When working with industrial lighting projects, we often receive questions about certifications and their actual meaning. One question that comes up quite often is: “If a luminaire is already certified for hazardous locations, why do we still need UL 924?” The answer is that these standards solve different problems. Difference Between UL 844 and UL924 UL 844 is mainly related to hazardous location safety. It ensures that luminaires can be safely used in environments where flammable gases, vapors, or combustible dust may exist. UL 924 addresses a different situation — what happens when the normal power supply fails. Emergency lighting is designed to keep operating during unexpected events such as power outages or emergencies. The purpose is to provide sufficient illumination for evacuation and emergency response. Why UL 924 is Important A common misunderstanding is that a hazardous location certification automatically means the luminaire can be used for emergency applications. However, these are separate requirements. For example, a light installed in an oil & gas facility may need to withstand a hazardous environment during normal operation. But if a power failure occurs, the facility may also need lighting that automatically switches to backup power and continues operating. This is why UL 924 is important. UL 924 Compliance & Requirements One key requirement of UL 924 is that emergency lighting equipment should automatically transfer to emergency power and provide illumination for at least 90 minutes. This helps ensure that people have enough time to evacuate safely when normal lighting is unavailable. In industries such as oil & gas, petrochemical, offshore, mining, pharmaceutical, and chemical processing, it is common for projects to require both hazardous location protection and emergency lighting capability. Recently, we have seen more customers looking for integrated solutions — explosion-proof luminaires that can provide normal lighting as well as emergency operation in one fixture. This approach can simplify installation and reduce maintenance compared with using separate systems. Understanding the differences between standards such as UL 924 and UL 844 helps engineers, contractors, and end users select the right lighting solution for each application. At GRINSAFE, we have developed explosion-proof emergency LED luminaires to meet these needs. Our solutions combine hazardous area protection with emergency lighting functionality and are certified to UL 924, together with UL 844, UL 1598, and UL 1598A for demanding industrial applications. For us, industrial lighting is not only about delivering enough brightness. It is about providing reliable performance when safety matters most.
