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Understanding Disinfection Lighting

How LED luminaires can complement disinfection strategies in foodservice applications

 

It’s common knowledge that LED lighting uses considerably less energy than legacy lighting sources. Owners and operators of industrial and commercial facilities are also becoming more comfortable and confident in emerging lighting controls technology beyond simple occupancy sensors and dimmers. LED technology presents exciting opportunities because an LED fixture is akin to an iPhone in the ceiling and customers can relay on/off, occupancy, color and dimming commands to these fixtures in an automated or manual manner.

 

Yet, today, LED lighting can also play a significant role in helping to keep an area, room or facility clear of bacteria. This concept of disinfecting through the use of light is actually not new. Hospitals have been disinfecting patient rooms for years with ultraviolet (UV), which utilizes 250-265 nm wavelengths. While certainly effective, this technology is unfortunately harmful to humans and many inorganic materials. Exposure to these wavelengths can cause severe damage, limiting its use in applications where the area is occupied by humans or sensitive materials.

 

The disciplines of lighting science and microbiology have over time been able to converge to create new technologies that combine white and narrowband 405 nanometer (“nm”) visible light to meet ambient and task lighting requirements while providing a continuous, unobtrusive disinfection option for foodservice operations.

 

The development of antimicrobial lighting should serve as welcome news for owners and operators in the US food industry where there’s an estimated $77 billion economic loss incurred from recalls related to foodborne illnesses every year.

 

The development of antimicrobial lighting should serve as welcome news for owners and operators in the US food industry where there’s an estimated $77 billion economic loss incurred from recalls related to foodborne illnesses every year. While rigorous food safety practices reduce the risk associated with these illnesses, they aren’t 100 percent foolproof since foodborne illness outbreaks continue.

 

Such ongoing problems could be caused by employee error, supply chain partner oversight, ineffective cleaning techniques, unacceptable hygiene, inadequate pest control or any number of other difficult to pinpoint causes. However, despite the difficulty in determining the exact cause, studies show that an average outbreak recall costs for food production organizations can exceed $100 million. This includes direct and indirect costs.

 

 

The Opportunity for Lighting

With antimicrobial light, the germicidal effects of such narrowband visible light can suppress a wide range of bacteria, molds, fungi and yeast. This light induces the production of damaging reactive oxygen species in harmful microorganisms to accelerate cell inactivation. Antimicrobial disinfection through illumination is proven effective with proper dosage levels on pathogens suspended in air or attached to a variety of surfaces, materials and objects.

 

Antimicrobial light also reduces or possibly eliminates the need for harmful chemicals. Being chemical free, certain disinfection lighting solutions are able to avoid the introduction of harsh residues or films to the application. In the case of food production and manufacturing facilities, the antimicrobial light is able to not accelerate spoilage or the integrity of the food.

 

The microorganisms treated by disinfection lighting technology include E. coli, Salmonella and Listeria. Surface microorganism include MRSA, Staph and various skin infections.

 

Disinfection Lighting Strategies

Options now exist for selecting specific modes of operation as directed by the needs of the application.

 

If the facility, area, or space is occupied continuously every day of the year, the option of blending the disinfecting light with the working light of a luminaire can allow heavily trafficked areas, such as office environments, transportation hubs and public restrooms, to be discreetly cleaned while maintaining the appearance of a traditional white LED source.

 

In areas with predictable occupancy schedules, disinfection lighting luminaires can be controlled to operate in a visible light disinfection mode during times when the area is free of workers and visitors. When the area is re-occupied, the luminaire can be returned to its combined white light state for ambient lighting and continuous disinfection. For example, food processing facilities may operate in visible light disinfection mode during breaks and production downtime. Commercial kitchens may choose this mode for time periods outside of normal work shifts.

 

If targeted, continuous disinfection is needed, visible light disinfection lighting can also be configured independent of white ambient lighting for high intensity disinfection in strategic areas where contamination risk is high.

 

Supporting Efficacy

It’s important to remember this technology should always be regarded as supplemental to a broader disinfection strategy. Although it does add a layer of protection to best practices already in use and automatically treats harmful microorganisms suspended in the air, trapped on objects and residing on surfaces through special luminaires, it is not designed to replace legacy protocols.

 

This technology has potential benefits for many commercial lighting applications. Through the blending of disinfecting light with the working light of a luminaire, heavily trafficked areas in the foodservice industry and beyond can be discreetly cleaned while maintaining the appearance of a traditional white LED source.

 

By Jeff McClow, Product Manager, Hubbell Lighting