Germicidal UV Light Technology
Updated: Sep 26, 2022
Will it Keep Our Food Transportation Safe?
Since the novel coronavirus pandemic has wreaked havoc on our world, the use of germicidal UV light (or UV-C light in the range of 200 to 400 nm) has emerged as a viable, effective method of preventing contamination and transmission of pathogenic organisms. Here at Healthy Trailer, we’ve relied on UV-C’s disinfecting power for a few years now in our trailer sanitation business. As new stories pop up and people call to tell us they have read about another use of UV-C technology, we are really not surprised.
This technology has been around for years. UV Technology’s website has a great article on UV-C’s history from the late 1800’s to present. Just as we are seeing UV-C being used in today’s determined struggle against the novel coronavirus, it seems that UV-C’s historical role has been a ‘no touch’ engineering solution in fighting a serious public health crisis.
Hospitals... and Planes, Buses and Ships?
Recently many of the discussions about where UV-C light has had the most valuable application is in the healthcare environment. But passenger transportation industries also have implemented the use of germicidal UV-C light to combat disease transmission.
We mentioned in our Healthy Trailer UV Story how the GermFalcon is being used to disinfect high touch surfaces in airplane cabins. And here is the story about how China put the disinfection power of UV-C light to work in its passenger buses. Both stories highlight the benefits of this chemical free, organic means of disinfection.
How about the marine industry? UV-C light is utilized in disinfecting a ship’s bilge water system. Ships serve the transportation industry much like our trucks and trailers do. They too have a UV-C solution that reduces risks associated with their transportation practices.
To provide stabilization and maneuverability during cargo loading and unloading, ships have a water ballast system that pumps water in and out of its tanks. These systems are regulated in the United States by the Coast Guard and the Environmental Protection Agency.
These regulations are intended to prevent cross contamination during the discharge of bilge water systems. Bilge pumps that sucked water in from one port and discharge it in another can cause severe damage when it distributes invasive species and toxic algae into waters at the receiving port.
One of the proven technologies used to reduce these risks is UV-C light in the range of 253 to 257 nm. You can read about it in a blog on the Light Source website. Like our truck transportation industry here at home, the shipping industry is a vital part of our food supply chain. Maybe it’s time to adopt one of their valuable and accepted means of reducing cross contamination and possible disease transmission in our refrigerated trailer transport industry.
How UV-C Works
Understanding the role of UV-C in reducing microorganisms can get technical. To keep it simple, keep in mind that a virus or bacteria is made of DNA and RNA. This is the material that causes microorganisms to reproduce itself.
Germicidal UV-C is ultraviolet light that has wavelengths of 100 nanometers (nm) to 280 nm. Healthy Trailer’s mercury filled lamps are 254 nm, engineered and manufactured by Atlantic UV. They have a great description of UV-C and their technical specs on their website. From their article:
“UV-C light is germicidal – i.e., it deactivates the DNA of bacteria, virus and other pathogens and thus destroys their ability to multiply and cause disease.”
Also UV Solutions Magazine has a recent article called the “Essentials of Germicidal Irradiation for Reduction of Microorganisms.” The author, Jeffrey E. Stines explains, “UV-C wavelengths (200-280) are readily absorbed by the DNA and RNA of microorganisms. When absorbed, UVGI damages the structure of the DNA by forming thymine dimers, which prevent the microorganism from replicating.”
When bacteria and viruses can’t replicate, they die and therefore cannot continue to grow on surfaces.
Chemicals can also be an effective method of sanitization and disinfection, but a valid concern is that often they are not used as directed and have residuals, which can lead either to a dangerous or ineffective result. In Healthy Trailer’s early market research, we learned from trucking companies that they did not want the floors of their trailers exposed to chemicals because of the potential damage they could cause in their equipment.
Truck drivers often mention that employees at washout facilities where chemicals are used for the purpose of sanitizing surfaces often leave residual amounts of the chemical on the trailer floor. The driver then has the added concern of making sure it doesn’t touch the food containers during the transportation process.
