Regulatory bodies worldwide require clinicians to sterilise medical devices to protect patients from the risks of infectious diseases caused by bacteria, viruses, and fungi.

Various sterilisation methods exist in the medical device space, including steam sterilisation, peracetic acid immersion, low-temperature plasma sterilisation, UV-C light and ethylene oxide (EtO).

Yet, with more awareness about the dangers of EtO, companies are striving to be at the forefront of the medical tech industry by innovating new sterilisation technologies and processes to progress beyond the widespread use of EtO.

EtO is a gas used to sterilise medical equipment that cannot be achieved through steam or radiation. It is typically produced in large volumes at chemical manufacturing facilities. According to the US Environmental Protection Agency (EPA), it is the only safe and effective sterilisation method available for some devices.

However, despite its widespread use, EtO is a human carcinogen, the EPA confirms. In August 2022, the agency released plans to progress understanding of the risks posed by air emissions of EtO from commercial sterilisers. Along with reviewing its current air regulations, the EPA has stated its aims to learn more about the chemical and address its use.

“Even though medical sterilisation accounts for less than 1% of all industrial uses of EtO, one area of focus has been on innovations to reduce EtO emissions further,” says Troy Kirkpatrick, spokesperson for BD.

However, EtO sterilisation is considered a niche problem, with tech developers facing inertia from the wider health industry. Responses to the Covid-19 pandemic struggled to go beyond meeting the individual needs of health providers rather than standardising sterilisation to move away from EtO. 

“Today, about 50% of all medical devices are sterilised using EtO because EtO is the only option for a large number of medical devices due to material sensitivities and/or design complexity,” explains Kirkpatrick. Applying EtO to approximately 50% of sterile medical devices amounts to around 20 billion devices sold annually in the US, the FDA says.

Alternative sterilisation approaches

Following the closure of sterilisation solutions company Sterigenics’ Willowbrook facility due to a high concentration of EtO in nearby air, the US Food and Drug Administration (FDA) launched multiple pilot programmes to streamline updated sterilisation methods, re-evaluate dosing requirements, and launch numerous innovation challenges.

On 15th July 2019, the FDA launched an innovation challenge to identify new sterilisation methods and technologies as an alternative to EtO and to reduce EtO emissions. Describing the FDA’s selection of BD’s proposal into the programme as “a critical step,” Fitzpatrick says it enables the company to continue to improve upon and ensure the continued safe use of EtO by combining process/cycle optimisation and facility design changes.

To respond to EtO concerns, tech developers and the wider healthcare community are looking for alternative sterilisation methods for medical devices. “The industry is looking for a modern technical change in the medical device space that demonstrates certain specific characteristics desired for sterilisation,” says Dr Halden Shane, CEO of TOMI Environmental Solutions. These desirable factors include a fast treatment speed, less corrosion, and a smaller micron that moves like a gas.

The sterility assurance level (SAL) refers to the probability of a single viable microorganism on an item after sterilisation. SALs can estimate the microbial population the sterilisation process will destroy.

A smaller micron, Shane says, “allows a product to get into the smallest space and simultaneously deliver a consistent six-log and greater kill on the medical device and in the cleanroom space”. As each log reduction indicates a 90% decrease in the microbial population, a process that achieves a six-log reduction will theoretically lower a population from a million microorganisms to very close to zero.

Evolving beyond standard sterilisation

There is an increasing concern for patient safety, a top priority for healthcare providers, clean rooms, and regulatory agencies. “The risk of healthcare-associated infections (HAIs) and novel pathogens is a significant concern, and the adoption of effective sterilisation technologies is critical in reducing the spread of these infections,” says Shane. Disinfection technologies help reduce the risk of HAIs and control unknown pathogens and enhance patient safety.

Environmental safety is also high on the agenda. Healthcare providers, clean rooms and regulatory agencies are looking for a small carbon footprint with reduced toxic by-products.

With increasing cost pressures in healthcare, there is growing demand for efficient and cost-effective sterilisation methods. Technologies can disinfect surfaces and devices, reducing the risk of HAIs and the need for costly reprocessing of devices. Disinfection technologies can decontaminate surfaces and devices quickly and effectively, preventing wear and tear on the equipment and reducing the need for multiple disinfectants while saving time and resources.

“Medical devices are becoming more complex and delicate, making traditional sterilisation methods like autoclaving less effective,” says Shane. The industry, therefore, needs new sterilisation technologies to ensure these devices are effectively disinfected and decontaminated without damage.

Compliance with regulatory standards is another core driver of new sterilisation technologies, presenting a competitive advantage and expanding market opportunities. “The medical device industry is highly regulated, and compliance with regulatory standards is essential for product approval and market access,” says Shane.

New sterilisation tech is also coming to the fore in response to infectious disease outbreaks, highlighting the need for effective disinfection and sterilisation in healthcare and cleanroom settings. Shane says these environments have adopted disinfection technologies worldwide “to help control the spread of infectious diseases, neutralise chemical and biological weapons, and decontaminate dangerous weaponised agents”.

Solving sterilisation limitations

Post-pandemic, the need for sterilisation technologies has increased to minimise adverse health implications. Addressing cost pressures in healthcare is also a key area that innovators are keen to solve. “The use of disinfection technologies can help tackle cost pressures in healthcare by enhancing efficiency and reducing the need for extra labour while delivering 6-log decontamination,” says Shane.

Adopting innovative disinfection and decontamination technologies can help to overcome sterilisation challenges. Resistant microorganisms are at the core of spurring new disinfection technology development. Manufacturers seek to produce effective solutions against highly resistant microorganisms, reducing the risk of infection.

“Traditional sterilisation methods may damage delicate medical devices,” says Shane. Newer sterilisation and disinfection methods can answer these problems and avoid causing damage to delicate medical devices.

Potential to progress

“Automation plays a significant role in the future of sterilisation,” says Shane. Automation technologies can be used to integrate products into medical device manufacturing processes and cleanrooms, reducing the risk of contamination and increasing the efficiency of the sterilisation process.