Germicidal ultraviolet (GUV) is a specific spectrum of ultraviolet (UV) light. UV-C (wavelengths of 200–280 nanometers) has powerful antimicrobial properties. GUV technology is used to disinfect air, water and surfaces by inactivating or destroying microorganisms, such as bacteria, viruses and fungi. This prevents the organisms from replicating and renders them harmless.

Before it is used in mainstream applications, the U.S. Department of Energy (DOE) has been testing GUVs to obtain accurate performance data. Commercial product developers can then use those same test methods to test their own products. This round showed that there needs to be more education and standards for GUVs.

The DOE published the results of its second round of testing in November 2024. A previous round of testing measured the radiation and electrical performance for a mix of GUV product types. This second round was quite specific, focusing on GUV luminaries. Eight GUV luminaires were tested, with three using UV-emitting LEDs and five using low-pressure mercury lamps.

However, this latest report highlights significant gaps and challenges in the GUV industry. Key issues include incomplete product data, exaggerated UV-C output claims, inconsistent energy efficiency and safety risks from some luminaires exceeding exposure limits. Testing inaccuracies and rapid UV-C output depreciation in certain LED products further complicate reliability. These findings reveal a pressing need for standardized testing, accurate reporting and improved product design to ensure safety, efficiency and informed decision-making.

GUV has many useful applications, including disinfection and sterilization. It is widely used in healthcare to sanitize hospital rooms, surgical tools and air systems. In can also be used in public spaces, water treatment, food processing, laboratories and manufacturing facilities.

While this round of testing found useful data about the energy consumed and radiation emitted from the lighting, it also indicated the need to overcome testing limitations and “improve test lab infrastructure and capabilities to support the accurate testing of GUV products.”