Fears of the COVID-19 virus lurking in supermarkets—on doors, carts, and packaging—have kept uneasy shoppers from spending more time browsing the aisles or even from brick-and-mortar grocery stores altogether.
The concern is justified.
A 2017 study showed that grocery store carts carry 361 times more bacteria than a bathroom doorknob—with three-quarters of the cart’s germs considered harmful. Other tests indicate that grocery store fridge doors may harbor 1,235 times more bacteria than a cell phone.To appease worried shoppers and combat the pandemic’s threat to public health, a handful of grocery retailers worldwide have begun disinfecting their stores with a type of ultraviolet radiation. UVC lighting can sterilize groceries, carts, and other high-touch surfaces potentially contaminated with DNA containing harmful viruses such as SARS, MERS, and influenza.
Here we explain what UV disinfection is and examine its risks and potential.
What is UV disinfection?
UV stands for ultraviolet, a type of invisible electromagnetic radiation emitted by the sun, There are three types: UVA, UVB, and UVC. The first two, which compose the majority of UV radiation that reaches Earth, can cause skin damage, sunburn, and cancer.
But the third type of UV radiation, UVC, is the most powerful—and the most dangerous—due to its shorter, more energetic wavelength that obliterates genetic material instantly. The ozone layer filters UVC from the sun and keeps it from reaching the planet’s surface, but scientists have found that UVC can serve as a disinfectant to kill or inactivate viruses carried within DNA.
What it can & can’t do
Because UV lights can be harmful to human eyes and skin, many businesses keep their virus-busting devices on timers to turn on at night when no one is around. Today’s UVC lights also have remote start functions and motion sensors to make them safer to use.
But ultraviolet radiation is not a guaranteed panacea for supermarkets. UVC radiation can only destroy a virus when directly exposed to the wavelengths. Dust and other contaminants can prevent the radiation from reaching the virus.
Which grocers are trying it
At least a handful of grocers across the world have begun piloting the technology inside their stores.
Sentry Foods in Delafield, Wisconsin worked with Neu-Tech Energy Solutions, an LED lighting supplier, to use UV lights to disinfect shopping carts. In Toronto, Summerhill Market worked with Xgerminator to install a machine at checkout that sanitizes groceries before they’re bagged.
Engineers in Belgium developed a machine last year that sanitizes carts by bathing them in a box of ultraviolet light. The customer wheels the cart into the box and retrieves it once the door pops open 10 seconds later.
Four supermarket chains in Belgium are testing the cart zapper, which starts at about $6,500, at 15 locations, according to an email interview with Jean Demarteau of Open Flow, which designed the technology.
Meanwhile, Dutch supermarket chain Ahold Delhaize partnered with Ava Robotics to test ultraviolet disinfection robots in two distribution centers in Schodack, N.Y., and Dunn, N.C.
Ava’s robot, which is designed to provide autonomous UV disinfection for corporate offices, warehouses and other workspaces, can disinfect both air and surfaces at a rate of approximately 9,000 square feet per hour. It is 99% effective against COVID-19, according to Ava.
Barrier for Adoption of New Retail Safety Precautions
The technology has garnered controversy over its potential dangers. The Belgian government initially proposed to ban the sale and use of UVC lamps for disinfection purposes in non-hospital settings due to the risk of cancer and eye damage. However, the proposal was withdrawn in June 2020.
Still, some stores, like Thai supermarket Central Food Hall, deploy the devices after business hours only.
The manufacturer of UVC air purifiers piloted at Edeka Clausen, a small supermarket in Hamburg, Germany, says the radiation cannot reach customers.“It is not harmful to people shopping in the store because the radiation is only in the upper third of the room,” a spokesperson from Signify told LEDs Magazine. “So we can make sure there is no radiation in the area where people walk around or sit. We do extensive measurements and tests to make sure the radiation is only there where we need it to be.”
How are shoppers responding?
Initial results at some stores show that shoppers seem to approve of the germ-busting devices.
The Xgerminator machine, which Toronto’s Summerhill Market began using in May, proved immediately popular among shoppers, according to the grocery store’s president Brad McMullen.
“The experiment was successful in many ways in that there is a great deal of interest from our customers in having their groceries sanitized,” McMullen told The Toronto Sun.
Will the tech have post-pandemic staying power?
More grocers say they plan to deploy more UVC devices in their stores this year. Ava’s robots are slated to ship to more locations this spring. Meanwhile, scientists at MIT are also developing a UVC robot to sanitize grocery stores.
Open Flow, the Belgium-based social collective that makes the cart zappers used in 15 Belgium grocery stores, said it has heard from manufacturers in the U.S., Mexico, Spain, Turkey, and South Africa interested in making the device.
Even after the pandemic, the technology is likely to endure as a retail safety precaution “especially when you know that the handles of the trolleys are more pathogen-full than the public toilet seats,” said Jean Demarteau, an Open Flow member responsible for innovation. “Toilet seats are at least washed every X hours, which is not the case with trolleys. They usually are, in the best case, washed once every six months, or every year, or never.”
The Future of UVC Disinfection in Grocery
Supermarkets have been dousing their carts, shelves, and checkout lines with sanitizing sprays and wipes since the onset of the COVID-19 virus early last year. But the ongoing threat of the pandemic has forced the grocery industry to develop more creative and effective retail safety precautions.
Ultraviolet radiation is now playing a larger role in the sanitization process, with supermarkets around the world piloting UVC devices to decontaminate public surfaces. With its shorter and more powerful wavelength, UVC applied in optimal doses has been proven to kill viruses and bacteria. A Boston University study showed that UVC can deactivate coronavirus within seconds.
Grocery stores will continue rolling out this equipment throughout 2021 to mitigate the virus’ ongoing threat to customers and employees. Given the crash course shoppers got in virology thanks to the pandemic, it’s reasonable to think that if it’s easy enough to adopt and effective enough to kill a wide range of bacteria, the technology might just be here to stay… even after the pandemic ends.
