Regulators Weigh Higher Thresholds for Safe Exposure to Far-UVC Light

When ACGIH talks, federal regulators listen. Also known as the American Conference of Governmental Industrial Hygienists, the nonprofit organization does baseline research on safe levels of human exposure to “various chemical and physical agents,” including ultraviolet light. And this year’s update to its threshold limits brings some big news for those of us developing germicidal disinfection solutions utilizing far-UVC light.

In its annual “notice of intent to change” guidance, ACGIH said it plans to recommend a dramatic increase in the threshold limit values (TLVs) deemed safe for continuous exposure to far-UVC light in the workplace. The changes—an increase of more than 20 times for exposure to skin, and a more than eight-fold increase in time of exposure to eyes—are great enough to open up a near-limitless array of far-UVC air- and surface-disinfection applications in occupied spaces.

What’s prompted the new guideline? And why are developers of far-UVC germicidal lighting technologies such as NS Nanotech optimistic that regulators might follow through with changes? Research done over the past several years at Columbia University in New York and University of Dundee in Scotland has started to demonstrate that far-UVC light in the range of 200-to-230 nanometers may be safe to use around humans. (UVC light at higher wavelengths can cause reddening of the skin and discomfort in the eyes, with long-term risk of cancers.) The research has also shown that short-wavelength far-UVC light can inactivate viruses as well as, or even better than, longer-wavelength UVC light.

Imagine far-UVC lights disinfecting the air you breathe in the elevator that take you to your office every day, eliminating the viral load of pathogens such as coronavirus and the flu. Imagine breathing disinfected air in the Uber ride you take to work, or disinfected surfaces on the escalator handrails carrying you to the mezzanine level in the mall. Or any number of other disinfection solutions. Developers of ultraviolet disinfection solutions are already working on these and other new far-UVC applications that may be deemed safe once regulators change their exposure guidelines.

When might we see new regulations go into place? Big federal bureaucracies proceed slowly and carefully when it comes to public safety. ACGIH asks for public comments on its annual “intent to change” notice, collects the feedback, and submits its final recommendations at the start of the following year. So, watch for the EPA, OSHA, and other regulators to start considering new ACGIH guidelines for exposure to far-UVC light in 2022.

In the meantime, there’s plenty of work to be done to deliver all those new solutions. At NS Nanotech we are developing the world’s first semiconductor to emit far-UVC disinfecting light, the ShortWaveLight™ Emitter. And we have already talked to dozens of potential business-to-business partners who are getting far-UVC disinfection solutions ready for the market in 2022.

With momentum building in the marketplace and in Washington, DC, we are looking forward to a future where far-UVC disinfecting light is ubiquitous, built into the global infrastructure to help prevent future pandemics.