中文The medical device industry is actively searching for alternatives to ethylene oxide (EO) sterilization, and chlorine dioxide is emerging as one of the most promising candidates. New guidance from the Association for the Advancement of Medical Instrumentation (AAMI) and growing regulatory pressure in the United States are pushing manufacturers to evaluate new modalities that can protect patients while reducing environmental and occupational health risks.
Ethylene oxide has been the workhorse of medical device sterilization for decades because it works at low temperatures and penetrates complex device geometries. However, EO is also a known carcinogen, and emissions from sterilization facilities have come under increasing scrutiny. The U.S. Environmental Protection Agency’s recent proposals to tighten and then relax EO emissions rules have created uncertainty, prompting lawmakers, healthcare providers, and manufacturers to look for alternatives.
AAMI’s paper “Alternative Sterilization Modalities to EO: Let’s Compare & Contrast” notes that legacy alternatives such as moist heat, dry heat, radiation, and liquid chemical sterilization can replace EO when device materials and packaging are compatible. But for heat-sensitive devices, moist and dry heat are often unsuitable because of their higher processing temperatures. Radiation is already widely used, accounting for roughly half of all medical device sterilization, yet manufacturers continue to seek additional options.
Chlorine dioxide (ClO₂) gas sterilization is gaining attention for several reasons. During a recent TÜV SÜD webinar, Emily Lorcheim, vice president of sterilization technologies at Clordisys Solutions, explained that chlorine dioxide is a yellow-green gas, allowing visual confirmation of its presence during processing. It is water-soluble and behaves as a true gas with a boiling point of approximately -40°C, enabling deep penetration into narrow lumens, microscopic openings, and other hard-to-reach areas within complex devices.
Lorcheim also emphasized safety advantages. Chlorine dioxide is non-carcinogenic and non-flammable, making it suitable for sterilizing devices that contain embedded batteries and sensitive electronics. It operates at relatively low temperatures, which is critical for heat-sensitive products. As an oxidizing agent, it is often described as gentler than some alternatives and is compatible with a broad range of materials, including cellulose-based materials that may challenge other sterilization technologies.
Process efficiency is another selling point. Chlorine dioxide vacuum-pressure sterilizers can process complex devices inside their final packaging, with sterilization and aeration occurring in a single chamber. Cycle times typically range from two to eight hours, potentially shorter than some EO processes. This could help manufacturers improve throughput and reduce work-in-progress inventory.
Packaging compatibility is, of course, essential. In a webinar hosted by Oliver Healthcare Packaging and Clordisys, Lorcheim discussed how gas permeability determines whether a package can be sterilized with chlorine dioxide. Fully sealed foil pouches are unsuitable because the gas cannot penetrate, but foil pouches with Tyvek headers can be processed. All-Tyvek pouches and film-based pouches with Tyvek components are generally compatible, as are secondary packaging materials such as paperboard, fiberboard, corrugated boxes, and instructions for use.
Jeremy Elwell, director of packaging engineering at Oliver Healthcare Packaging, reported positive results from joint compatibility studies across coated and uncoated Tyvek, medical-grade paper, corrugated materials, and polyester- and nylon-based pouch films. He identified two common concerns for vacuum-based gas sterilization: film delamination and seal creep.
Film delamination occurs when layers within a multilayer film separate after sterilization. Although usually cosmetic, it can concern customers. Adhesive-laminated films tend to resist delamination better than coextruded alternatives. Seal creep can occur when sterilization cycles combine vacuum, heat, and low-porosity materials. Manufacturers can mitigate this by ensuring adequate package porosity and optimizing package design for the specific process.
Regulatory pathways for chlorine dioxide are still developing. Jami McLaren, senior principal engineer at Johnson & Johnson, noted during the TÜV SÜD webinar that AAMI TIR17 has been expanded to include a dedicated section on chlorine dioxide sterilization, along with annexes addressing modality changes and material compatibility assessments. Industry groups such as the International Scientific Exchange and the Kilmer Collaboration are working to generate data that could support future ISO standardization.
A key initiative is the development of a centralized material compatibility database that documents how device and packaging materials respond to different sterilization processes. If made publicly accessible, such a database could help manufacturers evaluate compatibility more efficiently and reduce the time and cost of switching modalities.
Chlorine dioxide is unlikely to replace EO entirely. Many devices and materials will remain best suited to ethylene oxide or radiation. But as regulatory pressure and sustainability concerns grow, chlorine dioxide offers a compelling additional option: low-temperature processing, broad material compatibility, shorter cycles, and compatibility with many common packaging formats.
For packaging teams, the takeaway is that sterilization strategy is becoming a more dynamic and cross-functional discipline. Material selection, package design, and sterilization validation can no longer be treated as isolated decisions. Teams that understand the full landscape of emerging modalities will be better positioned to support device manufacturers through the transition.
Source: Packaging Digest
The packaging design community will need to become more literate in sterilization science. Historically, packaging engineers selected materials primarily for protection, appearance, and cost. In the future, sterilization modality may influence material choices earlier in the development process. This could lead to closer collaboration between packaging designers, device engineers, and sterilization specialists from the earliest stages of product development.
As more data becomes available and regulatory standards mature, chlorine dioxide could move from an emerging option to a mainstream modality for a significant subset of medical devices. The next few years will be critical. Manufacturers that invest in understanding the technology now will be better prepared to validate products and secure market access as the regulatory landscape continues to evolve.
