EPA Conclusion on Sterilizer Could Disrupt Medical Device Supply, Companies Say

By Pat Rizzuto

Nov. 14 — If the Environmental Protection Agency issues as final its draft conclusion that ethylene oxide can cause cancer in humans, the ability to sterilize medical devices will be disrupted, sterilization companies are telling agency advisers.

“The current draft [Integrated Risk Information System] assessment will have significant adverse impacts on the ability to sterilize healthcare products,” STERIS Corp., which specializes in infection prevention and critical care technologies, told the agency's Science Advisory Board (SAB) in comments submitted prior to a Nov. 18-20 meeting about the assessment.

“By inappropriately magnifying the risk associated with the use of ethylene oxide, users could be forced to switch to less effective, impractical alternatives with significant adverse public health consequences,” STERIS wrote.

Sterilization Companies

Midwest Sterilization Corp., Sterigenics International LLC and STERIS Corp. are among the sterilization companies that already have voiced concerns or plan to provide oral comments when the SAB's Chemical Assessment Advisory Committee meets Nov. 18-20 to peer review the agency's draft assessment of the carcinogenic hazards of inhaled ethylene oxide.

The committee will examine the science the agency used and how it used that science to reach a draft conclusion that ethylene oxide can cause cancer when inhaled.

The agency has been trying to update its assessment of ethylene oxide since 1998. A final assessment of the chemical was last issued by the EPA in 1985. At the time the agency concluded ethylene oxide was a probable human carcinogen.

Ethylene oxide primarily is used to make ethylene glycol, a key ingredient in antifreezes, polyester fibers and a plastic used for building materials and bottles. Ethylene oxide also is used to sterilize medical instruments and fumigate spices, the agency said in a draft, updated toxicological review released Aug. 15.

More Than 5.8 Billion Pounds Produced

Eleven chemical manufacturing plants owned by companies including BASF Corp., Dow Chemical Co., Eastman Chemical Co. and Shell Petroleum Inc. produced more than 5.8 billion pounds of ethylene oxide in 2011, the most recent year for which production volume data had to be submitted to the EPA.

Medical equipment manufacturer Boston Scientific said it uses ethylene oxide to sterilize 70 percent of its medical devices globally.

Decisions that would restrict the chemical's use would severely affect the availability of 32 million life-saving devices that must be sterilized annually, the company said in comments submitted to the advisory committee.

For many devices, ethylene oxide sterilization is the only option that can effectively sterilize all parts of the equipment, because it can reach deep crevices without the damage associated with other sterilization methods, Boston Scientific said.

The Ethylene Oxide Sterilization Association said the draft IRIS assessment significantly overestimates the hazards of ethylene oxide.

Ethylene Oxide Produced in the Body

People's bodies produce ethylene oxide as they carry out normal physiological processes, the EPA's draft assessment pointed out.

These naturally produced concentrations of ethylene oxide would be considered carcinogenic based on the assessment, the association said.

The association, sterilization companies and other industry organizations said they share concerns voiced by the American Chemistry Council on the ethylene oxide assessment.

The agency used inappropriate risk assessment methods to calculate—and overestimate—the potential of ethylene oxide to cause cancer, the chemistry council said.

Breast Cancer Fund Praises Assessment

Only one health advocacy group, the Breast Cancer Fund, provided oral comments to the Chemical Assessment Advisory Committee during a preparatory meeting it held in September.

“We commend the assessment authors for their unwavering conclusion that the scientific evidence on ethylene oxide exposures demonstrates that “there is strong confidence in the hazard characterization of ethylene oxide as ‘carcinogenic to humans,’ ” Janet Gray, a physiology professor at Vassar College, told the committee on behalf of the fund.

“This conclusion is drawn after a careful evaluation of the human epidemiological data with a special focus and analysis of the large National Institute for Occupational Safety and Health study examining associations between occupational exposures to ethylene oxide and subsequent incidence and mortality rates,” she said.

To contact the reporter on this story: Pat Rizzuto in Washington at prizzuto@bna.com

To contact the editor responsible for this story: Larry Pearl at lpearl@bna.com

Information about the advisory committee's Nov. 18-20 meeting including copies of comments submitted prior to the meeting are available at http://tinyurl.com/o2tj9v8.