October 1, 2020
Consumer UVC germicidal devices are entering the market rapidly because of an increased demand for sanitizing and germicidal capabilities in the face of COVID-19. But are they all safe?
UVC radiation (the most energetic in the UV spectrum; 180nm to 280 nm) is proven to have sanitizing and germicidal effects, and first proof of effectiveness against SARS-CoV-2 is emerging. Like many high energy devices, however, there are risks due to UVC exposure. For example, UVC over-exposure can cause damage to the eyes and skin, based on wavelength, intensity, proximity to the source, and time of exposure. In certain cases, there are also risks to the lungs if the UVC germicidal device also were to generate ozone. For high intensity sources, over-exposure can occur in just seconds, but symptoms may not become apparent for a day or two. UVC lamps have little visible light output, so our natural defensive reactions to optical hazards (blinking, squinting, or trying to look away) may not be triggered to protect us adequately.
Establishing and maintaining the safety of UVC devices is a priority in the lighting industry across all sectors, including consumer, commercial and healthcare applications. Warning: Consumers currently have no assurance against the risks of UVC over-exposure from consumer oriented UVC devices that do not provide proper containment of the UVC emissions. When used improperly, these types of devices may present an undue health risk.
One example of an adequate safety measure for UVC germicidal products intended for consumer use is proper containment of the UVC source. Proper containment designs, or other, equivalent means that prevent exposure, help to ensure that people are not over-exposed to UVC radiation. For example, if in an air cleaner, access to the UVC lamp (for servicing purposes) would result in activation of an interlock switch which in turn disables product operation (i.e. precludes UVC emissions).
Unfortunately, the online retail market is growing rapidly with handheld and portable consumer oriented UVC germicidal devices, many of which do not employ proper containment or other equivalent means of protection. Instead, these tend to rely solely on markings or integral timers, unreliable sensors, or remote controllers, which still leave room for scenarios where humans or animals can be over-exposed to the UVC light. Without better safeguards and without consumers being more fully aware of risks and trained in proper operation, this would place an unrealistic responsibility on the user and, consequently, such products at present cannot be certified. For all UVC consumer products sold, certification is essential.
Note: warning labels are not enough! Children or pets cannot be expected to follow written warnings, and home environments pose innumerable situations that could result in misuse and potential harm when the technical safeguards are inadequate.