due to questions over unsafe levels of the chemical in the air. The EPA is keeping a close eye on its use and impact on neighboring communities. Undoubtedly, lawsuits will be filed and we may even see the permanent closure of some EtO sterilization providers when the situation is finally resolved.

As a result of eliminating any potential threat EtO may be causing, a new problem emerges. EtO is a chemical used in the sterilization of medical devices (most estimates have it as being used for 50 percent of all products). If EtO is deemed no longer  acceptable for sterilization, firms will need to scramble to determine a new protocol that could be used for their products. Further, that new protocol will need to have the available capacity among current providers to handle the influx of new customers, which is highly unlikely.

Perhaps as an attempt to curb this potential outcome, AdvaMed reached out to a toxicologist—Gail Charnley, Ph.D.—to offer some clarity on the issue, and why EtO levels were suddenly being considered unsafe. Dr. Charnley is a principal at HealthRisk Strategies, a D.C.-based firm that provides independent scientific and policy analyses of issues relating to the assessment, management, and regulation of public health risks from chemical exposure.

Dr. Charnley penned a sort of open letter to the public entitled “The Truth About Ethylene Oxide” (visit http://bit.ly/odt200150 to read the full version). In it, she presents her qualifications and history as an independent scientist who adheres to the facts and the science (read: was not “paid off” by AdvaMed to present a pro-EtO opinion). While she has worked for the medtech industry, Dr. Charnley has also worked for non-profit organizations as well as government.

Given her qualifications, I found several items in the letter to be interesting enough to share and to help put the supposed dangers of EtO into a clearer picture.

“No doubt, scientific truths are desperately needed in the public dialogue. The most important truth being, there is no cancer threat from the tiny amounts of ethylene oxide released from these sterilization plants,” said Dr. Charnley. This statement made early in the letter seems to immediately call into question the entire reason behind the closure of several facilities. Were the environmental agencies too hasty in their actions? If so, why?

Dr. Charnley provided a reason: “Ethylene oxide is suddenly getting attention because an office within the EPA changed the way it calculated the amount it considers safe to breathe. No new science was used, just new math. Whether that change was justified is debated by scientists.”

The question remains whether the prior threshold was deemed unsafe, but Dr. Charnley stated there was no new science, so it doesn’t appear that new research was performed that determined the old measurement was wrong. Instead, a new way to calculate the chemical’s safe level was used.

Dr. Charnley went on in the letter to clarify the new measurement in a more understandable manner. “If valid, the new calculation means that the amount of ethylene oxide that we make normally in our bodies is almost 20,000 times higher than what would be considered safe to breathe. It would mean that the average amount of ethylene oxide normally found in urban and suburban air, including areas with no sterilization plants, is about 5,000 times higher than would be considered safe.”

I’m not sure what to make of the statement regarding the amount of the chemical within our bodies, but the comparison to EtO in urban and suburban air when no plant is in the area is telling. How does the EPA address that matter and, more importantly, if that level is considered dangerous, what is to be done about it? What is the source of the apparently hazardous levels of EtO if there is no sterilization facility in the area?

“Due in part to the disagreement in the scientific community about this new calculation, the U.S. EPA hasn’t used the new number to regulate anything. The number is over 5 million times more stringent than the scientific judgments underlying all other regulatory limits on ethylene oxide in the U.S. and worldwide,” added Dr. Charnley.

She goes on to be understanding of the public’s concern and sympathetic to the reaction people are having to being told their air is unsafe.

Whether one chooses to believe the explanations Dr. Charnley provided in her open letter or not, it’s apparent further discussion and research needs to happen before we make a final decision on this sterilization technology.  

Sean Fenske, Editor-in-Chief
[email protected]