For decades, ultraviolet or UV light has been used as a disinfectant. Drinking water in the Greater Boston area is treated by UV light. It’s used to clean hospitals and surgical rooms. Now, a form of the light called UVC is being pitted against a new pathogen: the novel coronavirus.
The Greater Boston Food Bank announced Monday it plans to put into use a robot that emits UVC light to disinfect surfaces and neutralize airborne forms of the coronavirus in its warehouse during nightly cleanings. The customized robot, which resembles blue lights attached to a giant vacuum cleaner, was created by the MIT Computer Science and Artificial Intelligence Laboratory (CSAIL) and Cambridge-based AVA Robotics.
“Research shows that ultraviolet germicidal irradiation, specifically shining UVC light at different surfaces, can neutralize and kill various microorganisms,” said Alyssa Pierson, a research scientist with MIT CSAIL.
UVC technologies picked up steam in the hunt for ways to disinfect and reuse N-95 masks, and the pandemic has continued to trigger a wave of new uses. In New York City, a pilot is underway to disinfect subway cars and buses using pulses of light from portable UVC lamps. Similar technology is being used to clean buses in Shanghai.
The pilot project at the Greater Boston Food Bank had been conducted in a testing phase over the past two months.
“The initial area where the UV robot will be used is in our Boston warehouse shipping area, which has the most human activity, where our partner agencies are picking up their food orders,” said Catherine D’Amato, president and CEO of the Greater Boston Food Bank.
How much virus is killed depends on the UVC dosage and duration, and MIT researchers estimate their UV robot would neutralize 90 percent of the coronavirus. It could potentially work in many other large spaces.
“This could be also used in grocery stores, schools, office buildings, hotels, these different types of places where you would want to reduce the risk of exposure between guests or occupants,” Pierson said.
But the UVC robot has to be used when people aren’t around, because while this form of UVC light is effective against pathogens, it’s dangerous for humans. It causes serious burns and severe eye damage. So for now, this robot is tele-operated by a human in protective gear.
“I would say within the next couple weeks we should see the complete autonomous operation where the robot is capable of just going through the warehouse at night on a patrol schedule and delivering those dosages,” Pierson said.
The kind of ultraviolet light used, UVC, is one of three forms given off by the sun’s rays but is largely filtered out before reaching the earth. It works by destroying a virus’ ability to replicate. While there is limited data specific to the novel coronavirus, it is believed UVC is effective.
“We don't expect to have reliable peer reviewed data on that organism, probably honestly for about a year. So we've been using its sister organism, SARS Cov-1, and a lot of H1N1 influenza data to, if you will, make educated guesses about the doses we need for a given amount of inactivation percent removal,” said Jim Malley, a professor of civil and environmental engineering at the University of New Hampshire who specializes in public health and disinfection.
There’s also growing interest in what’s called “far UVC” — a shorter wavelength of UVC light that is shown to be as effective against airborne coronaviruses as more conventionally used UVC light — but potentially without the human health risks.
Even before the pandemic, Boeing started testing “far UVC” light to disinfect washrooms and says its prototype gets the job done in less than three seconds. But this futuristic toilet still wouldn't be available for a while, because modifying a plane requires a long certification. So for now, Boeing says their UVC technology will be rolled out more quickly as a cleaning wand for cabins, and predict a prototype will be ready within weeks.
Current chemical cleaners can properly disinfect for coronavirus, according to Boeing, but use of a UV wand can help do the job faster.
“And we can limit the number of chemicals that are on the airplane,” said Dan Freeman, Boeing’s director of Payloads Engineering. “We want to limit exposure to both the people using them as well as the material on the airplane.”
Still, UV cleaning is viewed as only one tool in a multi-layered approach to disinfecting for the virus.
“It's not just one thing that's going to solve all of the issues of the virus. It's going to be disinfection. It's going to be screening. It's going to be masks, it’s going to be, I mean, there's a variety of things, each providing protection over the top of the next,” Freeman said.
Coronavirus has helped spawn hundreds of home UV devices — from room cleaners to phone disinfectants to cleaners for car keys. Experts say for them to work, they need to be UVC, not other types of UV. Even still, buyer beware.
While UV devices sold for water purification are well regulated, Malley said, all other consumer UV products are like “the Wild West.”
“It falls in this regulatory abyss where folks don't really know if my ultraviolet product is regulated by EPA or by FDA or by Federal Trade Commission or honestly, often by no one,” Malley said. “So a lot of the devices you find in social media, eBay, Amazon, popping up on your Facebook, quite honestly, are unregulated. Our experience has been many of them are rubbish, to be honest.”
Malley also serves as president of the International Ultraviolet Association, which focuses on research and uses of UV technology. So what does he use to clean his phone, laptop and other home items? A “quick-dry 70 percent alcohol solution that doesn’t leave a film,” he said.
“UV is a great tool in the toolbox,” Malley said. “If I'm a consumer right now, I wouldn't waste my money on any of the stuff unless I was going to spend significant dollars. I don't clean my phone with UV.”