Ushio

RANK40

If there is an unsung hero in the global fight against COVID-19—and deadly pathogens, generally—it may be ultraviolet light. For decades, owing to its microbe-killing powers, it has been deployed (when humans aren’t directly exposed) to sterilize operating rooms and public spaces, including, since earlier this year, the New York City subway system. In some countries, it has been used to control tuberculosis and measles outbreaks. Ushio, with $1.5 billion in annual revenues, is a manufacturer of the germicidal UV lamps used in such efforts. But for the past seven years, Ushio has also been advancing the science around a promising, more practical type of UV light—at a wavelength of 222 nanometers—which still kills microbes, but (as a growing number of studies suggest) does not penetrate the eye or skin and so can safely be used around humans. Ushio, in partnership with Japan’s Kobe University and Columbia University in the U.S., a few years ago hypothesized that such light could be used to prevent the transmission of airborne infectious diseases like influenza; it introduced a 222nm lamp in the U.S. in 2018. Now, COVID-19 has made the technology—which could be used in indoor spaces where the virus is thought to linger in the air—especially relevant. Ushio begins mass production this fall.