Medtech manufacturers Boston Scientific (Marlborough, MA) and 3M Health Care (St. Paul, MN), along with sterilization companies and industry associations, warn that an EPA draft conclusion stating that ethylene oxide (EO) can cause cancer in humans could, if finalized, seriously disrupt the availability of life-saving medical devices. EO is one of the primary forms of medical device sterilization, used to process more than 56% of all medical devices, according to industry estimates. "Restricting the use of EO as a viable sterilization method would severely impact the availability of approximately 32 million devices sterilized annually, many of which are life-saving," notes Boston Scientific in comments submitted to the EPA's Science Advisory Board (SAB).

The SAB's Chemical Assessment Advisory Committee (CAAC) met on Nov. 18 to 20 to evaluate the Integrated Risk Information System (IRIS) draft assessment of the carcinogenic effects of inhaled EO. In 1985, the EPA concluded that EO was a probable human carcinogen, and it has been trying to update this assessment since 1998, according to Bloomberg BNA.

Specifically, the EPA's primary goal in regards to the revised draft assessment is to examine the cancer risks of low exposure concentrations of EO and to estimate the cancer risk of occupational exposure to EO, writes Med Device Online. The agency's secondary goal is to review the accuracy, objectivity, and transparency of the revised draft.

EO and its derivatives are used to make plastics and countless products such as antifreeze, polyester fibers, and building materials. A small but important use of the chemical is in the sterilization of medical products, says the American Chemistry Council.

"EO sterilization is the primary method approved by the FDA to reduce microbial contamination and the attendant risks of infection from viruses, bacteria, and fungi, wrote Boston Scientific in its comments addressed to the SAB on Nov. 11. "It is one of the most commonly used sterilization methods of the medical device industry, and counted on by manufacturers, doctors, and patients around the world. Boston Scientific uses EO to sterilize 70% of its devices manufactured globally, and restricting the use of EO as a viable sterilization method would severely impact the availability of approximately 32 million devices sterilized annually," noted the medical device manufacturer.

In its comments to the committee, 3M Health Care (St. Paul, MN), which manufactures EO sterilization equipment and accessories, stressed that EO has been used for more than 50 years as the primary method for sterilization of heat- and moisture-sensitive medical instruments. "It is the most efficient sterilant for these medical devices because of its ability to penetrate complex geometries such as lumened devices," 3M Health Care added. "With the increased focus on reducing health-care associated infections and lower overall healthcare costs, EO is an important option that needs to be available to health care facilities."

Regarding occupational exposure to the chemical, 3M Healthcare notes that a number of standards exist that include guidelines for facility design, installation, maintenance, staff training, quality control, and environmental monitoring.

In essence, the Ethylene Oxide Sterilization Association and stakeholders in the medical device supply chain question the risk assessment methods used by the EPA, claiming that the potential of EO to cause cancer is overstated. "We strongly encourage the CAAC to carefully consider the potential impact of the IRIS assessment and weigh the risk/benefit analysis on the ability to provide sterile medical products to healthcare providers and the patients that need them," said Boston Scientific.

— Norbert Sparrow

Norbert Sparrow is Senior Editor at PlasticsToday. Follow him on twitter @norbertcsparrow and Google+.