UV-C definitely has the power to disinfect, but only if it has the opportunity to do so. Surfaces must be exposed to UV-C at the correct dose for specified periods of time, depending on the distance between the lamps and the surface.
For example, when our Healthy Trailer machines are being designed, we spend a significant amount of time determining lamp placement and travel times to allow for effective exposure on the surfaces. We rely on our machine engineers and UV vendor partners to help us get these specifics correct.
One question that we get from people is about how UV-C affects COVID-19. It’s better to leave that discussion to the experts so please read the International UltraViolet Association’s information. It’s good news and shows that those of us depending on the proven power of UV-C to keep things healthy are on the right path.
Does UV-C Work in Food Transport Trailers?
Healthy Trailer’s mission is to serve and support our customers’ food safety efforts and goals in the supply chain. We want them to know that in this critical area of trailer sanitation, their food safety plans are buttoned up. Our customers should be able to look their customers in the eye and say with confidence, “We have done everything we can, end to end, to make sure your food is safe, including transportation.”
We often invite people to come see our machine work and to observe our process. Most often, when our visitor has been a CEO, a sales manager, a transportation director, or owner, rarely do they come alone. Usually they bring at least one member of their food safety team, and usually it’s a food safety director or manager.
This has affirmed our assumption that Healthy Trailer’s use of UV-C light may be an awesome application of a proven technology, but in the end, we must satisfy the standards of the food safety professionals.
One method of checking our lamps to make sure the dosage is on target to achieve microbial reduction is to use dose cards. These simple test tools are commonly used in hospitals in their verification SOP’s. Our dose cards are made by UVDI, a Chlorox company specializing in germicidal UV-C light. UVDI was instrumental in helping Healthy Trailer design its first system and we have always felt that their guidance and help in our early days has been a key to our success.
We use dose cards along with our surface adenosine triphosphate (ATP) and microbial total plate count (TCP) test/verification protocols by placing dose cards near test sites throughout a trailer. For example, test sites are typically thresholds, bulkheads, walls, floors and ceilings because they are prone to collect contamination.
Each dose card has a strip of yellow paper in the center which turns green, hopefully dark green, when it’s exposed to the UV-C light.
This is a scientific means of testing exposure from the standpoint that this center strip is calibrated to specific dose levels. Because our cards are made for the healthcare industry, the target bacteria is MRSA and C-Diff, common sicknesses that can spread in a hospital without effective sanitization protocols.
Early in the development of our UV-C system, we knew we would need additional guidance from a UV-C expert. Dr. Tatiana Koutchma has filled a critical role in helping us learn how to use UV-C. She is a research scientist and recognized authority on the efficacy of UV-C, particularly in food safety applications.
To confirm that our doses were adequate to kill known food safety bacteria like Listeria, we sent our exposed cards to Dr. Koutchma to assess and hopefully calibrate our UV-C doses. Her conclusions confirmed that our doses for that test were correct.
Dose cards are a convenient method of validating and confirming our UV-C lamp output. But microbial testing tells a more accurate story about the effectiveness and sanitization capabilities of our UV-C system.
The word ‘sanitize’ means different things to different people. Most people think it means ‘free from dirt.’ Professionals in the study of eliminating bacteria and viruses refer to ‘sanitization’ as something that involves the use of chemicals. Scientifically and mathematically, it means a measurable and significant reduction in microbes.
When we started our 3rd test project, we learned that for Healthy Trailer, ‘sanitize’ should mean that we are achieving a 2-log microbial reduction. We classified a trailer environment as a non food contact Zone 2. For those unfamiliar with the zone concepts in food safety, zones are used as a method of specifying which particular cleaning and sanitizing standards should be used in different areas in a food processing facility.
A helpful definition of a Zone 2 surface can be found on the Penn State Extension website. It’s easy to see how a food transport trailer surface is very similar to Zone 2 surfaces in food processing plants by virtue of its nearness to food, even if it is away from a trailer wall and in cartons or packaging.
