By William Anderson, University of Waterloo; Tatiana Koutchma, Agriculture and Agri-Food Canada; and Richard Dixon, Coalition for Community and Healthcare Acquired Infection Reduction (CHAIR)
In response to concerns raised during the SARS-CoV2 pandemic, Health Canada’s Pest Management Regulatory Agency (PMRA) issued a new regulation for the approval of ultraviolet germicidal (UV-C) light devices, including those for surface treatment. The purpose of the regulation, in part, was to ensure that devices sold in Canada made claims about disinfection efficacy that were supported by validated testing.
The UV industry and researchers have struggled for years to get credible and consistent research data for surface and air disinfection to support such regulatory and end-user needs. The factors that can affect efficacy testing are multiple and well known, ranging from the target microbe to surface concentration, surface morphology, angle of UV incidence and many more. The lack of dose-response data for surfaces (and widely varying methods for making these measurements) imposes a barrier for those wishing to meet regulatory requirements. It also is recognized that having reliable dose-response data for surfaces eventually can lead to quantitative microbial risk assessment practices, analogous to those that have developed in the UV-C water disinfection field.
Benefits of UV-C in Healthcare and the Food Industry
The safe use of UV-C devices showed great benefits to healthcare and other industries that include:
- Significant reduction in pathogens and other organisms on surfaces, which in turn reduces the transmission of harmful pathogens from one surface to another.
- Controlled microbial reduction, which is the focus of the Quantitative Microbial Risk Assessment (QMRA).
- By applying UV-C disinfection to reduce harmful pathogens, the incidents of Healthcare Acquired Infections (HAI’s) and patient deaths will decrease.
- Savings can be obtained in the cost of treating infections that cause an increased length of stay in a healthcare facility well beyond insurance implications.
- The ripple effect is more beds will be available to see the surplus of patients waiting to be admitted.
UV-C also is used widely in the food industry, and its use has the following benefits:
- Longer shelf life of products, which decreases food waste with a corresponding financial impact.
- Control of food pathogens that result in safer products and safer consumers.
- Efficient as a disinfection step for food processing, storage and transportation facilities.
- Better quality products due to the nonthermal, nonionizing, nonchemical nature of UV-C light.
Assembling the Team
The Coalition for Community & Healthcare Acquired Infection Reduction (CHAIR) was asked by Health Canada to serve as the project manager for a new effort to overcome the data barriers. This would be based on a standardized dose response testing protocol at different UV-C wavelengths that would include varieties of commonly known bacteria, viruses, spores and fungi. CHAIR accepted this invitation as a challenge to search and scientifically justify the best solution that would benefit all Canadians and national/international UV companies and prospective end users of UV-C technologies.
The steering committee of this project includes membership from the International Ultraviolet Association (IUVA), experts from the US and Canada – Dr. Ashish Mather and Dr. Wladyslaw Kowalski, and medical microbiologist Dr. Elizabeth Bryce, with experience in Engineered Infection Prevention strategies. Also participating is Dr. Ted Mao, president of the IUVA, and several disinfection experts from Health Canada’s PMRA. Research will be done by partners at the University of Waterloo, including Dr. William Anderson, who has extensive research experience in UV-C processes, with input from Dr. Tatiana Koutchma, an expert in UV applications for food and beverages at the Guelph Food Research and Development Center of Agriculture and Agri-Food Canada. Several participants from Health Canada (PMRA) also are included in this project steering committee. The project manager is Richard Dixon, co-founder of the CHAIR.
Research Plan and Proposal
The steering committee has prepared a research proposal to funding agencies for the project and has begun work on finalizing suggested protocols for dose-response testing on surfaces. This project is intended to help remove barriers and accelerate UV-C device registration by developing established protocols and compiling data sets of results that can be used by all parties in the registration and evaluation process.
The steering committee recognizes the multitude of factors affecting dose-response microbial disinfection testing on surfaces. A plan that measures the effects of all factors across multiple microbes and wavelengths clearly is impractical at present, and a narrower vision has been assembled. Even the choice of target microbes is complicated as different groups have varying opinions and the pathogens of interest vary with the regulator and prospective end users of UV-C disinfection.
Taking these various issues into account, the research plan currently focuses on: 1) a select set of bacteria, viruses and fungi that cover a reasonable range of regulator and end-user interests, as well as varying UV-C sensitivities; 2) a standard set of test conditions on stainless steel surfaces, considering existing insights from literature and ASTM, ASHRAE and British Standards; 3) UV-C wavelengths at the far-end, 254 nm and slightly higher to include LED technologies; 4) best practices for UV-C radiometry and actinometry to ensure accurate UV-C dose measurements; and 5) some limited testing of surface, soil and other effects to roughly quantify their potential impact to provide insights into the limitations of these dose-response measurements in various practical situations.
Industry Feedback
As part of the outreach and consultation process, CHAIR and several steering committee members attended a strategic-type planning meeting with the IUVA at the offices of the National Institute Standards and Technology (NIST) in Washington, DC in March 2025. This group included approximately 80 researchers and other professionals in the UV area from around the world. There was a very high degree of support for the Canadian-based project as one that can become a benchmark testing process that may be used for the Health Canada regulatory process, as well as other international purposes, in combination with current standards. Valuable feedback was received from the NIST workshop to help guide and inform the research project as it eventually unfolds.
Also at this meeting, the participants went through a series of discussion group formats and concluded the energy of IUVA in the future should focus on two key issues:
- Efficacy – provide suitable research studies that focus on the efficacy of UV-C that can be used in the development of regulations and standards
- Education – development of written materials, videos and workshops that explain the research to build trust with end users to create an evidence-based format for the sale, installation and safe use of UV-C devices
Timeline and Future Use
Once the project funding is approved, it will take approximately 1.5 years of testing and analysis to complete the body of results and recommendations, although preliminary results will be presented to the wider UV-C community as they become available for feedback. The report will be turned over to the project’s partners at Health Canada for use in UV-C regulation and will be published for public use as a guideline or benchmark for national or international purposes. Colleagues at the Canadian PICNet, Canadian Standards Association, IPAC Canada and others will be interested in the research and documents for use in multiple healthcare standards.
Through this effort, it is anticipated that the UV-C industry will be able to obtain timely approval of their products via Health Canada (PMRA) for use in a wide variety of healthcare and other applications as a significant nonchemical adjunct to traditional cleaning and disinfection of surfaces. The use of UV-C will lower Healthcare Acquired Infections (HAIs) and other infections, with targeted applications developed through a Quantitative Microbial Risk Management process. This project will provide essential data to promote UV technology and communicate its advantages with international regulators and industry, while also educating research groups and the general public.
