The Halo™ is not merely a light, but a Personal Active Safety System™ designed to keep people safe and more productive on the job. Unlike reflective vests, which are passive and require an external source of light to be effective, the Halo actively illuminates the wearer in 360 degrees.
An ANSI Standard is now recognizing that Personal Active Safety Systems like Halo can help prevent incidents that might injure or kill workers. The ANSI/ASSE A10.47-2015 Standard Work Zone Safety for Highway Construction recognizes Personal Active Safety Systems/Devices in two sections. Section 5.2.2, the Flagger Safety segment, discusses the use of personal active safety devices as an additional method to protect flaggers. Section 14.2 (Illumination Levels) notes, “Personal active safety systems may also be used to enhance worker visibility.”
You can acquire the full standard via this link.