Healthy Trailer has assumed from the beginning that there are companies that do not want to deal with any consequences of an unclean trailer. In fact, they assume that the trailer will have bacteria and viruses on surfaces given the frequency and number of people and equipment that are in trailers during the loading and unloading process.
To confirm our level of cleaning and sanitizing, we had our first 3rd party audit completed last summer (2019.) While the first set of test results were not what we had hoped for, we made them go to work for us. We modified our process and our machine using the results from those test sites.
The changes led to success in achieving our goal of a 2 log reduction in microbial levels in a field trailer. A 53’ field trailer is used to transport fresh product from the field to a processing facility. These trailers are a convenient means of conducting microbial tests because the owners are willing to leave them with us for lengthy testing periods.
Validation and verification are critical to Healthy Trailer’s success. Not only do these testing processes prove what we are doing is working, but equally important to us is that we will continue to learn, improve, and innovate based on our test results.
We work with sanitation and food safety experts as well as third party auditors to keep us aligned with current food safety standards. And as mentioned earlier, our UV-C decisions have been guided by Dr. Koutchma and we’ll continue to ask for her professional advice in our pursuit of continually improving our UV-C process.
Yes, UV-C does work in food transport trailers.
Confirmation Outside of Science
UV-C is not only safe, simple and effective, but because it is a non-chemical means of disinfection, it is also organic! It makes sense that it is used in many industries as a ‘go to solution’ for companies that understand their obligation to maintain standards of cleanliness. We’ve already discussed the marine industry’s reliance on UV-C.
When we take a deeper look at how it’s usefulness affects our lives, the technology becomes more like a helpful friend than a just a needful science.
Think about it.
Families and friends can play together in water parks and not worry about getting sick from the water. The ill and injured in hospitals can look forward to speedier and uncomplicated recoveries, unhampered by needless and dangerous hospital acquired infections. Ships carry and bring fresh produce to and from foreign countries, thereby expanding business opportunities for companies worldwide while at the same time giving people culinary experiences that might otherwise not be available.
Air passengers can travel in UV disinfected airline cabins. Offices and homes are outfitted with UV-C air sanitizers, providing clean, life-giving breath to workers and families who struggle with breathing problems.
A number of food companies have implemented the power of UV-C in processing plants to kill dangerous microbes in their food products. For those of us who might have a glass of wine later today, we may be drinking out of a bottle that was treated with germicidal UV light before being filled with our favorite Petite Sirah.
Fresh produce? Absolutely.
Published scientific research and articles written by leading experts who have studied the benefits of UV-C help explain why companies are turning to UV-C to help them improve and strengthen their food safety protocols. And now we read that even out in the field, quietly working away in the dead of night, UV light is becoming a hero in the fight against destructive field pathogens. How about a robot in a strawberry field? Probably way more prevalent than people realize, chemical free microbial reduction is being used throughout the fresh produce industry.
Is UV-C a useful, helpful, viable technology for various applications? Yes, as confirmed not only by science but by the people using it everyday, all over the world.
Wouldn’t it be awesome to know that the strawberries you may grow, sell, ship, buy, and eat were transported in a UV-C sanitized transport trailer?
Our approach to helping the fresh produce industry understand and accept UV-C technology has been to start with showing that refrigerated trailers do carry microbial contamination at varying levels. The question then becomes, “Are you OK knowing that the trailer transporting your fresh product may also be carrying a dangerous pathogen?”
Rather than second guessing the cleanliness of a trailer, it makes more sense to clean and sanitize it.
We’ll know that we’re succeeding in our mission to improve the microbial health of food transport trailers in the supply chain when we hear more people proudly, and confidently tell their customers, “I’m shipping my produce in Healthy Trailer UV sanitized trailers for safety sake!”
In the meantime, stay safe. And keep your fresh produce safe too!